Catecholamine and cortisol responses to sufentanil-O2 and alfentanil-O2 anaesthesia during coronary artery surgery.

The effects of alfentanil-O2 and sufentanil-O2 anaesthesia on plasma catecholamines and cortisol were investigated in 32 patients undergoing coronary artery bypass grafting operations. After lorazepam-atropine premedication and pancuronium pretreatment, alfentanil was given to 16 patients at a rate of 3 mg.min-1 and sufentanil was given to 16 patients at 300 micrograms.min-1 until the patients were unconscious; at this time they were given succinylcholine and were intubated. After intubation an amount of alfentanil or sufentanil equal to the dose producing unconsciousness was infused over the next 30 min, at which time the operation began. Additional alfentanil or sufentanil were given whenever systolic arterial blood pressure increased more than 15 per cent of preanaesthetic values. Arterial blood samples were obtained for epinephrine, norepinephrine and cortisol assay and cardiovascular dynamics were recorded prior to anaesthetic induction, 5 min after tracheal intubation, immediately prior to and five min after incision, ten min after maximal sternal spread, just prior to beginning and after 30 and 60 min of bypass and at the end of operation. Cardiovascular dynamics were little changed throughout anaesthesia and operation. Plasma epinephrine and norepinephrine were not significantly changed until bypass. During bypass both hormones became increased and remained increased at the end of operation. Plasma cortisol decreased after incision and remained decreased until the end of operation. These data indicate that alfentanil-O2 and sufentanil-O2 anaesthesia produce similar changes in plasma catecholamines and cortisol as does fentanyl-O2 anaesthesia and hormonal effects are, therefore, not an explanation for any advantages the newer narcotics may have over fentanyl.