METHODS: We conducted a systematic review of interventional and observational studies. A search was performed using MEDLINE, EMBASE, CINAHL, Scopus, and Web of Science, from inception to October 15, 2018.
RESULTS: We included six studies evaluating 293 patients. All studies had a high risk of bias. The hospital mortality rates of patients with DNI and/or DNR orders receiving HFNC oxygen were variable and ranged from 40% to 87%. In two before and after studies, the initiation of HFNC oxygen was associated with improved oxygenation and reduced respiratory rates. One comparative study found no difference in dyspnea reduction or morphine doses between patients using HFNC oxygen versus conventional oxygen. No studies evaluated quality of life in survivors or quality of death in nonsurvivors. HFNC was generally well tolerated with few adverse events identified.
CONCLUSIONS: While HFNC oxygen remains a viable treatment option for hospitalized patients who have acute respiratory failure and a DNI and/or DNR order, there is a paucity of high-quality, comparative, effectiveness data to guide the usage of HFNC oxygen compared with other treatments, such as noninvasive ventilation, conventional oxygen, and palliative opioids.