Effect of Trendelenburg positioning on post-operative shoulder pain after gynecological laparoscopy: a randomized clinical trial.

This randomized, superiority, non-blinded clinical trial on parallel groups was conducted at Kowsar Hospital in Urmia, West Azerbaijan, Iran, from 2025/05/25 to 2025/07/25, involving female patients scheduled for gynecological laparoscopy; and reported in accordance with the Consolidated Standards of Reporting Trials (CONSORT 2025) checklist [ 17 ]. Using G*Power v3.1 [α = 0.05 and power = 80%], we determined our sample size based on post-operative Numerical Rating Scale (NRS) pain scores reported by Zeeni et al. [ 16 ]. The medians and interquartile ranges (IQR) were 6 [1-7.75] for the Control group ( n = 52) and 2 [ 1 – 4 ] for the Trendelenburg group ( n = 49). With an effect size of 0.65, we calculated that 39 participants were needed in each group. To account for a 15% attrition rate, we enrolled 45 patients per group, resulting in a total of 90 participants. Participants were randomly assigned (1:1) to the intervention ( n  = 45) or control ( n  = 45) group using a computer-generated permuted block sequence. Allocation was concealed using opaque, sequentially numbered, sealed envelopes prepared by an independent researcher who had no role in patient enrollment or post-operative assessments. This procedure ensured adequate allocation concealment despite the inherently non-blinded nature of the intervention. Blinding was not possible due to the nature of the intervention. Inclusion criteria for participation included being a female patient aged 18–60 years, scheduled for gynecological laparoscopy, having an abdominal incision of less than 1.5 cm, no history of major prior pelvic surgery, and providing written informed consent. Exclusion criteria included conversion to laparotomy, intra-abdominal pressure exceeding 14 mmHg, gastroesophageal reflux disease (GERD), thrombophilia or a high risk of deep vein thrombosis (DVT), pre-existing shoulder pain, chronic analgesic use, and documented drug abuse. According to the protocol, eight patients were excluded: three with pre-existing shoulder pain, two with thrombophilia, and three with GERD; the dropout rate was 8.89%. Post-operatively, patients in the intervention group were transferred to the inpatient ward and placed in complete bed rest (CBR) with a 20° Trendelenburg positioning for the first 8 h. After this period, they transitioned to relative bed rest (RBR), which was defined as allowing ambulation and walking within the room, in order to reduce the risk of immobilization-related complications such as ileus and thromboembolism. Similarly, patients in the control group were transferred to the ward after surgery and maintained in CBR with a supine 0° position for 8 h. The choice of 8 h was based on both prior literature and our institutional routine, in which patients are typically mobilized approximately 8 h after uncomplicated laparoscopic surgeries [ 18 ]. Following this, they also transitioned to RBR as per standard post-operative care. Patient demographic characteristics, including age, weight, and height, as well as comorbidities and laparoscopic indications, were documented. Intraoperative parameters included insufflated gas volume, time to the first request for analgesics, total analgesic consumption, and post-operative complications, such as nausea, vomiting, drowsiness, respiratory depression, and shivering, were recorded. Preoperatively, all patients received antithrombotic stockings with upper limbs positioned parallel to the torso, and heparin prophylaxis initiated 2 h pre-operatively. In our hospital, prophylactic unfractionated heparin is routinely administered 2 h before surgery for patients undergoing laparoscopic procedures. In addition, all patients continued to use lower-limb compression stockings (varicose-vein protective socks) immediately after surgery. Following intravenous access, anesthesia induction was achieved with midazolam (2 mg), fentanyl (1–2 µg/kg), lidocaine (1.5 mg/kg), and propofol (2 mg/kg), followed by atracurium (0.5 mg/kg) to facilitate endotracheal intubation. Mechanical ventilation maintained a tidal volume of 8–10 ml/kg, a respiratory rate of 12 breaths/minute, and an end-tidal CO 2 level of 30–35 mmHg. Patients were positioned in lithotomy with a 30–45° Trendelenburg positioning throughout the procedure. Anesthesia maintenance included propofol infusion with supplemental fentanyl and atracurium boluses for analgesia and neuromuscular blockade, respectively. Intra-abdominal pressure was standardized at 15 mmHg. Dexamethasone (8 mg IV) was administered