Comparison of serratus posterior superior intercostal plane block versus deep serratus anterior plane block for postoperative analgesia after breast surgery: a prospective randomized study

Comparison of serratus posterior superior intercostal plane block versus deep serratus anterior plane block for postoperative analgesia after breast surgery: a prospective randomized study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Comparison of serratus posterior superior intercostal plane block versus deep serratus anterior plane block for postoperative analgesia after breast surgery: a prospective randomized study Mustafa Burgaç, Senem Geçer, Hakan Baysal This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8686839/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Effective postoperative pain management is essential for recovery after breast surgery. Although regional fascial plane blocks are widely used as part of multimodal analgesia, direct comparative clinical data between serratus posterior superior intercostal plane block (SPSIPB) and serratus anterior plane block (SAPB) are limited. This study compared the analgesic efficacy of SPSIPB and SAPB in patients undergoing unilateral modified radical mastectomy (MRM). Methods This prospective, randomized study included 62 patients with American Society of Anesthesiologists (ASA) physical status I–III scheduled for unilateral MRM. Patients were randomized to either the SPSIPB group (n = 31) or the SAPB group (n = 31). The primary outcome was postoperative pain intensity assessed using the numeric rating scale (NRS). Secondary outcomes included total tramadol consumption during the first 24 hours, intraoperative remifentanil consumption, requirement for rescue analgesia (tenoxicam), postoperative nausea and vomiting (PONV), and patient satisfaction. Opioids were administered via an intravenous patient-controlled analgesia (PCA) device. Results Static NRS scores were significantly higher in the SPSIPB group compared with the SAPB group at postoperative 30 minutes and at the 1st, 4th, and 8th hours (all p < 0.05). No significant differences were observed at the 12th and 24th postoperative hours. Nevertheless, mean NRS scores remained ≤ 4 at all time points in both groups, indicating clinically acceptable analgesia. Total 24-hour tramadol consumption was comparable between the SPSIPB and SAPB groups (76.1 ± 51.1 mg vs. 74.2 ± 44.7 mg; p = 0.875). Intraoperative remifentanil consumption was significantly higher in the SPSIPB group (p = 0.038). There were no significant differences between the groups regarding rescue analgesic requirements, incidence of PONV, or patient satisfaction. Conclusion SPSIPB provides a clinically acceptable postoperative analgesic profile comparable to SAPB within a multimodal analgesia regimen following breast surgery. These findings should not be interpreted as evidence of superiority or equivalence. To better assess the clinical efficacy and potential applications of SPSIPB, more comprehensive and well-designed comparative studies are needed. Trial Registration ClinicalTrials.gov (NCT06436599), retrospectively registered on May 22, 2024. Postoperative pain Multimodal analgesia Serratus anterior plane block Serratus posterior superior intercostal plane block Breast surgery Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Breast cancer remains one of the leading causes of cancer-related mortality among women, and surgical treatment constitutes a cornerstone of its management [ 1 , 2 ]. Previous studies have reported that approximately 40% of women experience acute postoperative pain and up to 60% develop chronic pain following breast cancer surgery [ 3 , 4 ]. Acute postoperative pain after breast surgery adversely affects patients’ quality of life and, when inadequately controlled, represents a significant risk factor for the development of chronic postsurgical pain [ 5 ]. Effective postoperative pain management facilitates early mobilization, accelerates functional recovery, and is considered a fundamental component of contemporary Enhanced Recovery After Surgery (ERAS) protocols [ 6 ]. Postoperative pain management following breast surgery is commonly achieved through a multimodal approach combining systemic opioids, non-steroidal anti-inflammatory drugs, and various regional anesthesia techniques. Thoracic paravertebral block, pectoral nerve blocks (PECS I–II), erector spinae plane block (ESPB), and serratus anterior plane block (SAPB) are among the most frequently used regional techniques in this setting [ 7 , 8 ]. SAPB has gained widespread acceptance in clinical practice due to its ability to provide effective analgesia of the anterolateral chest wall, its relative ease of application under ultrasound guidance, and its favorable safety profile [ 9 , 10 ]. Previous studies have demonstrated that the deep approach to SAPB may reduce early postoperative opioid consumption compared with the superficial technique [ 11 ]. However, the analgesic coverage of the axillary region, particularly in procedures involving axillary dissection, may be variable and not consistently reliable across patients. Given the functional importance of the axillary region for shoulder movement and early mobilization, inconsistent analgesia in this area may have clinically relevant implications [ 9 , 12 ]. In addition, although uncommon, SAPB has been associated with complications such as pneumothorax [ 13 ]. The serratus posterior superior intercostal plane block (SPSIPB) is a relatively novel regional anesthesia technique described by Tulgar et al. [ 14 ], performed within the fascial plane between the serratus posterior superior muscle and the intercostal muscles. Anatomical and cadaveric studies have suggested that SPSIPB may provide a broader sensory spread across the lower cervical and upper thoracic regions, potentially including areas relevant to axillary analgesia [ 14 – 16 ]. Clinical studies have reported that SPSIPB may reduce postoperative pain intensity and opioid requirements following thoracic surgery [ 14 – 18 ]. To date, no randomized trials have directly compared SPSIPB and deep SAPB in the context of breast surgery. Given the importance of achieving consistent analgesia in the axillary region while maintaining an acceptable safety profile, a direct comparison of these two interfascial plane blocks appears clinically relevant. Therefore, the primary aim of this study was to compare the effects of ultrasound-guided SPSIPB and SAPB on postoperative pain scores in patients undergoing unilateral modified radical mastectomy and to evaluate the clinical analgesic profiles of both techniques Materials and Methods Study design This prospective, randomized study received approval from the Clinical Research Ethics Committee of the Ministry of Health, Istanbul Medeniyet University, Göztepe Training and Research Hospital (approval number: 2023/0870; December 13, 2023). Patient recruitment and follow-up were conducted between December 13, 2023, and June 30, 2024. The study was carried out in accordance with the Declaration of Helsinki and was retrospectively registered at ClinicalTrials.gov (NCT06436599). The manuscript was prepared in accordance with the Consolidated Standards of Reporting Trials (CONSORT) guidelines (Fig. 1 ). Written and verbal informed consent were obtained from all participants prior to enrollment. Study population A total of 62 female patients, aged ≥ 18 years, with an American Society of Anesthesiologists (ASA) physical status of I–III, who were scheduled for unilateral modified radical mastectomy under general anesthesia, were included. Exclusion criteria were bleeding diathesis, use of anticoagulant therapy, known allergy to study medications (local anesthetics, non-steroidal anti-inflammatory drugs, or opioids), infection at the block site, hemodynamic instability (persistent hypotension or arrhythmia preventing extubation), and refusal to participate. An independent anesthesia resident not involved in the study prepared opaque, sealed, and sequentially ordered envelopes and randomly numbered them. The enrolling anesthesiologist opened the envelope immediately before block performance and assigned patients to the SAPB group (n = 31) for even-numbered envelopes or to the SPSIPB group (n = 31) for odd-numbered envelopes, using a 1:1 allocation ratio. A blinded anesthesiologist conducted all postoperative assessments. Preoperative preparation Before block administration, patients were transferred to the block area, and demographic data, including age, body mass index (BMI), and ASA physical status, were recorded. All patients were informed about patient-controlled analgesia (PCA) and the numerical rating scale (NRS; 0 = no pain, 10 = worst imaginable pain). Standard monitoring, including pulse oximetry (SpO₂), non-invasive blood pressure (NIBP), and electrocardiography (ECG), was applied. Premedication consisted of intravenous midazolam 1 mg and fentanyl 1 µg/kg. Block techniques All blocks were performed 30 minutes before surgery under ultrasound (US) guidance, in the lateral decubitus position, under full aseptic conditions. A US device (Samsung Medison H60) with a 12-MHz linear probe (covered with a sterile sheath) and an 80-mm, 22-G sonovisible block needle (Stimuplex Ultra 360; B. Braun) was used. In both groups, 30 mL of 0.25% bupivacaine was injected. Serratus posterior superior intercostal plane block (SPSIPB) With the patient in the lateral decubitus position and the operative side up, the ultrasound probe was placed sagittally at the level of the scapular spine. The lateral border of the scapula, trapezius muscle, serratus posterior superior muscle (SPSM), and the second and third ribs were identified. Using an in-plane technique, the block needle was advanced from the level of the third rib in a caudocranial direction through the medial border of the scapula. The needle tip was positioned between the SPSM and the third rib. After negative aspiration, hydrodissection with 1–2 mL of saline was performed to confirm correct needle placement, followed by injection of 30 mL of 0.25% bupivacaine between the SPSM and the third rib. The patient position and ultrasound images are shown in Fig. 2 . Serratus anterior plane block (SAPB) With the patient in the lateral decubitus position and the surgical side up, the ultrasound probe was placed perpendicular to the mid-axillary line at the level of the fifth rib. The latissimus dorsi, serratus anterior, and intercostal muscles were identified. Using an in-plane technique, the needle was advanced in an anterior-to-posterior direction into the plane between the serratus anterior and intercostal muscles (deep SAPB). After negative aspiration, hydrodissection with 1–2 mL of saline confirmed needle placement, and 30 mL of 0.25% bupivacaine was injected. General anesthesia Thirty minutes after block administration, patients were transferred to the operating room. Standard monitoring was applied, and anesthesia depth was standardized using bispectral index (BIS) monitoring. Following preoxygenation, anesthesia was induced with intravenous propofol 2 mg/kg and rocuronium bromide 0.6 mg/kg. Anesthesia was maintained with sevoflurane in an oxygen/air mixture (50/50). Intraoperative analgesia was provided with a remifentanil infusion at 0.05–0.2 µg/kg/min, titrated to maintain systolic blood pressure within ± 20% of baseline values. Total remifentanil consumption and duration of surgery were recorded. Hemodynamic parameters were documented at 5-minute intervals. All procedures were performed using the same surgical technique. Postoperative analgesia protocol and follow-up Postoperative analgesia protocol and follow-up All patients received intravenous paracetamol (1 g), tramadol (1 mg/kg), and ondansetron (0,1 mg/kg) 30 minutes before the end of surgery. After reversal of neuromuscular blockade with sugammadex, patients were extubated and transferred to the post-anesthesia care unit (PACU), which was defined as postoperative hour 0. In the PACU, PCA with tramadol was initiated (no basal infusion, 2 mL bolus [5 mg/mL], 15-minute lockout interval, and a maximum dose of 100 mg over 4 hours). The total daily tramadol dose was limited to 400 mg. As part of the multimodal analgesia regimen, intravenous paracetamol 1 g was administered regularly every 8 hours during the postoperative period. Pain intensity was assessed using the NRS at rest (static) and during movement (dynamic). The first assessment obtained after achieving a Modified Aldrete Score (MAS) ≥ 10 was considered the baseline measurement (30 minutes). Subsequent assessments were performed at