Prognostic Value of Amplitude Integrated Electroencephalography (AEEG) and Near Infrared Spectroscopy (NIRS) in Cooled Infants with Hypoxic-Ischemic Encephalopathy (HIE)

Abstract

Background and aims: Brain cooling (BC) represents the elective treatment in asphyctic newborns. aEEG and NIRS monitoring may help to evaluate changes in cerebral electrical activity and cerebral hemodynamics during hypothermia. Aims: To evaluate the prognostic value of aEEG time course and NIRS data in asphyctic cooled infants. Methods: 12 term neonates admitted to our NICU with a moderate-severe HIE underwent selective BC. aEEG and NIRS monitoring were started as soon as possible and maintained during the whole hypothermic treatment. Follow-up was scheduled at regular intervals; adverse outcome was defined as death, cerebral palsy (CP) or global quotient < 88.7 at Griffiths' Scale. Results: 2/12 infants died, 2 developed CP, 1 was normal at 6 months of age and then lost at follow-up and 7 showed a normal outcome at least at 1 year of age. The aEEG background pattern at 24 hours of life was abnormal in 10 newborns; only 4 of them developed an adverse outcome, whereas the 2 infants with a normal aEEG developed normally. In infants with adverse outcome NIRS showed a higher Tissue Oxygenation Index (TOI) compared with those with normal outcome (80.0±10.5% vs 66.9±7.0%, p=0.057; 79.7±9.4% vs 67.1±7.9%, p=0.034; 80.2±8.8% vs 71.6±5.9%, p=0.069 at 6, 12 and 24 hours of life, respectively). Conclusions: The aEEG background pattern at 24 hours of life loses its positive predictive value after BC implementation; TOI could be useful to early predict non responder infants that may benefit from other innovative therapies.