Preoperative sepsis is a predictive factor for 30-day mortality after major lower limb amputation among patients with arteriosclerosis obliterans and diabetes.

Background: While many patients with lower limb ischemia also have severe infections, few studies have investigated whether the presence of preoperative sepsis affects patient prognosis following lower limb amputation (LLA). Therefore, we investigated the factors (including sepsis as defined in SEPSIS-3) that contribute to the acute mortality rate in patients who underwent LLA due to arteriosclerosis obliterans (ASO) or diabetes mellitus (DM).

Methods: In this retrospective, single-center, 10-year chart review study, 122 adult patients who underwent LLA due to ASO and/or DM were identified from 56,438 surgery cases. Patient characteristics, including co-morbidities, surgical conditions, the presence/absence of sepsis, and acute physiological condition after surgery, were investigated in patients who died within 30 days of LLA and those who survived. Univariate analysis between groups was performed using the chi-square test. Comparisons of age and American Society of Anesthesiologists-Physical Status classification between groups were performed using the Mann-Whitney U test. Risk factors for 30-day mortality after LLA were examined using stepwise logistic regression (backward elimination). Statistical results were considered significant at P < 0.05.

Results: Eight cases of mortality (6.6%) were found; we identified the causes as sepsis, myocardial infarction, fatal arrhythmia, and mesenteric artery occlusive disease in 5 (62.5%), 1 (12.5%), 1 (12.5%), and 1 (12.5%) cases, respectively. Using univariate analysis, we identified that age (≥74), delirium, sepsis, intensive care unit admission, non-DM (ASO only), hemodialysis, and acute kidney injury were significantly higher in the mortality group. In logistic regression analysis, non-DM (odds ratio [OR]: 35.2, 95% confidence interval [CI]: 2.8-432) and sepsis (OR: 80.7, 95% CI: 6.7-959) were potential risk factors for 30-day mortality.

Conclusions: This study suggests that cases resulting in amputation due to ASO pathology alone might have poor prognosis and that preoperative sepsis can increase perioperative mortality; hence, the decision to amputate must be considered before the development of sepsis.