A new oxygen mask, OxyMask (Southmedic Inc, Canada), has gained popularity despite limited clinical performance data. We compared FiO2 delivery of the OxyMask to other common devices over a range of ventilatory patterns.
Oxygen mask performance was assessed on a model consisting of a mannequin head with its trachea connected to a two compartment lung model to simulate spontaneous breathing. FiO2 and ventilatory patterns were measured at the trachea. Expiratory gasses were routed away from the analyzers and expelled into the room 20 feet away. Each mask was evaluated at oxygen flows of 5, 10, and 15 L/min over a VE range of 3–13 L/min. A nasal cannula and OxyMask were also compared at 2 L/min.
There was no difference in simulated breathing between groups. At VE ≤; 5 L/min there were no differences in FiO2 among the devices at equivalent oxygen flows. At VE between 5–8 L/min, FiO2 was significantly greater with the OxyMask than the simple mask at oxygen flows of 5, 10, and 15 L/min (56.8 vs 52.4%, 71.3 vs 57.7%, 74.1 vs 67.8%, respectively). At VE > 8 L/min the OxyMask delivered more FiO2 at 10 and 15 L/min (58.1 vs 47.8%, 63.4 vs 56.7%, respectively). Maximal FiO2 for both the simple mask and the OxyMask was 80% at flows of 10 and 15 L/min when VE was lowest. The FiO2 range of the OxyMask at 2 L/min was 29–57% and at 5 L/min was 40–67%.
Only at moderate and high VE did the OxyMask deliver a greater FiO2 than the simple mask at oxygen flows of 10 and 15 L/min. At low oxygen flows, moderate to high FiO2 may be delivered with the OxyMask.
The OxyMask provides a wide range of FiO2 dependent on the oxygen flow rate and ventilatory pattern. This mask should be used cautiously in patients with CO2 retention.
David Sonetti, No Financial Disclosure Information; No Product/Research Disclosure Information