The isolation arm test at upper limb for the study of muscle relaxants sensitivity of human muscle is described. In the healthy adults, succinylcholine 100ug/kg or vecuronium 5~6ug/kg combined with 20ml saline is given intravenously at various sites of injection while the circulation to the arm is occluded with upper arm pneumatic tournique. After injection of muscle relaxants, neuromuscular transmission is then studied by TOF stimulation to ulnar nerve with EMG monitor(ABM, Dates) and changes of twitch response in evoked muscle action potential amplitude from hypothenar muscle are recorded. In the results, twitch height is depressed weakly and slowly but incompletely after muscle relaxant is injected intravenously at cubital fossa, and declines further depression following recovery after the release of upper arm tourniquet occiuded systemic circulation(two stage response). There are not any changes of twitch response while muscle relaxants are given intravenously between upper arm and forearm pneumatic tourniquet. But twitch height is depressed rapidely and completely after muscle relaxants are given intravenously at doris hand under the upper arm or forearm pneumatic tourniquet. Conclusively, twitch response under the isolation arm test is influenced from the site of injection, and in order to obtain the correct assessment of neuromuscular blockade, muscle relaxants will be given intravenously at dorsi hand with forearm pneumatic tourniquet.
Action Potentials ; Adult ; Arm* ; Depression ; Forearm ; Hand ; Humans ; Neuromuscular Blockade ; Succinylcholine ; Tourniquets ; Ulnar Nerve ; Upper Extremity ; Vecuronium Bromide

This technique in the conscious volunteers to study the neuromuscular blockade was described in which two different muscle relaxants of ED95X10(-1) in 20ml 0.9% saline were injected simultaneously into one arm and the contralateral arm below the occlusion site of circulation with tourniquet, and then two different neuromuscular blockades were compared following tourniquet released after 80% twitch depression. The benefits of this technique were obtained as following; 1) Simplicity, saving and safety from easily to set up and using low dose of muscle relaxant. 2) Expected results from pure effects of muscle relaxant without any drug interactions. 3) Time shortening of experimental study. 4) Saving time and experiments from simultaneously comparison of control with study group in one experiment. 5) The study of pure receptor binding with muscle relaxant, since a presumed plasma concentration of muscle relaxants is near or actually zero after release of the tourniquet when fresh blood had flushed the limb. Conclusively bilateral isolated forearm technique is elegant method to study the biophase binding interacted of relaxants and cholinerceptor.
Arm ; Depression ; Drug Interactions ; Extremities ; Forearm* ; Neuromuscular Blockade* ; Neuromuscular Blocking Agents ; Plasma ; Tourniquets ; Volunteers

Recently, since muscle relxants has been used routinely, it is very important to understand the state of muscle relaxation during and after anethesia for safe anesthesia. But it is difficult that all patients have the opportunity to be helped by the auto-recording neuromuscular monitor, because of high in price. Therefore, many anesthesiologists have been using the simple tactile neuromuscular monitor for the evaluation of muscle relaxation, but there are many difference to evaluate for the reponse of muscle contraction by tactile or visual sensation. This study was designed to investigate the method of recording on the response of nerve stimulation from simple tactile neuromuscular monitor. The pressure generated from moving of thumb connected with finger ring lock syringe by ulnar nerve stimulation was transmitted to the invasive blood pressure monitor through the arterial pressure transducer. As a result, this method could record the response of single twitch stimulation, train-of-four stimulation, tetanic stimulation, post-tetanic count and double-burst stimulation displaying in the invasive blood pressure monitor, and was exellent in recording compared with auto-record- ing neuromuscular monitor.
Anesthesia ; Arterial Pressure ; Blood Pressure Monitors ; Fingers ; Humans ; Muscle Contraction ; Muscle Relaxation ; Sensation ; Syringes ; Thumb ; Transducers ; Ulnar Nerve