COMPARISON OF THE EFFECTS AND DISPOSITION KINETICS OF ARTICAINE AND LIDOCAINE IN 20 PATIENTS UNDERGOING INTRAVENOUS REGIONAL ANESTHESIA DURING DAY-CASE SURGERY

The aim of this investigation was to assess the effects and dispostion kinetics of the local anaesthetic drugs (+/-)articaine and lidocaine during intravenous regional anaesthesia (IVRA). The mean onset time of surgical analgesia of articaine was 2.5+/-1.1 min and that of lidocai ne 11.2 +/- 5.1 min (p = 0.0006). None of the patients exhibited objec tive symptoms of toxicity, either local or systemic, during injection of articaine or lidocaine, nor were there any subjective complaints. N o changes in blood pressure, heart rate or oxygen saturation were obse rved with these local anesthetics at any time during the procedure, no r after deflation of the tourniquet. After releasing the tourniquet, a rticaine appears in the blood and is rapidly eliminated with a t(1/2 a lpha) of 5+/-3 min and a t(1/2 beta) of 59+/-39 min due to hydrolysis. Lidocaine is rapidly and ponentially eliminated with similar half-liv es of t(1/2 alpha) Of 4+/-2 min and a t(1/2 beta) of 79+/-31 min. Tota l body clearance of articaine (8.9+/-3.5 L/min) is ten times greater t han that of lidocaine (0.9+/-0.4 L/min; p = 0.0005). We concluded that both (+/-)articaine and lidocaine are suitable and safe agents for IV RA with rapid onset of good surgical anaesthesia, Articaine is a racem ic mixture, which is nowadays considered as less favourable. After rel easing the tourniquet articaine is eliminated with a t(1/2 beta) Of 60 min and lidocaine with a t(1/2 beta) of 80 min. Quicker onset and sho rter elimination time favours (+/-)articaine over lidocaine for IVRA i n day case settings so that patients treated with articaine will be 'd rug free' more quickly than I those who receive lidocaine. faster elim ination and more rapid onset are important advantages for articaine in IVRA for day-case procedures.