Background: During the Coronavirus disease 2019 (COVID-19) pandemic, wearing facemasks became obligatory worldwide. Objectives: The objective of this study was to evaluate the effects of facemasks on gas exchange. Methods: Healthy adults were assessed at rest and during slow and brisk 5-minute walks, with and without masks. We monitored O2 saturation, end-tidal carbon dioxide (EtCO2), and heart and respiratory rates. Participants graded their subjective difficulty and completed individual sensations questionnaires. Results: Twenty-one participants with a median age of 38 years (range, 29–57 years) were recruited. At rest, all vital signs remained normal, without and with masks. However, during slow and brisk walks, EtCO2 increased; the rise was significantly higher while wearing masks: slow walk, mean EtCO2 (mmHg) change +4.5 ± 2.4 versus +2.9 ± 2.3, P = .004; brisk walk EtCO2 change +8.4 ± 3.0 versus +6.2 ± 4.0, P = .009, with and without masks, respectively. Wearing masks was also associated with higher proportions of participant hypercarbia (EtCO2 range, 46–49 mmHg) compared with walking without masks, though this was only partially significant. Mean O2-saturation remained stable (98%) while walking without masks but decreased by 1.2 % ± 2.2 while walking briskly with a mask ( P = .01). Mild desaturation (O2 range, 93% to 96%) was noted during brisk walks among 43% of participants with masks, compared with only 14% without masks ( P = .08). Borg's scale significantly increased while walking with a mask, for both slow and brisk walks ( P < .001). Sensations of difficulty breathing and shortness of breath were more common while walking with masks. Conclusion: While important to prevent viral spread, wearing facemasks during brisk 5-minute walks might be associated with mild hypercarbia and desaturation. The clinical significance of these minor gas exchange abnormalities is unclear and should be further investigated.

中文翻译：

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快走时戴口罩的影响：COVID-19 困境


背景：2019 年冠状病毒病 (COVID-19) 大流行期间，全球范围内必须佩戴口罩。目的：本研究的目的是评估面罩对气体交换的影响。方法：对健康成年人在休息时以及佩戴或不佩戴口罩的 5 分钟慢走和快走时进行评估。我们监测了 O2 饱和度、呼气末二氧化碳 (EtCO2) 以及心率和呼吸频率。参与者对他们的主观难度进行评分并完成个人感觉调查问卷。结果：招募了 21 名平均年龄为 38 岁（范围 29-57 岁）的参与者。休息时，无论戴口罩还是戴口罩，所有生命体征均保持正常。然而，在慢速和快走时，EtCO2 会增加；戴口罩时上升幅度显着更高：缓慢行走，平均 EtCO2 (mmHg) 变化 +4.5 ± 2.4 对比 +2.9 ± 2.3，P = .004；快走时戴口罩和不戴口罩时，EtCO2 变化分别为 +8.4 ± 3.0 与 +6.2 ± 4.0，P = .009。与不戴口罩行走相比，戴口罩还与较高比例的参与者高碳酸血症（EtCO2 范围，46-49 mmHg）相关，尽管这只是部分显着。不戴口罩行走时，平均氧饱和度保持稳定 (98%)，但戴口罩快步行走时，平均氧饱和度下降 1.2% ± 2.2 (P = .01)。 43% 戴口罩的参与者在快走时注意到轻度去饱和（氧气范围，93% 至 96%），而不戴口罩的参与者只有 14% (P = .08)。戴着面罩行走时，无论是慢走还是快走，Borg 的评分均显着增加 (P < .001)。戴着口罩行走时，呼吸困难和气短的感觉更为常见。 结论：虽然对于防止病毒传播很重要，但在 5 分钟快走时戴口罩可能会导致轻度高碳酸血症和饱和度降低。这些轻微气体交换异常的临床意义尚不清楚，应进一步研究。