Cardiovascular effects of I.V. Induction in children: Comparison between propofol and thiopentone

Abstract

Summary: We have compared the haemodynamic responses to i.v. propofol 2.5 mg kg-1 with those to thio-pentone 5.0 mg kg-1 in 41 healthy Chinese children at induction of anaesthesia. They were allocated to four groups according to their age and induction agent received: group 1 <2yr, propofol, n = 9; group II < 2 yr, thiopentone, n = 9; group III 2-12 yr. propofol, n = 12; group IV 2-12 yr, thiopentone, n = 11. Anaesthesia was maintained by spontaneous ventilation with 70% nitrous oxide and 0.5% halothane in oxygen. Arterial pressure and heart rate were monitored by automatic oscillo -tonometer. Stroke volume was measured by two-dimensional echocardiography and pulse Dopper. Measurements were made before induction and at 1-min intervals for 5 min after induction. The reduction in mean arterial pressure was significantly greater after propofol (28-31%) than after thiopentone (14-21%) (P = 0.001). The reduction in cardiac index (10-15%) after induction was not significantly different between the two agents (P = 0.122). Baroref/ex mediated increases in heart rate and systemic vascular resistance were less after propofol than after thiopentone. The baroreceptor reflex was more attenuated in children aged less than 2 yr than in older children. (Br. J. Anaesth. 1993; 70: 647-653) © 1993 British Journal of Anaesthesia.