Department of Physiology, All India Institute of Medical Sciences, New Delhi, India.
Ind Health. 2023 Apr 1;61(2):125-133. doi: 10.2486/indhealth.2021-0279. Epub 2022 Apr 20.
N95 masks filter 95% of the small particles and respiratory droplets (>0.3 µm diameter). Therefore, they are widely used both by general public and health workers during pandemic. When physical activity or exercise is performed wearing N95 mask, it induces hypercapnic environment. The heat burden is also increased leading to discomfort and reduced compliance. This study was done to compare physiological effects and subjective perceptions while wearing N95 mask and powered air-purifying respirator (PAPR) (2 fans, N95 filter) during incremental exercise. ECG, respiratory movement, SpO temperature inside the mask were recorded and perception of discomfort was also assessed. Heart rate variability (HRV) values during baseline were within normal limits in both the mask conditions signifying that cardiac autonomic tone is comparable. During incremental exercise, fall in SpO was significantly lesser in PAPR as compared to N95 mask at 60-70% and 70-80% of maximum achievable heart rate. The temperatures inside both the mask conditions were significantly higher than ambient temperature. The scores of humid, hot, breath resistance and fatigue were significantly lower in PAPR than N95 mask. In conditions where prolonged use of mask is required with strenuous physical exertion or exercise, PAPR could be preferred over N95 mask.
N95 口罩能过滤 95%的小颗粒和呼吸飞沫（直径>0.3 µm）。因此，在大流行期间，N95 口罩被普通民众和卫生工作者广泛使用。当佩戴 N95 口罩进行体育活动或运动时，会导致体内二氧化碳蓄积。热量负荷也会增加，导致不适和降低顺应性。本研究旨在比较在递增运动期间佩戴 N95 口罩和动力空气净化呼吸器（PAPR）（2 个风扇，N95 过滤器）的生理效应和主观感受。记录心电图、呼吸运动、口罩内的 SpO2 温度，并评估不适感。在两种口罩条件下，静息时的心率变异性（HRV）值均在正常范围内，表明心脏自主神经张力相当。在递增运动期间，与 N95 口罩相比，PAPR 在达到最大心率的 60-70%和 70-80%时，SpO2 的下降明显较少。两种口罩条件下的内部温度均明显高于环境温度。在湿度、热度、呼吸阻力和疲劳方面，PAPR 的评分均明显低于 N95 口罩。在需要长时间佩戴口罩并进行剧烈体力活动或运动的情况下，PAPR 可能优于 N95 口罩。
