Small doses of remifentanil or sufentanil for blunting cardiovascular changes induced by tracheal intubation: a double-blind comparison

Background and objective To compare the effects on cardiovascular changes i nduced by tracheal intubation when small doses of either remifentanil or su fentanil are used in the presence of midazolam. Methods Thirty normotensive, ASA physical status I-II patients, receiving g eneral anaesthesia for major abdominal surgery, received an intravenous mid azolam premedication (0.05 mg kg(-1)) 10 min before induction. They were ra ndomly allocated to receive in a double-blind fashion an intravenous bolus of either (a) remifentanil given as a bolus dose 1 mug kg(-1) (n = 15), or else (b) sufentanii 0.1 mug kg(-1) infused over 60 s (n = 15). In each inst ance this loading dose was followed by a continuous intravenous infusion (0 .1 mug kg(-1) min(-1) or 0.01 mug kg(-1) min(-1) of remifentanil or sufenta nil respectively). General anaesthesia was induced with propofol (2 mg kg(- 1)), followed by atracurium besilate (0.5 mg kg(-1)) to facilitate tracheal intubation. Following intubation, the lungs were mechanically ventilated w ith a 60% nitrous oxide in oxygen mixture and a 1% inspired sevoflurane. Results Arterial pressure and heart rate were recorded before induction of anaesthesia (baseline), immediately before intubation, immediately after tr acheal intubation and every minute for the first five minutes thereafter. N o differences in systolic and diastolic arterial pressures were observed be tween the two groups. At the end of the study period, systolic and diastoli c pressures slightly decreased from preinduction values in both groups. Fou r patients in the remifentanil group (26%) and five patients in sufentanil group (33%) showed at least one systolic pressure value <90 mmHg during the study period (P = not significant); however, the observed decreases in sys tolic pressure were transient and did not require treatment. Heart rate val ues were not affected by tracheal intubation in either group. Conclusions In healthy normotensive patients without cardiovascular disease the use of a relatively small dose of either remifentanil or sufentanil af ter standard midazolam premedication results in a similar and clinically ac ceptable effectiveness in blunting the cardiovascular changes induced by tr acheal intubation.