Long term continuous positive airway pressure prescription after an acute hypercapnic respiratory failure

Abstract

Rationale and aim. Sleep studies should be performed under stable condition to achieve correct obstructive sleep apnoea (OSA) diagnosis. However, real-life conditions sometimes lead to perform sleep studies after an acute respiratory hypercapnic failure (ARHF) treated with non-invasive mechanical ventilation (NIMV). The aim of the study was to evaluate the usefulness of sleep studies during an acute scenario in terms of long-term CPAP prescription and its effect on subsequent AHRF episodes.

Methods: Observational study of a historic cohort of patients admitted for ARHF in need of NIMV during 2017-2019. Once the AHRF was resolved, a sleep study was performed to rule out OSA during admission, and continuous positive airway pressure (CPAP) was prescribed if an apnoea-hypopnea index > 30 was documented. Two groups were designed: CPAP adherent (>4 hours/night) and No CPAP group. Main outcome was AHRF readmission. Statistical analysis included multivariate logistic regression analysis.

Results: A total of 147 patients were admitted for AHRF and 41 patients were diagnosed of severe OSA during admission (27.9%). Mean BMI was 38 ± 7.8 kg/m2. Main AHRF aetiology was a combination of COPD and obesity (43.9%). During follow-up 27 patients showed long-term CPAP adherence (65.9%), and 9 presented incident AHRF (22%), 6 in the No CPAP group (42.8%) and 3 in the adherent group (11.1%). CPAP use associated with less incident AHRF (Table 1).

Conclusions: Two out of three patients diagnosed of severe OSA during an AHRF admission in need of NIMV showed long-term CPAP adherence. Incident AHRF episodes were reduced by CPAP use.