Temperature control during therapeutic moderate whole body hypothermia for neonatal encephalopathy

Denis Azzopardi ^1* and Brenda Strohm ²

¹ Imperial College London, United Kingdom
² National Perinatal Epidemiology Unit, United Kingdom

^* To whom correspondence should be addressed. E-mail: d.azzopardi{at}imperial.ac.uk.

Accepted 2 August 2009

Abstract

Introduction: The precision of temperature control achieved in clinical practice during therapeutic hypothermia in neonates has not been described.

Methods: We examined hourly rectal temperature recordings from 17 infants treated with servo controlled and an equal number treated with manually adjusted cooling equipment. The target rectal temperature for all infants is 33.5oC rectal for 72 hours.

Results: During 6-72 hours after start of cooling the mean, (95% confidence interval) and variance of the averaged rectal temperatures was 33.6oC (33.4oC-33.8oC), 0.1oC in the manually adjusted group and 33.4oC (33.3oC-33.5oC), 0.04oC in the servo controlled group, means: P=0.08, equality of variance: P=0.03. The variance was also significantly different between infant groups during 1-5 hours after start of cooling, P=0.01, but not during rewarming.

Conclusion: The rectal temperature can be maintained close to the target temperature with either manually adjusted or servo controlled equipment, but there is less temperature variability with the servo controlled system in use in the UK.