CO₂ narcosis in a COVID-19 patient in prone position due to twisting of reservoir bag of a non-rebreathing mask: a case report

We know that oxygen therapy plays one of the important role for treating hypoxemia and it is widely used across a whole range of specialties and it involves administration of oxygen at concentrations greater than that in ambient air. We are reporting the first case of twisting of reservoir bag on using non-rebreathing face mask for providing supplemental oxygen in awake prone position in a 60 year old male tested COVID-19 positive. To prevent this twisting we recommend if a manufacturer do slight modification in making of these non-breathing face mask by adding a 1-2 cm L- shaped Plastic connector to the neck end of the oxygen reservoir bag. The sudden deflation of these reservoir bag not only increase the dead space, decrease alveolar ventilation but substantially compromised the gas exchange. So any twisting of these non-rebreathing face mask should be avoided. This twisting may compromise the patient condition due to rapid increase in PaCO2 and detrimental in patients with restrictive airway disease. On keeping the patient in prone position the twisting of the reservoir bag frequently occurs and this simple and useful modification may be beneficial for supplementation of oxygen therapy to COVID-19 patients requiring high fractional inspired oxygen concentration.