MUSCLE WEAKNESS DURING TRICAINE ANESTHESIA

An isolated preparation of tadpole tail muscle was used to assess the peripheral effects of tricaine (3-aminobenzoic acid ethyl ester) at an esthetic concentrations and under physiological conditions, The drug e ffect oil the electrically-evoked twitch was tested using short-pulse durations that elicited synaptically mediated effects or longer-durati on pulses that stimulated the. muscle directly, Tricaine reduced both types of response at anesthetic. and even subanesthetic concentrations , At steady state concentrations that produced surgical anesthesia in vivo, tricaine reduced the directly evoked response by about half. It is concluded that tricaine anesthesia has a pronounced peripheral effe ct on neuromuscular function and that direct effect(s) on muscle are a major component.