Comparison of the effects and disposition kinetics of articaine and lidocaine in 20 patients undergoing intravenous regional anaesthesia 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 lidocaine 11.2 ± 5.1 min (p = 0.0006). None of the patients exhibited objective symptoms of toxicity, either local or systemic, during injection of articaine or lidocaine, nor were there any subjective complaints. No changes in blood pressure, heart rate or oxygen saturation were observed with these local anesthetics at any time during the procedure, nor after deflation of the tourniquet. After releasing the tourniquet, articaine appears in the blood and is rapidly eliminated with a t1/2a of 5±3 min and a t1/2 of 59±39 min due to hydrolysis. Lidocaine is rapidly and biexponentially eliminated with similar halflives of t1/2a of 4±2 min and a t1/2 of 79±31 min. Total body clearance of articaine (8.9±3.5 L/min) is ten times greater than 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 IVRA with rapid onset of good surgical anaesthesia. Articaine is a racemic mixture, which is nowadays considered as less favourable. After releasing the tourniquet, articaine is eliminated with a t1/2 of 60 min and lidocaine with a t1/2 of 80 min. Quicker onset and shorter elimination time favours (±)articaine over lidocaine for IVRA in day case settings so that patients treated with articaine will be drug free more quickly than those who receive lidocaine. Faster elimination and more rapid onset are important advantages for articaine in IVRA for daycase procedures.