The dose effect of ephedrine on the onset time of vecuronium.
A small dose of ephedrine decreases the onset time of rocuronium and cisatracurium; however, ephedrine might be associated with adverse hemodynamic effects. The appropriate dose of ephedrine has not been determined. We, therefore, studied 120 patients anesthetized with fentanyl 2 microg/kg and propofol 2-2.5 mg/kg who were randomly divided to receive either ephedrine (30, 70, or 110 microg/kg) or saline. During propofol anesthesia, the neuromuscular block was monitored by mechanomyography by using submaximal current of train-of-four stimulation every 10 s. To determine cardiac output, a transcutaneous Doppler probe was placed externally at the suprasternal notch. Tracheal intubation was performed by a blinded investigator at 2 min after vecuronium. Neuromuscular block, intubating conditions, and hemodynamic effects were measured during the induction of anesthesia. Both ephedrine 70 and 110 microg/kg improved intubating conditions at 2 min after vecuronium; however, 110 microg/kg was associated with adverse hemodynamic effects. We conclude that ephedrine 70 microg/kg given before the induction of anesthesia improved intubating conditions at 2 min after vecuronium, probably by increased cardiac output without significant adverse hemodynamic effects.


CONCLUSIONS
Ephedrine 70 microg/kg given before the induction of anesthesia improved tracheal intubating conditions at 2 min after vecuronium by increased cardiac output without significant adverse hemodynamic effects.
Kim
Kyo S
KS
Department of Anesthesiology, Hanyang University Hospital, Seoul, Korea.
Cheong
Mi A
MA
Jeon
Jeong W
JW
Lee
Jeong H
JH
Shim
Jae C
JC
D000328:Adult; D000771:Anesthesia, Intravenous; D018686:Anesthetics, Intravenous; D001794:Blood Pressure / Q000187:drug effects; D001993:Bronchodilator Agents / Q000494:pharmacology*; D002302:Cardiac Output / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D004809:Ephedrine / Q000494:pharmacology*; D005260:Female; D005283:Fentanyl; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects; D003473:Neuromuscular Nondepolarizing Agents; D015742:Propofol; D013997:Time Factors; D014655:Vascular Resistance / Q000187:drug effects; D014673:Vecuronium Bromide
D018686:Anesthetics, Intravenous; D001993:Bronchodilator Agents; D003473:Neuromuscular Nondepolarizing Agents; D014673:Vecuronium Bromide; D004809:Ephedrine; D005283:Fentanyl; D015742:Propofol