title: Electroretinogram as a possible monitor of anesthetic depth.
abstract: The effects of volatile anesthetics, i.e., methoxyflurane, halothane and enflurane, on the electroretinogram (ERG) were studied in 15 albino rabbits. The ERG was analyzed in terms of the a-wave, and the first oscillatory component (01) in the b-wave. The 01 peak latency showed a significant dose-related prolongation when anesthetic end-tidal concentrations were in excess of 0.8 minimum alveolar concentration (MAC). One MAC, a measure of anesthetic potency, is the end-tidal concentration of an anesthetic at 1 atmosphere that induces immobility in 50% of animals against a noxious stimulus. The amplitudes of the a-wave and the 01 decreased in dose-dependent manners, but their changes were less striking than those of the 01 latency. The peak latency of the a-wave remained unchanged. We conclude that the 01 peak latency is a useful monitor of the depth of inhalational anesthesia.
mesh_terms: D000758:Anesthesia; D000818:Animals; D004596:Electroretinography; D004737:Enflurane; D006221:Halothane; D008733:Methoxyflurane; D008991:Monitoring, Physiologic / Q000379:methods*; D011817:Rabbits
chemical_list: D008733:Methoxyflurane; D004737:Enflurane; D006221:Halothane