Lower abdominal surgeries, encompassing procedures such as inguinal hernia repair, appendectomy, hysterectomy, cesarean section, and colorectal resections, constitute a substantial proportion of the global surgical burden [1,2]. The selection of an optimal anesthetic technique for these procedures is a critical determinant of perioperative safety, patient comfort, and surgical outcomes [3]. For decades, general anesthesia (GA) has been the conventional standard for lower abdominal surgery due to its provision of reliable hypnosis, muscle relaxation, and airway control [4]. However, the emergence of enhanced recovery after surgery (ERAS) protocols has renewed interest in regional anesthetic techniques, particularly spinal anesthesia (SA), which offers the potential for superior postoperative analgesia, reduced systemic opioid exposure, and faster functional recovery [5,6].

Spinal anesthesia involves the intrathecal injection of local anesthetics, producing a reversible blockade of sensory, motor, and sympathetic nerve fibers in the lower body [7]. This technique preserves consciousness, avoids airway instrumentation, and provides dense intraoperative anesthesia with profound early postoperative analgesia [8]. These attributes may translate into decreased stress response, reduced postoperative nausea and vomiting (PONV), and earlier mobilization compared to GA [9,10]. Nevertheless, SA is not devoid of limitations. Sympathetic blockade can precipitate hypotension and bradycardia, and the technique is associated with postoperative urinary retention and, rarely, post-dural puncture headache [11,12].

The comparative efficacy of SA versus GA has been extensively investigated across various surgical specialties, yet the evidence remains heterogeneous, particularly in the context of lower abdominal surgery in Indian populations [13-15]. Meta-analyses comparing regional and general anesthesia for abdominal procedures have reported favorable analgesic outcomes with regional techniques but have also highlighted substantial clinical and methodological heterogeneity [16,17]. Furthermore, the applicability of findings from high-income settings to Indian tertiary care hospitals, where patient comorbidities, resource availability, and surgical case mixes differ, warrants context-specific investigation [18].

Despite the widespread use of both techniques in South Indian hospitals, prospective comparative data from this region remain limited. The present study was therefore designed to evaluate the comparative efficacy of SA versus GA in patients undergoing elective lower abdominal surgery at a tertiary care hospital in South India, with a focus on hemodynamic stability, postoperative analgesia, recovery parameters, and complication profiles. The findings are expected to inform evidence-based anesthetic decision-making and contribute to the optimization of perioperative care in similar resource settings.

OBJECTIVE

The primary objective of this prospective study was to compare the intraoperative hemodynamic stability and early postoperative analgesic efficacy of spinal anesthesia versus general anesthesia in adult patients undergoing elective lower abdominal surgery. Specifically, the study aimed to quantify differences in intraoperative blood pressure and heart rate variability, postoperative Visual Analogue Scale (VAS) pain scores at predefined intervals, time to first analgesic request, and total postoperative analgesic consumption between the two groups.

The secondary objectives were to assess and compare the incidence of postoperative nausea and vomiting, time to recovery (defined as time to achieve an Aldrete score ≥9), length of post-anesthesia care unit (PACU) stay, time to first ambulation, and the frequency of anesthesia-related complications, including hypotension, bradycardia, urinary retention, and post-dural puncture headache. The study also sought to evaluate patient satisfaction scores and the overall safety profile of each technique in the South Indian surgical population.

This prospective, comparative observational study was conducted in the Department of Anaesthesiology at a tertiary care hospital in South India over a period of nine months, from April 2025 to December 2025. The study was approved by the Institutional Ethics Committee, and written informed consent was obtained from all participants prior to enrollment. A total of 48 adult patients of American Society of Anesthesiologists (ASA) physical status I and II, aged between 18 and 65 years, scheduled for elective lower abdominal surgery were recruited. Patients were allocated into two groups based on the attending anesthesiologist’s clinical judgment and patient preference: Group S (spinal anesthesia, n=24) and Group G (general anesthesia, n=24). The sample size was determined based on feasibility and the available patient pool during the study period, consistent with previous prospective comparative studies in similar settings. Inclusion criteria comprised: (i) age 18–65 years; (ii) ASA physical status I or II; (iii) scheduled for elective lower abdominal surgery (including inguinal hernia repair, appendectomy, hysterectomy, and colorectal procedures); (iv) ability to understand and provide informed consent; and (v) no contraindications to either anesthetic technique. Exclusion criteria included: (i) patient refusal; (ii) ASA physical status III or higher; (iii) known allergy to local anesthetics or anesthetic agents; (iv) coagulation disorders or anticoagulant therapy; (v) local site infection; (vi) severe cardiovascular, respiratory, hepatic, or renal disease; (vii) pregnancy; and (viii) emergency surgery. Data Collection Procedure: Preoperatively, all patients underwent a thorough clinical evaluation, including history, physical examination, and routine laboratory investigations. Baseline vital parameters were recorded. In Group S, spinal anesthesia was administered in the sitting or lateral decubitus position using a 25-gauge Quincke needle at the L3-L4 or L4-L5 interspace, with 2.5–3 mL of 0.5% hyperbaric bupivacaine. In Group G, general anesthesia was induced with propofol (2 mg/kg), fentanyl (2 µg/kg), and vecuronium (0.1 mg/kg), and maintained with sevoflurane in oxygen-air mixture. Intraoperative monitoring included electrocardiography, non-invasive blood pressure, pulse oximetry, and capnography. Hemodynamic parameters were recorded at baseline, after induction, at 5-minute intervals intraoperatively, and at the end of surgery. Postoperatively, pain was assessed using the VAS (0–10) at 2, 6, 12, and 24 hours. Time to first analgesic request, total analgesic consumption, PONV episodes, recovery time, and complications were documented by an independent observer blinded to the study group allocation. Statistical Data Analysis: Data were entered into Microsoft Excel and analyzed using SPSS version 25.0 (IBM Corp., Armonk, NY). Continuous variables were expressed as mean ± standard deviation (SD) and compared using the independent samples t-test or Mann-Whitney U test, as appropriate. Categorical variables were expressed as frequencies and percentages and compared using the chi-square test or Fisher’s exact test. A p-value of <0.05 was considered statistically significant. Effect sizes were calculated where applicable to assess the magnitude of differences between groups.

