Effects of N95 Masks on Cerebral Oxygen Saturation and End-Tidal Carbon Dioxide Partial Pressure in Healthcare Workers

Background: Healthcare workers must wear masks throughout their shifts, especially those in operating rooms for long periods. Objectives: This study evaluated the effects of wearing N95 masks on blood and cerebral oxygen saturation levels for three hours. Methods: The present case-control study enrolled 20 operating room workers wearing N95 masks. Their blood oxygen saturation (SaO2), end-tidal carbon dioxide partial pressure (PETCO2), and right- and left-sided cerebral oxygenation (rSO2) were measured in the beginning (0 h) and after wearing N95 masks for one and three hours. Results: Wearing a mask affected PETCO2, rSO2, and pulse rate and caused fatigue and lightheadedness in some cases. The participants' mean PETCO2 increased significantly, from 32 mmHg before putting on a mask to 38 mmHg after wearing it for three hours (P < 0.05). No significant change was observed in the participants' mean rSO2, though changes in their rSO2 levels were recorded (P > 0.05). Conclusions: We showed evidence of changes in different physiology parameters due to using masks for 1 to 3 h. Notably, wearing an N95 mask increased end-tidal carbon dioxide partial pressure and decreased cerebral oxygen saturation in individual cases, not all cases.