High-pressure NIV for acute hypercapnic respiratory failure in COPD: improved survival in a retrospective cohort study

Introduction Updated treatment guidelines for acute hypercapnic respiratory failure (AHRF) in chronic obstructive pulmonary disease (COPD) with non-invasive ventilation (NIV) in 2016 recommended a rapid increase in inspiratory positive airway pressure (IPAP) to 20 cm H2O with possible further increase for patients not responding. Previous guidelines from 2006 suggested a more conservative algorithm and maximum IPAP of 20 cm H2O. Aim To determine whether updated guidelines recommending higher IPAP during NIV were related with improved outcome in patients with COPD admitted with AHRF, compared with NIV with lower IPAP. Methods A retrospective cohort study comparing patients with COPD admitted with AHRF requiring NIV in 2012-2013 and 2017-2018. Results 101 patients were included in the 2012-2013 cohort with low IPAP regime and 80 patients in the 2017-2018 cohort with high IPAP regime. Baseline characteristics, including age, forced expiratory volume in 1 s (FEV1), pH and PaCO2 at initiation of NIV, were comparable. Median IPAP in the 2012-2013 cohort was 12 cm H2O (IQR 10-14) and 20 cm H2O (IQR 18-24) in the 2017-2018 cohort (p<0.001). In-hospital mortality was 40.5% in the 2012-2013 cohort and 13.8% in the 2017-2018 cohort (p<0.001). The 30-days and 1-year mortality were significantly lower in the 2017-2018 cohort. With a Cox model 1 year survival analysis, adjusted for age, sex, FEV1 and pH at NIV initiation, the HR was 0.45 (95% CI 0.27 to 0.74, p=0.002). Conclusion Short-term and long-term survival rates were substantially higher in the cohort treated with higher IPAP. Our data support the current strategy of rapid increase and higher pressure.