Bilateral erector spinae plane block versus thoracic epidural analgesia in living- donor hepatectomies

Bilateral erector spinae plane block versus thoracic epidural analgesia in living- donor hepatectomies | 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 Bilateral erector spinae plane block versus thoracic epidural analgesia in living- donor hepatectomies Seher Irem Kiran Paudel, Meltem Guner Can, Mehmet Bilhan Hayırlioglu, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7687505/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 We aimed to compare the effects of bilateral ESPB and thoracic epidural analgesia (TEA) on postoperative pain management and early recovery parameters in patients undergoing living-donor hepatectomy. Material and methods Patients donor hepatectomy from January 2020 to December 2022 were included in this study. They were divided into two groups: ‘group 1’ (TEA) and ‘group 2’ (ESPB). The primary outcome was analgesic efficacy based on the visual analogue scale (VAS), patient-controlled analgesia (PCA) metrics and the necessity of additional morphine administration. The secondary outcomes were the presence of nausea and vomiting, administration of additional antiemetic medication and dose, occurrence of pruritus, presence of gas/stool output, presence of urinary retention, first ambulation time, time of oral intake, Bromage score (leg movements are used to evaluate the efficacy of motor block and lower limb strength), and level of consciousness. Results Both groups exhibited similar demographic characteristics. While the overall VAS score was comparable between the groups, the scores at 1st and 3rd hours were statistically lower in the TEA group. The local anaesthetic dose administered via the PCA pump at six postoperative time points was consistently lower in ESPB group at each interval. No significant differences were observed in opioid consumption, opioid-related side effects, and postoperative early recovery parameters. Conclusions Compared with TEA, ESPB showed promise in effectively managing postoperative analgesia, while maintaining opioid consumption. Erector spinae plane block Thoracic epidural analgesia Donor hepatectomy Liver transplantation Introduction End-stage liver disease is the progression of inflammation, fibrosis formation, and cirrhosis due to acute or chronic liver diseases [ 1 ]. Due to the increasing demand for liver transplantation and unavailability of deceased donors, living-donor liver transplantation (LDLT) has emerged as a viable and effective option. Living donors are healthy individuals who voluntarily undergo surgery without any therapeutic benefits [ 2 ]. Severe pain remains a major concern after LDLT [ 3 ]. Researches show that donor hepatectomies are frequently associated with a higher pain level than other liver surgeries, such as tumour resection [ 4 ]. Notably, donors are often younger and healthier individuals, who may not have experienced significant postoperative pain, contributing to low pain threshold [ 5 ]. Inadequate postoperative analgesia management has been associated with increased morbidity, pain chronification, prolonged reliance on opioid medication, prolonged hospital stay, diminished quality of life (QoL) and increased patient dissatisfaction [ 6 , 7 ]. The current literature shows lack of consensus regarding the optimal analgesic strategy in this patient population [ 8 ]. Opioids have been widely used to manage surgery-related acute pain. But despite their efficacy, their adverse reactions, including addiction, chronic pain and prolonged hospital stay, necessitate the exploration for alternatives [ 9 ]. Regional anaesthetic nerve blocks are widely used to manage postoperative pain to reduce opioid consumption [ 8 , 10 ]. Although thoracic epidural analgesia (TEA) is considered a gold-standard technique in abdominal and thoracic surgery, multi-modal analgesic methods have been widely evaluated in LDLTS [ 11 ]. The most commonly used methods are; intravenous administration of opioid analgesics using a patient-controlled analgesia (PCA) pump or via continuous infusion, administration of intravenous non-opioid agents (acetaminophen, non-steroidal anti-inflammatory drugs [NSAIDs], ketamine, magnesium, lidocaine and dexmedetomidine) [ 9 ], local anaesthetic (LA) administration to the surgical incision site, and other regional analgesia techniques (e.g. intrathecal morphine administration [ 5 ], paravertebral block [ 12 ], transversus abdominis plane [TAP] block [ 13 ], quadratus lumborum block [QLB] [ 14 ] and erector spinae plane block [ESPB] [ 15 , 16 ]. The PROSPECT (procedure-specific postoperative pain management) guidelines recommend the use of peripheral nerve blocks to manage postoperative pain [ 17 ]. Similarly, the ERAS (enhanced recovery after surgery) guidelines emphasize the critical role of postoperative analgesia management in transplant units [ 18 ]. Ultrasound-guided ESPB is an emerging interfascial plane block initially introduced by Forero et al. in 2016 [ 19 ]. It involves injection of an LA agent between the deep fascia of the erector spinae musculature and the transverse process of the vertebra [ 20 ]. Although the analgesic mechanism is unclear, it induces somatic and visceral sensory blockade with technical simplicity, a relatively safe profile, and wide dermatomal spread (T1 to L3), making it an ideal regional anaesthetic technique for abdominal surgery [ 20 , 21 ]. Numerous studies have investigated the potential advantages of regional anaesthesia, particularly ESPB, within the LDLT context. The benefits of ESPB include postoperative pain relief, decreased postoperative pain scores, reduced opioid consumption, early ambulation, low risks of postoperative nausea and vomiting (PONV), few technique-related complications and fast patient recovery [ 22 , 23 , 24 ]. As regards safety profile, ESPB has not been correlated with any major complications, such as LA agent toxicity, neurological deterioration, pleural injury, or pneumothorax [ 25 , 26 , 27 ]. However, previous studies have reported minor adverse events, including transient paraplegia and priapism [ 28 , 29 ]. This study aims to evaluate the efficacy of bilateral ESPB, a minimally invasive and readily implementable analgesic technique, inducing both somatic and visceral sensory blockade, characterized by comparable effectiveness and a reduced complication profile, against thoracic epidural analgesia (TEA), the established gold standard technique, in managing postoperative pain in patients undergoing living-donor hepatectomy using VAS score and PCA metrics as primary outcome and postoperative early recovery parameters as secondary outcomes. Materials and Methods Patient selection This single-centre retrospective study included living liver donors who underwent open hepatectomy between January 2020 and December 2022. Among the 202 living donors, those aged between 18 and 60 years, classified as American society of anesthesiologist physical status 1 (ASA 1), and provided informed consent were included. Patients who disagreed with the use of their medical records for research purposes, preferred the intravenous analgesic procedure over the use of either central or peripheral nerve blocks, required reintervention due to technical failure, developed catheter-related complications, and required surgical intervention within 48 hours postoperatively were excluded. A total of 19 donors who received TEA were compared with 18 donors who received ESPB in terms of their analgesic efficacy and effects on early recovery parameters. Surgical procedure All the donor hepatectomies were performed by a highly experienced surgeon. The open technique, characterized by J-shaped incision was employed for the right-love living-donor hepatectomies. After mobilisation of the liver, cholecystectomy and hilar dissection were performed to adequately prepare the surgical field. The line of parenchymal transection was established via occlusion of the right hepatic artery and right portal vein using an atraumatic bulldog clamp. The hepatic parenchymal blood vessels were exposed; smaller vessels were effectively coagulated, whereas those larger than 4 mm, along with duct branches, were ligated to ensure hemostasis. After the graft was excised, the partially divided falciform ligament was reattached to the anterior abdominal wall to mitigate the risk of left-lobe rotation. For adequate drainage, one silastic drain was routinely placed at the surgical site. Finally, the fascia and skin were closed using an absorbable suture. Postoperative pain management The donors were assigned to either group 1 or 2 according to the preferred regional anaesthetic technique in their informed consent (TEA [n = 19] or ESPB [n = 18], respectively) and followed up postoperatively for 48 h. Each technique is discussed as follows: TEA All patients received intravenous sedation with midazolam (0.03 mg/kg) and ketamine (0.3–0.5 mg/kg) before nerve block application. Each patient was placed in the sitting position. Employing the landmark anatomical marking technique, the T10 vertebral level was identified via a midline approach, with the inferior angle of the scapula approximating T7 as the reference point. Employing the pressure-loss technique, the epidural space was identified at the T10 vertebral level using physiological saline. After 3 ml of a 2% lidocaine solution was administered, an epidural block was performed, which involved careful insertion of an 18G Tuohy catheter, advanced approximately 3–4 cm in the cranial direction. In addition, aspiration was performed to confirm correct positioning of the catheter and the absence of blood return. Subsequently, the catheter was secured with a sterile, transparent, semipermeable adhesive dressing (Tegaderm, 3M, St Paul, MN, ABD). A 0.25% bupivacaine hydrochloride (Marcaine) was administered using an epidural catheter at two time points: at the beginning (10 mL) and before the end (10 mL) of the surgical procedure. A PCA device was connected to the epidural catheter after the procedure. This device continuously infused the 0.125% bupivacaine hydrochloride solution at a rate of 3 mL/h. Furthermore, a specific protocol that allowed self-administration of a 5 mL bolus of medication three times per hour accompanied by a 20 min lockout period, was implemented. ESPB The Patients were sedated before the surgical procedure through intravenous administration of midazolam (0.03 mg/kg), and ketamine (0.3–0.5 mg/kg). Each patient was placed in the prone position to facilitate the nerve block application. The seventh rib was identified with ultrasound guidance using the paraspinal approach. Next, the ultrasound probe was medially oriented, which allowed for the visualization of the transverse process of the T7 vertebra at an approximate distance of 3 cm laterally from the spinal midline. Ultrasound-guided left ESPB was performed using an 18G Tuohy needle (Contiplex ®), specifically targeting the T7 vertebral level, and then 20 mL of 0.25% bupivacaine hydrochloride was administered. The same steps were performed for the right ESPB, after which 10 mL of 0.25% bupivacaine solution was also administered and an epidural block catheter was inserted between the deep fascia of the erector spinae musculature and the transverse process of the vertebra. An additional 10 mL of bupivacaine solution was administered via the catheter. As a result, a total volume of 20 mL was applied to each side, ensuring that an equal amount of anaesthetic