BACKGROUND: Options for removing cerumen include the use of a ceruminolytic, a curette, irrigation, or a combination. Irrigation and mechanical extraction carry the risk of patient discomfort, ossicle disruption, trauma, and infection. Ceruminolytics used in practice include water, sodium bicarbonate, hydrogen or carbamide peroxide, mineral or olive oil, glycerin, triethanolamine oleate, and propylene glycol. Although docusate has been used empirically, only in vitro data are available to support its use. The authors of this study evaluated the comparative efficacy of docusate and triethanolamine polypeptide for acute earwax removal.
POPULATION STUDIED: Fifty adult and pediatric patients from a university-based emergency department were enrolled on a convenience basis. The participants were older than 1 year, had a medical condition requiring tympanic membrane visualization, and had partially or totally obscured tympanic membranes. The sample subjects were 35% female and 26% very young (<5 years). Patients were excluded for known or suspected perforation, overt ear infection, or lack of cooperation.
STUDY DESIGN AND VALIDITY: The study was a randomized double-blind trial. A physician determined tympanic membrane obstruction. The authors reported an interobserver reliability of 79%, but the method of determination was not discussed. A 1-mL dose of either triethanolamine or docusate was placed in the affected ear canal and allowed to remain for 10 to 15 minutes. In an attempt to mask the treatments, doses were placed in opaque syringes to obscure the color difference. If the wax was not removed, the ear was irrigated once or twice with 50 mL normal saline. Overall the study has few faults. One concern is that a convenience sample of patients was used, and allocation may not have been concealed. As a result, the researchers could have chosen either particularly difficult or minor cerumen obstructions when enrolling patients in the study. The wide age range probably would not affect study results, because age does not affect cerumen quantity or quality.
OUTCOMES MEASURED: The main outcome measure was the percentage of tympanic membranes totally visualized with or without saline irrigation. The adverse events subjectively reported by patients were also recorded.
RESULTS: Immediately after ceruminolytic instillation there was no difference between the 2 treatments. However, after 2 irrigations with normal saline, complete clearing was achieved in 82% of the docusate-treated patients and 35% of the triethanolamine-treated patients (difference=47%; 95% confidence interval [CI], 22%-71%). In other words, every other patient treated with docusate instead of triethanolamine would have benefited (number needed to treat=2.13). Although this difference was markedly greater in children younger than 5 years (difference=90; 95% CI, 51%-100%), there were only 4 very young children who received triethanolamine. No adverse events were reported.
Docusate is superior to triethanolamine polypeptide for acute earwax removal in the office, especially in children younger than 5 years. This study was not designed to evaluate the efficacy of ceruminolytics on a chronic basis. Generic docusate liquid is less expensive than triethanolamine polypeptide. One pint (480 doses) costs approximately $7.00 compared with $2.50 for 15 mL of generic triethanolamine polypeptide. Clinicians should use the liquid formulation, not the syrup.