PLASMA BUPIVACAINE CONCENTRATIONS FOLLOWING AXILLARY BLOCK - A STUDY IN MALAYSIAN PATIENTS

Surgery on the upper limb can be performed under axillary block of the brachial plexus. Bupivacaine is often used as the local anaesthetic. To determine whether recommended doses are appropriate for the local p opulation, venous plasma bupivacaine concentrations were measured afte r axillary block in 14 Malaysian patients. Plasma bupivacaine was assa yed by high-performance liquid chromatography. With a dose range of 60 -160 mg or 1.7-3.0 mg kg(-1) (126 +/- 30 mg or 2.2 +/- 0.4 mg kg(-1), respectively, mean +/- SD) peak plasma concentrations of 0.72-3.65 mu g ml(-1) were obtained. There was a wide scatter of individual values. Peak concentrations occurred at about 20 min. These levels were in co ncurrence with other published studies. We conclude that at a dose ran ge of up to 3.0 mg kg(-1) in our patients, the plasma levels reached d id not result in those associated with developing clinical symptoms or signs of toxicity.