Covering the biopsy hole check valve with "enzymolysis gauze" reduces bacterial contamination in the endoscopy room.

BACKGROUND: Bacterial contamination during colonoscopy is a significant concern, yet few studies have evaluated bacterial aerosols. This study aimed to determine whether covering the biopsy hole check valve with enzymolysis gauze (refers to sterile gauze soaked in a multi-enzyme cleaning solution) reduces bacterial air pollution in endoscopy rooms. AIM: To evaluate the efficacy of an enzymolysis gauze cover in reducing bacterial aerosols from the biopsy valve. METHODS: This prospective, single-blind trial included 80 patients undergoing elective diagnostic colonoscopy. During the procedure, the biopsy hole check valve was either covered or left uncovered with enzymolysis gauze. Air samples (100 L) were collected at a distance of 30 cm from the biopsy hole check valve and approximately 140 cm above the floor using a percussive air sampling instrument. Gram-positive bacteria were cultured on standard 90 mm colimycin nalidixic agar blood plates. The primary outcome measures were bacterial load and species identification. RESULTS: Covering the biopsy hole check valve with enzymolysis gauze reduced bacterial load near the check valve from 50 colony-forming unit (CFU)/m3 [interquartile range (IQR): 30-80] to 20 CFU/m3 (IQR: 10-20). At the end of the procedure each day, covering the valve also decreased bacterial load in the endoscopy room from 35 CFU/m3 (IQR: 33-85) to 10 CFU/m3 (IQR: 5-10). The predominant bacteria identified were Gram-positive cocci. CONCLUSION: Applying enzymolysis gauze to cover the biopsy hole check valve significantly reduces bacterial aerosol contamination in endoscopy rooms during colonoscopy.