post-induction for antiemesis. Continuous hemodynamic monitoring prompted targeted interventions: ephedrine (5–10 mg) for hypotension [> 20% mean arterial pressure (MAP) decrease], nitroglycerin [50–100 µg] for hypertension [> 20% MAP increase], atropine (0.5 mg) for bradycardia [heart rate (HR)  100 bpm]. Arrhythmias received condition-specific management. Total gas consumption and surgical duration were documented post-procedure. All patients have hemodynamic monitoring and drains in place intraoperatively. Patients were clinically monitored for potential thromboembolic complications throughout their post-operative stay. Monitoring included regular vital-sign assessment, structured lower-limb examinations (tenderness, swelling, pain), and surveillance for cardiopulmonary symptoms such as new-onset dyspnea or unexplained tachycardia. RBR commenced 8 h post-surgery. Analgesic (Ketorolac 15 mg IV PRN, as needed, daily) and antiemetic (Metoclopramide 10 mg IV PRN, as needed, daily) usage was tracked. Analgesic administration was contingent upon NRS scores exceeding 4. Ward nurses precisely documented medication administration times. The primary outcome was the intensity of post-operative shoulder pain. Assessment occurred at four time points: baseline (upon admission to the inpatient ward), and at 6, 12, and 24 h post-operatively. A trained researcher evaluated pain intensity using the NRS, in which patients subjectively rated their shoulder pain on a scale of 0 to 10. This scale was verbally anchored as follows: 0 indicated no pain, scores of 1–3 denoted mild pain, 4–6 represented moderate pain, and 7–10 signified severe pain. All NRS scores were documented contemporaneously by the assessing researcher. Three secondary endpoints were evaluated: (1) the incidence of post-operative nausea and vomiting (PONV), (2) time to first analgesic request (defined as the interval from surgical completion to patient-initiated demand for pain relief), and (3) total analgesic dosage administered during the initial 24-hour post-operative period. PONV episodes were recorded dichotomously (present/absent) at each assessment interval, while analgesic metrics included both temporal parameters (minutes to first request) and cumulative opioid-equivalent dosing. Data analysis employed descriptive and inferential statistical methods. Demographic and baseline characteristics were summarized using descriptive statistics, presented as frequencies with percentages for categorical variables and means accompanied by either standard deviation (SD) or standard error (SE) for continuous variables. The normality assumption for quantitative variables was evaluated using the Kolmogorov-Smirnov test. Comparative analyses between groups utilized the independent samples t-test for normally distributed continuous variables and the Mann-Whitney U test for non-normally distributed continuous variables. Associations between categorical variables were examined using the Chi-square test, with Fisher’s exact test applied where appropriate. Pain scores over time were analyzed using repeated-measures ANOVA and confirmed with ANCOVA to adjust for potential baseline imbalances between groups. To account for potential confounding variables, covariate-adjusted analyses were performed using ANCOVA model including age, BMI, surgical indication, duration of surgery, and baseline pain score. These covariates were selected based on clinical relevance and their influence on post-operative pain according to literature. Post-hoc tests were performed using Bonferroni correction to account for multiple comparisons. Statistical significance was defined as a two-tailed P-value less than 0.05. All analyses were conducted using IBM SPSS Statistics software (Version 21).

A total of 90 women aged 18 to 60 years, who were scheduled for gynecological laparoscopy, were enrolled in the study. According to the protocol, eight patients were excluded: three with pre-existing shoulder pain, two with thrombophilia, and three with GERD. Finally, 82 participants completed the study, with 41 patients in each group. The participants were randomly assigned to equal groups (Fig.  1 ). Fig. 1 Participants flow diagram Participants flow diagram The cohort demonstrated a mean age of 32.68 ± 9.23 years (median: 33; range: 18–60). Anthropometric measurements included mean height 163.19 ± 6.50 cm (median: 165; range: 150–179), mean weight 73.43 ± 12.50 kg (median: 75; range: 47–107), and mean body mass index (BMI) 27.61 ± 4.74 kg/m² (median: 27.75; range: 18.83–38.76). Ovarian cystectomy represented the primary surgical indication ( n  = 47, 57.3%), followed by