postoperative 1, 4, 8, 12, and 24 hours. Intravenous tenoxicam 20 mg was administered as rescue analgesia for NRS scores > 4. Total tramadol consumption during the first 24 hours was recorded. Postoperative nausea and vomiting (PONV) was assessed using a 4-point scale (1 = no nausea or vomiting, 2 = nausea without vomiting, 3 = a single episode of vomiting or persistent nausea, 4 = recurrent vomiting or severe retching). PONV assessments were performed at 30 minutes and at 1, 4, 8, 12, and 24 hours postoperatively. Patients with a PONV score ≥ 3 received intravenous ondansetron 8 mg. Patient satisfaction was evaluated 24 hours after block administration using a 5-point Likert scale (1 = very dissatisfied, 2 = dissatisfied, 3 = neutral, 4 = satisfied, 5 = very satisfied). All postoperative assessments were conducted by the same anesthesiologist who was blinded to group allocation. The primary outcome was postoperative pain intensity, evaluated using NRS scores during the first 24 hours after surgery. Secondary outcomes included total 24-hour postoperative tramadol consumption, intraoperative remifentanil consumption, requirement for rescue analgesia, incidence of PONV, and patient satisfaction scores. Sample size Sample size calculation was performed using G*Power software (version 3.1.9.2; Heinrich Heine University, Düsseldorf, Germany). The calculation was based on a previous study evaluating postoperative pain scores in patients undergoing modified radical mastectomy with a serratus anterior plane block [ 19 ]. In that study, a clinically relevant difference of approximately 1 point in visual analog scale (VAS) pain scores with a standard deviation of 1.5 was reported. Assuming a two-sided alpha error of 0.05 and a statistical power of 85%, a minimum of 26 patients per group was required. To compensate for potential dropouts or missing data, 31 patients were included in each group. Statistical analysis Statistical analyses were performed using SPSS software version 27.0 (IBM Corp., Armonk, NY, USA). Continuous variables were expressed as mean ± standard deviation or median (minimum–maximum), depending on data distribution. Normality of distribution was assessed using the Shapiro–Wilk test and visual inspection of box plots. Comparisons between groups were performed using the independent samples Student’s t -test for normally distributed continuous variables and the Mann–Whitney U test for non-normally distributed variables. Categorical variables were analyzed using the chi-square test, Fisher’s exact test, or the Fisher–Freeman–Halton test, as appropriate. A p-value < 0.05 was considered statistically significant. Results The patient enrollment process is summarized in the CONSORT flow diagram (Fig. 1 ). The trial concluded after reaching the predetermined sample size. Of the 65 patients assessed for eligibility, three were excluded because they did not meet the inclusion criteria. The remaining 62 patients were randomized to either the SPSIPB group or the SAPB group. During the postoperative follow-up period, one patient in the SPSIPB group was excluded due to a technical malfunction of the patient-controlled analgesia (PCA) device. Consequently, data from 61 patients (SPSIPB, n = 30; SAPB, n = 31) were included in the final analysis. Baseline demographic characteristics and duration of surgery were comparable between the two groups, with no statistically significant differences observed (Table 1 ). Table 1 Comparison of demographic variables and duration of surgery SPSİPB (n:30) SAPB (n:31) p Age (year) 59.4 ± 13.7 56.2 ± 12.4 0.344 a 61.5 (23–80) 56 (31–78) BMI 30.17 ± 5.56 27.94 ± 4.37 0.086 a 30 (19.9–44.1) 28.1 (18.8–35.3) ASA I/II/III 2/20/8 3/20/8 1.000 b Operation Duration (min) 91 ± 38 75 (60–180) 100 ± 39.9 90 (60–180) 0.339 a a Student t-test, b Fisher-Freeman-Halton test. *p < 0.05, **p < 0.01. Values are expressed mean ± standard deviation or median (min-max). SPSIPB: serratus posterior superior intercostal plane block, SAPB: serratus anterior plane block, BMI: body mass index, ASA: American Society of Anesthesiologists physical status score, min: minute. Postoperative pain intensity, assessed using the numeric rating scale (NRS), differed between the groups during the early postoperative period. Static NRS scores were significantly lower in the SAPB group compared with the SPSIPB group during the first 8 postoperative hours (0–8 h; p < 0.05). Similarly, dynamic NRS scores were significantly lower in the SAPB group at the 1st and 4th postoperative hours (p < 0.05). No significant intergroup differences were observed in either static or dynamic NRS scores at the 12th or 24th postoperative hours. Importantly, mean NRS scores in both groups remained ≤ 4 at all assessed time points (Table 2 ). The postoperative static NRS score trajectory is illustrated in Fig. 3 . Table 2 Static and dynamic NRS assessments of the patients Static NRS SPSİPB(n:30) SAPB(n:31) Mean difference (95% CI) p 30th min 1.93 ± 1.17 1.29 ± 0.9 + 0.64 (+ 0.12 to + 1.16) 0.013* 2 (0–4) 1 (0–4) 1th h 1.63 ± 1.03 1.03 ± 0.75 + 0.60 (+ 0.14 to + 1.06) 0.012* 2 (0–4) 1 (0–3) 4th h 1.53 ± 0.94 0.61 ± 0.67 + 0.92 (+ 0.51 to + 1.33) 0.001** 2 (0–3) 1 (0–2) 8th h 1.17 ± 0.87 0.55 ± 0.72 + 0.62 (+ 0.22 to + 1.02) 0.004** 1 (0–3) 0 (0–2) 12th h 0.73 ± 0.87 0.39 ± 0.62 + 0.34 (-0.07 to + 0.75) 0.106 0,5 (0–3) 0 (0–2) 24th h 0.7 ± 0.99 0.42 ± 0.56 + 0.28 (-0.15 to + 0.71) 0.443 0 (0–3) 0 (0–2) Dynamic NRS 30th min 2.43 ± 1 2.03 ± 0.91 + 0.40 (-0.03 to + 0.83) 0.069 2 (0–4) 2 (1–4) 1th h 2.2 ± 0.96 1.71 ± 0.78 + 0.49 (+ 0.05 to + 0.93) 0.037* 2 (0–4) 2 (0–3) 4th h 2.03 ± 1.03 1.32 ± 0.65 + 0.71 (+ 0.28 to + 1.14) 0.002** 2 (0–4) 1 (0–3) 8th h 1.57 ± 0.9 1.35 ± 0.71 + 0.22 (-0.19 to + 0.63) 0.365 1 (0–4) 1 (0–3) 12th h 1.4 ± 0.77 1.16 ± 0.64 + 0.24 (-0.11 to + 0.59) 0.223 1 (0–3) 1 (0–2) 24th h 1.4 ± 1 1.13 ± 0.62 + 0.27 (-0.15 to + 0.69) 0.381 1 (0–4) 1 (0–2) Mann-Whitney test. *p < 0.05, **p < 0.01. Values are expressed mean ± standard deviation or median (min-max). SPSIPB: serratus posterior superior intercostal plane block, SAPB: serratus anterior plane block, NRS: numeric rating scale, CI: confidence interval, min: minute, h: hour. The mean total tramadol consumption during the first 24 postoperative hours was 76.1 ± 51.1 mg in the SPSIPB group and 74.2 ± 44.7 mg in the SAPB group (mean difference: 1.9 mg; 95% confidence interval [CI]: −22.1 to 25.9), with no statistically significant difference between the groups (p = 0.875). Tramadol consumption at individual postoperative time points (1, 4, 8, 12, and 24 h) was also comparable between the groups (Table 3 ). The total tramadol consumption during the first 24 postoperative hours is illustrated in Fig. 4 . Table 3 Comparison of postoperative and intraoperative analgesic consumption Tramadol (mg) SPSİPB(n:30) SAPB(n:31) Mean difference (95% CI) p 0th -1st h 13.5 ± 11 11.9 ± 12.2 + 1.6 (-4.2 to + 7.4) 0.483 a 10 (0–40) 10 (0–40) 1st -4th h 11.5 ± 9.2 9.7 ± 10.48 + 1.8 (-3.3 to + 6.9) 0.363 a 10 (0–30) 10 (0–40) 4th -8th h 13.5 ± 11.3 14.2 ± 12.5 -0.7 (-7.9 to + 6.5) 0.846 a 10 (0–40) 10 (0–40) 8th -12th h 13 ± 14.9 17.4 ± 13.1 -4.4 (-12.1 to + 3.3) 0.140 a 10 (0–50) 20 (0–50) 12th -24th h 24.5 ± 25.8 20.9 ± 17.9 + 3.6 (-7.8 to + 15) 0.886 a 20 (0-100) 20 (0–70) Total in 24 h 76.1 ± 51.1 74.2 ± 44.7 + 1.9 (-22.1 to + 25.9) 0.875 b 85 (0-190) 70 (0-160) Remifentanil (µg) 186.8. ± 89 144.9 ± 119.5 + 41.9 (+ 2.8 to + 81) 0.038 a* 165 (65–400) 100 (0-430) Tenoxicam N 25 (83.3%) 30 (96.8%) 0.104 c Y 5 (16.7%) 1 (3.2%) a Mann-Whitney test, b Student t-test, c Fisher's Exact test. *p < 0.05, **p < 0.01. Values are expressed mean ± standard deviation or median (min-max). SPSIPB: serratus posterior superior intercostal plane block, SAPB: serratus anterior plane block, CI: confidence interval, h: hour, Y: yes (indicates the number of patients that used rescue analgesia), N: no. Intraoperative remifentanil consumption was significantly higher in the SPSIPB group compared with the SAPB group (186.8 ± 89.0 µg vs. 144.9 ± 119.5 µg; mean difference: 41.9 µg; 95% CI: 2.8 to 81.0; p = 0.038). However, this difference was not associated with differences in postoperative pain scores or opioid consumption (Table 3 ). Rescue analgesia with intravenous tenoxicam was required in five patients (16.7%) in the SPSIPB group and in one patient (3.2%) in the SAPB group; however, this difference was not statistically significant (p = 0.104) (Table 3 ). With respect to postoperative adverse effects, no cases of postoperative nausea and vomiting (PONV) were observed in the SAPB group, whereas mild nausea (PONV score 1) occurred in two patients in the SPSIPB group. The difference in PONV incidence between the groups was not statistically significant (p = 0.238). Patient satisfaction scores, assessed using a five-point Likert scale, were similar between the groups (p = 0.516) and are presented in Table 4 . No cases of vascular or neuraxial injury, pruritus, pneumothorax, or hemodynamic instability were observed in either group. Table 4 Patient Satisfaction Scores Assessed with a 5-Point Likert Scale SPSİPB (n:30) SAP (n:31) p Satisfaction 4.53 ± 0.51 4.5 (4–5) 4.42 ± 0.56 4 (3–5) 0.516 Mann-Whitney test. *p < 0.05, **p < 0.01. Values are expressed mean ± standard deviation or median (min-max). SPSIPB: serratus posterior superior intercostal plane block, SAPB: serratus anterior plane block. In summary, both regional techniques achieved satisfactory postoperative analgesia with low pain scores and similar opioid consumption. The following discussion focuses on the clinical relevance of the observed differences in early postoperative pain and intraoperative opioid use. Discussion In this randomized controlled study, the effects of SPSIPB and SAPB on postoperative pain control were compared in patients undergoing modified radical mastectomy. The primary outcome of the study, postoperative NRS scores, demonstrated statistically significant differences in favor of SAPB during the early postoperative period. Nevertheless, the observation that mean NRS values remained ≤ 4 at all measurement time points in both groups indicates that both techniques provided clinically acceptable and adequate postoperative analgesia. The lower static (first 8 hours) and dynamic (first 4 hours) NRS scores observed in the SAPB group during the early postoperative period may be attributed to the more superficial anatomical location of SAPB and its more direct and rapid effect on nerve structures closely related to the surgical field [ 20 ]. Importantly, however, these statistically significant differences remained below the threshold generally considered clinically meaningful, suggesting that both techniques were sufficient to support early functional recovery in the immediate postoperative period. In the context of breast surgery, NRS values ≤ 4 are widely regarded as clinically adequate, particularly in terms of facilitating early mobilization and reducing the risk of pulmonary complications [ 21 – 25 ]. The analgesic efficacy of SAPB in breast surgery has been demonstrated in numerous randomized controlled trials and meta-analyses [ 21 – 25 ], and this technique is included among the recommended regional anesthesia strategies in the PROSPECT guidelines [ 26 ]. Accordingly, SAPB was selected as the comparator technique in the present study. Although both superficial and deep SAPB approaches have been shown to provide effective postoperative analgesia, the deep SAPB technique was preferred in this study. This preference was based on its potential advantages, including reduced early postoperative opioid consumption, shorter application time, facilitation of local anesthetic spread with respiratory movements, and a lower risk of interference with the surgical field [ 11 , 27 , 28 ]. Nevertheless, it should be acknowledged that high-quality clinical data directly comparing these technical variations remains limited [ 9 , 13 , 27 – 30 ]. Despite early postoperative NRS scores favoring SAPB, the absence of corresponding differences in clinically relevant outcomes such as opioid consumption, rescue analgesic requirements, or patient satisfaction warrants careful consideration. Although SAPB is an effective and widely used technique in breast surgery, variability in axillary analgesic coverage, particularly in procedures involving axillary dissection, has been reported in the literature [ 9 , 12 ]. Given the critical role of axillary pain control in shoulder movement, early mobilization, and overall functional recovery, consistency of analgesic coverage in this region is of considerable clinical importance. This clinical