Delivered Oxygen Concentrations of Two Nonrebreather Reservoir Masks

High-concentration nonrebreathing reservoir masks are frequently used for patients with hypoxemia but vary in shape, affecting mask fit. Mask fit affects the ability to inhale gas from the reservoir bag during inspiration and therefore makes it difficult to ensure a reliable concentration of oxygen delivered consistently to the patient. The EcoLite reservoir mask (EcoLite, Intersurgical, United Kingdom) reports a more consistent oxygen concentration delivery based on mask fit when compared with other products.

A bench study was conducted comparing the consistency of high oxygen concentration delivery via a conventional reservoir mask (Inspiron, Japan Medicalnext, Japan) and EcoLite. The study was performed using an electronic breathing simulator and a mannequin to simulate spontaneous breathing. Each mask was applied to the mannequin per the product instructions. An oxygen analyzer was placed in the simulated left bronchus, and oxygen was delivered through each mask at increasing flow. The delivered oxygen concentration was recorded for each procedure and measured 3 times.

The EcoLite exhibited higher delivered oxygen concentrations at each oxygen flow and the simulator's inspiratory flow. The cumulative mean oxygen concentration across set parameters was 64% (SD ± 13) for the EcoLite and 50% (SD ± 10) for the Inspiron, with a significant difference (P < .008). Oxygen flow impact on delivered oxygen concentration revealed a difference between the EcoLite and Inspiron of P value > .05.

EcoLite provided an oxygen concentration consistently higher than that of the conventional product observed. This may be attributed to mask fit, valve assembly, and reservoir bag function. These results may impact clinical decisions in product choice and applications. Further studies are needed to assess the clinical impact of this product.