Core-peripheral temperature gradient does not predict cardiac output or systemic vascular resistance in children.

We prospectively measured toe temperature, rectal temperature, systemic arterial pressure and cardiac output on two occasions one hour apart in 136 children who had had phenoxybenzamine after cardiac surgery while on cardiopulmonary bypass. Repeated measures analysis showed that there was no significant correlation between the change in temperature gradient over one hour in each patient and the change in cardiac index (r = 0.03, P greater than 0.1) or systemic vascular resistance (r = 0.007, P greater than 0.1). Although the peripheral temperature (toe temperature), and the core-peripheral temperature difference are simple, safe and inexpensive to measure in the population studied, they did not provide any guide to either cardiac output or systemic vascular resistance.