A prospective observational study on the evaluation of the risk of transmission due to droplets and aerosols during esophagogastroduodenoscopy and the usefulness of extraoral suction devices

ABSTRACT

Introduction: Health care workers are at risk of infection due to the global pandemic of COVID-19, caused by severe acute respiratory syndrome coronavirus 2. Since aerosol are generated during endoscopic procedure, medical staff need to take various countermeasures including standard precautions. However, the details of the aerosol generation during endoscopic procedure are not known. Also, changes in contamination of the environment around patients and equipment before and after the endoscopic procedure have not been clarified. Aims & Methods: We aimed to prospectively evaluate the size and number of the sprayed droplets and aerosol and where they are sprayed during esophagogastroduodenoscopy (EGD) procedure and the changes in contamination of the environment around the patient and equipment before and after EGD procedure. We also evaluated the effect of extraoral suction devices (Free arm arteo®, TOKYO GIKEN, INC.). EGD procedures were performed with the patient in the left lateral position, using a flexible video gastrointestinal scope (GIF-H290Z, H260Z, Olympus Corporation). For aerosol generation, particle counters (KC-01E®, RION CO., LTD.) were placed at two locations, 15 cm from the patient's mouth (Mouth side) and at the channel of the endoscope (Channel side), and the number of particles of 0.3, 0.5, 1.0, 2.0, and 5.0 μm was measured. For the number of particles, the rate of increase was evaluated. Contamination of the environment was assessed using ATP hygiene monitoring tests (Lumitester®, Kikkoman Biochemifa Co., Ltd.). This test was performed at a total of 18 locations, and changes before and after EGD procedures were evaluated. The details of the 18 locations are as follows. 7 locations near the patient (the face shield of the doctor and nurse, the doctor's right and left hands, and three point of the endoscopic equipment, i.e. monitor of endoscope, surface of the video system, under the endoscope tower), 8 locations 1.5 m from the patient (8 locations evenly spaced around the patient), and 3 locations further away (the walls of the endoscopy room) The effect of using an extraoral suction device was also evaluated. This device have air flow rate of 3,000L/min and was placed above the patient's head. Results: From Fe. 12, 2021 to Apr. 15, 2021, 22 patients were recruited into the study. In terms of aerosol generation, both at the Mouth side and the Channel side, high rates of increase were observed at 1.0, 2.0, and 5.0 μm. In the comparison between the Mouth side and the Channel side, the maximum increase rate was higher in the Channel side than in the Mouth side at 1.0 and 2.0 μm. These results did not change depending on an extraoral suction device. In terms of contamination of the environment, ATP hygiene monitoring tests were significantly elevated at near the patient (the face shield of the nurse, the doctor's right hands, and a point of the under the endoscope tower as well as two locations, 1.5 m from the patient (In front of the patient, 45 degrees dorsal to the patient's head). And, the extraoral suction device could reduce points that the number of ATP hygiene was significantly elevated, except for near patients. Conclusion: During EGD, aerosol of 1.0 and 2.0 μm were mainly dispersed, and the Channel side tended to have more droplets and aerosol than the Mouth side. These results indicated that droplets and aerosol are dispersed not only from the patient's mouth but also from the channel of the endoscope. The extraoral suction device could reduce contamination of the endoscopic procedure room due to EGD, except for near patients.