Efficacy of nitrous oxide, halothane, ether and spinal anaesthesia on hearing acuity and middle ear pressure

ABSTRACT

A prospective study was executed on 80 patients with 160 healthy ears to detect the efficacy of different anaesthetic agents and techniques on middle ear pressure and hearing acuity. The patients were randomly divided into 4 equal groups according to the received anaesthetic; nitrous oxide, halothane or ether general anesthesia and spinal anaesthesia respectively. Tympanograms and audiograms were done prior to, during and after the operation for every case. Significant middle ear pressure changes were recorded during the operation and 30 minutes subsequent to cessation of nitrous oxide anaesthesia. Moreover, significant hearing impairment especially at low frequencies were detected in all patients of group I who received nitrous oxide anaesthesia, and in 50% of cases of group IV who were anaesthetized spinally. On the other hand, halothane and ether anaesthesia had no effect on neither the hearing acuity, nor the middle ear pressure