[Catheter brachial plexus anesthesia for intra- and postoperative pain control. Plasma concentrations and analgesia interval in the use of bupivacaine].

In 15 orthopedic patients, undergoing plastic surgery of the upper extremity (elbow, forearm, hand) we studied plasma levels and pain free intervals, when performing catheter axillary plexus block with 0.5% and 0.25% bupivacaine as postoperative analgetic agent respectively. 30 minutes after injection of 40 ml of 0.5% bupivacaine maximum plasma levels were reached (means = 1.46 micrograms/ml), followed by a constant but slow decrease to 1 microgram/ml approximately after 2 h. 11.5 h (mean) after brachial plexus block there was a need for reinjection of local anesthetic solution for postoperative pain control. The pain free interval after 30 ml of 0.25% bupivacaine lasted 10.5 hours on the average. The 'top-up-dose' of 75 mg approximately equal to 30 ml of 0.25% bupicavaine caused only a small rise in plasma levels up to 0.6 micrograms/ml. Catheter brachial plexus block with bupivacaine is an appropriate procedure for both intra- and postoperative pain relief, especially in re-implantation surgery of the upper limb.