NEONATAL COLD INJURY: EVIDENCE OF DEFECTIVE THERMOGENESIS DUE TO IMPAIRED NOREPINEPHRINE RELEASE

Urinary catecholamine excretion was studied in six preterm newborn babies and one full-term newborn baby suffering from neonatal cold injury during the acute phase of the illness and 4 to 6 days after recovery. In all preterm infants the urinary excretion of norepinephrine (NE) during the acute phase (0.062 ± 0.047 ng/kg/min) was considerably lower than after recovery (0.684 ± 0.139). The only full-term baby studied had a milder form of cold injury; his urinary excretion of NE was efficient during the cold stress. The urinary excretion of epinephrine (E) was unaffected by cold stress; the values during the acute phase of hypothermia were almost identical to those found after recovery. It is speculated that prolonged exposure of the newborn to cold max exhaust NE stores leading to inability to stimulate and utilize chemical thermogenesis.