Obesity is a serious disorder with increasing prevalence. It is associated with multiple abnormalities in respiratory function that predispose to respiratory failure. This study assessed the prevalence of obesity among patients with chronic ventilator dependence (CVD) and evaluated the effect of BMI on their outcomes.
We performed a retrospective study of patients with CVD discharged from an LTAC facility between 3/01/01and 4/30/02. Data collected included age, gender, ethnicity, height, weight, number of days on ventilator (DOV), length of stay (LOS), weaning success, mortality and disposition.
We evaluated 141 patients with mean age of 69± 14 yrs, mean BMI of 30 ± 12, weaning success of 62% and mortality of 29%. We observed the following distribution of CVD patients among standard BMI categories: underweight (BMI<18.5) 5%; overweight (BMI≥25) 63% and obesity (BMI≥30) 38%. Morbid obesity (BMI≥40) was present in 12% of patients, at a prevalence nearly 3 times that of the US population. Causes of CVD differed among the BMI categories: COPD in underweight patients (OR= 8.4, 95% CI= 1.7-42.3, p=0.02), major CNS event in obese patients (OR= 2.4 with 95% CI=1.02-5.70, p=0.06) and multiorgan failure in morbidly obese patients (OR= 4.8, 95% CI= 1.6-13.8, p=0.005). Morbidly obese patients were among the youngest CVD patients (61 ± 12 yrs, p=0.01). While LOS and DOV were not different from those of other patients, morbidly obese patients had the highest weaning success (76%), the lowest mortality (12%) and were more likely to go home or to acute rehabilitation facility (OR=3.9, 95% CI=1.3-11.9, p=0.02).
We observed an increased prevalence of morbid obesity among patients with CVD. Morbidly obese patients developed CVD at a relatively younger age often in association with multiorgan failure, but had a favorable prognosis.
Critically ill patients with morbid obesity should be recognized as having high risk for CVD. A better understanding of obesity related respiratory dysfunction in the ICU setting would help to prevent this complication of critical illness.
H.M. Al-Dorzi, None.