salpingectomy (31.7%, predominantly for ectopic pregnancy), ovarian torsion (8.5%), and total abdominal hysterectomy with bilateral salpingo-oophorectomy (TAH-BSO, 2.4%). Obstetric history revealed a median gravidity and parity of 2 (IQR, 2) and 1 (IQR, 1), respectively, among parous women, with 20.7% ( n  = 17) being virgins. Comorbidities included hypothyroidism (11.0%), hypertension (7.3%), diabetes mellitus (3.7%), epilepsy (1.2%), and ischemic heart disease (IHD, 1.2%). As detailed in Table  1 , the intervention and control groups demonstrated comparable baseline demographics ( p  > 0.05), except for the distribution of surgical indications ( p  = 0.012). This discrepancy was accounted for in subsequent adjusted analyses. Table 1 Patient’s demographics Variable Categories / Units Intervention group ( n  = 41) Control group ( n  = 41) P -value Age [year] 31.90 ± 10.15 33.46 ± 8.25 0.447 Height [centimeter] 163.04 ± 6.39 163.34 ± 6.69 0.840 Weight [kilogram] 71.41 ± 12.33 75.46 ± 12.48 0.144 BMI [kg/m 2 ] 26.89 ± 4.63 28.34 ± 4.79 0.168 Surgery indication Cystectomy 27 (65.9%) 20 (48.8%) 0.012 Salpingectomy 7 (17.1%) 19 (46.3%) Ovarian torsion 5 (12.2%) 2 (4.9%) TAH-BSO 2 (4.9%) 0 Gravid † median (Q1-Q3) 2.5 [1–3] 2 [0–3] 0.777 Parity † median (Q1-Q3) 2 [1–3] 1 [0–3] 0.379 Virgin 11 (26.8%) 6 (14.6%) 0.228 Underlying disease Hypothyroidism 3 (7.3%) 6 (14.6%) 0.289 Diabetes mellitus 3 (7.3%) 0 0.078 Hypertension 4 (9.8%) 2 (4.9%) 0.396 Seizure 1 (2.4%) 0 0.500 IHD 1 (2.4%) 0 0.500 - Except † , the data were presented in mean ± SD or frequency (%) BMI Body mass index, IHD Ischemic heart disease, IQR Interquartile Patient’s demographics - Except † , the data were presented in mean ± SD or frequency (%) BMI Body mass index, IHD Ischemic heart disease, IQR Interquartile Repeated-measures ANOVA of NRS shoulder pain scores revealed three significant effects (Table  2 ; Fig.  2 ). First, a pronounced group effect was observed (F = 24.510, p  < 0.001), indicating substantially lower pain scores in the intervention group. Second, a significant time effect was demonstrated, showing a progressive reduction in pain across assessment intervals in both groups (F = 47.639, p  < 0.001). Critically, a significant group * time interaction emerged (F = 9.052, p  = 0.004), confirming differential pain trajectories between groups. Post-hoc analyses indicated accelerated pain resolution in the Trendelenburg group during the initial 12-hour post-operative period. Table 2 NRS values to determine the severity of shoulder pain in case and control group patients at the evaluation times Time Intervention group ( n  = 41) Control group ( n  = 41) Total ( n  = 82) P -value † Baseline 4.02 ± 0.28 5.21 ± 0.26 4.62 ± 0.20 0.003 6 h post-operative 1.65 ± 0.22 3.56 ± 0.31 2.60 ± 0.22 < 0.001 12 h post-operative 0.58 ± 0.17 2.34 ± 0.29 1.46 ± 0.19 < 0.001 24 h post-operative 0.26 ± 0.22 1.48 ± 0.22 0.87 ± 0.17 < 0.001 † The significance level is related to pairwise comparison of groups, and the findings are presented as mean ± SE P-values derived from repeated-measures ANOVA. Adjusted comparisons were additionally confirmed using ANCOVA including age, BMI, surgical indication, surgery duration, and baseline pain score as covariates NRS values to determine the severity of shoulder pain in case and control group patients at the evaluation times † The significance level is related to pairwise comparison of groups, and the findings are presented as mean ± SE P-values derived from repeated-measures ANOVA. Adjusted comparisons were additionally confirmed using ANCOVA including age, BMI, surgical indication, surgery duration, and baseline pain score as covariates Fig. 2 NRS changes in study groups at follow-up times NRS changes in study groups at follow-up times Post-operative complication frequencies are detailed in Table  3 . The incidence of nausea and vomiting was significantly higher in the control group relative to the intervention group ( p   0.05). The mean operative time for all patients was 98.17 ± 37.11 min, with no significant difference between the intervention and control groups. No between-group differences emerged for surgical duration or cumulative gas consumption (both p  > 0.05). Table 3 Frequency of postoperative complications and amount of analgesic and antiemetic medication used Variable Intervention group ( n  = 41) Control group ( n  = 41) Total ( n  = 82) P -value † PONV 12 (29.3%) 24 (58.5%) 36 (43.9%) 0.008 Shivering 7 (17.1%) 4 (9.8%) 11 (13.4%) 0.331 Surgery duration (min) 93.33 ± 34.12 102.51 ± 23.22 98.17 ± 37.11 0.232 cumulative gas consumption * 53 [38–65] 52 [42–64] 52 [41–65] 0.283 