was bilaterally implemented. After the procedure, the PCA device was connected to the indwelling block catheter on the right side, and 10 mL of 0.125% bupivacaine solution was administered on an hourly basis. Finally, a standardized protocol was implemented, which enabled the administration of a 5 mL bolus once per hour, ensuring a 60-min lockout period between doses. All patients from both groups received 0.05 mg/kg of morphine (i.v.) along with NSAIDs, as a standard protocol before the awakening phase. Rescue therapy As well known, morphine is superior to fentanyl due to its longer duration of action. The morphine was selected as rescue therapy in accordance with drug protocols in the country. In both groups, 3 mg of morphine (iv.) was administered when the visual analogue scale (VAS) scores exceeded 4 despite the prior use of NSAIDs twice per day and the utilization of a PCA device during the postoperative period. Postoperative patient follow-up and recovery parameters After extubation in the operating room, the patients were transferred to the intensive care unit (ICU) for close monitoring of hemodynamic parameters, biochemical markers, and coagulation profiles, early detection of potential surgical complications, and effective analgesia and safe ambulation. To assess the efficacy of the two analgesic methods, a structured evaluation was conducted at six time points (1st, 3rd, 6th, 12th, 24th, and 48th hours) postoperatively, and the results were recorded in the patient's pain assessment forms. The VAS scores, PCA metrics ( dose attempted (DA): Total number of times the patient pressed the PCA button to request a dose of pain medication, dose administered/dose given (DG): The number of times the PCA device actually administered a dose of pain medication, bolus dose (BD): A single, preset dose of medication delivered each time the patient presses the PCA button, total dose [TD: BD + DG]), and necessity for rescue analgesia or additional analgesic medications were also evaluated. All data were meticulously collected by specialized nurse team for pain control. The first choice for antiemetic therapy is metoclopramide hydrochloride and it is dosed if the patient suffers from nausea and/or vomitting (maximum dose 4 times a day, every 6 hours) in regard to our protocol. To effectively compare the impacts of the two methods on the patient’s early recovery outcomes, various postoperative parameters were evaluated, including the presence of nausea and vomiting (yes/no), administration of additional antiemetic medication (yes/no) and dose (mg), occurrence of pruritus, presence of gas/stool output (yes/no), presence of urinary retention, first ambulation time (h) (ambulation: getting the patient out of bed and walking), time of oral intake (h), Bromage score (leg movements are used to evaluate the efficacy of motor block and lower limb strength), and level of consciousness (LOC was measured using AVPU scale, A- alert, V- response to voice, P- response to pain, U- unresponsive). Visual analogue scale VAS is a reliable and frequently used pain measurement method for evaluating the severity of pain. The scale consists of horizontal line with a length of 10 cm. The patients is told to mark a point on the line. The observer systematically coded the patient’s facial expression, which serves as a non-verbal indicator of pain intensity. The observational data was then complemented by a self-reported pain scale, in which the patients were asked to quantify their pain on a continuum from ‘no pain’ (0) to - ‘ worst pain ever’ (10). This scale was further categorized into distinct levels of severity: mild (0.5–4.4), moderate (4.5–7.4), and severe (7.5–10). Mean value of these two measurements were used as VAS scores in this study. Correlating the observational data and self-reported pain scale, a numerical representation of pain intensity was derived, referred to as the VAS scale. Statistical analysis Statistical analysis was conducted using the SPSS software version 22.0 (IBM Corporation, Armonk, NY, USA), and a P-value < 0.05 was considered statistically significant. The numerical variables were analysed using visual (histograms, probability plots) and analytical (Kolmogorov–Smirnov/Shapiro–Wilk’s test) methods to determine whether they were normally distributed. Descriptive data were expressed as mean ± standard deviation for normally distributed variables and median and interquartile range for non-normally distributed variables. Categorical variables were compared using the chi-squared test. Comparisons between subgroups were performed using Student’s t-test for unpaired data as a parametric test for normally distributed variables and Mann Whitney U test as a nonparametric test for non-normally distributed or ordinal variables. Results We analyzed data from living donors who were aged 18 to 60 years, were classified as ASA 1, underwent elective LDLT, and provided informed consent. The patients were systematically classified into group 1 (TEA; n = 19) and group 2 (ESPB; n = 18) to facilitate subsequent statistical analysis. The groups exhibited comparable characteristics regarding demographic and health-related variables, including age, height, weight, body mass index, and history of smoking and previous surgeries (p > 0.05) (Table 1 ). Table 1 Patient characteristics Characteristics Total patients Group 1 (TEA) Group 2 (ESPB) P value Age (years), mean ± SD 32.9 ± 8 30.6 ± 6.3 35 ± 9 ¹ 0.08 Height (cm), mean ± SD 168.2 ± 5.9 171 ± 9.5 168.4 ± 8.6 ¹ 0.37 Body weight (kg), mean ± SD 71.9 ± 13.2 73.8 ± 5.3 69.9 ± 10.5 ¹ 0.36 Body-mass index (kg / m2), mean ± SD 24.64 ± 3.3 24.6 ± 3.1 24.7 ± 3.5 ¹ 0.92 Female sex, n (%) 17 (45.9%) 8 (42.1%) 9 (50%) ² 0.74 Smoking status n (%) 3 (8.1%) 0 (0%) 3 (16.7%) ² 0.06 Alcohol consumption, n (%) 3 (8.1%) 0 (0%) 3 (16.7%) ² 0.06 Previous surgery, n (%) 10 (27%) 5 (26.3%) 5 (27.8%) ² 0.9 TEA, thorasic epidural analgesia, ESPB, erector spinae plane block, SD, standard deviation , ¹ Student's t-test , ² chi-squared test. The analysis revealed a statistically significant VAS score in group 2 (ESPB) measured at the 1st (VAS1; P = 0.027) and 3rd (VAS2; P = 0.009) hours but did not achieve clinical significance. Notably, all the recorded VAS scores remained within the mild-pain range (VAS ≤ 4.5) (Table 2 ). Table 2 Comparison of postoperative pain assessment scale between the groups Visual analogue scale (VAS) Group 1 (TEA) Grou 2 (ESPB) P value 1. hr. VAS- 1, median (IQR) 3 (2) 4 (3) ³ 0.027 3. hr. VAS- 2, median (IQR) 2 (2) 3 (2) ³ 0.009 6. hr. VAS- 3, median (IQR) 2 (2) 2 (2) ³ 0.46 12. hr. VAS- 4, median (IQR) 1 (0.9) 2 (2) ³ 0.167 24. hr. VAS- 5, median (IQR) 3 (3) 2 (2) ³ 0.86 48. hr. VAS- 6, median (IQR) 2 (2) 2 (2) ³ 0.38 VAS, visual analogue scale; hr, hour; IQR, interquartile range; ³ Mann-Whitney U test A further promising finding was that the DG, BD, TD calculated using the PCA device was significantly lower in group 2. However, the number of DA was similar between the groups. (P > 0.05) (Table 3 ). Table 3 Comparison of the patient controlled analgesia device (PCA) metrics and LA agent amounts between groups PCA metrics Group 1 (TEA) (n:19) Grou 2 (ESPB) (n:18) P value DA- 1 (n), median (IQR) DA- 2 (n), median (IQR) DA- 3 (n), median (IQR) DA- 4 (n), median (IQR) DA- 5 (n), median (IQR) DA- 6 (n), median (IQR) 10 (8) 25 (8) 45 (15) 61 (34) 113 (43) 150 (41) 5 (2) 21 (17) 36 (11) 47 (24) 89 (36) 122 (41) ³ 0.13 ³ 0.56 ³ 0.18 ³ 0.28 ³ 0.48 ³ 0.5 DG- 1 (mL), median (IQR) DG- 2 (mL), median (IQR) DG- 3 (mL), median (IQR) DG- 4 (mL), median IQR) DG- 5 (mL), median IQR) DG- 6 (mL), median IQR) 1 (1) 3 (2) 5 (5) 9 (7) 17 (15) 28 (23) 1 (1) 2 (2) 3.5 (3) 6.5 (5) 11 (7) 17.5 (10) ³ 0.01 ³ 0.02 ³ <0.001 ³ 0.003 ³ <0.001 ³ <0.001 BD- 1 (mL), median (IQR) BD- 2 (mL), median (IQR) BD- 3 (mL), median (IQR) BD- 4 (mL), median (IQR) BD- 5 (mL), median (IQR) BD- 6 (mL), median (IQR) 5 (5) 14 (13) 20 (18) 35 (15) 65 (60) 115 (93) 5 (1) 10 (9) 20 (15) 32 (30) 55.5 (41) 75 (61) ³ 0.053 ³ 0.064 ³ 0.47 ³ 0.085 ³ 0.004 ³ 0.001 TD- 1 (mL), median (IQR) TD- 2 (mL), median (IQR) TD- 3 (mL), median (IQR) TD- 4 (mL), median (IQR) TD- 5 (mL), median (IQR) TD- 6 (mL), median(IQR) 6 (6) 18 (17) 30 (26) 42 (42) 78 (67) 138 (125) 6 (5) 12 (12) 23 (18) 39 (20) 66.5 (50) 90 (70) ³ 0.012 0.016 0.006 0.04 0.001 < 0.001 PCA, patient controlled analgesia; TEA, thoracic epidural analgesia; ESPB, erector spinae plane block; DA, dose attempted; DG, dose given; BD, bolus dose; TD, total dose (DG + Bolus); IQR: Interquartile range; mL, mililiter; ³ Mann-Whitney U test. Comparative analysis of the postoperative early recovery parameters among groups revealed no statistically significant differences in the presence of gas/stool output, timing of oral intake, timing of ambulation, duration of ICU stay, and length of hospital stay (P > 0.05). Similarly, no statistically significant differences were observed in the potential adverse effects associated with opioid use, such as presence of itching, instances of nausea and vomiting, the need for antiemetic medication, urinary retention, and requirement for additional doses of morphine between the groups (p > 0.05)( Table 4 ). Table 4 Comparison of early (first 48 hour) postoperative recovery parameters between the groups Early recovery parameters All patients Group 1 (TEA) Grou 2 (ESPB) P value Catheter-related undesirable effects, n (%) 3 (8.1%) 2 (10.5%) 1 (5.6%) ² 0.5 Itching, n (%) 4 (10.8%) 3 (15.8%) 1 (5.6%) ² 0.3 PONV, n (%) 15 (40.5%) 9 (74.4%) 6 (33.3%) ² 0.38 Antiemetic drug administration, median (IQR) 1 (2) 1 (2) 0.3 (1) ³ 0.09 Rescue analgesic demand, median (IQR) 2 (2) 1 (2) 2 (2) ³ 0.38 Urinary retention, n (%) 3 (8.1%) 3 (15.8%) 0 (0%) ² 0.07 Presence of gas/stool output, n (%) 29 (78.4%) 14 (73.7%) 15 (83.3%) ² 0.4 Median oral intake initiation time, hr, mean ± SD 19.65 ± 2.8 19.8 ± 2.9 19.5 ± 2.8 ¹ 0.7 Median ambulation time, hr, median (IQR) 23 (5) 23(4) 22.5 (3) ³ 0.84 ICU stay (day) 1 1 1 1 Hospital stay (day) median (IQR) 5 (3) 4 (2) 5 (1) ³ 0.08 PONV, Postoperative nausea vomiting; ICU, Intensive care unit; IQR: Interquartile range; ¹ Student’s t-test; ² chi-squared test; ³ Mann-Whitney U test Catheter-related side effects, including numbness (n = 1) and right shoulder pain (n = 1), were reported in group 1, whereas back pain (n = 1) was reported in group 2. Discussion To the best of our knowledge, this is the first study to directly compare bilateral ESPB and TEA, a gold standard for managing postoperative pain, and their respective impacts on VAS score, PCA metrics, and early recovery parameters 48 h after LDLTS. Studies have focused on reducing donor morbidity and enhancing QoL after LDLTS [ 6 , 7 ]. Donor hepatectomy is associated with numerous complications, such as potential development of transient coagulopathy [ 30 , 31 ] and drug metabolism alterations [ 32 ]. These complications raise questions regarding TEA application in pain management. An effective alternative to TEA in liver donor surgery remains an ongoing area of investigation. Among various peripheral nerve blocks, ESPB has gained considerable attention owing to its notable advantages, including its effectiveness in pain relief, low risk of associated complications, and relatively easy application [ 18 ]. Moreover, proficiency in performing ESPB can be achieved relatively quickly, with a short learning curve period [ 33 ]. These factors make ESPB a valuable option in procedure-specific analgesia guidelines. The groups were similar in terms of