1. Survival benefit of CPAP favors hypercapnic patients with the overlap syndrome.
- Author
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Jaoude P, Kufel T, and El-Solh AA
- Subjects
- Aged, Female, Humans, Hypercapnia complications, Hypercapnia diagnosis, Hypercapnia mortality, Kaplan-Meier Estimate, Male, Middle Aged, New York, Patient Compliance, Proportional Hazards Models, Pulmonary Disease, Chronic Obstructive complications, Pulmonary Disease, Chronic Obstructive diagnosis, Pulmonary Disease, Chronic Obstructive mortality, Retrospective Studies, Risk Factors, Sleep Apnea, Obstructive complications, Sleep Apnea, Obstructive diagnosis, Sleep Apnea, Obstructive mortality, Syndrome, Time Factors, Treatment Outcome, Veterans Health, Continuous Positive Airway Pressure adverse effects, Continuous Positive Airway Pressure mortality, Hypercapnia therapy, Pulmonary Disease, Chronic Obstructive therapy, Sleep Apnea, Obstructive therapy
- Abstract
Background: Patients with the combination of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA), known as the "overlap syndrome," have a substantially greater risk of morbidity and mortality compared to those with either COPD or OSA alone. The study's objective was to report on the long-term outcome of hypercapnic (PaCO2 ≥ 45 mmHg) and normocapnic patients with the overlap syndrome treated with continuous positive airway pressure (CPAP)., Methods: A nonconcurrent cohort of consecutive patients with the overlap syndrome was followed for a median duration of 71 months (range 1-100) at a VA sleep center. All patients were managed according to the prevailing recommendations of both diseases. The end point of the study was all-cause mortality., Results: Of the 271 patients identified, 104 were hypercapnic (PaCO2 = 51.6 ± 4.3 mmHg). Both normocapnic and hypercapnic patients had comparable apnea-hypopnea indexes (AHI) (29.2 ± 23.8 and 35.2 ± 29.2/h, respectively; p = 0.07) and similar adherence rates to CPAP (43 and 42 %, respectively, p = 0.9). Survival analysis revealed that hypercapnic patients who were adherent to CPAP had reduced mortality compared to nonadherent hypercapnic patients (p = 0.04). In contrast, the cumulative mortality rate for normocapnic patients was not significantly different between the adherent and the nonadherent group (p = 0.42). In multivariate analysis, the comorbidity index was the only independent predictor of mortality in normocapnic patients with the overlap syndrome [hazard ratio (HR) 1.68; p < 0.001] while CPAP adherence was associated with improved survival (HR 0.65; p = 0.04)., Conclusions: CPAP mitigates the excess risk of mortality in hypercapnic patients but not in normocapnic patients with the overlap syndrome.
- Published
- 2014
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