Nutritional status in patients with chronic respiratory failure receiving home mechanical ventilation: Impact on survival

Abstract

In patients with chronic respiratory diseases body mass index (BMI) is a predictor of long-term survival, whereas the prognostic value of body composition, especially fat-free mass index (FFMI), is unknown. In a prospectively collected cohort of 131 patients (50 females, 81 males; 71% chronic obstructive pulmonary disease, 29% severe restrictive disorders) undergoing home mechanical ventilation (HMV) due to chronic hypercapnic respiratory failure (CHRF), the prognostic value of nutritional composition assessed by bioelectrical impedance analysis was evaluated during a 4-year follow-up and compared to that of BMI, anthropometrics, and functional parameters. After follow-up, 53 patients (40.5%) had died. Regarding all-cause mortality cumulative survival percentages after 1, 2 and 3 years were 89.3, 76.3 and 67.9%, respectively. In univariate analyses, FFMI, BMI, sex, age, leukocyte number, FEV1 and 6-min walking distance were associated with survival (p<0.05). Multivariate analyses using the most significant percentiles identified by univariate analysis revealed FFMI (25th percentile; hazard ratio 0.338 [95% confidence interval: 0.189-0.605]), sex, leukocyte number (50th percentile) and FEV1 (50th percentile) as independent predictors of mortality. In patients with CHRF and HMV, body composition in terms of FFMI was an independent predictor of long-term survival. FFMI was superior to BMI and seems informative in the multidimensional assessment of these patients.