The purpose of the prospective clinical study described in this article by Bhattacharyya and Kepnes was to determine whether high-level disinfection renders flexible fiberoptic laryngoscopes free of nonviral infectious microorganisms. The investigation was conducted in an outpatient otolaryngology clinic staff ed by five general otolaryngologists 5 days a week. The high-level disinfection protocol used routinely in the clinic to reprocess laryngoscopes consisted of the following steps: rinsing with tap water and wiping with gauze, soaking in enzymatic detergent for 5 minutes and rinsing with tap water, soaking in glutaraldehyde for 20 minutes and rinsing with tap water, and storage in an upright holder. The EndoSheath® Technology was not used in any of the endoscopic procedures.
For the clinical study, samples for culture were obtained from six laryngoscopes after high level disinfection at the beginning, middle, and end of a work day. Control samples were obtained by directly contaminating the endoscopes with saliva.
Of the 48 samples obtained from “in use” but disinfected endoscopes, 1 yielded positive culture results (for a mold species). All control samples were positive for oral flora. The difference between the in-use and control samples with respect to the positive culture rate for all microorganisms was significant (P < 0.001). The confidence interval for the chance of a laryngoscope harboring any microorganism after the disinfection procedure was 0.11% to 11.6%.
Bhattacharyya and Kepnes concluded that their findings indicate that high-level disinfection provides reasonably effective decontamination of laryngoscopes but cannot remove all contaminants. They also noted that high-level disinfection is time consuming, potentially damaging to endoscopes, often hazardous to health care personnel performing the procedure, and only as effective as the personnel managing it. Thus, according to the researchers, other options for managing the cleaning of flexible fiberoptic endoscopes should be considered, including covering the instruments with a sheath (EndoSheath® Technology, Vision Sciences, Natick, MA) during use. Bhattacharyya and Kepnes commented that the disposable sheaths are expensive (per use) and increase endoscope diameter (which may make passage difficult in certain patients) but that the use of EndoSheath® Technology avoids the need for immersion-type disinfection and reduces the wear on endoscopes that results from repeated exposure to chemical solvents.