Effect of ketamine anaesthesia on middle ear pressure in rabbits: a pilot study

Abstract

Objectives: Although most studies about effect of anaesthetics on middle ear pressure were explained with gas effect there are no studies about effect of ketamine on middle ear pressure. The aim of this study was to evaluate the effect of ketamine anaesthesia on middle ear pressure.Methods: Male New Zealand rabbits (n=15), weighing between 2.5-3.2 kg were randomly divided into two groups. Those in Group I (n=9) were anaesthetized by intravenous ketamine 50 mg.kg-1 whilst Group II (n=6) were injected with the same volume of saline. Baseline tympanometry readings were performed on the left and right ears after otoscopy examination and again at 5 and 20 minutes.Results: The change of tympanometric measurements before ketamine, at 5th and 20th minutes of the administration was no statistically significant in both of Group I and II (p>0.05). There was a slightly significant difference at 20th min of administration when ketamine group compared with control group (-55.6±29.5 in Group I; -29.0±33.5 in Group II) (p=0.03).Conclusion:In this study it is concluded that ketamine anaesthesia has no effect on the pressure in middle ear.

Keywords

• ketamine
• tympanometry
• middle ear pressure
• saline
• rabbit