Background and aim: During the Coronavirus Disease 2019 pandemic, esophagogastroduodenoscopy (EGD) has been recognized as an aerosol-generating procedure. This study aimed to systematically compare the degree of face shield contamination between endoscopists who performed EGD on patients lying in the left lateral decubitus (LL) and prone positions.

Methods: This is a randomized trial in patients scheduled for EGD between April and June 2020. Eligible 212 patients were randomized with 1:1 allocation. Rapid adenosine triphosphate test was used to determine contamination level using relative light units of greater than 200 as a cutoff value. All eligible patients were randomized to lie in either the LL or prone position during EGD. The primary outcome was the rate of contamination on the endoscopist's face shield.

Results: The majority of patients were female (63%), with a mean age of 60 ± 13 years. Baseline characteristics were comparable between the two groups. There was no face shield contamination after EGD in either group. The number of coughs in the LL group was higher than the prone group (1.38 ± 1.8 vs 0.89 ± 1.4, P = 0.03). The mean differences in relative light units on the face shield before and after EGD in the LL and prone groups were 9.9 ± 20.9 and 4.1 ± 6 (P = 0.008), respectively.

Conclusion: As measured by the adenosine triphosphate test, performing diagnostic EGD does not lead to contamination on the face shield of the endoscopist. However, placing patients in the prone position may further mitigate the risk.