Non-invasive ventilation in the emergency department from 2004-2015

Background: Little is known of long term patterns of non-invasive ventilation (NIV) initiated in the emergency department (ED) setting. Aim: To determine the trends and outcomes for patients who had NIV initiated in the ED for acute respiratory failure (ARF). Methods: We enrolled consecutive patients who had received NIV in the ED from January 2004 to December 2015 to assess disease trends and hospital outcomes. Results: There were 849 episodes of ARF requiring NIV in the ED with an increasing trend [increase of 7 (95% CI 3 to 12 cases per year, p = 0.006]. The top causes of ARF were COPD 317 (37.3%) and acute pulmonary edema (APO) 292 (34.4%). Initially COPD was the most frequent cause of ARF requiring NIV but, by 2009, APO had overtaken COPD as the most frequent cause. The overall in-hospital mortality was 8.7%. Adjusting for case load, there was decrease in mortality of 0.732% (95% CI 0.2% to 1.4%) per year (p=0.04). The overall endotracheal intubation (ETI) rate was 10.8%. There is no difference in the mortality and ETI rates for COPD versus other causes of ARF (pu003e 0.05). In COPD patients who were for active resuscitation, the in-hospital mortality was 3.6% (5/165) with zero mortality in the last 3 years and the ETI rate was 15.2% (25/165). Conclusion: Despite the increasing usage of NIV in the ED, we observed a decrease in mortality. APO has overtaken COPD as the most frequent cause of ARF towards the latter half of the study. For COPD patients, there was consistently low in-hospital mortality.