Phase Changing Material for Therapeutic Hypothermia in Neonates with Hypoxic Ischemic Encephalopathy – A Multi-centric Study

ABSTRACT

Objective: To assess the feasibility and safety of coolingasphyxiated neonates using phase changing material baseddevice across different neonatal intensive care units in India.Design: Multi-centric uncontrolled clinical trial.Setting: 11 level 3 neonatal units in India from November 2014 toDecember 2015.Participants: 103 newborn infants with perinatal asphyxia,satisfying pre-defined criteria for therapeutic hypothermia.Intervention Therapeutic hypothermia was provided usingphase changing material based device to a target temperature of33.5±0.5oC, with a standard protocol. Core body temperature wasmonitored continuously using a rectal probe during the coolingand rewarming phase and for 12 hours after the rewarming wascomplete.Outcome measures: Feasibility measure - Time taken to reachtarget temperature, fluctuation of the core body temperatureduring the cooling phase and proportion of temperaturerecordings outside the target range. Safety measure - adverseevents during coolingResults: The median (IQR) of time taken to reach targettemperature was 90 (45, 120) minutes. The mean (SD) deviationof temperature during cooling phase was 33.5 (0.39) ºC.Temperature readings were outside the target range in 10.8%(5.1% of the readings were <33oC and 5.7% were >34oC). Mean(SD) of rate of rewarming was 0.28 (0.13)oC per hour. Thecommon adverse events were shock/ hypotension (18%),coagulopathy (21.4%), sepsis/probable sepsis (20.4%) andthrombocytopenia (10.7%). Cooling was discontinued before 72hours in 18 (17.5%) babies due to reasons such as hemodynamicinstability/refractory shock, persistent pulmonary hypertension orbleeding. 7 (6.8%) babies died during hospitalization.Conclusion: Using phase changing material based coolingdevice and a standard protocol, it was feasible and safe to providetherapeutic hypothermia to asphyxiated neonates across differentneonatal units in India. Maintenance of target temperature wascomparable to standard servo-controlled equipment.