Regional ketamine-induced depression of neuromuscular transmission in man

The intravenous injection of ketamine in the human arm with isolated circulation, using the same technique as for intravenous regional anesthesia, produces a dose-related depression of neuromuscular transmission, as evidenced by the evoked response to supramaximal stimulation of the ulnar nerve with a nerve stimulator. The dose range of ketamine was 200, 25, 10, 5, 1, 0.5 and 0.25 mg, in 20 ml of 5% dextrose in water. The exact mechanism of this effect is discussed. This depression may have clinical significance under certain circumstances.