Kyaw Sandy, Johns Moira, Lim Rimen, Stewart Warren C, Rojas Natalia, Thambiraj Solomon R, Shehabi Yahya, Arora Sumesh
Department of Intensive Care Medicine, Prince of Wales Hospital, Sydney, New South Wales, Australia.
Clinical School of Medicine, University of New South Wales.
Indian J Crit Care Med. 2021 Sep;25(9):976-980. doi: 10.5005/jp-journals-10071-23947.
Fogging of eyeglasses while wearing N95 respirators is common. It is commonly held that the N95 respirator has a poor fit if there is fogging of eyeglasses. We conducted this prospective, pilot study to determine if fogging of eyeglasses predicts poor fit of N95 respirator.
Seventy volunteer healthcare workers from a tertiary intensive care unit in Sydney, Australia participated. The participants donned one of the following N95 respirators: three-panel flat-fold respirator (3M 1870), cup-shaped respirator (3M 1860), or a duckbill respirator. After a satisfactory "user seal check" as recommended by the manufacturer, the participants donned eyeglasses and checked for fogging. A quantitative fit test (QnFT) of the respirator was then performed (using PortaCount Respirator Fit Tester 8048, TSI Inc., Minnesota, USA). A fit factor of <100 on quantitative fit testing indicates poor fit. The sensitivity and specificity for fogging of eyeglasses (index test) to predict the poor fit of N95 respirator was determined, compared to QnFT (gold standard test).
Fogging of eyeglasses as a predictor of poor respirator fit (i.e., fit factor <100 on QnFT) had sensitivity of 71% (95% CI, 54-85%) and specificity 46% (95% CI, 29-63%). The odds ratio of fogging as a predictor for poor fit was 2.10 (95% CI, 0.78-5.67), with a two-tailed -value of 0.22 (not significant). The receiver operating characteristic curve for fogging of eyeglasses as a diagnostic test had the area under the curve of 0.59.
Fogging of eyeglasses is neither a sensitive nor a specific predictor for poor fit of N95 respirators.
Kyaw S, Johns M, Lim R, Stewart WC, Rojas N, Thambiraj SR, Prediction of N95 Respirator Fit from Fogging of Eyeglasses: A Pilot Study. Indian J Crit Care Med 2021;25(9):976-980.
佩戴N95口罩时眼镜起雾是常见现象。人们普遍认为，如果眼镜起雾，N95口罩的贴合度就较差。我们开展了这项前瞻性试点研究，以确定眼镜起雾是否预示着N95口罩贴合度差。
来自澳大利亚悉尼一家三级重症监护病房的70名医护人员志愿者参与了研究。参与者佩戴以下N95口罩之一：三层平面折叠式口罩（3M 1870）、杯形口罩（3M 1860）或鸭嘴形口罩。按照制造商的建议进行令人满意的“用户密封检查”后，参与者戴上眼镜并检查是否起雾。然后对口罩进行定量贴合度测试（QnFT）（使用美国明尼苏达州TSI公司的PortaCount Respirator Fit Tester 8048）。定量贴合度测试中贴合系数<100表明贴合度差。与QnFT（金标准测试）相比，确定了眼镜起雾（指标测试）预测N95口罩贴合度差的敏感性和特异性。
眼镜起雾作为口罩贴合度差的预测指标（即QnFT中贴合系数<100），敏感性为71%（95%CI，54 - 85%），特异性为46%（95%CI，29 - 63%）。起雾作为贴合度差的预测指标的比值比为2.10（95%CI，0.78 - 5.67），双侧P值为0.22（无统计学意义）。眼镜起雾作为诊断测试的受试者工作特征曲线下面积为0.59。
眼镜起雾既不是N95口罩贴合度差的敏感预测指标，也不是特异预测指标。
觉梭、约翰斯、林、斯图尔特·W·C、罗哈斯、坦比拉伊·S·R，《从眼镜起雾预测N95口罩贴合度：一项试点研究》。《印度重症监护医学杂志》2021年；25(9):976 - 980。