need has spurred interest in alternative regional techniques capable of providing broader and potentially more uniform dermatomal coverage; in this context, SPSIPB has drawn attention due to its injection site being distant from the pleura and its potential for wider sensory distribution [ 14 , 16 ]. However, the extent to which these theoretical advantages translate into meaningful clinical benefits remains unclear, forming the primary rationale for the present study. SPSIPB is a relatively recently described fascial plane block technique introduced by Tulgar et al. [ 14 ]. Anatomical and cadaveric studies have suggested that SPSIPB may provide extensive sensory spread across dermatomes ranging from C3 to T10 [ 14 – 16 , 31 , 32 ]. Nevertheless, existing evidence regarding the clinical analgesic performance of SPSIPB is largely derived from case series, limited controlled studies, and anatomical inferences [ 15 – 17 , 31 ]. The scarcity of clinical studies directly comparing SPSIPB with SAPB in the context of breast surgery complicates the precise delineation of the true clinical role of SPSIPB. A recently published randomized controlled study reported that the analgesic effects of SPSIPB were predominantly associated with intercostal nerves at the T2–T5 levels and lower cervical nerves, and that dermatomal spread may be more limited and heterogeneous than previously assumed [ 18 ]. Cadaveric studies have similarly demonstrated variable spread of SPSIPB between C7 and T7 dermatomes, with homogeneous sensory coverage not consistently achieved in all subjects [ 14 ]. These findings suggest that the previously reported consistent C3–T10 dermatomal coverage may not be clinically predictable in every patient [ 14 – 16 ]. This inconsistency between anatomical and clinical data may help explain the higher early postoperative NRS scores observed in the SPSIPB group in the present study. As the analgesic effect of SPSIPB relies on interfascial diffusion and potentially wider but slower-onset spread, a more variable analgesic response to early postoperative surgical stimuli may occur [ 14 , 18 , 33 ]. Notably, the absence of significant differences between groups at 12 and 24 hours postoperatively suggests that the analgesic efficacy of SPSIPB approaches that of SAPB over time. This time-dependent analgesic pattern is consistent with previous reports indicating that the clinical effects of SPSIPB may become more pronounced in the later postoperative period rather than immediately after surgery [ 14 , 18 ]. The lack of a significant difference in total opioid consumption during the first 24 hours postoperatively indicates that the early NRS differences did not translate into a clinically meaningful increase in opioid requirements. Furthermore, the absence of differences between groups in terms of rescue analgesic use, incidence of postoperative nausea and vomiting, and patient satisfaction supports the clinical feasibility of SPSIPB as part of a multimodal analgesia regimen. These findings are consistent with the limited but growing body of clinical evidence supporting the use of SPSIPB [ 14 – 18 , 31 , 32 ]. Previous studies have shown that SAPB may reduce intraoperative opioid consumption [ 23 ]. In contrast, data regarding the intraoperative analgesic contribution of SPSIPB remain limited, and direct comparative studies are scarce [ 17 ]. In this study, the higher remifentanil use in the SPSIPB group may reflect a slower onset of pain relief due to its wider spread between tissue layers, rather than indicating that the analgesia was insufficient. Importantly, this difference did not adversely affect postoperative pain scores or opioid consumption, further indicating that SPSIPB ultimately provides clinically sufficient postoperative analgesia. Several limitations of this study should be acknowledged. First, the absence of detailed dermatomal sensory mapping limits mechanistic evaluation of block spread, although this does not detract from clinical applicability. Second, the evaluation period was limited to the first 24 postoperative hours, and long-term outcomes such as functional recovery or chronic postmastectomy pain were not assessed. Additionally, the lack of a control group without regional anesthesia precludes assessment of the absolute contribution of either block compared with standard care. Nonetheless, the present study represents one of the few randomized, blinded trials directly comparing SPSIPB and SAPB within the same surgical population, thereby providing a meaningful contribution to the existing literature. In conclusion, although SPSIPB was associated with higher early postoperative NRS scores compared with SAPB, it provided clinically adequate analgesia following mastectomy. These findings suggest that SPSIPB may be considered a viable alternative to SAPB in breast surgery. However, larger, multicenter comparative studies with detailed evaluation of dermatomal spread and clinically relevant outcomes are required to substantiate claims of superiority and to more clearly define the role of SPSIPB in perioperative analgesia. Abbreviations ASA American Society of Anesthesiologists BIS Bispectral Index BMI Body Mass Index CI Confidence Interval CONSORT Consolidated Standards of Reporting Trials ECG Electrocardiography ERAS Enhanced Recovery After Surgery ESPB Erector Spinae Plane Block GA General Anesthesia LA Local anesthetic MAS Modified Aldrete Score MRM Modified Radical Mastectomy NIBP Non–Invasive Blood Pressure NRS Numeric Rating Scale PACU Post–Anesthesia Care Unit PCA Patient–Controlled Analgesia PECS Pectoral Nerve Block PONV Postoperative Nausea and Vomiting PROSPECT Procedure–Specific Postoperative Pain Management RMM Rhomboid major muscle SAPB Serratus Anterior Plane Block SD Standard deviation SpO₂ Peripheral Oxygen Saturation SPSIPB Serratus Posterior Superior Intercostal Plane Block SPSM Serratus Posterior Superior Muscle US Ultrasound VAS Visual Analog Scale Declarations Ethics approval and consent to participate This prospective, randomized study received approval from the Clinical Research Ethics Committee of the Ministry of Health, Istanbul Medeniyet University, Göztepe Training and Research Hospital (approval number: 2023/0870; December 13, 2023). Patient recruitment and follow-up were conducted between December 13, 2023, and June 30, 2024. The study was carried out in accordance with the Declaration of Helsinki and was registered at ClinicalTrials.gov (NCT06436599). The manuscript was prepared in accordance with the Consolidated Standards of Reporting Trials (CONSORT) guidelines. Written and verbal informed consent were obtained from all participants prior to enrollment. Consent for publication Not applicable. Availability of data and materials The datasets generated and analyzed during the current study are available from the corresponding author upon reasonable request. The full study protocol is also available from the corresponding author upon reasonable request . After acceptance, these datasets will be submitted to the editorial office in accordance with the journal's policy. Competing interests The authors declare that they have no competing interests. Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Authors’ contributions M.B. was responsible for conceptualization, investigation, methodology, project administration, writing, resources, supervision, validation, and writing review and editing. S.G. supervised the clinical study, contributed to protocol implementation, performed formal analysis, and reviewed and edited the manuscript. H.B. contributed to protocol implementation, assisted with data collection, and reviewed the manuscript. All authors read and approved the final manuscript. Acknowledgements Not applicable. References Łukasiewicz S, Czeczelewski M, Forma A, Baj J, Sitarz R, Stanisławek A. Breast cancer—epidemiology, risk factors, classification, prognostic markers, and current treatment strategies—an updated review. Cancers (Basel). 2021;13:4287. https://doi.org/10.3390/cancers13174287 . Al-Gaithy ZK, Yaghmoor BE, Koumu MI, Alshehri KA, Saqah AA, Alshehri HZ. Trends of mastectomy and breast-conserving surgery and related factors in female breast cancer patients treated at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, 2009–2017: a retrospective cohort study. Ann Med Surg (Lond). 2019;41:47–52. https://doi.org/10.1016/j.amsu.2019.03.012 . Jacobs A, Lemoine A, Joshi GP, Van de Velde M, Bonnet F, PROSPECT Working Group. PROSPECT guideline for oncological breast surgery: a systematic review and procedure-specific postoperative pain management recommendations. Anaesthesia. 2020;75:664–73. https://doi.org/10.1111/anae.14964 . Cheng GS, Ilfeld BM. A review of postoperative analgesia for breast cancer surgery. Pain Manag. 2016. https://doi.org/10.2217/pmt-2015-0008 . Qian B, Huang S, Liao X, Wu J, Lin Q, Lin Y. Serratus anterior plane block reduces the prevalence of chronic postsurgical pain after modified radical mastectomy: a randomized controlled trial. J Clin Anesth. 2021;74:110410. https://doi.org/10.1016/j.jclinane.2021.110410 . Chen G, Li Y, Zhang Y, Fang X. Effects of serratus anterior plane block for postoperative analgesia after thoracoscopic surgery compared with local anesthetic infiltration: a randomized clinical trial. J Pain Res. 2019;12:2411–7. https://doi.org/10.2147/JPR.S207116 . Chin KJ, Pawa A, Forero M, Adhikary S. Ultrasound-guided fascial plane blocks of the thorax. Adv Anesth. 2019;37:187–205. https://doi.org/10.1016/j.aan.2019.08.007 . Li ZH, Hong WJ, Guo XL, Li XR, Jiang XY, Jiang Y, et al. Serratus plane block in breast cancer surgery: a systematic review and meta-analysis. Clin Breast Cancer. 2023;23:e1–13. https://doi.org/10.1016/j.clbc.2022.10.009 . Blanco R, Parras T, McDonnell JG, Prats-Galino A. Serratus plane block: a novel ultrasound-guided thoracic wall nerve block. Anaesthesia. 2013;68:1107–13. https://doi.org/10.1111/anae.12344 . Rahimzadeh P, Imani F, Faiz SHR, Boroujeni BV. Impact of the ultrasound-guided serratus anterior plane block on post-mastectomy pain: a randomised clinical study. Turk J Anaesthesiol Reanim. 2018;46:388–92. https://doi.org/10.5152/TJAR.2018.86719 . Edwards JT, Langridge XT, Cheng GS, McBroom MM, Minhajuddin A, Machi AT. Superficial vs. deep serratus anterior plane block for analgesia in patients undergoing mastectomy: a randomized prospective trial. J Clin Anesth. 2021;75:110470. https://doi.org/10.1016/j.jclinane.2021.110470 . Tighe SQM, Karmakar MK. Serratus plane block: do we need to learn another technique for thoracic wall blockade? Anaesthesia. 2013;68:1103–6. https://doi.org/10.1111/anae.12423 . Desai M, Narayanan MK, Venkataraju A. Pneumothorax following serratus anterior plane block. Anaesth Rep. 2020;8:14–6. https://doi.org/10.1002/anr3.12034 . Tulgar S, Ciftci B, Ahiskalioglu A, Bilal B, Sakul BU, Korkmaz AO et al. Serratus posterior superior intercostal plane block: a technical report on the description of a novel periparavertebral block for thoracic pain. Cureus . 2023;15:e34582. https://doi.org/10.7759/cureus.34582 Avci O, Gundogdu O, Balci F, Tekcan MN, Ozbey M. Efficacy of serratus posterior superior intercostal plane block (SPSIPB) on post-operative pain and total analgesic consumption in patients undergoing video-assisted thoracoscopic surgery (VATS): a double-blinded randomised controlled trial. Indian J Anaesth. 2023;67:1116–22. https://doi.org/10.4103/ija.ija_589_23 . Ciftci B, Alver S, Ahiskalioglu A, Bilal B, Tulgar S. Serratus posterior superior intercostal plane block for breast surgery: a report of three cases, novel block and new indication. Minerva Anestesiol. 2023;89. https://doi.org/10.23736/S0375-9393.23.17432-3 . Köksal BG, Baytar Ç, Bayraktar E, Balbaloğlu H. Effects of serratus posterior superior intercostal plane block on postoperative analgesia in patients undergoing breast cancer surgery: a randomized controlled trial. BMC Anesthesiol. 2025;25:209. https://doi.org/10.1186/s12871-025-03092-0 . Doğan G, Küçük O, Kayır S, Dal GÇ, Çiftçi B, Zengin M, et al. Serratus posterior superior intercostal plane block versus thoracic paravertebral block for pain management after video-assisted thoracoscopic surgery: a randomized prospective study. Braz J Anesthesiol (Engl Ed). 2025;75:844647. https://doi.org/10.1016/j.bjane.2025.844647 . Tang W, Luo G, Lu Y, Chen C, Liu H, Li Y. Application of a new serratus anterior plane block in modified radical mastectomy under ultrasound guidance: a prospective, randomized controlled trial. J Clin Anesth. 