A total of 48 patients were enrolled, with 24 patients in each group. The demographic and baseline characteristics, including age, sex, body mass index, ASA physical status, and type of surgery, were comparable between the two groups (p>0.05), indicating effective baseline matching (Table 1). The mean age was 42.3 ± 11.6 years in Group S and 44.1 ± 12.2 years in Group G. Inguinal hernia repair and hysterectomy were the most common procedures in both groups.

Intraoperative hemodynamic parameters revealed that patients in Group S experienced a significantly higher incidence of hypotension (defined as systolic blood pressure <90 mmHg or a >20% decrease from baseline) compared with Group G (37.5% vs. 12.5%; p=0.045). Bradycardia (heart rate <50 bpm) was also more frequent in Group S (25.0% vs. 8.3%; p=0.123), although this difference did not reach statistical significance (Table 2). All hypotensive episodes were managed successfully with intravenous fluids and vasopressors (ephedrine 6–12 mg), with no adverse sequelae.

Postoperative pain scores were significantly lower in Group S at 2 hours (2.4 ± 0.9 vs. 4.1 ± 1.2; p<0.001), 6 hours (3.1 ± 1.1 vs. 5.2 ± 1.4; p<0.001), and 12 hours (3.8 ± 1.3 vs. 5.0 ± 1.5; p=0.006) compared with Group G (Table 3). At 24 hours, the difference was not statistically significant (3.5 ± 1.4 vs. 4.2 ± 1.6; p=0.112). The time to first analgesic request was significantly longer in Group S (285.4 ± 62.3 minutes vs. 142.7 ± 48.9 minutes; p<0.001), and total analgesic consumption was lower in Group S (p=0.003). PONV was significantly more frequent in Group G (33.3% vs. 8.3%; p=0.028).

Recovery parameters favored Group S, with a significantly shorter mean recovery time (28.6 ± 6.4 minutes vs. 41.2 ± 8.7 minutes; p<0.001) and shorter PACU stay (42.3 ± 9.1 minutes vs. 58.7 ± 11.5 minutes; p<0.001) (Table 4). Time to first ambulation was also shorter in Group S (6.2 ± 1.8 hours vs. 9.4 ± 2.3 hours; p<0.001). Urinary retention occurred in 3 patients (12.5%) in Group S and 1 patient (4.2%) in Group G (p=0.298). Post-dural puncture headache was reported by 2 patients (8.3%) in Group S, while no such cases occurred in Group G. No major cardiac, respiratory, or surgical complications were observed in either group.

