EFFECT OF RENAL-FUNCTION ON NEUROMUSCULAR BLOCK INDUCED BY CONTINUOUS-INFUSION OF MIVACURIUM

We have studied the effect of renal function on the pharmacodynamics o f mivacurium. Sixty patients were allocated to three groups according to creatinine clearance: group C(control), creatinine clearance > 50 m l min(-1); group P(preterminal renal failure), creatinine clearance ( 50 ml min(-1) > 20 ml min(-1); group T(terminal renal failure), creati nine clearance < 20 ml min(-1). Neuromuscular transmission (train-of-f our) was monitored using electromyography from the hypothenar muscle w ith stimulation of the ulnar nerve. After an initial bolus, mivacurium was administered continuously to maintain a T1 of 5 (4)% of baseline. The dose of mivacurium necessary to maintain 95% neuromuscular block was similar in patients with normal renal function and patients with d ifferent levels of renal impairment. Recovery from neuromuscular block after ceasing mivacurium infusion was significantly prolonged in pati ents with preterminal renal impairment. There was a close correlation between mivacurium pharmacodynamics and pseudocholinesterase activity, but not creatinine clearance.