European Journal of Cardio-Thoracic Surgery, Vol 7, 524-527, Copyright © 1993 by European Association for Cardio-thoracic Surgery
Pancuronium, vecuronium, and heart rate during anesthesia for aortocoronary bypass operations
D Mangar, WS Turnage, GR Connell and D Graubert
Department of Anesthesiology, University of South Florida, College of Medicine, Tampa 33612-4799.
To determine the effects of pancuronium and vecuronium on heart rate, 90
patients scheduled for aortocoronary bypass were randomly assigned to one
of three groups (30 patients each) which received vecuronium 100
micrograms[sdot]kg-1, pancuronium 100 micrograms[sdot]kg-1, or a mixture of
vecuronium (50 micrograms[sdot]kg-1) and pancuronium (50
micrograms[dot]kg-1) in a double-blind fashion during induction of
anesthesia. All patients were premedicated with lorazepam prior to surgery,
hence avoiding the effects of scopolamine. Our results showed no
significant increase in heart rate from the administration of pancuronium,
following administration of this drug the heart rate increased by only four
beats per minute. The heart rate was unchanged after the mixture, but
decreased by twelve beats per minute after vecuronium (P < 0.05). The
heart rate response differed by 16 beats per minute between pancuronium and
vecuronium. All patients who received either of the neuromuscular relaxants
and who were on beta blockers showed a decrease in heart rate. In this
study, the administration of pancuronium after an adequate induction dose
of fentanyl did not cause tachycardia. We therefore feel that pancuronium
still has a role in cardiac anesthesia, especially as the newer muscle
relaxants such as vecuronium, pipecuronium and doxacurium are significantly
more expensive.