Table 1: Demographic and Baseline Characteristics of Study Participants

Table 2: Intraoperative Hemodynamic Parameters and Events

Table 3: Postoperative Pain Scores, Analgesic Requirement, and PONV

Table 4: Recovery Parameters and Complications

The present study demonstrates that spinal anesthesia provides superior early postoperative analgesia, reduces PONV, and accelerates recovery compared with general anesthesia in patients undergoing elective lower abdominal surgery, albeit with a higher incidence of transient intraoperative hypotension. These findings are broadly consistent with the existing literature, which has consistently reported analgesic and recovery advantages for neuraxial techniques across various surgical procedures [21,22]. The significantly lower VAS scores observed in the SA group during the first 12 postoperative hours align with the findings of a systematic review and meta-analysis by Lalchanzani et al., which reported that SA was associated with significantly lower pain scores compared with GA in patients undergoing hysterectomy (MD, 0.84; 95% CI, 0.11–1.56; p=0.02) [23]. Similarly, Sarakatsianou et al. found that although quality of life outcomes were comparable between SA and GA in laparoscopic inguinal hernia repair, SA remained an attractive alternative with comparable efficacy [24]. The hemodynamic findings of our study warrant careful interpretation. The higher incidence of hypotension in the SA group (37.5%) is a well-recognized consequence of sympathetic blockade and has been documented in multiple studies. Imbelloni et al. reported perioperative vasopressor requirements in 41% of patients receiving SA versus 3% of those receiving GA [25]. Mehta et al. observed hypotension in 30% of SA patients compared with 10% in the GA group [26]. These figures closely mirror our findings. Importantly, all hypotensive episodes in our study were transient and responded promptly to vasopressor therapy, with no associated morbidity. This underscores the importance of vigilant hemodynamic monitoring and preparedness for prompt intervention when SA is selected. The reduced incidence of PONV in the SA group (8.3% vs. 33.3%) is clinically meaningful and consistent with previous reports. Tiwari et al. noted that patients receiving SA had significantly lower incidences of PONV and sore throat compared with GA, while GA patients had more stable blood pressure profiles [27]. The avoidance of airway instrumentation and systemic anesthetic agents in SA likely contributes to the reduced PONV burden, which is a major contributor to patient discomfort and delayed discharge [28]. Furthermore, the significantly shorter recovery time and PACU stay in the SA group have important implications for resource utilization and patient throughput in high-volume surgical settings. Asaad et al., in a meta-analysis of randomized evidence, concluded that regional anesthesia may offer advantages in terms of recovery profiles and postoperative outcomes compared with GA for laparoscopic cholecystectomy [29]. The strengths of this study include its prospective design, standardized anesthetic protocols, and comprehensive assessment of both efficacy and safety outcomes. However, several limitations must be acknowledged. The relatively small sample size (n=48) limits the statistical power to detect small but clinically relevant differences, particularly for rare complications such as post-dural puncture headache and urinary retention. The non-randomized allocation of patients introduces the possibility of selection bias, although baseline characteristics were comparable between groups. The single-center design may limit the generalizability of the findings to other settings with different patient populations and resource availability. Furthermore, the short follow-up duration (24 hours postoperatively) precludes assessment of longer-term outcomes such as chronic postsurgical pain, long-term functional recovery, and patient-reported quality of life. These limitations notwithstanding, the study provides valuable region-specific data that contribute to the ongoing discourse on anesthetic selection for lower abdominal surgery in South Indian tertiary care settings. Limitations of the Study This study has several limitations that should be considered when interpreting the findings. First, the small sample size of 48 patients, while feasible for the study duration, limits the statistical power to detect differences in rare outcomes and may increase the risk of Type II errors. Second, the non-randomized allocation of patients, based on anesthesiologist judgment and patient preference, introduces potential selection bias, although baseline characteristics were statistically comparable between groups. Third, the study was conducted at a single tertiary care hospital in South India, which may limit the generalizability of the results to other geographic regions, healthcare settings, and patient populations with different demographic and comorbidity profiles. Fourth, the follow-up period was restricted to 24 hours postoperatively, precluding assessment of longer-term outcomes such as chronic pain, delayed complications, and quality of life. Fifth, the study did not employ blinding of the anesthesiologist or the surgeon, which could introduce performance bias, although outcome assessment was performed by an independent observer. Finally, the sample size precluded meaningful subgroup analyses based on surgery type, patient age, or comorbidity status, which may have revealed differential effects of anesthetic technique across patient subgroups. Acknowledgement The authors wish to express their sincere gratitude to the Department of Anaesthesiology and the Department of Surgery at the participating tertiary care hospital in South India for their invaluable support and cooperation throughout the study period. We extend our heartfelt appreciation to all the patients who consented to participate in this study, without whom this research would not have been possible. We are grateful to the nursing and technical staff of the operation theatre and post-anesthesia care unit for their assistance with data collection and patient monitoring. We also thank the institutional research committee for their guidance and the biostatistician for assistance with data analysis.

In conclusion, this prospective comparative study demonstrates that spinal anesthesia offers significant advantages over general anesthesia in patients undergoing elective lower abdominal surgery, particularly in terms of early postoperative analgesia, reduced incidence of postoperative nausea and vomiting, and faster recovery parameters. Patients receiving SA experienced significantly lower VAS pain scores at 2, 6, and 12 hours postoperatively, required fewer analgesics, and had shorter recovery and PACU stays. However, the higher incidence of transient intraoperative hypotension in the SA group highlights the need for vigilant hemodynamic monitoring and preparedness for prompt vasopressor intervention. These findings are consistent with the broader body of evidence supporting the judicious use of neuraxial techniques as part of enhanced recovery protocols for lower abdominal surgery.

From a clinical and health-system perspective, the adoption of spinal anesthesia as the primary anesthetic technique for appropriately selected patients undergoing lower abdominal surgery may contribute to improved patient comfort, reduced opioid consumption, and more efficient utilization of postoperative care resources. Nevertheless, the choice of anesthetic technique should remain individualized, taking into account patient preferences, comorbidities, surgical requirements, and the availability of skilled anesthesia personnel. Future multicenter randomized controlled trials with larger sample sizes, longer follow-up periods, and stratification by surgery type and patient characteristics are warranted to confirm and extend these findings, and to identify patient subgroups most likely to benefit from spinal anesthesia in the South Indian context.