Haemodynamic differences between pancuronium and vecuronium in an experimental pig model

Abstract

ObjectiveTo compare baseline cardiovascular function in anesthetised pigs using either pancuronium or vecuronium as a neuromuscular blocker. Study designRetrospective, non-randomized comparison. AnimalsNorwegian Land Race pigs (Sus scrofa domesticus) weighing mean 42 ± SD 3 kg. MethodsOne hundred and sixteen animals from four different research protocols premedicated with identical doses of ketamine, diazepam, atropine and isoflurane, and anaesthetised with pentobarbital, fentanyl, midazolam and N2O were arranged into three uniform groups with respect to neuromuscular blocking agent: pancuronium bolus of 0.063 mg kg−1 followed by 0.14 mg kg−1 hour−1 (n = 54), low-dose vecuronium 0.4 mg kg−1/0.2 mg kg−1 hour−1 (n = 29) and high-dose vecuronium 0.6 mg kg−1/0.3 mg kg−1 hour−1 (n = 33). ResultsThe majority of cardiovascular parameters demonstrated no significant differences between groups. For heart rate, there was an overall group difference, p = 0.036. Dromotropy was low in the pancuronium group, with an increased normalised PR-interval compared to the high-dose vecuronium group, median 0.200 interquartile range (0.190, 0.215) versus 0.182 (0.166, 0.199), p < 0.05. Left ventricular compliance was increased in pancuronium-treated animals, demonstrated as a reduction in the nonlinear end-diastolic pressure volume relationship β compared to both vecuronium groups, 0.021 (0.016, 0.025) versus 0.031 (0.025, 0.046) and 0.031 (0.022, 0.048), p < 0.05. The linear end-diastolic pressure volume relationship EDPVRlin was reduced as well in the pancuronium group, compared to the low-dose vecuronium group, 0.131 (0.116, 0.169) versus 0.181 (0.148, 0.247), p < 0.05. ConclusionsThere are only minor haemodynamic differences when using pancuronium compared to vecuronium in the fentanyl-pentobarbital-midazolam-N2O anesthetised domestic pigs. Furthermore, increasing doses of vecuronium have minimal haemodynamic effects. Clinical relevanceExperimental studies in pigs using either pancuronium or vecuronium as a neuromuscular blocking agent are comparable with regard to cardiac and haemodynamic performance.