Analgesic  No need for analgesic 10 (24.4%) 3 (7.3%) 13 (15.8%) 0.034  Cumulative dose (mg) † 20.00 ± 1.66 25.54 ± 1.52 23.05 ± 1.16 0.017  Interval between first dose requests (min) † 176.00 ± 29.01 206.75 ± 27.99 192.98 ± 20.12 0.448 Antiemetic  No need for antiemetic 28 (68.3%) 18 (43.9%) 46 (56.1%) 0.026  Cumulative dose (mg) † 11.53 ± 1.04 12.17 ± 0.88 11.94 ± 4.01 0.645  Interval between first dose requests (min) † 126.00 ± 12.05 144.11 ± 10.03 137.19 ± 13.06 0.567 * The findings are presented as median [Q1-Q3] † The findings are presented as mean ± SE Frequency of postoperative complications and amount of analgesic and antiemetic medication used * The findings are presented as median [Q1-Q3] † The findings are presented as mean ± SE The mean time interval from the end of surgery to the first request for analgesia was 192.98 ± 20.12 min, which also did not differ significantly between the groups. Similarly, the mean time from the end of surgery to the first need for antiemetic administration was 137.19 ± 13.06 min, with no statistically significant difference observed between the groups. Critically, mean analgesic requirements were substantially reduced in the Trendelenburg group compared to the control group ( p  < 0.05).

Recent advancements in minimally invasive surgical techniques for diagnostic and therapeutic applications have substantially transformed disease management paradigms [ 1 ]. These approaches (including laparoscopy) are now extensively adopted as the primary intervention for numerous gynecological conditions, superseding laparotomy in most clinical contexts [ 2 ]. Consequently, laparoscopy represents the gold standard therapeutic approach for specific pathologies, such as endometriosis [ 3 ]. Laparoscopy was first performed approximately one century ago but has become a common surgical approach over the past five decades [ 4 ]. The technique was initially employed primarily in gynecology for diagnostic procedures and sterilization. Historically, laparoscopic procedures have been primarily confined to appendectomy (over the past 30 years) and cholecystectomy (over the past 20 years). Contemporary gynecological practice utilizing laparoscopy now encompasses ovarian surgery, uterine fibroid removal, and hysterectomy. Compared with laparotomy for diagnostic purposes, laparoscopy confers a significant reduction in post-operative complications [ 5 ]. Laparoscopy offers several significant clinical advantages over laparotomy. These benefits include reduced surgical trauma due to smaller incisions, less post-operative pain, lower need for pain relief medications, and better cosmetic results. Additionally, this technique allows for shorter hospital stays, quicker recovery times, and an earlier return to daily activities [ 6 – 8 ]. Even with the benefits of laparoscopy, post-operative pain remains a significant clinical concern. A considerable percentage of patients (35–80%) experience severe pain that requires analgesics for effective symptom management [ 9 ]. Additionally, pain characteristics vary significantly between laparoscopic and laparotomy procedures. This difference is illustrated by the common occurrence of referred pain, particularly in the shoulder and upper abdomen, following laparoscopy [ 10 ]. Various intraoperative strategies aim to mitigate post-laparoscopic pain by reducing residual carbon dioxide (CO 2 ) within the abdominal cavity. These include utilizing low inflation pressure and volume [ 11 ], performing the Valsalva maneuvers [ 12 , 13 ], instilling lactated Ringer’s solution [ 14 ], and minimizing intra-abdominal volume [ 15 ]. Beyond gas evacuation, patient positioning represents another modifiable factor that may be associated with pain reduction. Limited evidence suggests the Trendelenburg position may be optimal for attenuating post-operative discomfort. This positioning plausibly reduces mechanical pressure from CO 2 on the diaphragm and upper abdominal musculature. Furthermore, as CO 2 exhibits high solubility, its pooling in the highly vascularized pelvic compartment during pneumoperitoneum facilitates accelerated systemic absorption [ 16 ]. While pneumoperitoneum-induced pain (particularly shoulder pain) remains a prevalent complication of laparoscopic gynecology, and despite established interventions (drains, pharmacotherapy), the therapeutic potential of intraoperative positioning remains underexplored. This study, therefore, investigates the efficacy of the Trendelenburg position in mitigating post-laparoscopic shoulder pain following gynecological procedures, addressing a critical gap in post-operative pain management strategies.

