Abstract
Lidocaine, a local anesthesia frequently used in bronchofiberscopy, is metabolized in the liver and excreted. The question of lidocaine toxicity during bronchofiberscopy in cases accompanied by liver diseases is important thus it is of interest to follow the blood concentration of lidocaine during bronchofiberscopy procedures. A total of 78 samples of lidocaine blood samples obtained during bronchofiberscopy were examined from 20 cases of respiratory diseases, which were classified into two groups. Group A consisted of 10 cases accompanied by liver diseases and group B consisted of 10 cases without any recognized liver disease. All patients received 2% lidocaine nebulized during the first ten minutes and lidocaine spray anesthesia to the larynx was performed for the next five minutes and then they underwent examination under instillation of anesthesia for ten minutes. Blood samples were taken at 20, 40, 60 and 120 minutes after the commencement of administration of lidocaine. There was no significant difference in the mean lidocaine doses of the two groups ; 8.58±1.33mg/kg for group A and 7.60±2.76mg/kg for group B. The mean peak concentration and the time to peak concentration showed no significant difference between the two groups. Blood levels of lidocaine continued to increase for 40 minutes after the commencement of lidocaine administration in all cases. From 40 minutes to 60 minutes, most of the group A cases, which had abnormal laboratory values in tansaminase, γ-globulin, cholinesterase, and I.C.G. level, tended to show a plateau, while most group B cases showed a downward curve. From 60 minutes to 120 minutes, the blood concentration curves tended to decrease smoothly in group A and B. We should pay particular attention to cases of liver diseases undergoing bronchofiberscopic examination, especially from 40 minutes to 60 minutes after the commencement of lidocaine administration.
