Study objective: To determine the predictive factors of morbidity and mortality in patients with end-stage respiratory disease.
Design: Prospective, multicenter cohort study.
Setting: Thirteen outpatient chest clinics within the Association Nationale de Traitement à Domicile de l’Insuffisance Respiratoire.
Participants: Stable adult patients with chronic respiratory failure receiving long-term oxygen therapy and/or home mechanical ventilation (n = 446; 182 women and 264 men; aged 68.5 ± 12.1 years [± SD]); Respiratory diseases were COPD in 42.8%, restrictive disorders in 36.3%, mixed respiratory failure in 13.5%, and bronchiectasis in 7.4%. Recruitment was performed during the yearly examination. Patients with neuromuscular diseases and sleeping apnea were excluded.
Measurements and results: Hospitalization days and survival were recorded during a follow-up of 14.3 ± 5.6 months. Body mass index (BMI), serum albumin, and transthyretin levels were considered for their predictive value of outcome, together with demographic data, underlying respiratory disease, respiratory function, hemoglobin, C-reactive protein, smoking habits, oral corticosteroid use, and antibiotic treatment courses. Overall, 1.8 ± 1.7 hospitalizations (cumulative stay, 17.6 ± 27.1 days) were observed in 254 of 446 patients (57%). Independent predictors of hospitalization were oral corticosteroids, FEV1, and plasma C-reactive protein. One-year and 2-year cumulative survivals were 93% and 69%, respectively. Plasma C-reactive protein, BMI, Pao2 on room air, and oral corticosteroids independently predicted survival in multivariate analysis.
Conclusion: Besides established prognosis factors such as FEV1 and Pao2, nutritional depletion as assessed by BMI and overall systemic inflammation as estimated by C-reactive protein appear as major determinants of hospitalization and death risks whatever the end-stage respiratory disease. BMI and C-reactive protein should be included in the monitoring of chronic respiratory failure. Oral corticosteroids as maintenance treatment in patients with end-stage respiratory disease are an independent risk factor of death, and should be avoided in most cases.