[Impact of mild hypothermia therapy on hemodynamics during the induction stage in neonates with moderate to severe hypoxic-ischemic encephalopathy]

OBJECTIVE

To study the changes in hemodynamics during the induction stage of systemic mild hypothermia therapy in neonates with moderate to severe hypoxic-ischemic encephalopathy (HIE).

METHODS

A total of 21 neonates with HIE who underwent systemic mild hypothermia therapy in the Department of Neonatology, Dongguan Children's Hospital Affiliated to Guangdong Medical University, from July 2017 to April 2020 were enrolled. The rectal temperature of the neonates was lowered to 34℃ after 1-2 hours of induction and maintained at this level for 72 hours using a hypothermia blanket. The impedance method was used for noninvasive hemodynamic monitoring, and the changes in heart rate (HR), mean arterial pressure (MAP), stroke volume (SV), cardiac output (CO), cardiac index (CI), and total peripheral resistance (TPR) from the start of hypothermia induction to the achievement of target rectal temperature (34℃). Blood lactic acid (LAC) and resistance index (RI) of the middle cerebral artery were recorded simultaneously.

RESULTS

The 21 neonates with HIE had a mean gestational age of (39.6±1.1) weeks, a mean birth weight of (3 439±517) g, and a mean 5-minute Apgar score of 6.8±2.0. From the start of hypothermia induction to the achievement of target rectal temperature (34℃), there were significant reductions in HR, CO, and CI (P < 0.05), while there was no significant change in SV and MAP (P > 0.05). There was a significant increase in TPR (P < 0.05) and a significant reduction in LAC (P < 0.05), while there was no significant change in RI (P > 0.05).

CONCLUSIONS

The systemic mild hypothermia therapy may have a significant impact on hemodynamics in neonates with moderate to severe HIE, and continuous hemodynamic monitoring is required during the treatment.