Interscalene brachial plexus blockade with lidocaine in chronic renal failure--a pharmacokinetic study.

Plasma lidocaine concentrations, latency of onset, and duration of anaesthesia, were determined after interscalene brachial plexus block in 16 patients presenting for elective upper limb surgery. Eight patients had normal renal function and eight had chronic renal failure, as determined by creatinine clearance. Significantly higher plasma lidocaine levels were recorded ten minutes after infiltration in patients with chronic renal failure (p less than 0.05). Cmax plasma levels for normal patients (5.6 +/- 1.1 micrograms.ml-1) and for patients with chronic renal failure (6.6 +/- 1.6 micrograms.ml-1) were not significantly different. The latency of onset and duration of anaesthesia were similar in both groups. One per cent lidocaine solution may be administered to patients with normal and impaired renal function to provide effective brachial plexus blockade for short surgical procedures.