Effect of General Anesthesia versus Thoracic Spinal Anesthesia on Postoperative Pain and Opioid Consumption After Modified Radical Mastectomy

Background: Modified radical mastectomy (MRM) is often associated with significant postoperative pain and high opioid requirements. Thoracic spinal anesthesia (TSA) has been proposed as an alternative to general anesthesia (GA) to improve perioperative outcomes. This study aimed to compare the effects of TSA versus GA on postoperative pain scores, opioid consumption, intraoperative hemodynamics, and complications in patients undergoing MRM. Methods: In this randomized clinical trial, 52 female patients (ASA I–III) scheduled for unilateral MRM were allocated to either GA (n = 26) or TSA (n = 26). TSA was performed at the T5–T6 interspace using 0.5% isobaric bupivacaine with fentanyl, dexmedetomidine, and dexamethasone. Postoperative pain was assessed using the Visual Analogue Scale (VAS) at 2, 4, 8, 12, 16, and 24 hours. Results: TSA significantly reduced VAS scores at all postoperative intervals (p < 0.001 at each time point), prolonged the mean time to first rescue analgesia (TSA: 10.2 ± 1.3 h vs GA: 4.1 ± 1.1 h; p < 0.001), and lowered total 24-hour opioid use (TSA: 6.8 ± 1.9 mg vs GA: 14.5 ± 2.6 mg morphine equivalents; p < 0.001). TSA maintained more stable intraoperative MAP and HR (p = 0.02 and p = 0.03, respectively) and resulted in shorter recovery room stays (p = 0.01). Complications such as hypertension (p = 0.04), tachycardia (p = 0.03), and urinary retention (p = 0.02) were significantly less frequent with TSA, while postoperative nausea and vomiting incidence was lower but not statistically significant (p = 0.09).