2021;74:110377. https://doi.org/10.1016/j.jclinane.2021.110377 . Baytar MS, Yılmaz C, Karasu D, Baytar Ç. Comparison of ultrasonography-guided serratus anterior plane block and thoracic paravertebral block in video-assisted thoracoscopic surgery: a prospective randomized double-blind study. Korean J Pain. 2021;34:234–40. https://doi.org/10.3344/kjp.2021.34.2.234 . Mensah DK, deGraft-Johnson PKG, Darkwa EO, Akowuah A, Danso O-S, Aryee G, et al. Perioperative analgesic effect of serratus anterior plane block for breast surgery: a randomized controlled study at a large teaching hospital in Ghana. Cureus. 2024;16:e63397. https://doi.org/10.7759/cureus.63397 . Yao Y, Li J, Hu H, Xu T, Chen Y. Ultrasound-guided serratus plane block enhances pain relief and quality of recovery after breast cancer surgery: a randomised controlled trial. Eur J Anaesthesiol. 2019;36:436–44. https://doi.org/10.1097/EJA.0000000000001004 . Bhan S, Mishra S, Gupta N, Garg R, Vig S, Thulkar S, et al. A prospective randomised study to assess the analgesic efficacy of serratus anterior plane (SAP) block for modified radical mastectomy under general anaesthesia. Turk J Anaesthesiol Reanim. 2021;49:124–9. https://doi.org/10.5152/TJAR.2020.13 . Ahiskalioglu A, Yayik AM, Demir U, Ahiskalioglu EO, Celik EC, Ekinci M, et al. Preemptive analgesic efficacy of the ultrasound-guided bilateral superficial serratus plane block on postoperative pain in breast reduction surgery: a prospective randomized controlled study. Aesth Plast Surg. 2020;44:37–44. https://doi.org/10.1007/s00266-019-01542-y . Hu NQ, He QQ, Qian L, Zhu JH. Efficacy of ultrasound-guided serratus anterior plane block for postoperative analgesia in patients undergoing breast surgery: a systematic review and meta-analysis of randomised controlled trials. Pain Res Manag. 2021;2021:7849623. https://doi.org/10.1155/2021/7849623 . Feray S, Lubach J, Joshi GP, Bonnet F, Van de Velde M, PROSPECT Working Group of the European Society of Regional Anaesthesia and Pain Therapy. PROSPECT guidelines for video-assisted thoracoscopic surgery: a systematic review and procedure-specific postoperative pain management recommendations. Anaesthesia. 2022;77:311–25. https://doi.org/10.1111/anae.15609 . Abdallah FW, Cil T, MacLean D, Madjdpour C, Escallon J, Semple J, et al. Too deep or not too deep? a propensity-matched comparison of the analgesic effects of a superficial versus deep serratus fascial plane block for ambulatory breast cancer surgery. Reg Anesth Pain Med. 2018;43:480–7. https://doi.org/10.1097/AAP.0000000000000768 . Piracha MM, Thorp SL, Puttanniah V, Gulati A. A tale of two planes: deep versus superficial serratus plane block for postmastectomy pain syndrome. Reg Anesth Pain Med. 2017;42:259–62. https://doi.org/10.1097/AAP.0000000000000555 . Diéguez García P, Fajardo Pérez M, López Álvarez S, de la Alfaro P, Pensado Castiñeiras AP. Abordaje guiado por ultrasonidos de los nervios intercostales en la línea media axilar para cirugía de mama no reconstructiva y de la axila. Rev Esp Anestesiol Reanim. 2013;60:365–70. https://doi.org/10.1016/j.redar.2013.04.002 . Kunigo T, Murouchi T, Yamamoto S, Yamakage M. Spread of injectate in ultrasound-guided serratus plane block: a cadaveric study. JA Clin Rep. 2018;4:10. https://doi.org/10.1186/s40981-018-0147-4 . Balci F, Tekcan MN, Gündoğdu O, Avci O. Ultrasound-guided serratus posterior superior intercostal plane block in modified radical mastectomy surgeries: a case series. A&A Pract. 2024;18:e01830. https://doi.org/10.1213/XAA.0000000000001830 . Gundogdu O, Avci O, Balci F, Tekcan MN, Kol YC. Efficacy of serratus posterior superior intercostal plane block on postoperative pain and total analgesic consumption in patients undergoing reduction mammoplasty surgery: an evidence-based report. J Coll Physicians Surg Pak. 2024;34:348–50. https://doi.org/10.29271/jcpsp.2024.03.348 . Factors to consider. for fascial plane blocks’ success in acute and chronic pain management. Minerva Anestesiol. 2024;90:87–97. https://doi.org/10.23736/S0375-9393.23.17866-7 . Additional Declarations No competing interests reported. Supplementary Files CONSORT2010checklist.doc Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8686839","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":602659591,"identity":"7bba8296-4dce-4c7b-9483-12f4ad41405d","order_by":0,"name":"Mustafa Burgaç","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9klEQVRIiWNgGAWjYNACG4YECKMCiJmZGwipZ2xgSINpOQPSwkiKFsY2qAA+oDsj/fmDHwl2eQa3j1/88HNebTR/O1DLj4ptOLWY3cgxbOxJSC42OJdTLNm77XjujMOMDYw9Z27j08LYwPuDOXHDGZ4EacZtx3IbgFqYGdvwaUl/2PgnoR6kJfk345xjufMJa0kwbOZJOAzUwn5MmrGhJncDQS1n3hjOlkk4Xix5hofNsufYgdyNQC0H8frlePqDj28SqvP4zrA/vvGjpi533vnDBx/8qMCtBQnwGACJw2DmAWLUAwH7AyBRR6TiUTAKRsEoGEkAABAPZDNuiinyAAAAAElFTkSuQmCC","orcid":"","institution":"Kosuyolu High Specialization Training and Research Hospital","correspondingAuthor":true,"prefix":"","firstName":"Mustafa","middleName":"","lastName":"Burgaç","suffix":""},{"id":602659592,"identity":"e89fac97-d7dd-4868-971e-93bfb253673b","order_by":1,"name":"Senem Geçer","email":"","orcid":"","institution":"Istanbul Medeniyet University Faculty of Medicine, Göztepe Prof. Dr. Süleyman Yalçın City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Senem","middleName":"","lastName":"Geçer","suffix":""},{"id":602659593,"identity":"e80d0dcf-73f3-4207-80b4-6ec48b54d315","order_by":2,"name":"Hakan Baysal","email":"","orcid":"","institution":"Istanbul Medeniyet University Faculty of Medicine, Göztepe Prof. Dr. Süleyman Yalçın City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Hakan","middleName":"","lastName":"Baysal","suffix":""}],"badges":[],"createdAt":"2026-01-24 12:54:25","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-8686839/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8686839/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104405452,"identity":"2b196a69-7bb9-40dc-b49f-da162bc357b9","added_by":"auto","created_at":"2026-03-11 12:22:57","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":41509,"visible":true,"origin":"","legend":"\u003cp\u003eConsolidated Standards of Reporting Trials (CONSORT) 2010 flow diagram\u003c/p\u003e\n\u003cp\u003eConsolidated Standards of Reporting Trials (CONSORT) 2010 flow diagram showing patient enrolment and randomization. n: Number of Patients; SPSIPB: Serratus Posterior Superior Intercostal Plane Block; SAPB: Serratus Anterior Plane Block; h: hour.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8686839/v1/f01e455d20527c9c64aefc4a.png"},{"id":104341468,"identity":"e13156e9-8b6b-4311-9831-e1f4f407befe","added_by":"auto","created_at":"2026-03-10 16:49:45","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":966353,"visible":true,"origin":"","legend":"\u003cp\u003ePatient position and ultrasound images for serratus posterior superior intercostal plane block\u003c/p\u003e\n\u003cp\u003ePosition of the patient (a). Sonoanatomy before Serratus Posterior Superior İntercostal Plane\u003c/p\u003e\n\u003cp\u003eBlock (SPSIPB) \u0026nbsp;(b). Position of the needle and spread of LA during the SPSIPB (c). SS:\u003c/p\u003e\n\u003cp\u003eScapular Spine; TM: Trapezius Muscle; RMM: Rhomboid Major Muscle; SPSM: Serratus Posterior Superior Muscle; LA: Local Anesthetic.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8686839/v1/a458f68a6bce376c10ec1ce3.png"},{"id":104341469,"identity":"4444f496-e489-4613-aacb-bb5bc34d634d","added_by":"auto","created_at":"2026-03-10 16:49:45","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":67451,"visible":true,"origin":"","legend":"\u003cp\u003ePostoperative static numeric rating scale (NRS) graph\u003c/p\u003e\n\u003cp\u003eSPSİPB: Serratus Posterior Superior İntercostal Plane Block; SAPB: Serratus Anterior Plane Block. *p \u0026lt; 0.05, **p \u0026lt; 0.01.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8686839/v1/9cfa3b44c4a74adfd921bd30.png"},{"id":104341470,"identity":"e2868602-5f81-4e3a-a7dd-c20b0895af97","added_by":"auto","created_at":"2026-03-10 16:49:45","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":35736,"visible":true,"origin":"","legend":"\u003cp\u003e24-hour total tramadol consumption among groups\u003c/p\u003e\n\u003cp\u003e24-hour total tramadol consumption among groups (mg, minimum, maximum, mean ± SD). SPSIPB: Serratus Posterior Superior Intercostal Plane Block; SAPB: Serratus Anterior Plane Block.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-8686839/v1/f3b6fc3353c674613da35f47.png"},{"id":108491187,"identity":"44e11b89-b498-4078-90dc-f11f42f9eb12","added_by":"auto","created_at":"2026-05-05 09:52:46","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1900510,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8686839/v1/63905bc5-ccdd-4787-a6f3-660a4273cf28.pdf"},{"id":104341466,"identity":"bd36b4cb-3c83-418c-aed1-5540139f94a2","added_by":"auto","created_at":"2026-03-10 16:49:45","extension":"doc","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":223744,"visible":true,"origin":"","legend":"","description":"","filename":"CONSORT2010checklist.doc","url":"https://assets-eu.researchsquare.com/files/rs-8686839/v1/beeacabe1af0b57d96534fa5.doc"}],"financialInterests":"No competing interests reported.","formattedTitle":"Comparison of serratus posterior superior intercostal plane block versus deep serratus anterior plane block for postoperative analgesia after breast surgery: a prospective randomized study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eBreast cancer remains one of the leading causes of cancer-related mortality among women, and surgical treatment constitutes a cornerstone of its management [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Previous studies have reported that approximately 40% of women experience acute postoperative pain and up to 60% develop chronic pain following breast cancer surgery [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Acute postoperative pain after breast surgery adversely affects patients\u0026rsquo; quality of life and, when inadequately controlled, represents a significant risk factor for the development of chronic postsurgical pain [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Effective postoperative pain management facilitates early mobilization, accelerates functional recovery, and is considered a fundamental component of contemporary Enhanced Recovery After Surgery (ERAS) protocols [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePostoperative pain management following breast surgery is commonly achieved through a multimodal approach combining systemic opioids, non-steroidal anti-inflammatory drugs, and various regional anesthesia techniques. Thoracic paravertebral block, pectoral nerve blocks (PECS I\u0026ndash;II), erector spinae plane block (ESPB), and serratus anterior plane block (SAPB) are among the most frequently used regional techniques in this setting [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. SAPB has gained widespread acceptance in clinical practice due to its ability to provide effective analgesia of the anterolateral chest wall, its relative ease of application under ultrasound guidance, and its favorable safety profile [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Previous studies have demonstrated that the deep approach to SAPB may reduce early postoperative opioid consumption compared with the superficial technique [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. However, the analgesic coverage of the axillary region, particularly in procedures involving axillary dissection, may be variable and not consistently reliable across patients. Given the functional importance of the axillary region for shoulder movement and early mobilization, inconsistent analgesia in this area may have clinically relevant implications [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. In addition, although uncommon, SAPB has been associated with complications such as pneumothorax [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e The serratus posterior superior intercostal plane block (SPSIPB) is a relatively novel regional anesthesia technique described by Tulgar et al. [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], performed within the fascial plane between the serratus posterior superior muscle and the intercostal muscles. Anatomical and cadaveric studies have suggested that SPSIPB may provide a broader sensory spread across the lower cervical and upper thoracic regions, potentially including areas relevant to axillary analgesia [\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Clinical studies have reported that SPSIPB may reduce postoperative pain intensity and opioid requirements following thoracic surgery [\u003cspan additionalcitationids=\"CR15 CR16 CR17\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo date, no randomized trials have directly compared SPSIPB and deep SAPB in the context of breast surgery. Given the importance of achieving consistent analgesia in the axillary region while maintaining an acceptable safety profile, a direct comparison of these two interfascial plane blocks appears clinically relevant. Therefore, the primary aim of this study was to compare the effects of ultrasound-guided SPSIPB and SAPB on postoperative pain scores in patients undergoing unilateral modified radical mastectomy and to evaluate the clinical analgesic profiles of both techniques\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy design\u003c/h2\u003e \u003cp\u003e This prospective, randomized study received approval from the Clinical Research Ethics Committee of the Ministry of Health, Istanbul Medeniyet University, G\u0026ouml;ztepe Training and Research Hospital (approval number: 2023/0870; December 13, 2023). Patient recruitment and follow-up were conducted between December 13, 2023, and June 30, 2024. The study was carried out in accordance with the Declaration of Helsinki and was retrospectively registered at ClinicalTrials.gov (NCT06436599). The manuscript was prepared in accordance with the Consolidated Standards of Reporting Trials (CONSORT) guidelines (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Written and verbal informed consent were obtained from all participants prior to enrollment.