The value of fentanyl/diazepam anesthesia for experimental operations and recordings of compound action potentials in the guinea pig cochlea.

Fentanyl/diazepam anesthesia is an appropriate combination for surgical operations on the guinea pig, since it ensures definitive anesthesia and analgesia without respiratory depression. Comparative investigations with pentobarbital and urethane were carried out to check their applicability for electrocochleographic recordings. We found that fentanyl/diazepam combination anesthesia is more suitable for electrocochleographic investigations than pentobarbital. We were thereby able to prove that pentobarbital has an attenuating effect on electrocochleographic recordings in contrast to the findings reported in the available literature. For this reason, and because the lowest rates of animal morbidity occurred with fentanyl/diazepam, this combination anesthesia should be used preferentially for electrophysiological experiments in guinea pigs.