demographic and health-related variables (P > 0.05). Existing literature indicates that age and sex play pivotal roles in how pain is experienced and interpreted. Specifically, younger individuals tend to exhibit lower pain tolerance, whereas older adults generally display higher pain thresholds [ 34 ]. The findings of this study provide valuable insights to this disclosure, as the homogeneity of the groups regarding demographic variables allows for an objective interpretation. Pain involves not only physiological aspects but also psychological dimensions that shape an individual’s perception of discomfort. The use of the VAS poses notable challenges, as the effectiveness of this method is largely contingent upon the individual’s sensory discrimination capabilities [ 35 ]. In pain management, clinical decision-making predominantly relies on established pain scales, despite their inherent limitations in capturing the complex nature of the pain experience [ 36 ]. It is crucial to acknowledge that a decrease in pain scores is not necessarily correlated with enhancement in the overall patient experience or clinically significant alleviation of pain [ 37 ]. VAS, which is frequently preferred in studies owing to its ease of use, has the potential to underrepresent pain experience [ 38 ]. In techniques that involve the use of numerical rating scales, the scoring ranges across various categories are not uniformly distributed. VAS is particularly effective in differentiating the absence of pain from mild pain. However, its limitations become apparent when distinguishing moderate from severe pain [ 39 ]. Consequently, pain scores should not be used as the sole determinant in assessing the efficacy of analgesic interventions. The Current literature suggests that aiming for a VAS score of 4.5 or lower is necessary to achieve optimal analgesia, categorizing the patient’s pain as mild or non-existent [ 40 ]. Examination of the VAS records from our study, showed that both analgesic techniques provided effective pain relief 48 h postoperatively. Notably, the VAS recorded at the first hour (VAS 1, P = 0.027) and third hour (VAS 2, P = 0.009) were lower in group 1. However, it is noteworthy that all the recorded VAS scores remained within the optimal analgesia range (VAS ≤ 4.5). Hence, we propose that while these findings are statistically significant, their clinical relevance is limited. The overall VAS scores were comparable between both groups, suggesting that ESPB effectively induces analgesia similar to TEA. This finding is consistent with those of Ghielmini et al., who evaluated the efficacy of ESPB in comparison with transversus abdominis plane (TAP) block, specifically in the context of robotic inguinal hernia repair [ 44 ]. The use of ESPB against TEA in patients suffering from traumatic flail chest also yielded similar results [ 45 ]. Recently, a study conducted by Zubair M et al. reported that ESPB exhibited improved analgesic efficacy compared with TEA, along with enhanced safety profile and a concomitant reduction in opioid consumption as well as PONV incidence after living-donor hepatectomy [ 24 ]. We observed no significant differences despite bilateral ESPB catheter implantation, high LA dose and more frequent VAS scores interpretation. Further research is warranted to elucidate the discrepancies between these findings and to explore the factors contributing to the variability in ESPB efficacy. The duration of the recording intervals plays a pivotal role in the accurate assessment of the efficacy of analgesic interventions. As the length of these intervals increases, the reliability of the pain scales to reflect the analgesic effect diminishes. This discrepancy arises from the fact that the assessment intervals are not consistent with the timing of drug administration. While certain studies have opted to evaluate pain levels once or twice daily [ 43 ], more frequent assessments- typically every 2 to 4 h- are preferred [ 44 , 45 ]. In our study, we evaluated pain scores at six time points: 1st, 3rd, 6th, 12th, 24th, 48th hours postoperatively. Considering this recording time intervals is critical for the accurate interpretation of the findings. Traditional pain assessment tools, including VAS, mainly rely on subjective interpretations, leading to inaccurate gauging of pain levels. Consequently, functional pain assessment methods, particularly those leveraging the analysis of electronic medical records (EMRs), have gained considerable attention. PCA metrics are among the components of these methods [ 46 ]. Piccioni et al. evaluated the ratio between the DA and DG of analgesics. Their findings indicated a significant correlation between the ratio and the traditional pain assessment scores, as well as total opioid consumption [ 47 ]. We focused on PCA metrics, specifically in assessing the analgesic effectiveness. Our findings indicated that the DG, BD, and TD were significantly lower in the group 2. Nevertheless, notable variations were observed in the infusion dose volume, BD volume, and lockout intervals within the PCA setup across the groups. Recognizing the inherent variability within the PCA setup, caused by the different nature of these blocks, is crucial for the accurate evaluation of the clinical significance of the findings. The frequency of patients requesting medication from PCA devices may be influenced by various factors, except pain intensity, which contributes to a falsely elevated DA count [ 48 ]. These factors include anxiety, cognitive confusion, inappropriate use of medication request buttons, inability to differentiate between pain and other distressing sensations, and use of devices by individuals other than patients etc. [ 49 ]. We found no significant difference in the DA from the PCA device between the groups. This finding is consistent with the results of the VAS assessments, suggesting that both groups received effective analgesia. Our results indicated that ESPB is equally effective to TEA in inducing postoperative pain control. While the consumption of LA drugs was significantly reduced in group 2, opioid consumption, presence of gas/stool passage within the first 24 h, timing of oral intake and PONV incidence were similar in both groups. Oraee S et al. highlighted the efficacy of ESPB in decreasing pain scores, reducing the need for opioid analgesics, and increasing the time to first rescue analgesia compared with placebo or TAP block in laparoscopy. A lower PONV rate was observed in ESPB than in the placebo groups, yet a comparable rate with QLB [ 50 ]. In a systematic review and meta-analysis of randomized controlled trials (RCT), the cumulative opioid consumption and PONV were significantly lower in patients who received ESPB than in those who received intravenous analgesia. However, neither of these parameters showed significant differences between those who received ESPB and those who received regional nerve blocks, such as the oblique subcostal TAP block and QLB [ 51 ]. Likewise, a meta-analysis of five RCTs revealed no significant difference between ESPB and thoracolumbar interfascial plane block with respect to postoperative analgesia and 24 h opioid consumption after lumbar spine surgery [ 52 ]. Unlike research that may have compared ESPB with less frequently utilized regional blocks, our study directly distinguished ESPB from TEA, a gold standard for regional pain management. ESPB has also been useful in pain management of rib fractures due to several distinct advantages, including their suitability for outpatient management, an enhanced safety profile, simplified administration, the potential for use in patients with coagulopathy or those receiving anticoagulant therapies and increased incentive spirometry volumes [ 53 ].All these findings suggest that ESPB serves as a viable alternative to TEA in the context of LDLTS. No complications associated with catheter removal (development of coagulopathy, epidural hematoma, or dural puncture) as well as motor block duration extension, paraesthesia, or hypotension occurred. No instances of urinary retention in the ESPB group may be attributable to its mechanism, which functions as a facial plane block, and is not directly affecting the sacral and lumbar plexus responsible for bladder innervation. In addition, the length of stay in the ICU and the total hospitalization duration were comparable between the groups. This finding aligns with our expectation as in our clinical practice, patients typically remain in the ICU for one day. Limitations of our study: This study is subject to several limitations that may affect the validity and generalizability of its findings. Such limitations include its retrospective design, relatively small sample size, lack of blinding among the researchers, absence of a placebo control group, omission of a control group that received only intravenous analgesics, exclusive recording of pain scores during periods of rest, neglecting to evaluate dynamic pain experienced with movement, and follow up period limited to 48 h postoperatively, which does not provide insights into the long term implications of the procedures on the patient’s QoL. Meanwhile, a phenomenon called ‘Hawton effect’ suggests that in a prospective study, researchers may exert additional effort and care, which could lead to more favourable results than those under normal clinical circumstances. Our study employed a retrospective approach, avoiding the increased attention and care typically observed in prospective studies [ 54 ]. Conclusion The erector spinae block (ESPB) is considered a safe and effective alternative to TEA for procedures expected to cause significant postoperative pain (14, 15, 44, 50, 55). This study demonstrated that ESPB can be used as a part of multimodal analgesia strategy, offering the advaltage of reduced local anesthetic consumption compared to TEA in living donor liver transplantation. ESPB provided comparable effects on early recovery parameters (within 48 hours), without an associated increase in the complication rate observed with TEA. Prospective studies with larger sample sizes are warranted to confirm and strenghten these findings. List of abbreviations Erector spinae plane block ,ESPB Intensive care unit, ICU Local anaesthetic, LA Living-donor liver transplantation, LDLT Non-steroidal anti-inflammatory drugs, NSAIDs Patient-controlled analgesia, PCA Postoperative nausea and vomiting, PONV Thoracic epidural analgesia, TEA Transversus abdominis plane, TAP Thoracic epidural analgesia, TEA Quadratus lumborum block, QLB Quality of life, QoL Visual analogue scale, VAS, Declarations Ethics approval and consent to participate: The Instutional Review Board (The Acibadem University Medical Research Ethics Committee) approved the study after which access to medical records was authorized by the office of the chief physician (approval number: 2024-14/582, Date: 19.09.2024). The study was conducted in accordance with the ethical principles outlined in the Declaration of Helsinki. Accordingly, the ethics committee waived the requirement for individual informed consent. Consent for publication: Not applicable. Availability of data and materials: The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests: The authors declare that they have no competing interests. Funding: Not applicable. Authors' contributions: SIKP, MGC and HK designed the research. MGC, MBH , AO and TUY analyzed the data. SIKP, MGC and AO wrote the main manuscript. SIKP, MBH, AO and MGC researced the literature. MGC and HK revisied the article for intellectual content and finalized the manucript. All authors participated in the performance of the research. All authors reviewed the manuscript. Acknowledgements: The authors thank all study participants for their involvement in the study. We acknowledge the nurses for their excellent work of patient organization and nursing assistance. The authors gratefully acknowledge Dr. Sena Sert Sekerci for her contributions to the statistical analysis presented in this study. 