Postoperative delirium in elderly patients with critical limb ischemia undergoing major leg amputation: a retrospective study.

Background: Critical limb ischemia has been identified as a risk factor for the incidence of postoperative delirium in elderly patients. Limb amputation is the last option in critical limb ischemia treatments. We investigated the incidence and predisposing factors of postoperative delirium in patients undergoing major leg amputation.

Methods: From January 2012 to December 2016, 121 patients aged over 60 years who had undergone major leg amputation were enrolled in this study. Various factors related to the patients' outcomes were assessed, including demographic, preoperative laboratory, anesthetic, surgical, and postoperative indicators.

Results: Twenty two patients were excluded and 99 patients were assigned to either the delirium group or no delirium group. Forty of them (40%) developed a delirium during 30 days postoperatively. Univariate analysis implied that end-stage renal disease on hemodialysis, alcohol consumption, C-reactive protein, staying in an intensive care unit (ICU), duration of an ICU stay, occurrence of complications, and mortality during six months, were the factors that accounted for significant differences between the two groups. In multivariate analysis, three factors were significantly related to the development of delirium: mortality during six months (odds ratio [OR] = 13.86, 95% CI [2.10-31.90]), alcohol (OR = 8.18, 95% CI [1.13-16.60]), and hemodialysis (OR = 4.34, 95% CI [2.06-93.08]).

Conclusions: Approximately 40% of the elderly patients suffered from postoperative delirium in major leg amputation. Identifying those with risk factors for postoperative delirium and intervening at the early stage will be of great benefit in major leg amputations for the elderly population.