Cardiovascular changes at antagonism of atracurium. Effects of different doses of premixed neostigmine and glycopyrronium in a ratio of 5:1.
The cardiovascular changes in the 10 minutes following antagonism of an atracurium-induced block were studied in 32 patients. A 5:1 ratio combination of either 15, 35, 55 or 75 micrograms/kg neostigmine, with a corresponding dose of 3, 7, 11, or 15 micrograms/kg of glycopyrronium was used for antagonism. The least change in heart rate was with neostigmine 15 micrograms/kg with an increase of more than 15 beats/minute found in only one patient. Antagonism with 35, 55 and 75 micrograms/kg neostigmine mixture produced the greatest increase in heart rate at one minute and this was significantly different from the effect of the 15 micrograms/kg dose. Twenty out of 24 patients given the larger doses had heart rate increases in excess of 15 beats/minute and in nine patients this ranged from 30 to 52 beats/minute, representing increases of 46-80% above baseline values. Arterial pressure increases after antagonism were statistically significant in all four groups, with no between-group difference; these were clinically unimportant. When antagonising an atracurium-induced block with clinically useful doses of neostigmine, the standard 5 : 1 ratio combination with glycopyrronium will result in an initial tachycardia.
Suresh
D
D
Anaesthetics Unit, London Hospital.
Carter
J A
JA
Whitehead
J P
JP
Goldhill
D R
DR
Flynn
P J
PJ
D000768:Anesthesia, General; D001279:Atracurium / Q000037:antagonists & inhibitors*; D001794:Blood Pressure / Q000187:drug effects*; D006024:Glycopyrrolate / Q000008:administration & dosage / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D009388:Neostigmine / Q000008:administration & dosage / Q000494:pharmacology*
D001279:Atracurium; D009388:Neostigmine; D006024:Glycopyrrolate