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eStudy population\u003c/h3\u003e\n\u003cp\u003eA total of 62 female patients, aged\u0026thinsp;\u0026ge;\u0026thinsp;18 years, with an American Society of Anesthesiologists (ASA) physical status of I\u0026ndash;III, who were scheduled for unilateral modified radical mastectomy under general anesthesia, were included.\u003c/p\u003e \u003cp\u003eExclusion criteria were bleeding diathesis, use of anticoagulant therapy, known allergy to study medications (local anesthetics, non-steroidal anti-inflammatory drugs, or opioids), infection at the block site, hemodynamic instability (persistent hypotension or arrhythmia preventing extubation), and refusal to participate.\u003c/p\u003e \u003cp\u003eAn independent anesthesia resident not involved in the study prepared opaque, sealed, and sequentially ordered envelopes and randomly numbered them. The enrolling anesthesiologist opened the envelope immediately before block performance and assigned patients to the SAPB group (n\u0026thinsp;=\u0026thinsp;31) for even-numbered envelopes or to the SPSIPB group (n\u0026thinsp;=\u0026thinsp;31) for odd-numbered envelopes, using a 1:1 allocation ratio. A blinded anesthesiologist conducted all postoperative assessments.\u003c/p\u003e\n\u003ch3\u003ePreoperative preparation\u003c/h3\u003e\n\u003cp\u003eBefore block administration, patients were transferred to the block area, and demographic data, including age, body mass index (BMI), and ASA physical status, were recorded. All patients were informed about patient-controlled analgesia (PCA) and the numerical rating scale (NRS; 0\u0026thinsp;=\u0026thinsp;no pain, 10\u0026thinsp;=\u0026thinsp;worst imaginable pain).\u003c/p\u003e \u003cp\u003eStandard monitoring, including pulse oximetry (SpO₂), non-invasive blood pressure (NIBP), and electrocardiography (ECG), was applied. Premedication consisted of intravenous midazolam 1 mg and fentanyl 1 \u0026micro;g/kg.\u003c/p\u003e\n\u003ch3\u003eBlock techniques\u003c/h3\u003e\n\u003cp\u003eAll blocks were performed 30 minutes before surgery under ultrasound (US) guidance, in the lateral decubitus position, under full aseptic conditions. A US device (Samsung Medison H60) with a 12-MHz linear probe (covered with a sterile sheath) and an 80-mm, 22-G sonovisible block needle (Stimuplex Ultra 360; B. Braun) was used. In both groups, 30 mL of 0.25% bupivacaine was injected.\u003c/p\u003e\n\u003ch3\u003eSerratus posterior superior intercostal plane block (SPSIPB)\u003c/h3\u003e\n\u003cp\u003eWith the patient in the lateral decubitus position and the operative side up, the ultrasound probe was placed sagittally at the level of the scapular spine. The lateral border of the scapula, trapezius muscle, serratus posterior superior muscle (SPSM), and the second and third ribs were identified.\u003c/p\u003e \u003cp\u003eUsing an in-plane technique, the block needle was advanced from the level of the third rib in a caudocranial direction through the medial border of the scapula. The needle tip was positioned between the SPSM and the third rib. After negative aspiration, hydrodissection with 1\u0026ndash;2 mL of saline was performed to confirm correct needle placement, followed by injection of 30 mL of 0.25% bupivacaine between the SPSM and the third rib. The patient position and ultrasound images are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eSerratus anterior plane block (SAPB)\u003c/h2\u003e \u003cp\u003eWith the patient in the lateral decubitus position and the surgical side up, the ultrasound probe was placed perpendicular to the mid-axillary line at the level of the fifth rib. The latissimus dorsi, serratus anterior, and intercostal muscles were identified.\u003c/p\u003e \u003cp\u003eUsing an in-plane technique, the needle was advanced in an anterior-to-posterior direction into the plane between the serratus anterior and intercostal muscles (deep SAPB). After negative aspiration, hydrodissection with 1\u0026ndash;2 mL of saline confirmed needle placement, and 30 mL of 0.25% bupivacaine was injected.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eGeneral anesthesia\u003c/h3\u003e\n\u003cp\u003eThirty minutes after block administration, patients were transferred to the operating room. Standard monitoring was applied, and anesthesia depth was standardized using bispectral index (BIS) monitoring. Following preoxygenation, anesthesia was induced with intravenous propofol 2 mg/kg and rocuronium bromide 0.6 mg/kg. Anesthesia was maintained with sevoflurane in an oxygen/air mixture (50/50).\u003c/p\u003e \u003cp\u003eIntraoperative analgesia was provided with a remifentanil infusion at 0.05\u0026ndash;0.2 \u0026micro;g/kg/min, titrated to maintain systolic blood pressure within \u0026plusmn;\u0026thinsp;20% of baseline values. Total remifentanil consumption and duration of surgery were recorded. Hemodynamic parameters were documented at 5-minute intervals. All procedures were performed using the same surgical technique.\u003c/p\u003e\n\u003ch3\u003ePostoperative analgesia protocol and follow-up\u003c/h3\u003e\n\u003cdiv class=\"Heading\"\u003ePostoperative analgesia protocol and follow-up\u003c/div\u003e \u003cp\u003eAll patients received intravenous paracetamol (1 g), tramadol (1 mg/kg), and ondansetron (0,1 mg/kg) 30 minutes before the end of surgery. After reversal of neuromuscular blockade with sugammadex, patients were extubated and transferred to the post-anesthesia care unit (PACU), which was defined as postoperative hour 0.\u003c/p\u003e \u003cp\u003eIn the PACU, PCA with tramadol was initiated (no basal infusion, 2 mL bolus [5 mg/mL], 15-minute lockout interval, and a maximum dose of 100 mg over 4 hours). The total daily tramadol dose was limited to 400 mg. As part of the multimodal analgesia regimen, intravenous paracetamol 1 g was administered regularly every 8 hours during the postoperative period.\u003c/p\u003e \u003cp\u003ePain intensity was assessed using the NRS at rest (static) and during movement (dynamic). The first assessment obtained after achieving a Modified Aldrete Score (MAS)\u0026thinsp;\u0026ge;\u0026thinsp;10 was considered the baseline measurement (30 minutes). Subsequent assessments were performed at postoperative 1, 4, 8, 12, and 24 hours. Intravenous tenoxicam 20 mg was administered as rescue analgesia for NRS scores\u0026thinsp;\u0026gt;\u0026thinsp;4. Total tramadol consumption during the first 24 hours was recorded.\u003c/p\u003e \u003cp\u003ePostoperative nausea and vomiting (PONV) was assessed using a 4-point scale (1\u0026thinsp;=\u0026thinsp;no nausea or vomiting, 2\u0026thinsp;=\u0026thinsp;nausea without vomiting, 3\u0026thinsp;=\u0026thinsp;a single episode of vomiting or persistent nausea, 4\u0026thinsp;=\u0026thinsp;recurrent vomiting or severe retching). PONV assessments were performed at 30 minutes and at 1, 4, 8, 12, and 24 hours postoperatively. Patients with a PONV score\u0026thinsp;\u0026ge;\u0026thinsp;3 received intravenous ondansetron 8 mg.\u003c/p\u003e \u003cp\u003ePatient satisfaction was evaluated 24 hours after block administration using a 5-point Likert scale (1\u0026thinsp;=\u0026thinsp;very dissatisfied, 2\u0026thinsp;=\u0026thinsp;dissatisfied, 3\u0026thinsp;=\u0026thinsp;neutral, 4\u0026thinsp;=\u0026thinsp;satisfied, 5\u0026thinsp;=\u0026thinsp;very satisfied). All postoperative assessments were conducted by the same anesthesiologist who was blinded to group allocation.\u003c/p\u003e \u003cp\u003eThe primary outcome was postoperative pain intensity, evaluated using NRS scores during the first 24 hours after surgery. Secondary outcomes included total 24-hour postoperative tramadol consumption, intraoperative remifentanil consumption, requirement for rescue analgesia, incidence of PONV, and patient satisfaction scores.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eSample size\u003c/h2\u003e \u003cp\u003eSample size calculation was performed using G*Power software (version 3.1.9.2; Heinrich Heine University, D\u0026uuml;sseldorf, Germany). The calculation was based on a previous study evaluating postoperative pain scores in patients undergoing modified radical mastectomy with a serratus anterior plane block [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. In that study, a clinically relevant difference of approximately 1 point in visual analog scale (VAS) pain scores with a standard deviation of 1.5 was reported. Assuming a two-sided alpha error of 0.05 and a statistical power of 85%, a minimum of 26 patients per group was required. To compensate for potential dropouts or missing data, 31 patients were included in each group.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eStatistical analyses were performed using SPSS software version 27.0 (IBM Corp., Armonk, NY, USA). Continuous variables were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation or median (minimum\u0026ndash;maximum), depending on data distribution. Normality of distribution was assessed using the Shapiro\u0026ndash;Wilk test and visual inspection of box plots. Comparisons between groups were performed using the independent samples Student\u0026rsquo;s \u003cem\u003et\u003c/em\u003e-test for normally distributed continuous variables and the Mann\u0026ndash;Whitney \u003cem\u003eU\u003c/em\u003e test for non-normally distributed variables. Categorical variables were analyzed using the chi-square test, Fisher\u0026rsquo;s exact test, or the Fisher\u0026ndash;Freeman\u0026ndash;Halton test, as appropriate. A p-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eThe patient enrollment process is summarized in the CONSORT flow diagram (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The trial concluded after reaching the predetermined sample size. Of the 65 patients assessed for eligibility, three were excluded because they did not meet the inclusion criteria. The remaining 62 patients were randomized to either the SPSIPB group or the SAPB group. During the postoperative follow-up period, one patient in the SPSIPB group was excluded due to a technical malfunction of the patient-controlled analgesia (PCA) device. Consequently, data from 61 patients (SPSIPB, n\u0026thinsp;=\u0026thinsp;30; SAPB, n\u0026thinsp;=\u0026thinsp;31) were included in the final analysis.\u003c/p\u003e \u003cp\u003eBaseline demographic characteristics and duration of surgery were comparable between the two groups, with no statistically significant differences observed (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of demographic variables and duration of surgery\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSPSİPB (n:30)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSAPB (n:31)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e \u003cp\u003eAge (year)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e59.4\u0026thinsp;\u0026plusmn;\u0026thinsp;13.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e56.2\u0026thinsp;\u0026plusmn;\u0026thinsp;12.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.344 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e61.5 (23\u0026ndash;80)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e56 (31\u0026ndash;78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e \u003cp\u003eBMI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.17\u0026thinsp;\u0026plusmn;\u0026thinsp;5.