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The perception of pain in others: how gender, race, and age influence pain expectations. J Pain. 2012;13(3):220–7. Peters ML, Patijn J, Lamé I. Pain assessment in younger and older pain patients: psychometric properties and patient preference of five commonly used measures of pain intensity. Pain Med. 2007;7:601–10. Jensen MP, Chen C, Brugger AM. Interpretation of visual analog scale ratings and change scores: a reanalysis of two clinical trials of postoperative pain. J Pain. 2003;4(7):407–14. Mudgalkar N, Bele SD, Valsangkar S, Bodhare TN, Gorre M. Utility of numerical and visual analog scales for evaluating the post-operative pain in rural patients. Indian J Anaesth. 2012;56(6):553–7. Kersten P, White PJ, Tennant A. Is the pain visual analogue scale linear and responsive to change? An exploration using Rasch analysis. PLoS ONE. 2014;9(6):e99485. Jensen MP, Karoly P. Self-report scales and procedures for assessing pain in adults. In: Turk DC, Melzack R, editors. Handbook of pain assessment. 2nd ed. New York: The Guilford Press; 1992. pp. 15–34. pp:135 – 52. Jensen MP, Chen C, Brugger AM. Interpretation of visual analog scale ratings and change scores: a reanalysis of two clinical trials of postoperative pain. J Pain. 2003;4(7):407–14. Ghielmini EM, Greco L, Spampatti S, Kubli R, Saporito A, La Regina D. Erector Spinae Plane Block versus Transversus Abdominis Plane Block for Robotic Inguinal Hernia Repair: A Blinded, Active-Controlled, Randomized Trial. Pain Physician. 2024;27(1):27–34. Mostafa SF, Eid GM. Ultrasound guided erector spinae plane block versus thoracic epidural analgesia in traumatic flail chest, a prospective randomized trial. J Anaesthesiol Clin Pharmacol. 2023;39(2):250–7. Khor WT, Chang Y, Tien CH, et al. Erector spinae plane block versus thoracolumbar interfascial plane block in lumbar spine surgery: A meta-analysis of randomized controlled trials. Global Spine J. 2024;24:21925682241266518. Muthu S, Viswanathan VK, Annamalai S, Thabrez M. Bilateral erector spinae plane block for postoperative pain relief in lumbar spine surgery: A PRISMA-compliant updated systematic review & meta-analysis. World Neurosurg X. 2024;23:100360. Pang J, You J, Chen Y, Song C. Comparison of erector spinae plane block with paravertebral block for thoracoscopic surgery: a meta-analysis of randomized controlled trials. J Cardiothorac Surg. 2023;18(1):300. Adeboye A, Hart R, Senapathi SH, Ali N, Holman L, Thomas HW. Assessment of functional pain score by comparing to traditional pain scores. Cureus. 2021;13(8):e16847. Piccioni F, Doronzio A, Brambilla R, Melis M, Langer M. Integration of pain scores, morphine consumption and demand/delivery ratio to evaluate patient-controlled analgesia: the C-SIA score. Korean J Anesthesiol. 2017;70(3):311–7. Macintyre PE. Safety and efficacy of patient-controlled analgesia. Br J Anaesth. 2001;87(1):36–46. Pastino A, Lakra A, Patient-controlled analgesia. 2023 Jan 29. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan. Oraee S, Rajai Firouzabadi S, Mohammadi I, Alinejadfard M, Golsorkh H, Hatami S. Erector spinae plane block for laparoscopic surgeries: a systematic review and meta-analysis. BMC Anesthesiol. 2024;24(1):389. Yang X, Zhang Y, Chen Y, Xu M, Lei X, Fu Q. Analgesic effect of erector spinae plane block in adults undergoing laparoscopic cholecystectomy: a systematic review and meta-analysis of randomized controlled trials. BMC Anesthesiol. 2023;23(1):7. Khor WT, Chang Y, Tien CH, et al. Erector Spinae Plane Block Versus Thoracolumbar Interfascial Plane Block in Lumbar Spine Surgery: A Meta-Analysis of Randomized Controlled Trials. Global Spine J. 2025;15(2):1367–74. Ian J, Coblentz BM, Iıfeld, John J, Finneran IV. Thoracic Epidural as a Rescue Analgesic in a patient with a continuous Erector Spinae Plane Block for Rib Fractures: A case report. Am J Case Rep. 2023 april 18; doi: 10. 12659/AJCR.938875. McCarney R, Warner J, Iliffe S, van Haselen R, Griffin M, Fisher P. The Hawthorne Effect: a randomised, controlled trial. BMC Med Res Methodol. 2007;7:30. Xin Huang J, Wang J, Zhang Y, Kang B, Sandeep, Yang J. Ultrasound-guided erector spinae plane block improves analgesia after laparoscopic hepatectomy: a randomised controlled trial. Br J Anaesth. 2022;29(3):445–53. Additional Declarations No competing interests reported. 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. We do this by developing innovative software and high quality services for the global research community. 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progression of inflammation, fibrosis formation, and cirrhosis due to acute or chronic liver diseases [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Due to the increasing demand for liver transplantation and unavailability of deceased donors, living-donor liver transplantation (LDLT) has emerged as a viable and effective option. Living donors are healthy individuals who voluntarily undergo surgery without any therapeutic benefits [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Severe pain remains a major concern after LDLT [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Researches show that donor hepatectomies are frequently associated with a higher pain level than other liver surgeries, such as tumour resection [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Notably, donors are often younger and healthier individuals, who may not have experienced significant postoperative pain, contributing to low pain threshold [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Inadequate postoperative analgesia management has been associated with increased morbidity, pain chronification, prolonged reliance on opioid medication, prolonged hospital stay, diminished quality of life (QoL) and increased patient dissatisfaction [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe current literature shows lack of consensus regarding the optimal analgesic strategy in this patient population [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Opioids have been widely used to manage surgery-related acute pain. But despite their efficacy, their adverse reactions, including addiction, chronic pain and prolonged hospital stay, necessitate the exploration for alternatives [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Regional anaesthetic nerve blocks are widely used to manage postoperative pain to reduce opioid consumption [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Although thoracic epidural analgesia (TEA) is considered a gold-standard technique in abdominal and thoracic surgery, multi-modal analgesic methods have been widely evaluated in LDLTS [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. The most commonly used methods are; intravenous administration of opioid analgesics using a patient-controlled analgesia (PCA) pump or via continuous infusion, administration of intravenous non-opioid agents (acetaminophen, non-steroidal anti-inflammatory drugs [NSAIDs], ketamine, magnesium, lidocaine and dexmedetomidine) [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], local anaesthetic (LA) administration to the surgical incision site, and other regional analgesia techniques (e.g. intrathecal morphine administration [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], paravertebral block [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], transversus abdominis plane [TAP] block [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], quadratus lumborum block [QLB] [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] and erector spinae plane block [ESPB] [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. The PROSPECT (procedure-specific postoperative pain management) guidelines recommend the use of peripheral nerve blocks to manage postoperative pain [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Similarly, the ERAS (enhanced recovery after surgery) guidelines emphasize the critical role of postoperative analgesia management in transplant units [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e\u003cp\u003e Ultrasound-guided ESPB is an emerging interfascial plane block initially introduced by Forero et al. in 2016 [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. It involves injection of an LA agent between the deep fascia of the erector spinae musculature and the transverse process of the vertebra [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Although the analgesic mechanism is unclear, it induces somatic and visceral sensory blockade with technical simplicity, a relatively safe profile, and wide dermatomal spread (T1 to L3), making it an ideal regional anaesthetic technique for abdominal surgery [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Numerous studies have investigated the potential advantages of regional anaesthesia, particularly ESPB, within the LDLT context. The benefits of ESPB include postoperative pain relief, decreased postoperative pain scores, reduced opioid consumption, early ambulation, low risks of postoperative nausea and vomiting (PONV), few technique-related complications and fast patient recovery [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. As regards safety profile, ESPB has not been correlated with any major complications, such as LA agent toxicity, neurological deterioration, pleural injury, or pneumothorax [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. However, previous studies have reported minor adverse events, including transient paraplegia and priapism [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThis study aims to evaluate the efficacy of bilateral ESPB, a minimally invasive and readily implementable analgesic technique, inducing both somatic and visceral sensory blockade, characterized by comparable effectiveness and a reduced complication profile, against thoracic epidural analgesia (TEA), the established gold standard technique, in managing postoperative pain in patients undergoing living-donor hepatectomy using VAS score and PCA metrics as primary outcome and postoperative early recovery parameters as secondary outcomes.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003ePatient selection\u003c/h2\u003e\u003cp\u003eThis single-centre retrospective study included living liver donors who underwent open hepatectomy between January 2020 and December 2022. Among the 202 living donors, those aged between 18 and 60 years, classified as American society of anesthesiologist physical status 1 (ASA 1), and provided informed consent were included. Patients who disagreed with the use of their medical records for research purposes, preferred the intravenous analgesic procedure over the use of either central or peripheral nerve blocks, required reintervention due to technical failure, developed catheter-related complications, and required surgical intervention within 48 hours postoperatively were excluded. A total of 19 donors who received TEA were compared with 18 donors who received ESPB in terms of their analgesic efficacy and effects on early recovery parameters.