Anesthesiology
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Cumulative d-tubocurarine dose-response curves were determined in 35 unpremedicated adult surgical patients. In five awake patients with and five awake patients without ulnar nerve block the median effective doses of d-tubocurarine necessary for 50 per cent depression of twitch tension (ED50) were 8.3 and 9.1 mg/m2, respectively. ⋯ The ED50's of d-tubocurarine were 4.8, 4.5, 2.5, 3.2, and 3.8 mg/m2 in patients anesthetized with 1.0 to 1.3 per cent alveolar concentrations of halothane for 10, 20, 40, 80, and 160 minutes, respectively. It is concluded that duration of anesthesia has no effect on neuromuscular blockade by d-tubocurarine.