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.94\u0026thinsp;\u0026plusmn;\u0026thinsp;4.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.086 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30 (19.9\u0026ndash;44.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e28.1 (18.8\u0026ndash;35.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eASA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eI/II/III\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2/20/8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3/20/8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.000 \u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eOperation Duration (min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e91\u0026thinsp;\u0026plusmn;\u0026thinsp;38\u003c/p\u003e \u003cp\u003e75 (60\u0026ndash;180)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e100\u0026thinsp;\u0026plusmn;\u0026thinsp;39.9\u003c/p\u003e \u003cp\u003e90 (60\u0026ndash;180)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.339 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003ea\u003c/sup\u003e Student t-test, \u003csup\u003eb\u003c/sup\u003e Fisher-Freeman-Halton test. *p\u0026thinsp;\u0026lt;\u0026thinsp;0.05, **p\u0026thinsp;\u0026lt;\u0026thinsp;0.01.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eValues are expressed mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation or median (min-max). SPSIPB: serratus posterior superior intercostal plane block, SAPB: serratus anterior plane block, BMI: body mass index, ASA: American Society of Anesthesiologists physical status score, min: minute.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003ePostoperative pain intensity, assessed using the numeric rating scale (NRS), differed between the groups during the early postoperative period. Static NRS scores were significantly lower in the SAPB group compared with the SPSIPB group during the first 8 postoperative hours (0\u0026ndash;8 h; p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Similarly, dynamic NRS scores were significantly lower in the SAPB group at the 1st and 4th postoperative hours (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). No significant intergroup differences were observed in either static or dynamic NRS scores at the 12th or 24th postoperative hours. Importantly, mean NRS scores in both groups remained\u0026thinsp;\u0026le;\u0026thinsp;4 at all assessed time points (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The postoperative static NRS score trajectory is illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eStatic and dynamic NRS assessments of the patients\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStatic NRS\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSPSİPB(n:30)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSAPB(n:31)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003eMean difference (95% CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e30th min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.93\u0026thinsp;\u0026plusmn;\u0026thinsp;1.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.29\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" morerows=\"1\" nameend=\"c6\" namest=\"c4\" rowspan=\"2\"\u003e \u003cp\u003e+\u0026thinsp;0.64 (+\u0026thinsp;0.12 to +\u0026thinsp;1.16)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.013*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (0\u0026ndash;4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (0\u0026ndash;4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e1th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.63\u0026thinsp;\u0026plusmn;\u0026thinsp;1.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" morerows=\"1\" nameend=\"c6\" namest=\"c4\" rowspan=\"2\"\u003e \u003cp\u003e+\u0026thinsp;0.60 (+\u0026thinsp;0.14 to +\u0026thinsp;1.06)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.012*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (0\u0026ndash;4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e4th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" morerows=\"1\" nameend=\"c6\" namest=\"c4\" rowspan=\"2\"\u003e \u003cp\u003e+\u0026thinsp;0.92 (+\u0026thinsp;0.51 to +\u0026thinsp;1.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.001**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (0\u0026ndash;2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e8th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" morerows=\"1\" nameend=\"c6\" namest=\"c4\" rowspan=\"2\"\u003e \u003cp\u003e+\u0026thinsp;0.62 (+\u0026thinsp;0.22 to +\u0026thinsp;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.004**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0\u0026ndash;2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e12th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.73\u0026thinsp;\u0026plusmn;\u0026thinsp;0.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.39\u0026thinsp;\u0026plusmn;\u0026thinsp;0.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" morerows=\"1\" nameend=\"c6\" namest=\"c4\" rowspan=\"2\"\u003e \u003cp\u003e+\u0026thinsp;0.34 (-0.07 to +\u0026thinsp;0.75)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.106\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0,5 (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0\u0026ndash;2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e24th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003e+\u0026thinsp;0.28 (-0.15 to +\u0026thinsp;0.71)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.443\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0\u0026ndash;2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDynamic NRS\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e30th min\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.43\u0026thinsp;\u0026plusmn;\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003e+\u0026thinsp;0.40 (-0.03 to +\u0026thinsp;0.83)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.069\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (0\u0026ndash;4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (1\u0026ndash;4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e1th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.71\u0026thinsp;\u0026plusmn;\u0026thinsp;0.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003e+\u0026thinsp;0.49 (+\u0026thinsp;0.05 to +\u0026thinsp;0.93)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.037*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (0\u0026ndash;4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e4th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.03\u0026thinsp;\u0026plusmn;\u0026thinsp;1.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.32\u0026thinsp;\u0026plusmn;\u0026thinsp;0.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003e+\u0026thinsp;0.71 (+\u0026thinsp;0.28 to +\u0026thinsp;1.14)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.002**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (0\u0026ndash;4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e8th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.57\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.35\u0026thinsp;\u0026plusmn;\u0026thinsp;0.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003e+\u0026thinsp;0.22 (-0.19 to +\u0026thinsp;0.63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.365\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (0\u0026ndash;4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e12th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003e+\u0026thinsp;0.24 (-0.11 to +\u0026thinsp;0.59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.223\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (0\u0026ndash;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (0\u0026ndash;2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e24th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003e+\u0026thinsp;0.27 (-0.15 to +\u0026thinsp;0.69)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.381\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (0\u0026ndash;4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (0\u0026ndash;2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003eMann-Whitney test. *p\u0026thinsp;\u0026lt;\u0026thinsp;0.05, **p\u0026thinsp;\u0026lt;\u0026thinsp;0.01.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003eValues are expressed mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation or median (min-max). SPSIPB: serratus posterior superior intercostal plane block, SAPB: serratus anterior plane block, NRS: numeric rating scale, CI: confidence interval, min: minute, h: hour.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe mean total tramadol consumption during the first 24 postoperative hours was 76.1\u0026thinsp;\u0026plusmn;\u0026thinsp;51.1 mg in the SPSIPB group and 74.2\u0026thinsp;\u0026plusmn;\u0026thinsp;44.7 mg in the SAPB group (mean difference: 1.9 mg; 95% confidence interval [CI]: \u0026minus;22.1 to 25.9), with no statistically significant difference between the groups (p\u0026thinsp;=\u0026thinsp;0.875). Tramadol consumption at individual postoperative time points (1, 4, 8, 12, and 24 h) was also comparable between the groups (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The total tramadol consumption during the first 24 postoperative hours is illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of postoperative and intraoperative analgesic consumption\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eTramadol (mg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSPSİPB(n:30)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSAPB(n:31)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMean difference (95% CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e0th -1st h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.5\u0026thinsp;\u0026plusmn;\u0026thinsp;11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.9\u0026thinsp;\u0026plusmn;\u0026thinsp;12.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u0026thinsp;1.6 (-4.2 to +\u0026thinsp;7.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.483 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (0\u0026ndash;40)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10 (0\u0026ndash;40)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e1st -4th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11.5\u0026thinsp;\u0026plusmn;\u0026thinsp;9.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.7\u0026thinsp;\u0026plusmn;\u0026thinsp;10.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u0026thinsp;1.8 (-3.3 to +\u0026thinsp;6.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.363 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (0\u0026ndash;30)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10 (0\u0026ndash;40)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e4th -8th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.5\u0026thinsp;\u0026plusmn;\u0026thinsp;11.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14.2\u0026thinsp;\u0026plusmn;\u0026thinsp;12.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.7 (-7.9 to +\u0026thinsp;6.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.846 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (0\u0026ndash;40)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10 (0\u0026ndash;40)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e8th -12th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13\u0026thinsp;\u0026plusmn;\u0026thinsp;14.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17.4\u0026thinsp;\u0026plusmn;\u0026thinsp;13.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-4.4 (-12.1 to +\u0026thinsp;3.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.140 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (0\u0026ndash;50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20 (0\u0026ndash;50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e12th -24th h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24.5\u0026thinsp;\u0026plusmn;\u0026thinsp;25.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20.9\u0026thinsp;\u0026plusmn;\u0026thinsp;17.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u0026thinsp;3.6 (-7.8 to +\u0026thinsp;15)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.886 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20 (0-100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20 (0\u0026ndash;70)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eTotal in 24 h\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e76.1\u0026thinsp;\u0026plusmn;\u0026thinsp;51.