Post-operative shoulder pain is a common source of morbidity following gynecologic laparoscopy, and our findings demonstrate that maintaining a 20° Trendelenburg position for 8 h significantly reduces pain intensity during the first 24 h. These results are consistent with the trial by Zeeni et al. [ 16 ], but our study provides evidence that a substantially shorter duration of Trendelenburg positioning may achieve similar analgesic benefit, while also allowing earlier mobilization, which aligns with enhanced recovery principles. Early post-operative mobilization is widely endorsed in enhanced recovery after surgery pathways and has been associated with reduced post-operative complications, improved functional recovery, and shorter hospitalization times [ 18 ]. While laparoscopy offers reduced surgical trauma, faster convalescence, and shorter hospitalizations [ 19 ], referred shoulder pain) mediated by diaphragmatic irritation from residual CO 2 (afflicts 35–80% of patients within the first 24 h [ 16 , 20 ]. This often-severe symptom frequently exceeds incisional discomfort [ 21 ], potentially persisting for 72 h and triggering secondary complications including PONV, hemodynamic instability, and delayed mobilization [ 22 , 23 ]. Our randomized trial demonstrates that 8-hour post-operative Trendelenburg positioning significantly mitigates this burden through synergistic mechanisms: mechanical decompression via reduced cephalad CO 2 displacement minimizes diaphragmatic tension and phrenic nerve irritation, while enhanced vascular absorption through pelvic pooling accelerates CO 2 clearance during pneumoperitoneum [ 16 ]. A notable strength of this study is the early transition of patients to relative bed rest just 8 h after surgery, reflecting enhanced post-operative readiness and functional recovery. In line with our findings, Hassan Ahmed et al. [ 24 ] reported a superior effect of Trendelenburg positioning compared with other measures. However, in their protocol, patients remained in the Trendelenburg position for 24 h, whereas in our study it was limited to 8 h, allowing for earlier mobilization. This early mobilization was well tolerated and did not increase complication rates, suggesting that Trendelenburg positioning may facilitate a smoother and more efficient post-operative recovery. Multiple strategies; both invasive (e.g., hemovac drainage) and noninvasive (intensified lithotomy positioning, low-pressure pneumoperitoneum with active gas evacuation), have been proposed to mitigate post-laparoscopic shoulder pain [ 20 , 23 , 25 ]. Among noninvasive approaches, positional therapy holds particular promise by modulating physiological pathways. Optimized blood flow may help attenuate inflammatory cascades, while targeted posture adjustments can limit the propagation of nociceptive signals. This randomized trial specifically investigated Trendelenburg positioning as a mechanistically grounded, nurse-implementable intervention for gynecological laparoscopy. Post-operatively, intervention group patients were maintained in a 20° Trendelenburg position during transfer and for eight post-operative hours, while controls received standard supine positioning. Our results demonstrate clinically and statistically superior outcomes in the intervention cohort. Shoulder pain severity was significantly reduced at all assessed timepoints ( p < 0.001), with the most pronounced differential emerging at 12 h post-operatively (0.58 ± 0.17 vs. 2.34 ± 0.29 NRS). This accelerated pain resolution aligns with the proposed dual-pathway mechanism: First, gravitational redistribution of residual CO 2 toward the pelvis reduces diaphragmatic distension and phrenic nerve irritation. Second, pooling within the highly vascularized pelvic compartment enhances CO 2 absorption due to greater perfusion density compared to subdiaphragmatic regions [ 14 ]. These physiological effects were directly translated to reduced analgesic requirements ( p < 0.001) and a lower incidence of secondary complications, such as nausea/vomiting (29.3% vs. 58.5%; p = 0.008). Although pain scores and analgesic consumption were lower in the Trendelenburg group, the time to the first request for analgesia did not significantly differ between groups. This finding was unexpected and may reflect several explanations: (1) patients may request their first analgesic dose based on subjective thresholds that are less sensitive to positioning-related differences in early discomfort; (2) some women may delay their first request until fully awake or mobilized regardless of pain intensity; and (3) baseline anxiety or perioperative expectations may influence the first request more strongly than objective pain levels. Further research, including qualitative assessments of patient pain-perception behavior, may help clarify this discrepancy. The 20° Trendelenburg positioning investigated in this study demonstrably reduced shoulder pain by alleviating mechanical pressure from residual CO 2 on the diaphragm. This aligns with established physiological