“Thirty randomized participants (mean [SD] age, 26.1 [2.9] years; 15 women [50%]) completed the study. Wearing the N95 mask resulted in reduced respiration rate and oxygen saturation by pulse oximetry (Spo2) within 1 hour, with elevated heart rate (mean change, 3.8 beats/min [95% CI, 2.6-5.1 beats/min]) 2 hours later until mask off at 22:00. During the light-intensity exercise at 11:00, mask-induced cardiopulmonary stress was further increased, as heart rate (mean change, 7.8 beats/min [95% CI, 5.3-10.2 beats/min]) and blood pressure (systolic: mean change, 6.1 mm Hg [95% CI, 0.6-11.5 mm Hg]; diastolic: mean change, 5.0 mm Hg [95% CI, 0.3-9.6 mm Hg]) increased, while respiration rate (mean change, −4.3 breaths/min [95% CI, −6.4 to 2.3 breaths/min]) and Spo2 (mean change, −0.66% [95% CI, −1.0% to 0.3%]) decreased. Energy expenditure (mean change, 0.5 kJ [95% CI, 0.2-0.8] kJ) and fat oxidation (mean change, 0.01 g/min [95% CI, −0.01 to 0.03 g/min]) were elevated at 11:00. After the 14-hour masked intervention, venous blood pH decreased, and calculated arterial pH showed a decreasing trend. Metanephrine and normetanephrine levels were increased. Participants also reported increased overall discomfort with the N95 mask.
The findings contribute to existing literature by demonstrating that wearing the N95 mask for 14 hours significantly affected the physiological, biochemical, and perception parameters.4,5 The effect was primarily initiated by increased respiratory resistance and subsequent decreased blood oxygen and pH, which contributed to sympathoadrenal system activation and epinephrine as well as norepinephrine secretion elevation. The extra hormones elicited a compensatory increase in heart rate and blood pressure. Although healthy individuals can compensate for this cardiopulmonary overload, other populations, such as elderly individuals, children, and those with cardiopulmonary diseases, may experience compromised compensation. Chronic cardiopulmonary stress may also increase cardiovascular diseases and overall mortality.6 However, the study was limited to only 30 young healthy participants in a laboratory setting; further investigation is needed to explore the effects of different masks on various populations in clinical settings.“
Bao RNing GSun YPan SWang W. Evaluation of Mask-Induced Cardiopulmonary Stress: A Randomized Crossover Trial. JAMA Netw Open. 2023;6(6):e2317023. doi:10.1001/jamanetworkopen.2023.17023.
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2805809
