Clinical study of passive cooling in treatment of severe asphyxiated newborn infants

Abstract

Objective Therapeutic hypothermia has become a standard neuroprotective treatment in term newborn infants following perinatal asphyxia, but active cooling with whole body surface or head cooling is both complex and expensive.The clinical feasibility of passive cooling in treatment of full term infants with severe asphyxia was investigated. Methods Thirty-two severe asphyxiated term newborns treated with hypothermia were analyzed, who were randomly divided into 2 groups: passive cooling group(n=17) and active cooling group(n=15). Active cooling group adopted MTRE ALLON™-thermo regulatory systems, passive cooling group using natural cooling method.Hypothermia treatment time was 72 hours.At the end of treatment, the clinical manifestations, biochemical parameters and clinical efficacy of infants between the 2 groups were compared. Results During treatment all infants had no cardiac arrhythmia, hypoglycemia, sustained metabolic acidosis, blood-borne infections, local cold injury or bleeding.Infants in passive cooling group had a relatively wide range of rectal temperature fluctuations[average (33.47±0.71) ℃] and infants in active cooling group had a relatively narrow range of rectal temperature fluctuations[average (33.66±0.29) ℃], but there was no statistically significant difference in their mean rectal temperature(t=1.941, P=0.055). One patient died in active cooling group, but there were no significant differences in suckling age, length of hospital stay, neonatal behavioral neurological assessment score, abnormal cranial ultrasound and MRI between the survivors of the two groups(all P>0.05). Conclusions In NICU, environmental temperature is relatively stable, passive cooling for asphyxiated newborns appears to be feasible for maintenance of hypothermia with a lower risk of adverse reactions. Key words: Asphyxia; Hypothermia; Infant, newborn; Passive cooling; Active cooling