Whole body hypothermia for the treatment of hypoxic-ischaemic encephalopathy in term infants – a safety study in Hungary

Abstract

Hypoxic-ischaemic encephalopathy is a major cause of long-term morbidity and mortality in term infants. Prolonged systemic hypothermia is a promising new approach for reducing brain damage in neonates. The aim of the open cohort-series clinical study was to collect data about the safety and technical feasibility of the hypothermia treatment in Hungary before joining to a randomised efficacy trial. The authors treated 28 asphyxiated term neonates with hypothermia between 2003 and 2005. Hypothermia (rectal temperature 33-34 degrees C) was maintained for 72 hours during continuous morphine analgesia. For historical control group 23 asphyxiated neonates were selected treated with standard therapy between 1996 and 2002. Entry criteria were the following: a 5-minute Apgar score 5 or less, the evidence of serious metabolic acidosis in the first hour of life (a BE of 15 mmol/l) and clinical sign of encephalopathy at the same time. Routine laboratory measurements of liver enzymes, renal functions, blood cell count, head ultrasound were performed daily. The anthropometric and clinical parameters (Apgar, pH, BE, neurological signs of encephalopathy) of the hypothermia and control infants were similar. There were no significant differences between the mortality of the hypothermia (10/28 36%) and the control (10/21 48%) groups. The clinical parameters (laboratory values, abnormality on the head ultrasound, incidence of serious hypotension, hypoglycaemia, bleeding, need for cardiovascular support, oliguria) and the neurological outcome after 1.5-2 year follow-up were also similar. This study demonstrated that prolonged whole body hypothermia of the asphyxiated neonate is safe and not associated with increased mortality and morbidity up to 18 month of age.