Low flow nasal oxygen supplementation in addition to non-rebreathing mask: An alternative to high flow nasal cannula oxygenation for acute hypoxemic COVID-19 patients in resource limited settings

Approximately 14% COVID-19 patients, develop acute hypoxic respiratory failure. A high flow nasal cannula device might be preferred to obtain an oxygen saturation above 90% in these cases. In resource limited settings, where high flow nasal cannula is not an option, additional low flow oxygen therapy through nasal prongs could be added to non-rebreathing mask with a reservoir bag. The possible mechanisms of the improved oxygenation could be: 1. improved oxygen-air mixing in large airways, 2. increased oxygen concentration inside the non-rebreathing mask, 3. decrease in rebreathing of carbon-dioxide from the non-rebreathing mask. This method of oxygen supplementation is easy to assemble, cost-effective and helpful in management of acute hypoxemic COVID-19 patients, whenever there is crisis of high flow nasal cannula machine. Its effectiveness needs to be assessed by a randomized controlled trial.