Acute Hypoxemic Respiratory Failure in Immunocompromised Patients: Taking Aggressive Measures to Identify Etiology

Abstract

Immunocompromised patients often experience pulmonary complications especially acute respiratory failure (ARF) (1-3), the main cause of which is infection (4). To avoid increasing the risk of infection, non-invasive mechanical ventilation (NIV) is recommended as a first line treatment for immunocompromised patients (5, 6). However, recent studies have cast some doubts on the protective effects of NIV as a first-line treatment in immunocompromised patients with ARF (7-9). Meanwhile, a high-flow nasal cannula (HFNC) may potentially be a better alternative to NIV or standard oxygenation therapy (SOT) in immunocompromised patients due to its unique functions (4), but the results of studies of the effect of HFNC are also obscure (10-12). It has been determined that the identification of ARF etiology in immunocompromised patients currently contributes extensively to the survival rates of these patients. Recently, Azoulay et al. (13) conducted a large, multinational prospective cohort study named the Efraim study, in which 1,611 critically ill immunocompromised patients with ARF were enrolled. They compared the intubation rate between four groups: standard oxygen only, HFNC only, NIV only, and both HFNC + NIV. Meanwhile, they also included patients who received firstline invasive mechanical ventilation (IMV) and all-cause hospital mortality rates were compared between these groups. The study illustrated that the use of NIV did not impact outcomes. Although HFNC reduced the intubation rate, it did not influence all-cause hospital mortality. However, more importantly, they found that the etiology of ARF had an impact on hospital mortality, acting as a vital confounder in the association between oxygenation strategy and mortality, and the study proved that patients with undetermined ARF have a very high mortality rate.