Late presentation of acute hypercapnic respiratory failure carries a high mortality risk in COPD patients treated with ward-based NIV.

INTRODUCTION: Non-invasive ventilation (NIV) is recommended for treatment of acute hypercapnic respiratory failure (AHRF) refractory to medical management in patients with COPD. This study investigated the relationship between time from hospital presentation to diagnosis of AHRF and in-hospital mortality.

METHODS: Retrospective analysis of hospitalised COPD patients treated with a first episode of ward-based NIV for AHRF at a large UK teaching hospital between 2004 and 2017. Data collected prospectively as part of NIV service evaluation. Multivariable logistic regression performed to identify predictors of in-hospital mortality.

RESULTS: In total, 547 unique patients were studied comprising 245 males (44.8%), median age 70.6 years, median FEV1% predicted 34%. Overall in-hospital mortality was 19% (n = 104); median survival was 1.7 years. In univariate analysis, a longer time between hospital presentation to diagnosis of AHRF was associated with in-hospital mortality (median [IQR]: 8.7 [0.7-75.8] hours vs. 1.9 [0.3-13.6] hours, p < 0.0001). In multivariable logistic regression, significant predictors of in-hospital mortality were AHRF >24 h after hospital presentation (odds ratio [95% CI]: 2.29 [1.33-3.95], p = 0.003), pneumonia on admission (1.81 [1.07-3.08], p = 0.027), increased age (1.10 [1.07-1.14], p < 0.001) and NIV as ceiling of treatment (5.86 [2.87-11.94], p < 0.001).

CONCLUSIONS: Hospitalised COPD patients with late presentation of AHRF, requiring acute ward-based NIV, may have increased in-hospital mortality. These patients may benefit from closer monitoring and earlier specialist respiratory review.