Abstract
Rationale: The clinical course of patients with overlap syndrome is poorly described and the ventilatory management of these patients is still controversial. This study was aimed to analyze the clinical characteristics of overlap patients treated either by domiciliary noninvasive ventilation (NIV) or continuous positive pressure (CPAP).
Methods: Retrospective study in 129 patients diagnosed has having overlap syndrome (clinical diagnosis of COPD, FEV1/FVC <70% at stable state and apnea-hypopnea index (AHI) >10).
Results: The diagnosis of overlap syndrome was performed in the immediate outcome of acute hypercapnic respiratory failure in 29% of cases. Patients were mostly men (86%), ex-smokers (61%) and obese (77%). The mean FEV1 was 53.7±18.5% pred. and mean AHI was 42.4±24.1. At discharge, 61% of the patients were treated by NIV and 39% by CPAP. The NIV-treated patients had a lower FEV1 at stable state (48.9 vs 59%, p<0.01), a lower mean nocturnal SpO2 (86 vs 90%, p<0.01) and longer time spent with SpO2<90% (67.0 vs 40.1%, p<0.01) as compared with CPAP-treated patients who had a higher AHI (49.9 vs 40.9, p=0.05). At stable state before the initiation of ventilation, the NIV-treated patients were more hypoxemic (63.4 vs 71.0 mmHg, p<0.01) and more hypercapnic (49.1 mmHg vs 42.0 mmHg, p<0.01). The compliance after one year was better in the NIV than the CPAP group (8.1 vs 5.8 h/day, p<0.01). During a 13 years follow-up, the death rate was 30% and similar in both groups (p=0.98).
Conclusion: In our practice, those overlap patients having the most severe COPD are preferentially treated by domiciliary NIV with a better compliance and a similar death rate than in less severe patients treated by domiciliary CPAP.
- Copyright ©ERS 2015
