Utilisation du propofol pour l'anesthésie en chirurgie cardiaque. Résultats préliminaires

Abstract

Nine patients, all NYHA class III and IV, who were to undergo surgery with cardiopulmonary bypass, were divided into two groups. All nine were premedicated with 2 mg flunitrazepam orally 90 min before surgery. Group A consisted in five men, mean age 53 years (extremes : 43 and 73), with no significant difference in weight and body surface area, who were to undergo aortic valve replacement (2), mitral valve replacement (2), and aortic and mitral valve replacement (1). They were given 1.5 mg · kg −1 propofol as a bolus at induction, followed by an infusion of 50 μg · kg −1 · min −1 propofol. Group B consisted in four patients, two men and two women, mean age 60 years (extremes : 49 and 76), with no significant difference in weight and body surface area, who were to undergo aortic valve replacement (3) and corrective surgery for left ventricular aneurysm (1). They were given 2 mg · kg −1 propofol as a bolus at induction, followed by an infusion of 100 μg · kg −1 · min −1 propofol. All the patients were intubated after 0.1 mg · kg −1 pancuronium; they were given 10 μg · kg −1 before intubation and 10 μg · kg −1 before skin incision. Repeat doses of fentanyl and pancuronium were given as required. The haemodynamic parameters studied were : heart rate, systolic, diastolic and mean blood pressures, central venous pressure, mean pulmonary pressure, wedge pressure, and cardiac output measured by thermodilution. The following indices were calculated : cardiac index, systolic index, right and left systolic work indices, and pulmonary and systemic vascular resistances. All the data was obtained before induction (control), 1 to 3 min after induction, 1 to 3 min after intubation, before sternotomy and 5 min after sternotomy. The results were compared between each group for each experimental time. They suggested that propofol had little effect on cardiac output, despite a small fall in blood pressure at induction due to a fall in systemic vascular resistances. Propofol did not alter the cardiac work indices. Also, with propofol, the increase in blood pressure during intubation was largely avoided, but less so at the time of sternotomy.