Predicting Factors for Neurologic Outcome in Full-term Neonates with Hypoxic-Ischemic Encephalopathy

Yeo, Chae Young; Kim, Do Kyun; Kim, Sun Hee; Song, Eun Song; Woo, Young Jong; Choi, Young Youn

Abstract

PURPOSE
Hypoxic injury during delivery and subsequent ischemic encephalopathy is still remained as one of the important cause of neonatal death and associated with neurologic complication. We investigated the predicting factors for neurologic outcome in full-term hypoxic-ischemic encephalopathy (HIE).
METHODS
Twenty-two full-term neonates with HIE stage II or III from Jan. 2001 to Dec. 2004 were enrolled. We reviewed the medical records retrospectively including obstetric history, initial pH, creatine kinase (CK), ionized calcium, seizure type and duration, EEG, cranial sonography, CT or MRI, and neurologic outcome.
RESULTS
Among 22 patients, outborn was 86.3%, vaginal delivery 68.2%, and male 72.7%. Regarding the obstetrical events, two-thirds had meconium staining or aspiration and prolonged rupture of membrane. Initial arterial pH, CK and ionized calcium were not significantly different between normal and abnormal neurologic outcome group. All of 5 patients recovered from seizure after more than 5 days had neurologic sequelae (P= 0.008). Eight of 16 cases with abnormal EEG showed abnormal development, and all of 4 cases with normal EEG showed normal development. Eight of 12 cases with abnormal imaging study showed neurologic sequelae, however, all of 10 cases with normal study showed normal outcome (P=0.005).
CONCLUSION
This study suggests that seizure duration and imaging study are the best predicting factors for prognosis in full-term HIE. Although the EEG finding was not signigicant, the normal finding is expected to have good prognosis. The initial laboratory findings had no prognostic significance because of delayed blood sampling in most patients, who transferred from other hospitals after immediate postnatal resuscitation. We encourage the maternal transport especially when the high-risk delivery is anticipated.