Influence of hypothermia on the prognostic value of early EEG in full-term neonates with hypoxic ischemic encephalopathy.

OBJECTIVE: To determine the prognostic value of early electroencephalograms (EEG) in full-term neonates suffering from hypoxic ischemic encephalopathy (HIE) exposed to whole-body hypothermia (cooled group), compared to neonates treated conventionally (control group). METHODS: The study included all term neonates born at Grenoble Hospital between 2000 and 2006 with symptoms of HIE. The first two EEGs were reviewed retrospectively and classified according to current electrophysiological criteria. In the cooled group, EEGs were recorded with a mean body temperature of 33°C. Neurological outcome was correlated with EEG pattern. RESULTS: An EEG inactive or paroxysmal pattern was associated with death in 60% of the controls, while all survivors had neurological sequels. In the cooled group, this EEG pattern was only predictive of death in 40% while survivors had normal examination at 1 year of age. Mild abnormalities on the first EEG correlated with a good prognosis in both groups. The second EEG had a high predictive value, particularly in the cooled group. Persistence of inactivity at 3 days after birth was always associated with death. CONCLUSIONS: After HIE, the first two EEGs are good prognostic indicators, also in the cooled group. Strong discontinuity in the EEG observed on the first hours after hypothermia induction can be associated with a good outcome. SIGNIFICANCE: Early Stage 4 EEGs recorded during the hypothermia may not always indicate a poor prognosis in HIE.

[Assessment of a hypothermia protocol implementation for hypoxic-ischemic encephalopathy in term newborns]. / Évaluation d'un protocole de prise en charge de l'encéphalopathie anoxo-ischémique du nouveau-né par hypothermie.

BACKGROUND: A whole-body hypothermia protocol for term infants with hypoxic-ischemic encephalopathy (HIE) was implemented in our network in May 2004. The main objective of this study was to assess the feasibility of the protocol. The impact on the outcome was also assessed. METHODS: Monocentric retrospective study of all term infants admitted for HIE after the implementation of the protocol. The feasibility of the protocol was evaluated by its observance during the first 72 h. The neurodevelopmental outcome at 12 months of age of this population was compared with a historical control group. RESULTS: Twenty-five children were included. The protocol was not correctly applied for 8 children. The target temperature (33-34°C) was not reached for 3 infants. Four infants were admitted after 6h of age. In 1 infant, HIE was not diagnosed at admission. In the 17 patients with a good protocol observance, rectal temperature fell to the target temperature on average at 6.4h of age. The long-term follow-up rate was improved after the implementation of the protocol (100 % versus 92 % before protocol implementation). Death or neurodevelopmental disability occurred in 40 % during the protocol period versus 87 % before protocol implementation (p<0.01). CONCLUSIONS: The main limiting factor for implementation of whole-body hypothermia in infants with HIE is admission delay. The follow-up and the rate of death or disability in infants with HIE improved after implementing the protocol.