[Local anesthesia in ambulatory phlebectomy by the method of R. Muller: risk assessment by lidocaine dosage].

Local anesthesia for ambulatory phlebectomy makes it necessary to inject a considerable quantity of lidocaine. This study involved 50 operations. The doses of lidocaine containing 1% adrenaline and injected after cooling (between 2 and 5 degrees C) ranged from 200 mg to nearly 900 mg in a single administration. The assays of lidocaine in the peripheral venous blood were carried out by means of F.P.I.A. (Fluorescence Polarization Immuno Assay) at times 0, 30 min 60 min, 90 min., 24 hours and 48 hours. The peak concentration obtained (1.8 micrograms/ml) for a dose of 700 mg in a subject weighting 65 kg, i.e. 10.9 mg/kg, was only one-half the concentration considered to be neurologically toxic (4 to 12 micrograms/ml) or one-twelfth of the toxic levels with regard to the cardiovascular system (24 micrograms/ml). The performance of local anesthesia in the physician's office is devoid of major risks, even though the doses used during AP are much higher than those usually administered in routine dematological surgery.