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eSurgical procedure\u003c/h3\u003e\n\u003cp\u003eAll the donor hepatectomies were performed by a highly experienced surgeon. The open technique, characterized by J-shaped incision was employed for the right-love living-donor hepatectomies. After mobilisation of the liver, cholecystectomy and hilar dissection were performed to adequately prepare the surgical field. The line of parenchymal transection was established via occlusion of the right hepatic artery and right portal vein using an atraumatic bulldog clamp. The hepatic parenchymal blood vessels were exposed; smaller vessels were effectively coagulated, whereas those larger than 4 mm, along with duct branches, were ligated to ensure hemostasis. After the graft was excised, the partially divided falciform ligament was reattached to the anterior abdominal wall to mitigate the risk of left-lobe rotation. For adequate drainage, one silastic drain was routinely placed at the surgical site. Finally, the fascia and skin were closed using an absorbable suture.\u003c/p\u003e\n\u003ch3\u003ePostoperative pain management\u003c/h3\u003e\n\u003cp\u003eThe donors were assigned to either group 1 or 2 according to the preferred regional anaesthetic technique in their informed consent (TEA [n\u0026thinsp;=\u0026thinsp;19] or ESPB [n\u0026thinsp;=\u0026thinsp;18], respectively) and followed up postoperatively for 48 h. Each technique is discussed as follows:\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eTEA\u003c/strong\u003e\u003cp\u003eAll patients received intravenous sedation with midazolam (0.03 mg/kg) and ketamine (0.3\u0026ndash;0.5 mg/kg) before nerve block application. Each patient was placed in the sitting position. Employing the landmark anatomical marking technique, the T10 vertebral level was identified via a midline approach, with the inferior angle of the scapula approximating T7 as the reference point. Employing the pressure-loss technique, the epidural space was identified at the T10 vertebral level using physiological saline. After 3 ml of a 2% lidocaine solution was administered, an epidural block was performed, which involved careful insertion of an 18G Tuohy catheter, advanced approximately 3\u0026ndash;4 cm in the cranial direction. In addition, aspiration was performed to confirm correct positioning of the catheter and the absence of blood return. Subsequently, the catheter was secured with a sterile, transparent, semipermeable adhesive dressing (Tegaderm, 3M, St Paul, MN, ABD).\u003c/p\u003e\u003c/p\u003e\u003cp\u003eA 0.25% bupivacaine hydrochloride (Marcaine) was administered using an epidural catheter at two time points: at the beginning (10 mL) and before the end (10 mL) of the surgical procedure. A PCA device was connected to the epidural catheter after the procedure. This device continuously infused the 0.125% bupivacaine hydrochloride solution at a rate of 3 mL/h. Furthermore, a specific protocol that allowed self-administration of a 5 mL bolus of medication three times per hour accompanied by a 20 min lockout period, was implemented.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eESPB\u003c/strong\u003e\u003cp\u003eThe Patients were sedated before the surgical procedure through intravenous administration of midazolam (0.03 mg/kg), and ketamine (0.3\u0026ndash;0.5 mg/kg). Each patient was placed in the prone position to facilitate the nerve block application. The seventh rib was identified with ultrasound guidance using the paraspinal approach. Next, the ultrasound probe was medially oriented, which allowed for the visualization of the transverse process of the T7 vertebra at an approximate distance of 3 cm laterally from the spinal midline. Ultrasound-guided left ESPB was performed using an 18G Tuohy needle (Contiplex \u0026reg;), specifically targeting the T7 vertebral level, and then 20 mL of 0.25% bupivacaine hydrochloride was administered. The same steps were performed for the right ESPB, after which 10 mL of 0.25% bupivacaine solution was also administered and an epidural block catheter was inserted between the deep fascia of the erector spinae musculature and the transverse process of the vertebra. An additional 10 mL of bupivacaine solution was administered via the catheter. As a result, a total volume of 20 mL was applied to each side, ensuring that an equal amount of anaesthetic was bilaterally implemented. After the procedure, the PCA device was connected to the indwelling block catheter on the right side, and 10 mL of 0.125% bupivacaine solution was administered on an hourly basis. Finally, a standardized protocol was implemented, which enabled the administration of a 5 mL bolus once per hour, ensuring a 60-min lockout period between doses.\u003c/p\u003e\u003c/p\u003e\u003cp\u003eAll patients from both groups received 0.05 mg/kg of morphine (i.v.) along with NSAIDs, as a standard protocol before the awakening phase.\u003c/p\u003e\n\u003ch3\u003eRescue therapy\u003c/h3\u003e\n\u003cp\u003eAs well known, morphine is superior to fentanyl due to its longer duration of action. The morphine was selected as rescue therapy in accordance with drug protocols in the country.\u003c/p\u003e\u003cp\u003eIn both groups, 3 mg of morphine (iv.) was administered when the visual analogue scale (VAS) scores exceeded 4 despite the prior use of NSAIDs twice per day and the utilization of a PCA device during the postoperative period.\u003c/p\u003e\n\u003ch3\u003ePostoperative patient follow-up and recovery parameters\u003c/h3\u003e\n\u003cp\u003eAfter extubation in the operating room, the patients were transferred to the intensive care unit (ICU) for close monitoring of hemodynamic parameters, biochemical markers, and coagulation profiles, early detection of potential surgical complications, and effective analgesia and safe ambulation. To assess the efficacy of the two analgesic methods, a structured evaluation was conducted at six time points (1st, 3rd, 6th, 12th, 24th, and 48th hours) postoperatively, and the results were recorded in the patient's pain assessment forms. The VAS scores, PCA metrics ( dose attempted (DA): Total number of times the patient pressed the PCA button to request a dose of pain medication, dose administered/dose given (DG): The number of times the PCA device actually administered a dose of pain medication, bolus dose (BD): A single, preset dose of medication delivered each time the patient presses the PCA button, total dose [TD: BD\u0026thinsp;+\u0026thinsp;DG]), and necessity for rescue analgesia or additional analgesic medications were also evaluated. All data were meticulously collected by specialized nurse team for pain control. The first choice for antiemetic therapy is metoclopramide hydrochloride and it is dosed if the patient suffers from nausea and/or vomitting (maximum dose 4 times a day, every 6 hours) in regard to our protocol.\u003c/p\u003e\u003cp\u003eTo effectively compare the impacts of the two methods on the patient\u0026rsquo;s early recovery outcomes, various postoperative parameters were evaluated, including the presence of nausea and vomiting (yes/no), administration of additional antiemetic medication (yes/no) and dose (mg), occurrence of pruritus, presence of gas/stool output (yes/no), presence of urinary retention, first ambulation time (h) (ambulation: getting the patient out of bed and walking), time of oral intake (h), Bromage score (leg movements are used to evaluate the efficacy of motor block and lower limb strength), and level of consciousness (LOC was measured using AVPU scale, A- alert, V- response to voice, P- response to pain, U- unresponsive).\u003c/p\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eVisual analogue scale\u003c/h2\u003e\u003cp\u003eVAS is a reliable and frequently used pain measurement method for evaluating the severity of pain. The scale consists of horizontal line with a length of 10 cm. The patients is told to mark a point on the line. The observer systematically coded the patient\u0026rsquo;s facial expression, which serves as a non-verbal indicator of pain intensity. The observational data was then complemented by a self-reported pain scale, in which the patients were asked to quantify their pain on a continuum from \u0026lsquo;no pain\u0026rsquo; (0) to - \u0026lsquo; worst pain ever\u0026rsquo; (10). This scale was further categorized into distinct levels of severity: mild (0.5\u0026ndash;4.4), moderate (4.5\u0026ndash;7.4), and severe (7.5\u0026ndash;10). Mean value of these two measurements were used as VAS scores in this study. Correlating the observational data and self-reported pain scale, a numerical representation of pain intensity was derived, referred to as the VAS scale.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eStatistical analysis was conducted using the SPSS software version 22.0 (IBM Corporation, Armonk, NY, USA), and a P-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant. The numerical variables were analysed using visual (histograms, probability plots) and analytical (Kolmogorov\u0026ndash;Smirnov/Shapiro\u0026ndash;Wilk\u0026rsquo;s test) methods to determine whether they were normally distributed. Descriptive data were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation for normally distributed variables and median and interquartile range for non-normally distributed variables. Categorical variables were compared using the chi-squared test. Comparisons between subgroups were performed using Student\u0026rsquo;s t-test for unpaired data as a parametric test for normally distributed variables and Mann Whitney U test as a nonparametric test for non-normally distributed or ordinal variables.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003e We analyzed data from living donors who were aged 18 to 60 years, were classified as ASA 1, underwent elective LDLT, and provided informed consent. The patients were systematically classified into group 1 (TEA; n\u0026thinsp;=\u0026thinsp;19) and group 2 (ESPB; n\u0026thinsp;=\u0026thinsp;18) to facilitate subsequent statistical analysis.\u003c/p\u003e\u003cp\u003eThe groups exhibited comparable characteristics regarding demographic and health-related variables, including age, height, weight, body mass index, and history of smoking and previous surgeries (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (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\u003ePatient characteristics\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=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCharacteristics\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eTotal patients\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eGroup 1 (TEA)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eGroup 2 (ESPB)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eP value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge (years), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e32.9\u0026thinsp;\u0026plusmn;\u0026thinsp;8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30.6\u0026thinsp;\u0026plusmn;\u0026thinsp;6.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e35\u0026thinsp;\u0026plusmn;\u0026thinsp;9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026sup1;\u003c/b\u003e 0.08\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeight (cm), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e168.2\u0026thinsp;\u0026plusmn;\u0026thinsp;5.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e171\u0026thinsp;\u0026plusmn;\u0026thinsp;9.