Droplet nuclei are generated during colonoscopy and are decreased by the use of carbon dioxide and water immersion technique

• Published in: Digestive endoscopy 2023-01, Vol.35 (1), p.77-85
• Main Authors: Chan, Shannon Melissa, Ma, Tsz Wah, Chu, Simon, Fei, Hon Sok, Futaba, Kaori, Yip, Hon Chi, Teoh, Anthony Yuen Bun, Wong, Martin Chi‐Sang, Ng, Simon Siu Man, Ng, Enders Kwok Wai, Chiu, Philip Wai Yan
• Format: Article
• Language: English
• Subjects: Aerosolized Particles and Droplets; aerosol‐generating procedure; Carbon Dioxide; colonoscopy; Colonoscopy - methods; COVID-19 - prevention & control; COVID‐19; health‐care worker safety; Humans; Immersion; Pandemics; Respiratory Aerosols and Droplets; SARS‐CoV‐2; Water
• ISSN: 0915-5635; 1443-1661
• DOI: 10.1111/den.14387

Objectives The COVID‐19 pandemic has raised concerns on whether colonoscopies (CS) carry a transmission risk. The aim was to determine whether CS are aerosol‐generating procedures. Methods This was a prospective observational trial including all patients undergoing CS at the Prince of Wales Hospital from 1 June to 31 July 2020. Three particle counters were placed 10 cm from each patient’s anus and near the mouth of endoscopists and nurses. The particle counter recorded the number of particles of size 0.3, 0.5, 0.7, 1, 5, and 10 μm. Patient demographics, seniority of endoscopists, use of CO2 and water immersion technique, and air particle count (particles/cubic foot, dCF) were recorded. Multilevel modeling was used to test all the hypotheses with a post‐hoc analysis. Results A total of 117 patients were recruited. During CS, the level of 5 μm and 10 μm were significantly higher than the baseline period (P = 0.002). Procedures performed by trainees had a higher level of aerosols when compared to specialists (0.3 μm, P