Prospective analysis of the physiological changes caused by prolonged use of N95-type masks

INTRODUCTION: The clinical and physiological effects of long-duration use of N95-type masks without ventilation valves, on health-care workers during the coronavirus disease-2019 (COVID-19) pandemic, were evaluated. METHODS: All volunteering personnel working in operating theater or intensive care unit, using nonventilated N95 type respiratory masks, minimum for a 2-h noninterrupted duration were observed. The partial oxygen saturation (SpO(2)) and heart rate (HR) were recorded before wearing the N95 mask and at 1(st) and 2(nd) h. Volunteers were then questioned for any symptoms. RESULTS: A total of 210 measurements were completed in 42 (24 males and 18 females) eligible volunteers, each having 5 measurements, on different days. The median age was 32.7. Premask, 1(st) h, and 2(nd) h median values for SpO(2) were 99%, 97%, and 96%, respectively (P < 0.001). The median HR was 75 premask, 79 at 1(st) h, and 84/min at 2(nd) h (P < 0.001). A significant difference between all three consecutive measurements of HR was achieved. Statistical difference was only reached between premask and other SpO(2) measurements (1(st) and 2(nd) h). Complaints seen in the group were head ache (36%), shortness of breath (27%), palpitation (18%), and nausea feeling (2%). Two individuals took off their masks to breathe, on 87(th) and 105(th) min, respectively. CONCLUSIONS: Long duration (>1 h) use of N95-type masks causes a significant reduction in SpO(2) measurements and increase in HR. Despite being an essential personal protective equipment in COVID-19 pandemic, it should be used with short intermittent time periods in health-care providers with known heart disease, pulmonary insufficiency, or psychiatric disorders.