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e168.4\u0026thinsp;\u0026plusmn;\u0026thinsp;8.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026sup1;\u003c/b\u003e 0.37\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBody weight (kg), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e71.9\u0026thinsp;\u0026plusmn;\u0026thinsp;13.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e73.8\u0026thinsp;\u0026plusmn;\u0026thinsp;5.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e69.9\u0026thinsp;\u0026plusmn;\u0026thinsp;10.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026sup1;\u003c/b\u003e 0.36\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBody-mass index (kg / m2), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e24.64\u0026thinsp;\u0026plusmn;\u0026thinsp;3.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e24.6\u0026thinsp;\u0026plusmn;\u0026thinsp;3.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e24.7\u0026thinsp;\u0026plusmn;\u0026thinsp;3.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026sup1;\u003c/b\u003e 0.92\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale sex, n (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e17 (45.9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8 (42.1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e9 (50%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026sup2;\u003c/b\u003e 0.74\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSmoking status\u003c/p\u003e\u003cp\u003en (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3 (8.1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0 (0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3 (16.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026sup2;\u003c/b\u003e 0.06\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAlcohol consumption, n (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3 (8.1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0 (0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3 (16.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026sup2;\u003c/b\u003e 0.06\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePrevious surgery, n (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10 (27%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5 (26.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5 (27.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026sup2;\u003c/b\u003e 0.9\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003cem\u003eTEA, thorasic epidural analgesia, ESPB, erector spinae plane block, SD, standard deviation\u003c/em\u003e, \u003cb\u003e\u0026sup1;\u003c/b\u003e \u003cem\u003eStudent's t-test\u003c/em\u003e, \u003cb\u003e\u0026sup2;\u003c/b\u003e \u003cem\u003echi-squared test.\u003c/em\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe analysis revealed a statistically significant VAS score in group 2 (ESPB) measured at the 1st (VAS1; P\u0026thinsp;=\u0026thinsp;0.027) and 3rd (VAS2; P\u0026thinsp;=\u0026thinsp;0.009) hours but did not achieve clinical significance. Notably, all the recorded VAS scores remained within the mild-pain range (VAS\u0026thinsp;\u0026le;\u0026thinsp;4.5) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\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\u003eComparison of postoperative pain assessment scale between the groups\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=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVisual analogue scale (VAS)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGroup 1 (TEA)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eGrou 2 (ESPB)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1. hr. VAS- 1, median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026sup3; 0.027\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3. hr. VAS- 2, median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026sup3; 0.009\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e6. hr. VAS- 3, median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026sup3; 0.46\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e12. hr. VAS- 4, median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (0.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026sup3; 0.167\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e24. hr. VAS- 5, median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3 (3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026sup3; 0.86\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e48. hr. VAS- 6, median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026sup3; 0.38\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003cem\u003eVAS, visual analogue scale; hr, hour; IQR, interquartile range; \u0026sup3; Mann-Whitney U test\u003c/em\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eA further promising finding was that the DG, BD, TD calculated using the PCA device was significantly lower in group 2. However, the number of DA was similar between the groups. (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\" width=\"120%\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of the patient controlled analgesia device (PCA) metrics and LA agent amounts between groups\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\u003cp\u003ePCA metrics\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGroup 1 (TEA)\u003c/p\u003e\u003cp\u003e(n:19)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eGrou 2 (ESPB) (n:18)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDA- 1 (n), median (IQR)\u003c/p\u003e\u003cp\u003eDA- 2 (n), median (IQR)\u003c/p\u003e\u003cp\u003eDA- 3 (n), median (IQR)\u003c/p\u003e\u003cp\u003eDA- 4 (n), median (IQR)\u003c/p\u003e\u003cp\u003eDA- 5 (n), median (IQR)\u003c/p\u003e\u003cp\u003eDA- 6 (n), median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10 (8)\u003c/p\u003e\u003cp\u003e25 (8)\u003c/p\u003e\u003cp\u003e45 (15)\u003c/p\u003e\u003cp\u003e61 (34)\u003c/p\u003e\u003cp\u003e113 (43)\u003c/p\u003e\u003cp\u003e150 (41)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5 (2)\u003c/p\u003e\u003cp\u003e21 (17)\u003c/p\u003e\u003cp\u003e36 (11)\u003c/p\u003e\u003cp\u003e47 (24)\u003c/p\u003e\u003cp\u003e89 (36)\u003c/p\u003e\u003cp\u003e122 (41)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026sup3; 0.13\u003c/p\u003e\u003cp\u003e\u0026sup3; 0.56\u003c/p\u003e\u003cp\u003e\u0026sup3; 0.18\u003c/p\u003e\u003cp\u003e\u0026sup3; 0.28\u003c/p\u003e\u003cp\u003e\u0026sup3; 0.48\u003c/p\u003e\u003cp\u003e\u0026sup3; 0.5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDG- 1 (mL), median (IQR)\u003c/p\u003e\u003cp\u003eDG- 2 (mL), median (IQR)\u003c/p\u003e\u003cp\u003eDG- 3 (mL), median (IQR)\u003c/p\u003e\u003cp\u003eDG- 4 (mL), median IQR)\u003c/p\u003e\u003cp\u003eDG- 5 (mL), median IQR)\u003c/p\u003e\u003cp\u003eDG- 6 (mL), median IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (1)\u003c/p\u003e\u003cp\u003e3 (2)\u003c/p\u003e\u003cp\u003e5 (5)\u003c/p\u003e\u003cp\u003e9 (7)\u003c/p\u003e\u003cp\u003e17 (15)\u003c/p\u003e\u003cp\u003e28 (23)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (1)\u003c/p\u003e\u003cp\u003e2 (2)\u003c/p\u003e\u003cp\u003e3.5 (3)\u003c/p\u003e\u003cp\u003e6.5 (5)\u003c/p\u003e\u003cp\u003e11 (7)\u003c/p\u003e\u003cp\u003e17.5 (10)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026sup3; 0.01\u003c/p\u003e\u003cp\u003e\u0026sup3; 0.02\u003c/p\u003e\u003cp\u003e\u0026sup3; \u0026lt;0.001\u003c/p\u003e\u003cp\u003e\u0026sup3; 0.003\u003c/p\u003e\u003cp\u003e\u0026sup3; \u0026lt;0.001\u003c/p\u003e\u003cp\u003e\u0026sup3; \u0026lt;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBD- 1 (mL), median (IQR)\u003c/p\u003e\u003cp\u003eBD- 2 (mL), median (IQR)\u003c/p\u003e\u003cp\u003eBD- 3 (mL), median (IQR)\u003c/p\u003e\u003cp\u003eBD- 4 (mL), median (IQR)\u003c/p\u003e\u003cp\u003eBD- 5 (mL), median (IQR)\u003c/p\u003e\u003cp\u003eBD- 6 (mL), median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5 (5)\u003c/p\u003e\u003cp\u003e14 (13)\u003c/p\u003e\u003cp\u003e20 (18)\u003c/p\u003e\u003cp\u003e35 (15)\u003c/p\u003e\u003cp\u003e65 (60)\u003c/p\u003e\u003cp\u003e115 (93)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5 (1)\u003c/p\u003e\u003cp\u003e10 (9)\u003c/p\u003e\u003cp\u003e20 (15)\u003c/p\u003e\u003cp\u003e32 (30)\u003c/p\u003e\u003cp\u003e55.5 (41)\u003c/p\u003e\u003cp\u003e75 (61)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026sup3; 0.053\u003c/p\u003e\u003cp\u003e\u0026sup3; 0.064\u003c/p\u003e\u003cp\u003e\u0026sup3; 0.47\u003c/p\u003e\u003cp\u003e\u0026sup3; 0.085\u003c/p\u003e\u003cp\u003e\u0026sup3; 0.004\u003c/p\u003e\u003cp\u003e\u0026sup3; 0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTD- 1 (mL), median (IQR)\u003c/p\u003e\u003cp\u003eTD- 2 (mL), median (IQR)\u003c/p\u003e\u003cp\u003eTD- 3 (mL), median (IQR)\u003c/p\u003e\u003cp\u003eTD- 4 (mL), median (IQR)\u003c/p\u003e\u003cp\u003eTD- 5 (mL), median (IQR)\u003c/p\u003e\u003cp\u003eTD- 6 (mL), median(IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6 (6)\u003c/p\u003e\u003cp\u003e18 (17)\u003c/p\u003e\u003cp\u003e30 (26)\u003c/p\u003e\u003cp\u003e42 (42)\u003c/p\u003e\u003cp\u003e78 (67)\u003c/p\u003e\u003cp\u003e138 (125)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6 (5)\u003c/p\u003e\u003cp\u003e12 (12)\u003c/p\u003e\u003cp\u003e23 (18)\u003c/p\u003e\u003cp\u003e39 (20)\u003c/p\u003e\u003cp\u003e66.5 (50)\u003c/p\u003e\u003cp\u003e90 (70)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026sup3; 0.012\u003c/p\u003e\u003cp\u003e0.016\u003c/p\u003e\u003cp\u003e0.006\u003c/p\u003e\u003cp\u003e0.04\u003c/p\u003e\u003cp\u003e0.001\u003c/p\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003cem\u003ePCA, patient controlled analgesia; TEA, thoracic epidural analgesia; ESPB, erector spinae plane block; DA, dose attempted; DG, dose given; BD, bolus dose; TD, total dose (DG\u0026thinsp;+\u0026thinsp;Bolus); IQR: Interquartile range; mL, mililiter; \u0026sup3; Mann-Whitney U test.\u003c/em\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eComparative analysis of the postoperative early recovery parameters among groups revealed no statistically significant differences in the presence of gas/stool output, timing of oral intake, timing of ambulation, duration of ICU stay, and length of hospital stay (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05). Similarly, no statistically significant differences were observed in the potential adverse effects associated with opioid use, such as presence of itching, instances of nausea and vomiting, the need for antiemetic medication, urinary retention, and requirement for additional doses of morphine between the groups (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05)( Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\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\u003eComparison of early (first 48 hour) postoperative recovery parameters between the groups\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\" colname=\"c1\"\u003e\u003cp\u003eEarly recovery parameters\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAll patients\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eGroup 1 (TEA)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eGrou 2 (ESPB)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eP value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCatheter-related undesirable effects, n (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3 (8.1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (10.