Bispectral index-guided induction of general anaesthesia in patients undergoing major abdominal surgery using propofol or etomidate: a double-blind, randomized, clinical trial.

Background: In a double-blind, randomized trial, we compared the haemodynamic effects of a bispectral index (BIS)-guided etomidate and propofol infusion for anaesthesia induction in patients undergoing major abdominal surgery.

Methods: Forty-six patients were randomly assigned to two groups based on the induction of anaesthesia, performed with a BIS value of 60 titrated infusion of etomidate (E group) or propofol (P group). Mean arterial pressure (MAP), cardiac index (CI), heart rate, and systemic vascular resistance index (SVRI) measurements were taken 1 min before induction and recorded at 1-min intervals for 20 min. P<0.05 was considered statistically significant.

Results: Before intubation, no significant differences between the two groups regarding the haemodynamics were noticed. At intubation and up to 7 min after intubation MAP (P=0.019) was significantly higher in the E group. CI was significantly higher in the E group with respect to the P group 2, 6, and 7 min after intubation. Twenty-three patients developed complications. The incidence of hypotension was higher in the P group than that in the E group (8 vs 3; P=0.08), and the incidence of hypertension was significantly higher in the E group than that in the P group (10 vs 2; P=0.007).

Conclusions: Our study showed that the use of propofol resulted in less hypertension and tachycardia at and after intubation than etomidate. But even with the reduced doses given with the BIS-guided protocol, it often caused significant hypotension.