Thiopentone reduces the haemodynamic response to induction of high–dose fentanyl–pancuronium anaesthesia in coronary artery surgical patients

Thirty-three coronary artery bypass graft patients anaesthetized with high-dose fentanyl (50 micrograms/kg)-pancuronium-oxygen were divided into one control group receiving additional saline and two groups receiving additional 1 mg/kg or 2.5 mg/kg of thiopentone before laryngoscopy and intubation. During laryngoscopy and intubation, systemic arterial pressures, heart rate and rate-pressure-product remained at considerably elevated levels caused by pancuronium in the control group. Both doses of thiopentone reduced these haemodynamic values close to their initial levels. Cardiac index and left ventricular stroke work index were significantly decreased, especially by the higher thiopentone dose, as compared with the control group. However, there were no statistical differences between the haemodynamic changes produced by the two doses of thiopentone. Sedative or hypnotic supplementation of high-dose fentanyl anaesthesia seems to be necessary if pancuronium is used as a muscle relaxant. A small increment of thiopentone, 1 mg/kg, was enough to return haemodynamic parameters almost to their initial levels, whereas the effect of 2.5 mg/kg of thiopentone was unnecessarily strong.