Heat flux from the head surface in healthy newborns and in newborns with cerebral pathology.

Scalp heat flux of fetuses during labor was shown to be related to metabolic and circulatory factors. We therefore investigated whether heat flux from the head of newborns was also related to cerebral pathology. Heat flux from the head was measured in three groups: Group A consisted of 7 newborn infants with micro- and/or hydrocephalus and with cerebral asphyxia, who were considered to have decreased heat flux from the head due to decreased heat production. Group B consisted of 3 newborn infants with hypoplastic left heart syndrome, who were considered to have increased heat flux from the head due to low cerebral blood flow and, thus, decreased heat convection from the brain. Group C consisted of 17 randomly selected healthy neonates, who served as controls. Heat flux from the head was measured by heat flux transducers attached to the skin of the forehead. The effective operative temperature in the incubator was measured with thermistors. The heat flux from the head of neonates with micro-and/or hydrocephalus and of neonates with cerebral asphyxia was distinctly below, the heat flux from the head of the neonates with hypoplastic left heart syndrome were above two standard deviations of the mean of the heat flux of healthy neonates. The results suggest that heat flux from the head is related to the metabolic or circulatory condition of the underlying brain.