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1 (5.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026sup2;\u003c/b\u003e 0.5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eItching, n (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4 (10.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3 (15.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1 (5.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026sup2;\u003c/b\u003e 0.3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePONV, n (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e15 (40.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9 (74.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6 (33.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026sup2; 0.38\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAntiemetic drug administration, median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.3 (1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026sup3; 0.09\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRescue analgesic demand, median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026sup3; 0.38\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUrinary retention, n (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3 (8.1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3 (15.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0 (0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e\u0026sup2;\u003c/b\u003e 0.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePresence of gas/stool output, n (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e29 (78.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14 (73.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15 (83.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026sup2; 0.4\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMedian oral intake initiation time, hr, mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e19.65\u0026thinsp;\u0026plusmn;\u0026thinsp;2.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e19.8\u0026thinsp;\u0026plusmn;\u0026thinsp;2.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e19.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026sup1; 0.7\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMedian ambulation time, hr, median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23 (5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e23(4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e22.5 (3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026sup3; 0.84\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eICU stay (day)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHospital stay (day) median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5 (3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5 (1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u0026sup3; 0.08\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003cem\u003ePONV, Postoperative nausea vomiting; ICU, Intensive care unit; IQR: Interquartile range;\u003c/em\u003e \u003cb\u003e\u0026sup1;\u003c/b\u003e \u003cem\u003eStudent\u0026rsquo;s t-test;\u003c/em\u003e \u003cb\u003e\u0026sup2;\u003c/b\u003e \u003cem\u003echi-squared test; \u0026sup3; Mann-Whitney U test\u003c/em\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eCatheter-related side effects, including numbness (n\u0026thinsp;=\u0026thinsp;1) and right shoulder pain (n\u0026thinsp;=\u0026thinsp;1), were reported in group 1, whereas back pain (n\u0026thinsp;=\u0026thinsp;1) was reported in group 2.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eTo the best of our knowledge, this is the first study to directly compare bilateral ESPB and TEA, a gold standard for managing postoperative pain, and their respective impacts on VAS score, PCA metrics, and early recovery parameters 48 h after LDLTS. Studies have focused on reducing donor morbidity and enhancing QoL after LDLTS [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Donor hepatectomy is associated with numerous complications, such as potential development of transient coagulopathy [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e] and drug metabolism alterations [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. These complications raise questions regarding TEA application in pain management. An effective alternative to TEA in liver donor surgery remains an ongoing area of investigation. Among various peripheral nerve blocks, ESPB has gained considerable attention owing to its notable advantages, including its effectiveness in pain relief, low risk of associated complications, and relatively easy application [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Moreover, proficiency in performing ESPB can be achieved relatively quickly, with a short learning curve period [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. These factors make ESPB a valuable option in procedure-specific analgesia guidelines.\u003c/p\u003e\u003cp\u003eThe groups were similar in terms of demographic and health-related variables (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05). Existing literature indicates that age and sex play pivotal roles in how pain is experienced and interpreted. Specifically, younger individuals tend to exhibit lower pain tolerance, whereas older adults generally display higher pain thresholds [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. The findings of this study provide valuable insights to this disclosure, as the homogeneity of the groups regarding demographic variables allows for an objective interpretation.\u003c/p\u003e\u003cp\u003ePain involves not only physiological aspects but also psychological dimensions that shape an individual\u0026rsquo;s perception of discomfort. The use of the VAS poses notable challenges, as the effectiveness of this method is largely contingent upon the individual\u0026rsquo;s sensory discrimination capabilities [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. In pain management, clinical decision-making predominantly relies on established pain scales, despite their inherent limitations in capturing the complex nature of the pain experience [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. It is crucial to acknowledge that a decrease in pain scores is not necessarily correlated with enhancement in the overall patient experience or clinically significant alleviation of pain [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. VAS, which is frequently preferred in studies owing to its ease of use, has the potential to underrepresent pain experience [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. In techniques that involve the use of numerical rating scales, the scoring ranges across various categories are not uniformly distributed. VAS is particularly effective in differentiating the absence of pain from mild pain. However, its limitations become apparent when distinguishing moderate from severe pain [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. Consequently, pain scores should not be used as the sole determinant in assessing the efficacy of analgesic interventions. The Current literature suggests that aiming for a VAS score of 4.5 or lower is necessary to achieve optimal analgesia, categorizing the patient\u0026rsquo;s pain as mild or non-existent [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eExamination of the VAS records from our study, showed that both analgesic techniques provided effective pain relief 48 h postoperatively. Notably, the VAS recorded at the first hour (VAS 1, P\u0026thinsp;=\u0026thinsp;0.027) and third hour (VAS 2, P\u0026thinsp;=\u0026thinsp;0.009) were lower in group 1. However, it is noteworthy that all the recorded VAS scores remained within the optimal analgesia range (VAS\u0026thinsp;\u0026le;\u0026thinsp;4.5). Hence, we propose that while these findings are statistically significant, their clinical relevance is limited. The overall VAS scores were comparable between both groups, suggesting that ESPB effectively induces analgesia similar to TEA. This finding is consistent with those of Ghielmini et al., who evaluated the efficacy of ESPB in comparison with transversus abdominis plane (TAP) block, specifically in the context of robotic inguinal hernia repair [\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e]. The use of ESPB against TEA in patients suffering from traumatic flail chest also yielded similar results [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]. Recently, a study conducted by Zubair M et al. reported that ESPB exhibited improved analgesic efficacy compared with TEA, along with enhanced safety profile and a concomitant reduction in opioid consumption as well as PONV incidence after living-donor hepatectomy [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. We observed no significant differences despite bilateral ESPB catheter implantation, high LA dose and more frequent VAS scores interpretation. Further research is warranted to elucidate the discrepancies between these findings and to explore the factors contributing to the variability in ESPB efficacy.\u003c/p\u003e\u003cp\u003eThe duration of the recording intervals plays a pivotal role in the accurate assessment of the efficacy of analgesic interventions. As the length of these intervals increases, the reliability of the pain scales to reflect the analgesic effect diminishes. This discrepancy arises from the fact that the assessment intervals are not consistent with the timing of drug administration. While certain studies have opted to evaluate pain levels once or twice daily [\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e], more frequent assessments- typically every 2 to 4 h- are preferred [\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]. In our study, we evaluated pain scores at six time points: 1st, 3rd, 6th, 12th, 24th, 48th hours postoperatively. Considering this recording time intervals is critical for the accurate interpretation of the findings.\u003c/p\u003e\u003cp\u003eTraditional pain assessment tools, including VAS, mainly rely on subjective interpretations, leading to inaccurate gauging of pain levels. Consequently, functional pain assessment methods, particularly those leveraging the analysis of electronic medical records (EMRs), have gained considerable attention. PCA metrics are among the components of these methods [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e]. Piccioni et al. evaluated the ratio between the DA and DG of analgesics. Their findings indicated a significant correlation between the ratio and the traditional pain assessment scores, as well as total opioid consumption [\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e]. We focused on PCA metrics, specifically in assessing the analgesic effectiveness. Our findings indicated that the DG, BD, and TD were significantly lower in the group 2. Nevertheless, notable variations were observed in the infusion dose volume, BD volume, and lockout intervals within the PCA setup across the groups. Recognizing the inherent variability within the PCA setup, caused by the different nature of these blocks, is crucial for the accurate evaluation of the clinical significance of the findings.