Haemodynamic stability during anaesthesia induction with propofol – impact of phenylephrine. A double-blind, randomised clinical trial

Background. We studied the effects of a parallel phenylephrine infusion during bispectral index guided anaesthesia in-duction with propofol on haemodynamic parameters. We hypothesised that mean ar-terial pressure and cardiac index would be better maintained in the group of patients receiving the phenylephrine infusion dur-ing induction.Methods. We studied ASA I-III patients scheduled for oncological abdominal sur-gery. Forty patients randomly received ei-ther a 0.9% NaCl or a phenylephrine (0.5 μg/kg/min) infusion during the induction of anaesthesia with propofol to a bispectral index value of 60. Mean arterial pressure, stroke volume index and systemic vascular resistance index were recorded, starting at one minute before induction for 20 min-utes, at one-minute intervals.Results. After induction of anaesthesia before intubation mean arterial pressure and stroke volume index decreased sig-nificantly compared to baseline in both groups, while the systemic vascular resist-ance index increased slightly. At the end of measurements, mean arterial pressure (66 ± 11 vs. 94 ± 14 mmHg; 0.9% NaCl vs. phenylephrine group p<0.01) and stroke volume index (34.2 ± 9.1 vs. 44.0 ± 9.7 ml/m2; 0.9% NaCl vs. phenylephrine group p<0.01) were lower in both groups in com-parison to baseline values, but were better maintained in the phenylephrine group, whereas systemic vascular resistance index was higher than at baseline (2308 ± 656 vs. 3198 ± 825 dynes s/cm5/m2; 0.9% NaCl vs. phenylephrine group p<0.01) with signifi-cant differences between groups. Conclusion. Our study shows that a con-tinuous phenylephrine infusion can atten-uate the drop in mean arterial pressure and stroke volume index during anaesthesia induction with propofol.