Background Patients with severe acute exacerbations of COPD (AECOPD) often require treatment with non-invasive ventilation (NIV). The BTS audit reported that patients who develop respiratory acidosis and require NIV after 24 h in hospital have a high mortality risk but this relationship has not been investigated prospectively.1
Methods Consecutive patients hospitalised with AECOPD and receiving assisted ventilation (NIV or IPPV) were identified. Demographic information, time from admission to commencement of ventilation, arterial blood gases at admission and at time of development of respiratory acidosis (if different), and outcomes of treatment were recorded.
Results 195 of 920 patients admitted with AECOPD were initially treated with NIV and four were ventilated invasively. Mean (SD) age was 73.6 (9.8) years, and most: were female (61.4%); had experienced frequent exacerbations in the previous year (median 3, IQR 1–4); were of normal weight (mean (SD) BMI 25.1 (7.0) kg/m2); and had severe airflow obstruction (mean (SD) FEV1 38.1 (16.1) % predicted). 27.6% of patients had received NIV previously for treatment of AECOPD, and 81 (40.7%) patients had coexistent pneumonia on admission.
Median duration of ventilation was 4 days (IQR 1.5–5) and four of the patients who initially received NIV progressed to invasive ventilation. 49 (24.6%) patients died in-hospital. The risk of death increased with longer time from hospital admission to ventilation commencement (Abstract P266 figure 1), with more than 60% of patients who required ventilation after day 2 of their hospital admission not surviving to discharge.
Conclusion Mortality in AECOPD is particularly high in patients who deteriorate and require ventilation after day 2 of the admission. The time from admission to needing ventilation (NIV or IPPV) should inform clinicians considering the prognosis of patients hospitalised with AECOPD.