Anesthetic Technique and Perioperative Morbidity in Lower Extremity Amputation: A Retrospective Cohort Study

Objectives: To evaluate the association between anesthetic technique and postoperative outcomes in patients undergoing lower extremity amputation (LEA). Design: Retrospective cohort study. Setting: Single tertiary-care academic hospital in Pakistan. Participants: Adult patients undergoing nontraumatic, nonmalignant LEA between January 2014 and December 2024. Interventions: General anesthesia (GA), spinal anesthesia (SA), or peripheral nerve block (PNB) as the sole anesthetic technique. Measurements and Main Results: The primary outcome was composite perioperative morbidity, defined as major adverse cardiovascular events, cardiopulmonary resuscitation, unplanned intubation, unplanned intensive care unit admission, or prolonged mechanical ventilation. Secondary outcomes included in-hospital mortality, intensive care unit (ICU) length of stay, and hospital length of stay. Among 392 patients, 149 received GA, 181 SA, and 62 PNB. Composite morbidity occurred in 22.8% of GA, 10.5% of SA, and 19.4% of PNB patients (p = 0.009), driven primarily by unplanned intubation and unplanned ICU admission. Major adverse cardiovascular events, cardiopulmonary resuscitation, and in-hospital mortality did not differ significantly across anesthetic groups. After adjustment, SA was associated with lower odds of composite morbidity compared with GA (adjusted odds ratio [aOR], 0.38; 95% CI, 0.19-0.75; p = 0.005), whereas PNB was not significantly associated with morbidity after adjustment (aOR, 0.44; 95% CI, 0.18-1.07; p = 0.069). A propensity score–matched sensitivity analysis comparing GA and SA was directionally consistent with the primary analysis. Conclusions: In this high-risk LEA cohort, SA was associated with lower composite perioperative morbidity compared with GA, primarily reflecting respiratory and escalation-of-care outcomes. Prospective studies are needed to confirm these observational findings.