In immunocompromised patients, acute respiratory failure (ARF) is prevalent. Low/intermediate-flow oxygen devices have various limitations, including poor humidification and heating up of the inspired gas, or restricted FiO2, implying inefficient therapeutic treatment. Immunocompromised patients are more likely to develop ARF than unselected patients, and ARF is associated with a twofold increase in critical care unit or hospital mortality. As a result, reducing the need for intubation through improved oxygenation and breathing procedures has emerged as a significant focus of treatment in this group.

High-flow treatment (HFT), which can give up to 60 to 70 L/min of FiO2 regulated, heated, and humidified oxygen, appears to be a promising alternative to noninvasive ventilation. HFT benefits are explained by a variety of processes, including dead space washout, reduced oxygen dilution and nasopharyngeal resistance, more consistent FiO2 delivery, a moderate positive end-expiratory pressure effect that may induce alveolar recruitment, and reduced labor of breathing. To present, retrospective and prospective investigations in immunocompromised patients indicate that HFT is well-tolerated, relieves respiratory distress symptoms, and increases oxygenation. Furthermore, as compared to noninvasive ventilation, it may be associated with a reduction in intubation and mortality. Finally, HFT appears to be a safe alternative to noninvasive ventilation when it comes to preventing respiratory symptoms and eventual intubation during fiberoptic bronchoscopy and bronchoalveolar lavage. 

Large prospective randomized controlled studies done exclusively in immunocompromised patients are needed to confirm these potential advantages of HFT in immunocompromised patients.