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e74.2\u0026thinsp;\u0026plusmn;\u0026thinsp;44.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u0026thinsp;1.9 (-22.1 to +\u0026thinsp;25.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.875 \u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e85 (0-190)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e70 (0-160)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eRemifentanil (\u0026micro;g)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e186.8. \u0026plusmn; 89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e144.9\u0026thinsp;\u0026plusmn;\u0026thinsp;119.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e+\u0026thinsp;41.9 (+\u0026thinsp;2.8 to +\u0026thinsp;81)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.038 \u003csup\u003ea*\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e165 (65\u0026ndash;400)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e100 (0-430)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTenoxicam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25 (83.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30 (96.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.104 \u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eY\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (16.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (3.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003ea\u003c/sup\u003e Mann-Whitney test, \u003csup\u003eb\u003c/sup\u003e Student t-test, \u003csup\u003ec\u003c/sup\u003e Fisher's Exact test. *p\u0026thinsp;\u0026lt;\u0026thinsp;0.05, **p\u0026thinsp;\u0026lt;\u0026thinsp;0.01.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eValues are expressed mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation or median (min-max). SPSIPB: serratus posterior superior intercostal plane block, SAPB: serratus anterior plane block, CI: confidence interval, h: hour, Y: yes (indicates the number of patients that used rescue analgesia), N: no.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIntraoperative remifentanil consumption was significantly higher in the SPSIPB group compared with the SAPB group (186.8\u0026thinsp;\u0026plusmn;\u0026thinsp;89.0 \u0026micro;g vs. 144.9\u0026thinsp;\u0026plusmn;\u0026thinsp;119.5 \u0026micro;g; mean difference: 41.9 \u0026micro;g; 95% CI: 2.8 to 81.0; p\u0026thinsp;=\u0026thinsp;0.038). However, this difference was not associated with differences in postoperative pain scores or opioid consumption (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eRescue analgesia with intravenous tenoxicam was required in five patients (16.7%) in the SPSIPB group and in one patient (3.2%) in the SAPB group; however, this difference was not statistically significant (p\u0026thinsp;=\u0026thinsp;0.104) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eWith respect to postoperative adverse effects, no cases of postoperative nausea and vomiting (PONV) were observed in the SAPB group, whereas mild nausea (PONV score 1) occurred in two patients in the SPSIPB group. The difference in PONV incidence between the groups was not statistically significant (p\u0026thinsp;=\u0026thinsp;0.238). Patient satisfaction scores, assessed using a five-point Likert scale, were similar between the groups (p\u0026thinsp;=\u0026thinsp;0.516) and are presented in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. No cases of vascular or neuraxial injury, pruritus, pneumothorax, or hemodynamic instability were observed in either group.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePatient Satisfaction Scores Assessed with a 5-Point Likert Scale\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSPSİPB (n:30)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSAP (n:31)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSatisfaction\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.51\u003c/p\u003e \u003cp\u003e4.5 (4\u0026ndash;5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.56\u003c/p\u003e \u003cp\u003e4 (3\u0026ndash;5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.516\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eMann-Whitney test. *p\u0026thinsp;\u0026lt;\u0026thinsp;0.05, **p\u0026thinsp;\u0026lt;\u0026thinsp;0.01.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eValues are expressed mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation or median (min-max). SPSIPB: serratus posterior superior intercostal plane block, SAPB: serratus anterior plane block.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIn summary, both regional techniques achieved satisfactory postoperative analgesia with low pain scores and similar opioid consumption. The following discussion focuses on the clinical relevance of the observed differences in early postoperative pain and intraoperative opioid use.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this randomized controlled study, the effects of SPSIPB and SAPB on postoperative pain control were compared in patients undergoing modified radical mastectomy. The primary outcome of the study, postoperative NRS scores, demonstrated statistically significant differences in favor of SAPB during the early postoperative period. Nevertheless, the observation that mean NRS values remained\u0026thinsp;\u0026le;\u0026thinsp;4 at all measurement time points in both groups indicates that both techniques provided clinically acceptable and adequate postoperative analgesia.\u003c/p\u003e \u003cp\u003eThe lower static (first 8 hours) and dynamic (first 4 hours) NRS scores observed in the SAPB group during the early postoperative period may be attributed to the more superficial anatomical location of SAPB and its more direct and rapid effect on nerve structures closely related to the surgical field [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Importantly, however, these statistically significant differences remained below the threshold generally considered clinically meaningful, suggesting that both techniques were sufficient to support early functional recovery in the immediate postoperative period. In the context of breast surgery, NRS values\u0026thinsp;\u0026le;\u0026thinsp;4 are widely regarded as clinically adequate, particularly in terms of facilitating early mobilization and reducing the risk of pulmonary complications [\u003cspan additionalcitationids=\"CR22 CR23 CR24\" citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe analgesic efficacy of SAPB in breast surgery has been demonstrated in numerous randomized controlled trials and meta-analyses [\u003cspan additionalcitationids=\"CR22 CR23 CR24\" citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e], and this technique is included among the recommended regional anesthesia strategies in the PROSPECT guidelines [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Accordingly, SAPB was selected as the comparator technique in the present study. Although both superficial and deep SAPB approaches have been shown to provide effective postoperative analgesia, the deep SAPB technique was preferred in this study. This preference was based on its potential advantages, including reduced early postoperative opioid consumption, shorter application time, facilitation of local anesthetic spread with respiratory movements, and a lower risk of interference with the surgical field [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Nevertheless, it should be acknowledged that high-quality clinical data directly comparing these technical variations remains limited [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan additionalcitationids=\"CR28 CR29\" citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Despite early postoperative NRS scores favoring SAPB, the absence of corresponding differences in clinically relevant outcomes such as opioid consumption, rescue analgesic requirements, or patient satisfaction warrants careful consideration.\u003c/p\u003e \u003cp\u003eAlthough SAPB is an effective and widely used technique in breast surgery, variability in axillary analgesic coverage, particularly in procedures involving axillary dissection, has been reported in the literature [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Given the critical role of axillary pain control in shoulder movement, early mobilization, and overall functional recovery, consistency of analgesic coverage in this region is of considerable clinical importance. This clinical need has spurred interest in alternative regional techniques capable of providing broader and potentially more uniform dermatomal coverage; in this context, SPSIPB has drawn attention due to its injection site being distant from the pleura and its potential for wider sensory distribution [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. However, the extent to which these theoretical advantages translate into meaningful clinical benefits remains unclear, forming the primary rationale for the present study.\u003c/p\u003e \u003cp\u003e SPSIPB is a relatively recently described fascial plane block technique introduced by Tulgar et al. [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Anatomical and cadaveric studies have suggested that SPSIPB may provide extensive sensory spread across dermatomes ranging from C3 to T10 [\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. Nevertheless, existing evidence regarding the clinical analgesic performance of SPSIPB is largely derived from case series, limited controlled studies, and anatomical inferences [\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. The scarcity of clinical studies directly comparing SPSIPB with SAPB in the context of breast surgery complicates the precise delineation of the true clinical role of SPSIPB.\u003c/p\u003e \u003cp\u003eA recently published randomized controlled study reported that the analgesic effects of SPSIPB were predominantly associated with intercostal nerves at the T2\u0026ndash;T5 levels and lower cervical nerves, and that dermatomal spread may be more limited and heterogeneous than previously assumed [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Cadaveric studies have similarly demonstrated variable spread of SPSIPB between C7 and T7 dermatomes, with homogeneous sensory coverage not consistently achieved in all subjects [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. These findings suggest that the previously reported consistent C3\u0026ndash;T10 dermatomal coverage may not be clinically predictable in every patient [\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis inconsistency between anatomical and clinical data may help explain the higher early postoperative NRS scores observed in the SPSIPB group in the present study. As the analgesic effect of SPSIPB relies on interfascial diffusion and potentially wider but slower-onset spread, a more variable analgesic response to early postoperative surgical stimuli may occur [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Notably, the absence of significant differences between groups at 12 and 24 hours postoperatively suggests that the analgesic efficacy of SPSIPB approaches that of SAPB over time. This time-dependent analgesic pattern is consistent with previous reports indicating that the clinical effects of SPSIPB may become more pronounced in the later postoperative period rather than immediately after surgery [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe lack of a significant difference in total opioid consumption during the first 24 hours postoperatively indicates that the early NRS differences did not translate into a clinically meaningful increase in opioid requirements. Furthermore, the absence of differences between groups in terms of rescue analgesic use, incidence of postoperative nausea and vomiting, and patient satisfaction supports the clinical feasibility of SPSIPB as part of a multimodal analgesia regimen. These findings are consistent with the limited but growing body of clinical evidence supporting the use of SPSIPB [\u003cspan additionalcitationids=\"CR15 CR16 CR17\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePrevious studies have shown that SAPB may reduce intraoperative opioid consumption [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. In contrast, data regarding the intraoperative analgesic contribution of SPSIPB remain limited, and direct comparative studies are scarce [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. In this study, the higher remifentanil use in the SPSIPB group may reflect a slower onset of pain relief due to its wider spread between tissue layers, rather than indicating that the analgesia was insufficient. Importantly, this difference did not adversely affect postoperative pain scores or opioid consumption, further indicating that SPSIPB ultimately provides clinically sufficient postoperative analgesia.