principles: gravitational redistribution facilitates CO 2 migration toward the highly vascularized pelvis, enhancing absorption rates and decreasing subphrenic gas volume post-operatively [ 16 , 26 ]. Our intervention and control groups exhibited comparable demographic profiles (in terms of age, BMI, obstetric history, and comorbidities; p > 0.05), minimizing confounding bias. These findings align with the demographic consistency reported by Mohamed et al. [ 27 ], El-Naser et al. [ 28 ], and Zeeni et al. [ 16 ], thereby reinforcing the methodological rigor. Literature corroborates our pain-reduction outcomes. Zeeni et al. documented significantly lower shoulder pain with Trendelenburg versus supine positioning during 24-hour monitoring [ 16 ], while Jafarkhani et al. replicated this benefit in laparoscopic cholecystectomy [ 29 ]. Hassan Ahmed et al.‘s three-arm trial further validated Trendelenburg’s efficacy: their 24-hour VAS scores (Trendelenburg: 2.70 ± 1.47 vs. breathing exercises: 3.97 ± 1.83 vs. warm water: 3.90 ± 1.95) reflect our observed advantage, though our lower absolute scores (intervention: 0.26 ± 0.22; control: 1.48 ± 0.22) may stem from shorter pneumoperitoneum duration and standardized analgesia [ 24 ]. Notably, Soliman Ahmed et al. found massage to be superior to Trendelenburg alone [ 30 ], suggesting that combinatorial approaches (e.g., positioning + thermotherapy) warrant future investigation. Our findings also reinforce the physiologic rationale that Trendelenburg positioning may enhance cephalad displacement of residual CO 2 , reduce diaphragmatic irritation, and promote more efficient gas clearance. Despite demonstrated efficacy, Trendelenburg positioning presents clinical challenges. Two intervention patients reported cervical discomfort from initial mispositioning, which resolved through repositioning. Nonetheless, Trendelenburg positioning carries known potential risks, particularly when maintained for prolonged periods. More critically, Del Campo et al. identified a 1.77-fold increase in peripheral neuropathy risk per hour in Trendelenburg [ 31 ], highlighting the need for strict postural protocols during extended application. Reported adverse effects include reduced pulmonary compliance, transient increases in intracranial pressure, hemodynamic alterations, brachial plexus neuropathies, and rare cases of post-operative peripheral nerve injury [ 31 ]. Although none of these complications occurred in our study, a more detailed discussion is warranted to emphasize that even short-duration Trendelenburg positioning requires careful monitoring in patients with cardiopulmonary comorbidities. Our institution routinely mobilizes patients approximately 8 h after uncomplicated laparoscopic surgery, and so the 8-hour Trendelenburg duration aligned with our clinical workflow. This differs from Zeeni et al., who used 24 h of positioning. Studies supporting early mobilization in gynecologic and general surgery populations [ 16 ] also reinforce the value of limiting prolonged immobilization, reducing the risk of discomfort, nausea, and other complications. The main limitations of the current study were its single-center design and the limited availability of Trendelenburg position beds in the ward, which were addressed through coordination with the ICU. Another important limitation is the study’s non-blinded design. Although post-operative positioning makes blinding impractical, the lack of patient and assessor blinding may introduce performance and detection bias, particularly for subjective outcomes such as pain intensity. While randomization and standardized protocols help mitigate this concern, the absence of blinding remains a significant methodological limitation and is now emphasized more prominently. Additionally, although all patients received routine institutional venous thromboembolism prophylaxis (including early heparin administration and lower-limb compression stockings) and underwent structured post-operative clinical monitoring, our study was not powered to detect rare thromboembolic complications. The lack of imaging-based screening further limits our ability to comment on VTE risk associated with Trendelenburg positioning, and this should be considered when interpreting the safety profile of the intervention.

Post-operative maintenance of a 20° Trendelenburg position for 8 h significantly reduced shoulder pain intensity and analgesic requirements following gynecological laparoscopy. This shorter duration offers a practical alternative to previously studied 24-hour protocols, allowing earlier mobilization while providing meaningful analgesic benefit. Importantly, this strategy requires no additional equipment or cost, and can be readily implemented by trained nursing staff within existing post-operative protocols. By enhancing the redistribution and absorption of residual intraperitoneal CO 2 , Trendelenburg positioning offers a safe, practical, and evidence-based method to improve post-operative recovery in minimally invasive gynecologic procedures.