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

To evaluate the association between anesthetic technique and postoperative outcomes in patients undergoing lower extremity amputation (LEA).

Retrospective cohort study.

Single tertiary-care academic hospital in Pakistan.

Adult patients undergoing nontraumatic, nonmalignant LEA between January 2014 and December 2024.

General anesthesia (GA), spinal anesthesia (SA), or peripheral nerve block (PNB) as the sole anesthetic technique.

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.

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.