Plasma concentrations of bupivacaine after intercostal nerve block in patients after orthotopic liver transplantation.

Bilateral intercostal nerve blocks were performed on 12 occasions in 11 patients after liver transplantation. Group 1 (six patients) received bupivacaine 2 mg kg-1 on one occasion; in group 2 (five patients) bupivacaine 2 mg kg-1 with adrenaline 1:200,000 was injected on two occasions separated by 6 h. Arterial blood was sampled repeatedly and analysed for total bupivacaine concentrations by high performance liquid chromatography (HPLC). Six patients had bupivacaine concentrations within the putative toxic threshold of 2-4 micrograms ml-1. The use of adrenaline-containing solutions neither slowed absorption reliably nor decreased peak concentrations of bupivacaine. Cumulation of bupivacaine occurred in group 2. No patient had adverse effects attributable to the bupivacaine.