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

Objective: To assess the feasibility and safety of cooling asphyxiated neonates using phase changing material based device 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 to December 2015. Participants: 103 newborn infants with perinatal asphyxia, satisfying pre-defined criteria for therapeutic hypothermia. Intervention: Therapeutic hypothermia was provided using phase changing material based device to a target temperature of 33.5 +/- 0.5 degrees C, with a standard protocol. Core body temperature was monitored continuously using a rectal probe during the cooling and rewarming phase and for 12 hours after the rewarming was complete. Outcome measures: Feasibility measure - Time taken to reach target temperature, fluctuation of the core body temperature during the cooling phase and proportion of temperature recordings outside the target range. Safety measure - adverse events during cooling Results: The median (IQR) of time taken to reach target temperature was 90 (45, 120) minutes. The mean (SD) deviation of temperature during cooling phase was 33.5 (0.39) degrees C. Temperature readings were outside the target range in 10.8% (5.1% of the readings were < 33 degrees C and 5.7% were > 34 degrees C). Mean (SD) of rate of rewarming was 0.28 (0.13) degrees C per hour. The common adverse events were shock/hypotension (18%), coagulopathy (21.4%), sepsis/probable sepsis (20.4%) and thrombocytopenia (10.7%). Cooling was discontinued before 72 hours in 18 (17.5%) babies due to reasons such as hemodynamic instability/refractory shock, persistent pulmonary hypertension or bleeding. 7 (6.8%) babies died during hospitalization. Conclusion: Using phase changing material based cooling device and a standard protocol, it was feasible and safe to provide therapeutic hypothermia to asphyxiated neonates across different neonatal units in India. Maintenance of target temperature was comparable to standard servo-controlled equipment.