Changes in skin blood flow over the foot with warming of the contralateral heel.

Abstract

Vasospasm in one leg is a common complication of umbilical artery catheterization in preterm infants. It is a common practice to wrap the contralateral leg in a warm washcloth. The rationale for this intervention is to induce reflex vasodilatation of the affected extremity, thereby avoiding the necessity to remove or replace the catheter. This study tested the hypothesis that heating the contralateral extremity in preterm infants would increase peripheral blood flow to the contralateral foot. Ten stable preterm infants who had had no umbilical catheter inserted for at least 2 weeks were studied. Skin perfusion was measured using the laser Doppler method in the distal leg after heating of the opposite foot to 40.5 degrees C. Blood flow to the skin of the contralateral foot was measured before and after warming the ipsilateral one. The skin blood flow measured with and without heat application to the contralateral foot was not significantly different. Direct heat does not induce contralateral reflex vasodilatation in the foot of preterm infants.