RESUMO
The purpose of this paper was to find a safe and effective concentration of lido- caine in intravenous combining anesthesia.33 cases had been maintained with the intravenous instillation of 0.5% lidocaine and 0.1% scotine the lidocaine concentrations at the period of after introduction,30＇,60＇,90＇,120＇and recovery were measured respectively.The safty and effective range of this drug would be 2.1—5?g/ml. Also,in this paper,the relationship between the rate of instilation and the concentration of Lidocaine was studied.There was a positive correlation between the drope per minute amd the concentration during the period of the first 60 minutes. After 90 minutes from the beginning,there was no linear correlation.If we want to maintain the safty and effective blood concentration(2.1—5?g/ml), the necessary rate of instillation is 46?10 drops/minute during the first 60 minutes and 27.8?5 drops/minute after 90 minutes.This result shows that lidocaine is easy to accumulate obviously in the body.If we want the patient to recover at the time of the operation just performed,we must stop this drug 50 miuutes before the operation is finished.