The Effects of Experimental Acid - base Imbalance on the Neuromuscular Blocking Action of Atracurium of Vecuronium / 대한마취과학회지

ABSTRACT

Action of neuromuscular blocking agents are known to be largely affected by acid-base imbalance. In general, acidosis potentiates and alkalosis antagonizes the action of the neuromuscular blockers. To evaJuate the effects of acid-base imbalance on the neuromuscular actions of atracurium or vecuronium in 24 cats, we induced respiratory and metabolic acid-base imbalance and performed cumulative dose response studies. The results are as follows; 1) ED(50) and ED(95) of the atracurium was smaller in metabolic acidosis than those of respiratory and metabolic alkalosis. 2) ED(50) of vecuronium was not affected by acid-base imbalance in either agent. 3) Duration and recovery index were not affected by acid-base imbalance in either agent. 4) In atracurium group, serum potassium and calcium values during respiratory or metabolic alkalosis were smaller than those of control, but did not influence the neuromuscular action of atracurium. 5) Dose-response curve of the atracurium shifted to the right with metabolic acidosis, respiratory acidosis, metabolic alkalosis and respiratory alkalosis in order, but acid-base imbalance did not influence the dose-response curve of the vecuronium. In conclusion, the potency might be increased in respiratory and metabolic acidosis with atracurium, but not with vecuronium. However, action and recovery were not influenced by a experimental imbalance in either agent.