Chlorhexidine is a common antiseptic used to prevent surgical infection. However, its exposure to the middle ear may lead to deafness. The mechanisms of the ototoxicity of chlorhexidine are reviewed. The importance of recognizing its toxicity cannot be overstated in preventing injury to patients undergoing ear surgery.
A systematic literature search was performed looking at data from human and animal studies. Search engines included MEDLINE, EMBASE, The Cochrane Library, CENTRAL, CINAHL, and Web of Science to November 1, 2010, for relevant studies published in all languages. Two independent reviewers (P.L. and D.D.P.) screened the references from published articles for additional relevant studies. Medical Subject Headings and key words including intervention (chlorhexidine, antiseptic), exposure (myringoplasty, intratympanic), and adverse effects (sensorineural hearing loss, ototoxicity, vestibular toxicity) were used.
Twelve studies were identified, two of which were non-English and were excluded. Only 2 articles on human subjects and 12 articles on animal models concerning chlorhexidine ototoxicity were identified.
Chlorhexidine in both human studies and animal models demonstrates ototoxicity if it reaches the inner ear. The toxicity of chlorhexidine appears to be related to its concentration and probable contact time with the round window membrane intraoperatively. It is conceivable that the incidence of chlorhexidine toxicity may be higher than stated if unrecognized or has resulted in subsequent medicolegal actions. From the evidence available, safer preparation solutions are available without clinical risks for ototoxicity should surgeons continue with this practice.
To conduct a survey of the antiseptic preparations used for ear surgeries among otolaryngologists in Canada.
An electronic survey was sent to active members of the Canadian Society of Otolaryngology-Head and Neck Surgery via e-mail. Questions included the use of antiseptic, choice of preparation solution, duration of preparation, use of a barrier method, and compliance with hospital protocol changes.
The e-mail was received by 253 otolaryngologists, and 85 completed the survey. Four of 85 respondents did not perform tympanoplasty surgery and were not included in the analysis. Of those who performed tympanoplasty (n ?=? 81), 78 of the 81 respondents (96%) used an antiseptic preparation solution at surgery, whereas 3 respondents (4%) did not. Sixty-six of the 77 respondents (86%) used aqueous povidone-iodine, 4 (5%) used a chlorhexidine-based preparation, 3 (4%) used an alcohol-based solution, 3 (4%) used others, and 1 answered "I don't know." Thirty-eight of 75 (29%) respondents used a barrier method, 23 (31%) answered "always," 18 (24%) answered "sometimes," and 5 (7%) answered "I don't know." When asked if they would comply with a hypothetical hospital policy to use chlorhexidine in ear surgery, 15 of 79 (19%) respondents agreed, whereas 64 (81%) disagreed. Among the aqueous povidone-iodine users (n ?=? 66), 7 (11%) agreed to change to chlorhexidine.
There is a wide variation in practice in the use of surgical preparation solution among otolaryngologists performing ear surgery. Surgeons must be vigilant to avoid ototoxicity. A national society consensus on appropriate preparation solutions for ear surgery would minimize patients' risk and minimize future medicolegal actions.