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The effect of bambuterol on plasma cholinesterase activity and suxamethonium‐induced neuromuscular blockade in subjects heterozygous for abnormal plasma cholinesterase
Author(s) -
Bang U.,
VibyMogensen J.,
Wirén J. E.
Publication year - 1990
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/j.1399-6576.1990.tb03153.x
Subject(s) - medicine , cholinesterase , anesthesia , neuromuscular blockade , bupivacaine
Bambuterol is a new bronchodilator which is also a reversible inhibitor of plasma cholinesterase. In patients with normal plasma cholinesterase genotype, bambuterol prolongs suxamethonium‐induced neuromuscular blockade. In the present study, we investigated the interaction of bambuterol and suxamethonium in nine patients heterozygous for abnormal plasma cholinesterase during anaesthesia with fentanyl, thiopentone, halothane and nitrous oxide in oxygen. The patients (seven E u 1 E a 1 and two E u 1 E a 1 ) were given 20 mg of bambuterol orally 2 h before anaesthesia. Suxamethonium 1 mg ± kg ‐1 was given for tracheal intubation. The neuromuscular function was monitored using train‐of‐four (TOF) stimulation of the ulnar nerve and a force displacement transducer. Plasma cholinesterase activity decreased in all patients following bambuterol ( P < 0.001). In patients with genotype E u 1 E a 1 , median time to 90% recovery of twitch height and TOF ration ± 0.7 (37.5 min) was prolonged compared to 28 E u 1 E a 1 patients not treated with bambuterol (14.0 min) ( P < 0.001). Four of these patients developed a phase II block apparently not correlated to plasma cholinesterase activity. In the E u 1 E a 1 patients, full recovery was seen after 22.0 and 31.4 min, respectively. It is concluded that in patients heterozygous for abnormal plasma cholinesterase, bambuterol 20 mg taken 2 h before anaesthesia causes a 2–3 times prolongation of the neuromuscular blockade following suxamethonium 1 mg ± kg ‐1 and in some patients a phase II block.