The pharmacokinetics of ropivacaine after four different techniques of brachial plexus blockade

• Published in: Anaesthesia 2007-10, Vol.62 (10), p.1008-1014
• Main Authors: Rettig, H. C., Lerou, J. G. C., Gielen, M. J. M., Boersma, E., Burm, A. G. L.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Amides - administration & dosage; Amides - blood; Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthesiology; Anesthetics, Local - administration & dosage; Anesthetics, Local - blood; Biological and medical sciences; Brachial Plexus; Drug Administration Schedule; Female; Humans; Male; Medical procedures; Medical sciences; Middle Aged; Nerve Block - methods; Neurons; Veins & arteries
• ISSN: 0003-2409; 1365-2044
• DOI: 10.1111/j.1365-2044.2007.05197.x

Summary Arterial plasma concentrations of ropivacaine were measured after brachial plexus blockade using four different approaches: lateral interscalene (Winnie), posterior interscalene (Pippa), axillary and vertical infraclavicular. Four groups of 10 patients were given a single 3.75 mg.kg−1 injection of ropivacaine 7.5 mg.ml−1. The pharmacokinetics of ropivacaine were evaluated for 1 h after local anaesthetic injection. The supraclavicular techniques (lateral and posterior) were associated with earlier and higher peak plasma concentrations of local anaesthetic than the infraclavicular techniques (axillary and vertical infraclavicular): mean (SD) values = 3.30 (0.65) μg.ml−1 vs 2.55 (0.62) μg.ml−1 (p = 0.001) in 13.4 (6.9) min vs 25.0 (10.8) min (p = 0.0002). More ropivacaine is taken up by the systemic circulation in the first hour after the supraclavicular approaches; the mean (SD) area under the concentration‐time curve was larger: 2.63 (0.51) μg.ml−1.h vs 2.10 (0.49) μg.ml−1.h (p = 0.002). These results show that the technique used for brachial plexus blockade significantly influences the systemic uptake of ropivacaine.