\u003c/p\u003e\u003cp\u003eThe frequency of patients requesting medication from PCA devices may be influenced by various factors, except pain intensity, which contributes to a falsely elevated DA count [\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e]. These factors include anxiety, cognitive confusion, inappropriate use of medication request buttons, inability to differentiate between pain and other distressing sensations, and use of devices by individuals other than patients etc. [\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e]. We found no significant difference in the DA from the PCA device between the groups. This finding is consistent with the results of the VAS assessments, suggesting that both groups received effective analgesia.\u003c/p\u003e\u003cp\u003eOur results indicated that ESPB is equally effective to TEA in inducing postoperative pain control. While the consumption of LA drugs was significantly reduced in group 2, opioid consumption, presence of gas/stool passage within the first 24 h, timing of oral intake and PONV incidence were similar in both groups. Oraee S et al. highlighted the efficacy of ESPB in decreasing pain scores, reducing the need for opioid analgesics, and increasing the time to first rescue analgesia compared with placebo or TAP block in laparoscopy. A lower PONV rate was observed in ESPB than in the placebo groups, yet a comparable rate with QLB [\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e]. In a systematic review and meta-analysis of randomized controlled trials (RCT), the cumulative opioid consumption and PONV were significantly lower in patients who received ESPB than in those who received intravenous analgesia. However, neither of these parameters showed significant differences between those who received ESPB and those who received regional nerve blocks, such as the oblique subcostal TAP block and QLB [\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e]. Likewise, a meta-analysis of five RCTs revealed no significant difference between ESPB and thoracolumbar interfascial plane block with respect to postoperative analgesia and 24 h opioid consumption after lumbar spine surgery [\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e]. Unlike research that may have compared ESPB with less frequently utilized regional blocks, our study directly distinguished ESPB from TEA, a gold standard for regional pain management. ESPB has also been useful in pain management of rib fractures due to several distinct advantages, including their suitability for outpatient management, an enhanced safety profile, simplified administration, the potential for use in patients with coagulopathy or those receiving anticoagulant therapies and increased incentive spirometry volumes [\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e].All these findings suggest that ESPB serves as a viable alternative to TEA in the context of LDLTS.\u003c/p\u003e\u003cp\u003eNo complications associated with catheter removal (development of coagulopathy, epidural hematoma, or dural puncture) as well as motor block duration extension, paraesthesia, or hypotension occurred. No instances of urinary retention in the ESPB group may be attributable to its mechanism, which functions as a facial plane block, and is not directly affecting the sacral and lumbar plexus responsible for bladder innervation. In addition, the length of stay in the ICU and the total hospitalization duration were comparable between the groups. This finding aligns with our expectation as in our clinical practice, patients typically remain in the ICU for one day.\u003c/p\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003eLimitations of our study:\u003c/h2\u003e\u003cp\u003eThis study is subject to several limitations that may affect the validity and generalizability of its findings. Such limitations include its retrospective design, relatively small sample size, lack of blinding among the researchers, absence of a placebo control group, omission of a control group that received only intravenous analgesics, exclusive recording of pain scores during periods of rest, neglecting to evaluate dynamic pain experienced with movement, and follow up period limited to 48 h postoperatively, which does not provide insights into the long term implications of the procedures on the patient\u0026rsquo;s QoL. Meanwhile, a phenomenon called \u0026lsquo;Hawton effect\u0026rsquo; suggests that in a prospective study, researchers may exert additional effort and care, which could lead to more favourable results than those under normal clinical circumstances. Our study employed a retrospective approach, avoiding the increased attention and care typically observed in prospective studies [\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e].\u003c/p\u003e\u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe erector spinae block (ESPB) is considered a safe and effective alternative to TEA for procedures expected to cause significant postoperative pain (14, 15, 44, 50, 55). This study demonstrated that ESPB can be used as a part of multimodal analgesia strategy, offering the advaltage of reduced local anesthetic consumption compared to TEA in living donor liver transplantation. ESPB provided comparable effects on early recovery parameters (within 48 hours), without an associated increase in the complication rate observed with TEA. Prospective studies with larger sample sizes are warranted to confirm and strenghten these findings.\u003c/p\u003e"},{"header":"List of abbreviations","content":"\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\u003ch2\u003e\u003c/h2\u003e\u003cp\u003eErector spinae plane block ,ESPB\u003c/p\u003e\u003cp\u003eIntensive care unit, ICU\u003c/p\u003e\u003cp\u003eLocal anaesthetic, LA\u003c/p\u003e\u003cp\u003eLiving-donor liver transplantation, LDLT\u003c/p\u003e\u003cp\u003eNon-steroidal anti-inflammatory drugs, NSAIDs\u003c/p\u003e\u003cp\u003ePatient-controlled analgesia, PCA\u003c/p\u003e\u003cp\u003ePostoperative nausea and vomiting, PONV\u003c/p\u003e\u003cp\u003eThoracic epidural analgesia, TEA\u003c/p\u003e\u003cp\u003eTransversus abdominis plane, TAP\u003c/p\u003e\u003cp\u003eThoracic epidural analgesia, TEA\u003c/p\u003e\u003cp\u003eQuadratus lumborum block, QLB\u003c/p\u003e\u003cp\u003eQuality of life, QoL\u003c/p\u003e\u003cp\u003eVisual analogue scale, VAS,\u003c/p\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u0026nbsp;\u003c/strong\u003eThe Instutional Review Board (The Acibadem University Medical Research Ethics Committee) \u0026nbsp;approved the study after which access to medical records was authorized by the office of the chief physician (approval number: 2024-14/582, Date: 19.09.2024). The study was conducted in accordance with the ethical principles outlined in the Declaration of Helsinki.\u0026nbsp;Accordingly, the ethics committee waived the requirement for individual informed consent.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u0026nbsp;\u003c/strong\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions:\u0026nbsp;\u003c/strong\u003eSIKP, MGC and HK designed the research. MGC, MBH , AO and TUY analyzed the data. \u0026nbsp;SIKP, MGC and AO wrote the main manuscript. SIKP, MBH, AO and MGC researced the literature. \u0026nbsp; MGC and HK revisied the article for intellectual content and finalized the manucript. \u0026nbsp;All authors participated in the performance of the research. All authors reviewed the manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors thank all study participants for their involvement in the study. We acknowledge the nurses for their excellent work of patient organization and nursing assistance. The authors gratefully acknowledge Dr. Sena Sert Sekerci for her contributions to the statistical analysis presented in this study.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBrezeanu LN, Brezeanu RC, Diculescu M, Droc G. Anaesthesia for liver transplantation: An Update. 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New York: The Guilford Press; 1992. pp. 15\u0026ndash;34. pp:135\u0026thinsp;\u0026ndash;\u0026thinsp;52.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJensen MP, Chen C, Brugger AM. Interpretation of visual analog scale ratings and change scores: a reanalysis of two clinical trials of postoperative pain. J Pain. 2003;4(7):407\u0026ndash;14.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGhielmini EM, Greco L, Spampatti S, Kubli R, Saporito A, La Regina D. Erector Spinae Plane Block versus Transversus Abdominis Plane Block for Robotic Inguinal Hernia Repair: A Blinded, Active-Controlled, Randomized Trial. Pain Physician. 2024;27(1):27\u0026ndash;34.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMostafa SF, Eid GM. Ultrasound guided erector spinae plane block versus thoracic epidural analgesia in traumatic flail chest, a prospective randomized trial. 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Br J Anaesth. 2022;29(3):445\u0026ndash;53.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"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":"Erector spinae plane block, Thoracic epidural analgesia, Donor hepatectomy, Liver transplantation","lastPublishedDoi":"10.21203/rs.3.rs-7687505/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7687505/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eWe aimed to compare the effects of bilateral ESPB and thoracic epidural analgesia (TEA) on postoperative pain management and early recovery parameters in patients undergoing living-donor hepatectomy.\u003c/p\u003e\u003ch2\u003eMaterial and methods\u003c/h2\u003e\u003cp\u003ePatients donor hepatectomy from January 2020 to December 2022 were included in this study. They were divided into two groups: \u0026lsquo;group 1\u0026rsquo; (TEA) and \u0026lsquo;group 2\u0026rsquo; (ESPB). The primary outcome was analgesic efficacy based on the visual analogue scale (VAS), patient-controlled analgesia (PCA) metrics and the necessity of additional morphine administration. The secondary outcomes were the presence of nausea and vomiting, administration of additional antiemetic medication and dose, occurrence of pruritus, presence of gas/stool output, presence of urinary retention, first ambulation time, time of oral intake, Bromage score (leg movements are used to evaluate the efficacy of motor block and lower limb strength), and level of consciousness.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eBoth groups exhibited similar demographic characteristics. While the overall VAS score was comparable between the groups, the scores at 1st and 3rd hours were statistically lower in the TEA group. The local anaesthetic dose administered via the PCA pump at six postoperative time points was consistently lower in ESPB group at each interval. No significant differences were observed in opioid consumption, opioid-related side effects, and postoperative early recovery parameters.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003eCompared with TEA, ESPB showed promise in effectively managing postoperative analgesia, while maintaining opioid consumption.\u003c/p\u003e","manuscriptTitle":"Bilateral erector spinae plane block versus thoracic epidural analgesia in living- donor hepatectomies","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-24 06:53:47","doi":"10.21203/rs.3.rs-7687505/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":"32bf4c2e-c5ea-4fe6-8edb-e654bd9ec26a","owner":[],"postedDate":"October 24th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-12-17T02:38:44+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-24 06:53:47","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7687505","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7687505","identity":"rs-7687505","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}