[Evidence summary:] Does the prolonged use of face-masks by HCWs interfere with the respiratory system by inducing oxidative stress and blood oxygen/carbon dioxide imbalance? [v1.0]

Main Points 1.The average face mask does not limit the flow of oxygen to the lungs, even in people with severe lung diseases. 2.For healthy, active people, wearing a face mask during vigorous exercise has minimal effect on arterial or muscle oxygen levels and no effects on exercise performance. 3.WHO advises not to wear masks during vigorous intensity physical activity because masks may reduce the ability to breathe comfortably. 4.Face masks, including N95 respirators, surgical masks and cloth face-mask shave small effect on the work of breathing, blood gases and other physiological parameters during physical activity, even with heavy/maximal exercise. 5.In a study following 10 nurses over two 12-hour shifts, the only negative physiologic change resulting from long-term respiratory protection use was elevated CO2levels, with CO2increasing over time. However, these changes were not clinically relevant. 6.Effects of prolonged mask and respirator use in healthcare settings include headaches, skin sensitivity, acne, itchy nose,and excessive sweating around the mouth. 7.Frequent breaks, improved hydration and rest, skin care, and newly designed, more comfortable masks are recommendations for future management of adverse effects related to prolonged mask use.