The role of delirium and other risk factors on mortality in elderly patients with critical limb ischemia undergoing major lower limb amputation

Background Delirium in patients with critical limb ischemia (CLI) is associated with increased mortality. The main goal of this study was to investigate the association between delirium and mortality in patients undergoing major lower limb amputation for CLI. In addition, other risk factors associated with mortality were analyzed. Methods An observational cohort study was conducted including all patients aged ≥70 years with CLI undergoing a major lower limb amputation between January 2014 and July 2017. Delirium was scored using the Delirium Observation Screening Score in combination with the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Risk factors for mortality were analyzed by calculating hazard ratios using a Cox proportional hazards model. Results In total, 95 patients were included; of which, 29 (31%) patients developed a delirium during admission. Delirium was not associated with an increased risk of mortality (hazard ratio [HR] = 0.84; 95 % confidence interval [CI]: 0.51–1.73; P = 0.84). Variables independently associated with an increased risk of mortality were age (HR 1.1; 95% CI 1.0–1.1), cardiac history (HR 3.3; 95% CI 1.8–6.1), current smoking (HR 2.9; 95% CI 1.6–5.5), preoperative anemia (HR 2.8; 95% CI 1.1–7.2), and living in a nursing home (HR 2.2; 95% CI 1.1–4.4). Conclusion Delirium was not associated with an increased mortality risk in elderly patients with CLI undergoing a major lower limb amputation. Factors related to an increased mortality risk were age, cardiac history, current smoking, preoperative anemia, and living in a nursing home.