Continuous versus intermittent mask use by nurses in COVID times (CIMNIC) – A CUSUM study

Abstract

Objectives: The coronavirus disease 2019 pandemic has reinforced the use of personal protective equipments in healthcare settings. Although filtering face piece 2 respirators provide adequate protection from the aerosolised viral spread, their prolonged use is often associated with subjective discomfort. The study aimed to identify whether an intervening mask-free period is less harmful in terms of discomfort and desaturation when compared against continuous use for 6-h. Material and Methods: This was a prospective and interventional study. A cohort of 87 previously healthy nurses from a multidisciplinary tertiary care hospital were recruited. Study participants were subjected to continuous and intermittent (with 15 min break) mask use, each for a 2-month duration, during their 6-h clinical shifts. Baseline and post-shift oxygen saturation (SpO2) were compared in real time using cumulative sum (CUSUM) statistics. Comfort level was also assessed on a scale of 0–10 in the two groups with 10 subjective parameters. Results: Nurses have experienced a significant drop in SpO2 in both phases with 525 and 984 recordings in continuous and intermittent mask group, respectively. The mean % (2SD) saturation drop in the two groups was 4.688 (39.35) and 1.169 (2.62). The overall discomfort level was more in the continuous phase (8.89 ± 1.610) than in intermittent (7.28 ± 3.216) mask use. CUSUM statistics helped in the real-time monitoring of subjects in the intermittent mask group. Conclusions: Significant adverse health effects in healthcare workers are highlighted using objective and subjective parameters such as desaturation and discomfort levels while using protective face masks. A mask-free period of 15 min, in between their duty shifts, might help reduce the unfavourable effects without compromising efficacy.