Low- versus high-flow oxygen delivery systems in children with lower respiratory infection

Superiority of OxyMaskTM with less carbon dioxide rebreathing in children

Despite the growing importance of oxygen-delivery devices worldwide, there are only a few reports of physiological data on various oxygen masks in children. The possibility of carbon dioxide (CO₂) rebreathing has been a prevalent concern with the use of oxygen-delivery devices. OxyMask Kid^TM (Southmedic Inc. Canada; hereafter OxyMask) is expected to reduce CO₂ rebreathing even at low oxygen flow rates because of its structural features. Biological data using OxyMask in children have not been well investigated. Measured respiratory parameters of OxyMask with those of a simple oxygen mask in healthy children were compared. Ten subjects were enrolled, with a median age of 5.4 years. All subjects used both OxyMask and a simple oxygen mask. The fraction of inspiratory oxygen (F_IO₂), partial pressure of inspiratory CO₂ (P_ICO₂), and partial pressure of end-tidal CO₂ were measured using a sidestream gas-sampling monitor in all subjects. The oxygen flow rate was set at 1, 3, 5, and 10 L/min. F_IO₂ levels were higher with OxyMask than those with the simple oxygen mask at 3 L/min of oxygen. P_ICO₂ levels were significantly lower with OxyMask than those with the simple oxygen mask (1.5 mmHg vs. 3.7 mmHg at 1 L/min, P = 0.005; 1.0 mmHg vs. 2.7 mmHg at 3 L/min, P = 0.005, respectively), whereas P_ICO₂ levels were higher at low oxygen flow rates with both masks.Conclusion: Our results showed that higher F_IO₂ and less CO₂ rebreathing were achieved with OxyMask than those with a simple oxygen mask at low flow rates of oxygen in healthy children. What is Known: • OxyMask is expected to reduce carbon dioxide rebreathing even at low oxygen flow rates because of its structural features. • Efficacy has been demonstrated in experimental models and adult data, but clinical data on the use of the OxyMask in children are limited. What is New: • Higher fraction of inspiratory oxygen and lesser carbon dioxide rebreathing were achieved with OxyMask than with a simple oxygen mask at low flow rates of oxygen in healthy children.