The Impact of Combining Surgical and Cloth Masks on End-Tidal Carbon Dioxide Levels in Medical Students

The Impact of Combining Surgical and Cloth Masks on End-Tidal Carbon Dioxide Levels in Medical Students. During the COVID-19 pandemic, layering multiple masks has been a common practice, with the expectation of enhancing their effectiveness in preventing COVID-19 transmission. However, this practice could lead to CO2 retention. This study sought to measure changes in the End-Tidal CO2 (EtCO2) level when surgical and cloth masks were layered and worn by medical students. This study used the time series method and included 36 non-COVID-19 medical students selected through a simple random sampling process. The participants were divided into two equal groups: an intervention group (wearing surgical and cloth masks) and a control group (not wearing masks). EtCO2 data was collected using a capnograph at five different time intervals (0, 30th, 60th, 90th, and 120th minutes) and was subjected to a normality test using the Kolmogorov-Smirnov test. The Independent Sample t-test was used for normally distributed data to compare the differences in EtCO2 changes between the two groups, and the Mann-Whitney test was used for non-normally distributed data. Our study showed that there was no significant difference in the EtCO2 with p>0.05 in the 30th (p=0.575), 60th (p=0.461), 90th (p=0.882) and 120th minutes (p=0.547) between the control and intervention groups. Layering surgical and cloth masks for 120 minutes did not result in excessive CO2 retention. Further research is required to evaluate the efficacy and safety of this practice for extended periods and in individuals with pre-existing respiratory conditions.