Intravenous Regional Anesthesia with Lidocaine

Abstract

Intravenous regional anesthesia was re-evaluated, and the rational use of this technic was discussed.
In five healthy medical students lidocaine anesthesia was examined for the onset, recovery time, analgesia with sustained motor activity or the effect of dif-ferential block, safety dose and optimal concentration of lidocaine. Using our own mechanogram, the twitch responses of the left finger and E. M. G. of the hypothenar group evoked by an electrostimulator were recorded on the monitor oscilloscope.
By Holmes' technic, analgesia followed by anesthesia was produced with 3mg/kg of 0.5% lidocaine solution. Volitional movement of volunteers' fingers were sustained up to ten minutes after the infusion of lidocaine but in this research twitch responses scarcely continued for 30 minutes when the tourniquet was released. During the process of this regional block, the phenomena of ‘post-tetanic facilitation’ were observed.
It is still uncertain that this kind of nerve block belongs to ‘non-depolarizing block’ or ‘mixed block’ at the neuromuscular junction. Anyway, exsanguination of the arm to be anesthetized is quite essential for this technic. Venous blood gas analysis at the time of tourniquet release revealed the effect of ‘ischemia’ or ‘exsanguination’. From the data of pyruvate/lactate ratio, venous pCO₂, and base excess, oxygen deficit was assumed in association with the progress of anaerobic metabolism. This study was performed for only half an hour and the results of analysis do not indicate harmful effect of the treatment for human subjects. Our experiment also suggests that man can tolerate almost without danger the present anesthetic procedure.