153 - Development of an animal model for neonatal hypothermia and safety testing of a novel biomedical device (NeoWarm) to augment Kangaroo Mother Care utilizing live newborn pigs

Poster Number: 153
Publication Number: 153.112

Sherri L. Bucher, Indiana University School of Medicine, Indianapolis, IN, United States; Nicholas Bluhm, Purdue University, West Lafayette, IN, United States; Grant Tomlin, Indiana University School of Medicine, Lafayette, IN, United States; Saptarshi Purkayastha, Indiana University Purdue University Indianapolis, Indianapolis, IN, United States; Jacqueline C. Linnes, Purdue University, West Lafayette, IN, United States

Background: Each year, 15 million babies are born prematurely. Many suffer from hypothermia, which contributes to millions of neonatal deaths each year, particularly within low/middle-income countries. Kangaroo Mother Care (KMC) is an effective intervention to prevent hypothermia. Our multidisciplinary team has developed a low-cost biomedical device, NeoWarm, to augment KMC with thermal support and vital signs monitoring.

Objective: To develop an animal model for neonatal hypothermia in order to demonstrate safety and efficacy of NeoWarm.

Design/Methods: From July – October 2021, piglets < 12 - 120 hours old, weighing 0.8 – 1.4 kg (average 1.1 kg), were convenience sampled from litters born at the Purdue Animal Sciences Research and Education Center farm. Over 6 – 9 hours, rectal temperatures of non-sedated, ambulatory piglets were monitored at 30-minute intervals throughout a combination of up to 4 cooling and warming phases, including: Ambient room temperature (18.5oC); Cooling Box (convective cooling to induce hypothermia); NeoWarm ON (heating technology engaged, with self-regulating temperature sensing; Fig. 1); NeoWarm OFF (device worn but heating not engaged). Purdue University veterinary staff continuously monitored animal welfare during trials. At completion, they examined each piglet for skin injuries or burns. Data analysis: Across each phase, subjects’ raw body temperature measurements were converted to ‘change from initial (baseline) temperature’ at start of that phase.  The converted data were then averaged across all subjects and graphed as mean change and standard deviations, over time.

Results: 16 total neonatal pigs participated; data from 13 (5M, 8F) are reported. Initial rectal temperatures (prior to any cooling) ranged from 37.2-39.80C (average 38.80C).  Four pigs engaged in Ambient Cooling only (4 – 5 hours; -10C average change). In the Ambient + Cooling Box phase (2.5 – 4.5 hours), 9 pigs organized into two distinct groups – those that maintained thermal stability (n=5; -1.50C average) and those that became hypothermic (n = 4; up to -3.50C drop from baseline temperature). After any cooling, piglets assigned to the NeoWarm ON group demonstrated significantly improved warming (up to +40C increase) from the end of the cooling period, and stronger thermal stability, over time (up to 4 hours), as compared to Ambient or NeoWarm OFF groups. No skin injuries or burns were detected.Conclusion(s): These pilot data, from an exploratory pre-clinical porcine model of neonatal hypothermia, indicate that NeoWarm may be a safe and effective device.
Figure 1An neonatal piglet wearing the NeoWarm biomedical device, with self-warming technology engaged (NeoWarm ON phase).