\u003c/p\u003e \u003cp\u003eSeveral limitations of this study should be acknowledged. First, the absence of detailed dermatomal sensory mapping limits mechanistic evaluation of block spread, although this does not detract from clinical applicability. Second, the evaluation period was limited to the first 24 postoperative hours, and long-term outcomes such as functional recovery or chronic postmastectomy pain were not assessed. Additionally, the lack of a control group without regional anesthesia precludes assessment of the absolute contribution of either block compared with standard care. Nonetheless, the present study represents one of the few randomized, blinded trials directly comparing SPSIPB and SAPB within the same surgical population, thereby providing a meaningful contribution to the existing literature.\u003c/p\u003e \u003cp\u003eIn conclusion, although SPSIPB was associated with higher early postoperative NRS scores compared with SAPB, it provided clinically adequate analgesia following mastectomy. These findings suggest that SPSIPB may be considered a viable alternative to SAPB in breast surgery. However, larger, multicenter comparative studies with detailed evaluation of dermatomal spread and clinically relevant outcomes are required to substantiate claims of superiority and to more clearly define the role of SPSIPB in perioperative analgesia.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eASA\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAmerican Society of Anesthesiologists\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eBIS\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eBispectral Index\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eBMI\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eBody Mass Index\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eCI\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eConfidence Interval\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eCONSORT\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eConsolidated Standards of Reporting Trials\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eECG\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eElectrocardiography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eERAS\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEnhanced Recovery After Surgery\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eESPB\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eErector Spinae Plane Block\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eGA\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eGeneral Anesthesia\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eLA\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eLocal anesthetic\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eMAS\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eModified Aldrete Score\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eMRM\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eModified Radical Mastectomy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eNIBP\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eNon\u0026ndash;Invasive Blood Pressure\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eNRS\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eNumeric Rating Scale\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003ePACU\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePost\u0026ndash;Anesthesia Care Unit\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003ePCA\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePatient\u0026ndash;Controlled Analgesia\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003ePECS\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePectoral Nerve Block\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003ePONV\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePostoperative Nausea and Vomiting\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003ePROSPECT\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eProcedure\u0026ndash;Specific Postoperative Pain Management\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eRMM\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eRhomboid major muscle\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eSAPB\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSerratus Anterior Plane Block\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eSD\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eStandard deviation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eSpO₂\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePeripheral Oxygen Saturation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eSPSIPB\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSerratus Posterior Superior Intercostal Plane Block\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eSPSM\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSerratus Posterior Superior Muscle\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eUS\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eUltrasound\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cb\u003eVAS\u003c/b\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eVisual Analog Scale\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis prospective, randomized study received approval from the Clinical Research Ethics Committee of the Ministry of Health, Istanbul Medeniyet University, G\u0026ouml;ztepe Training and Research Hospital (approval number: 2023/0870; December 13, 2023). Patient recruitment and follow-up were conducted between December 13, 2023, and June 30, 2024. The study was carried out in accordance with the Declaration of Helsinki and was registered at ClinicalTrials.gov (NCT06436599). The manuscript was prepared in accordance with the Consolidated Standards of Reporting Trials (CONSORT) guidelines.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWritten and verbal informed consent were obtained from all participants prior to enrollment.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and analyzed during the current study are available from the corresponding author upon reasonable request. The full study protocol is also available from the corresponding author upon reasonable request\u003cstrong\u003e.\u003c/strong\u003e After acceptance, these datasets will be submitted to the editorial office in accordance with the journal\u0026apos;s policy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eM.B. was responsible for conceptualization, investigation, methodology, project administration, writing, resources, supervision, validation, and writing review and editing. S.G. supervised the clinical study, contributed to protocol implementation, performed formal analysis, and reviewed and edited the manuscript. H.B. contributed to protocol implementation, assisted with data collection, and reviewed the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eŁukasiewicz S, Czeczelewski M, Forma A, Baj J, Sitarz R, Stanisławek A. Breast cancer\u0026mdash;epidemiology, risk factors, classification, prognostic markers, and current treatment strategies\u0026mdash;an updated review. 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Ultrasound-guided serratus posterior superior intercostal plane block in modified radical mastectomy surgeries: a case series. A\u0026amp;A Pract. 2024;18:e01830. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1213/XAA.0000000000001830\u003c/span\u003e\u003cspan address=\"10.1213/XAA.0000000000001830\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGundogdu O, Avci O, Balci F, Tekcan MN, Kol YC. Efficacy of serratus posterior superior intercostal plane block on postoperative pain and total analgesic consumption in patients undergoing reduction mammoplasty surgery: an evidence-based report. J Coll Physicians Surg Pak. 2024;34:348\u0026ndash;50. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.29271/jcpsp.2024.03.348\u003c/span\u003e\u003cspan address=\"10.29271/jcpsp.2024.03.348\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFactors to consider. for fascial plane blocks\u0026rsquo; success in acute and chronic pain management. Minerva Anestesiol. 2024;90:87\u0026ndash;97. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.23736/S0375-9393.23.17866-7\u003c/span\u003e\u003cspan address=\"10.23736/S0375-9393.23.17866-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Postoperative pain, Multimodal analgesia, Serratus anterior plane block, Serratus posterior superior intercostal plane block, Breast surgery","lastPublishedDoi":"10.21203/rs.3.rs-8686839/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8686839/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eEffective postoperative pain management is essential for recovery after breast surgery. Although regional fascial plane blocks are widely used as part of multimodal analgesia, direct comparative clinical data between serratus posterior superior intercostal plane block (SPSIPB) and serratus anterior plane block (SAPB) are limited. This study compared the analgesic efficacy of SPSIPB and SAPB in patients undergoing unilateral modified radical mastectomy (MRM).\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis prospective, randomized study included 62 patients with American Society of Anesthesiologists (ASA) physical status I\u0026ndash;III scheduled for unilateral MRM. Patients were randomized to either the SPSIPB group (n\u0026thinsp;=\u0026thinsp;31) or the SAPB group (n\u0026thinsp;=\u0026thinsp;31). The primary outcome was postoperative pain intensity assessed using the numeric rating scale (NRS). Secondary outcomes included total tramadol consumption during the first 24 hours, intraoperative remifentanil consumption, requirement for rescue analgesia (tenoxicam), postoperative nausea and vomiting (PONV), and patient satisfaction. Opioids were administered via an intravenous patient-controlled analgesia (PCA) device.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eStatic NRS scores were significantly higher in the SPSIPB group compared with the SAPB group at postoperative 30 minutes and at the 1st, 4th, and 8th hours (all p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). No significant differences were observed at the 12th and 24th postoperative hours. Nevertheless, mean NRS scores remained\u0026thinsp;\u0026le;\u0026thinsp;4 at all time points in both groups, indicating clinically acceptable analgesia. Total 24-hour tramadol consumption was comparable between the SPSIPB and SAPB groups (76.1\u0026thinsp;\u0026plusmn;\u0026thinsp;51.1 mg vs. 74.2\u0026thinsp;\u0026plusmn;\u0026thinsp;44.7 mg; p\u0026thinsp;=\u0026thinsp;0.875). Intraoperative remifentanil consumption was significantly higher in the SPSIPB group (p\u0026thinsp;=\u0026thinsp;0.038). There were no significant differences between the groups regarding rescue analgesic requirements, incidence of PONV, or patient satisfaction.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eSPSIPB provides a clinically acceptable postoperative analgesic profile comparable to SAPB within a multimodal analgesia regimen following breast surgery. These findings should not be interpreted as evidence of superiority or equivalence. To better assess the clinical efficacy and potential applications of SPSIPB, more comprehensive and well-designed comparative studies are needed.\u003c/p\u003e\u003ch2\u003eTrial Registration\u003c/h2\u003e \u003cp\u003eClinicalTrials.gov (NCT06436599), retrospectively registered on May 22, 2024.\u003c/p\u003e","manuscriptTitle":"Comparison of serratus posterior superior intercostal plane block versus deep serratus anterior plane block for postoperative analgesia after breast surgery: a prospective randomized study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-10 16:49:25","doi":"10.21203/rs.3.rs-8686839/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c9416ecd-be85-4922-8035-5be43014e5f2","owner":[],"postedDate":"March 10th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-28T21:09:21+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-10 16:49:25","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8686839","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8686839","identity":"rs-8686839","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}