Reservoir Masks Are Essential for Critically Ill Patients

Supplemental oxygen is fundamental to the care of critically ill patients, and the delivery method is key. The amount of oxygen actually delivered depends on the flow rate and how fast and deeply the patient breathes. In the absence of tachypnea, the expiratory pause is sufficient to allow accumulation of oxygen in the pharynx, even when low-flow devices (e.g., nasal cannula) are used; however, during respiratory distress associated with rapid breathing, the expiratory pause is insufficient to allow oxygen accumulation. Devices with an oxygen reservoir, such as nonrebreathing face masks, can help compensate in such cases. In this study, researchers measured the fraction of inspired oxygen (FiO₂) achieved with different oxygen delivery devic…