Severe Obesity and Prolonged Postoperative Mechanical Ventilation in Elderly Vascular Surgery Patients.

Background: Severe obesity, defined as body mass index (BMI) ≥ 40 kg/m Methods: We assembled a retrospective cohort of patients ≥ 65 years who underwent inpatient surgical procedures and were either severely obese or normal weight (BMI 18.6 - 24.9 kg/m Results: We studied 34,936 patients who were ≥ 65 years of age. The incidence of PPMV was 2.0% (624/31,700) in normal weight patients and 2.8% (92/3,236) in severely obese patients (odds ratio (OR): 1.46; 95% confidence interval (CI): 1.17 - 1.82, P = 0.001). Multivariable analysis, controlling for confounders, estimated a 56% relative increase in the risk of PPMV in severely obese patients, relative to their normal weight peers (OR: 1.56; 95% CI: 1.22 - 1.99, P = 0.001). In normal weight patients, the risk of mortality was multiplied by 23 times in patients who required PPMV (39.6% vs. 2.64%; OR: 23.10; 95% CI: 18.96 - 28.16; P < 0.001). In severely obese patients, PPMV multiplied the risk of mortality by 25 times (30.4% vs. 1.6%; OR: 25.26, 95% CI: 13.44 - 47.50; P < 0.001). Conclusions: Severe obesity increased the odds of PPMV. Although the incidence of PPMV was low, its requirement conferred up to 25 times greater risk of postoperative mortality, underscoring the need for perioperative mitigation strategies to minimize PPMV risk in elderly patients undergoing vascular surgery.