Author:Patricia Kritek, MD reviewing
NEJM Journal Watch
A meta-analysis showed lower mortality with noninvasive ventilation compared with standard oxygen therapy.
Comparisons of effectiveness among noninvasive ventilation (NIV), high-flow nasal cannula (HFNC), and standard oxygen therapy have yielded conflicting results in patients with respiratory failure who do not require immediate endotracheal intubation. Researchers performed a meta-analysis of 25 trials in which in which different forms of respiratory support were examined in such patients. The majority of trials were designed to compare face-mask NIV and standard oxygen therapy. Most trials involved patients with moderate hypoxemia (partial pressure of arterial oxygen to fraction of inspired oxygen ratio [PaO2:FiO2] <200). Studies that focused on treating patients with chronic obstructive pulmonary disease or heart failure were excluded, although individual patients with these diseases were included in some evaluated trials.
NIV, delivered by face mask or helmet, was associated with lower mortality than standard oxygen therapy. Mortality was similar when HFNC was compared with standard oxygen therapy. HFNC and NIV (by face mask or helmet) were associated with lower rates of endotracheal intubation. Helmet NIV had the largest effect on mortality and risk for endotracheal intubation, but this finding was based on a small number of trials.
Using either NIV or HFNC makes sense to initially support patients with moderate hypoxemia with the hope of avoiding intubation. The mortality data suggest NIV is a better choice; however, patients often can’t tolerate face-mask NIV. Most hospitals in the U.S. do not have helmet NIV yet, but these data suggest it might be a reasonable option moving forward. Finally, this meta-analysis doesn’t address issues that are specific to COVID-19 patients; another recent review addressed that topic (NEJM JW Gen Med Jul 1 2020 and Ann Intern Med 2020 May 22.