Efficacy and Safety of Meperidine Plus Bupivacaine versus Bupivacaine Alone for the Induction of Anesthesia in Women Undergoing Cesarean Delivery: A Dose-Based Systematic Review and Meta-Analysis

Background Spinal anesthesia is widely used for cesarean sections due to its rapid onset and minimal fetal drug exposure. However, post-spinal anesthesia shivering (PSAS) is common, affecting 40–70% of cases, leading to patient discomfort. Bupivacaine, a commonly used anesthetic, has a high incidence of PSAS. Meperidine, an opioid with anti-shivering properties, modulates thermoregulation and reduces shivering. This meta-analysis evaluates the efficacy and safety of meperidine as an adjunct to bupivacaine in preventing PSAS. Objectives To assess the effectiveness of meperidine as an adjunct to bupivacaine in reducing PSAS incidence, severity, and related adverse effects in cesarean deliveries under spinal anesthesia. Methods A systematic review and meta-analysis followed PRISMA guidelines. 13 randomized controlled trials (RCTs) from PubMed, Google Scholar, and Cochrane Library were analyzed using Review Manager (RevMan) 5.4. Primary outcomes included shivering incidence and severity. Secondary outcomes included recovery time, Apgar scores, and adverse events. Risk of bias was assessed using the Rob-2 tool. Results Meperidine + bupivacaine significantly reduced shivering incidence (RR = 0.29; 95% CI = 0.19–0.45; p < 0.00001). Significant reductions were noted for Grade 2 (p < 0.00001), Grade 3 (p = 0.0004), and Grade 4 (p = 0.0002) shivering. The optimal dose was 10 mg. Meperidine increased nausea/vomiting (RR = 1.81; p < 0.0001) and pruritus (RR = 15.26; p < 0.00001), with no significant effects on Apgar scores, recovery time, hypotension, or bradycardia. Conclusions Meperidine + bupivacaine significantly reduces PSAS compared to Bupivacaine alone. The dose range of 8-10 mg offers the best efficacy. Further studies should optimize dosing to minimize side effects.