Outcomes in immunocompromised patients with acute hypoxemic respiratory failure treated by high-flow nasal oxygen

Purpose: Acute hypoxemic respiratory failure (ARF) is a major challenge in immunocompromised patients, often complicated by severe respiratory distress and organ dysfunction. High-flow nasal oxygen (HFNO) therapy is the standard of care, but data on its effectiveness and outcomes are limited. This study evaluated the outcomes of HFNO in this population, predictors of invasive mechanical ventilation (IMV), and factors associated with 28-day mortality. Methods: We analyzed data from a multicenter cohort of 986 immunocompromised patients with ARF treated with HFNO. Predictive factors for IMV and mortality were assessed using multivariable survival models, and the predictive value of the respiratory rate‑oxygenation (ROX) index for IMV was evaluated. Results: Patients had a median age of 63 years [IQR 54–70], and 66% were male. Primary causes of immunosuppression included hematologic malignancies (55%), solid tumors (30%), and solid-organ transplantation (10%). Bacterial pneumonia (40%) and opportunistic infections (15%) were the most common ARF etiologies. IMV was required in 46% of patients. Day 28 mortality was 33%, with better outcomes for solid-organ transplant recipients compared to hematologic malignancy or solid tumor (70% vs. 48% vs. 51% mortality, respectively). Predictors of IMV included a lower ROX index, higher respiratory rates, and lower PaO₂/FiO₂ ratios. Mortality was highest among patients requiring IMV, particularly those with myeloid malignancies or viral pneumonia. Conclusions: HFNO outcomes in immunocompromised patients with ARF vary widely, influenced by immunosuppression type, ARF etiology, and clinical factors. Optimizing treatment and identifying high-risk patients could improve outcomes. Prospective studies are needed to enhance HFNO strategies.