Table 2 Results for chlorhexidine and ethanol-based antiseptic preparations
From: Systematic review of ototoxic pre-surgical antiseptic preparations – what is the evidence?
Author, Year | Population | Intervention | Control | Outcomes |
|---|---|---|---|---|
R. Perez, 2000 [10] | 25 Sand Rats | a) Solutions tested Povidone-iodine 10% solution b) Chlorhexidine Gluconate 0.5% solution c) Ethyl alcohol in 70% aqueous solution Exposure time 3 days ABR and vestibular evoked potentials (VsEP) testing 8 days after initial exposure | a) Saline as negative control b) Gentamycin as positive control | a) ABR not present after Chlorhexidine Gluconate 0.5% solution b) ABR present at baseline after application of Povidone-iodine 10% solution, VsEP present in all test animals c) No ABR or VsEP recorded in 2/5 animals after Ethyl alcohol 70% solution, 3/5 had elevated thresholds (70-80 dB) d) Erythema and oedema noted in 5/5 middle ear cavities after application of ethyl alcohol |
Y. Igarashi, 1985 [9] | 12 Cats | Solutions tested a) Chlorhexidine Gluconate 2.0% b) Chlorhexidine Gluconate 0.05% Exposure time every 2 days × 3 applications. Histologic examination at 7 days and 4 weeks | Contralateral ear to the experimental ear | a) Gross examination of middle ear space showed thick serous fluid retention in12/12 animals b) Histological examination showed loss of outer hair less in lower cochlear turns, with 85% loss near the round window after application of Chlorhexidine gluconate 2% solutions c) Little to no damage to the outer hair cells seen with Chlorhexidine 0.05% solution |
J. Aursnes, 1981 [14] | 48 Guinea Pigs | Solutions tested a) Chlorhexidine 0.1% in 70% alcohol b) Chlorhexidine 0.1% in aqua. Solution c) Chlorhexidine 0.5% in 70% alcohol d) Chlorhexidine 0.5% in aqua. Solution Exposure time 10, 30 and 60 mins. Histological examination done after 2, 3, 4 or 10 weeks post exposure | Contralateral ear to experimental ear | a) Gross examination showed extensive fibrotic tissue after 60 min exposure time b) Greater degree of fibrosis with 0.5% solution compared to 0.1% solution c) Total destruction of outer hair cells seen 3 weeks after exposure with Chlorhexidine 0.5% in 70% alcohol |
H. G. Galle, 1986 [18] | 2 Guinea Pigs | Solution tested a) Savlon™* in 1:100 dilution Cochlear microphonics, histologic examination and behaviour measured at 24 h and 48 h after exposure * Composed of 1.5% Chlorhexidine Gluconate and 0.15% cetrimide (quaternary ammonium compound) | Contralateral ear to experimental ear | a) Severe vestibular dysfunction based on behaviour but effects diminished after 24 h and again after 48 h b) Hearing thresholds increased from baseline of 35 dB to 70 dB SPL |
T. Morizono, 1981 [11] | 23 Chinchillas | Solutions tested a) Ethanol in contractions of 0.1, 1, 3, 10, 25, 50, 70 and 100% Exposure time was 10mins, 24 h. Cochlear mircophonics and endocochlear Action potentials tested | Contralateral ear to experimental ear | a) Variable outcomes with some animals showing decrease in all frequencies tested with cochlear microphonics with 3% solutions while others showed no deficits with 50% solution |