Abstract
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 (SaO(2)), end-tidal carbon dioxide partial pressure (P(ET)CO(2)), and right- and left-sided cerebral regional oxygen saturation (rSO(2)) were measured in the beginning (0 h) and after wearing N95 masks for one and three hours. RESULTS: Wearing a mask affected P(ET)CO(2), rSO(2), and pulse rate and caused fatigue and lightheadedness in some cases. The participants' mean P(ET)CO(2) 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 rSO(2), though changes in their rSO(2) 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.