Evaluation of Prognostic Findings in Newborns with Hypoxic Ischemic Encephalopathy: 5-Year Experience

Hypoxic-ischemic encephalopathy (HIE) is a constellation of neurological signs as a result of hypoxia, hypercapnia, metabolic acidosis, and cerebral ischemia before birth. The aim was to evaluate risk factors, clinical and laboratory findings, and morbidity and mortality in neonates diagnosed with HIE who underwent therapeutic hypothermia (TH). Between January 2015 and December 2020, neonates diagnosed with HIE were evaluated in the neonatal intensive care unit. Risk factors, sociodemographic characteristics, degree of encephalopathy, clinical and laboratory findings, results of amplitude-integrated electroencephalography (aEEG), electroencephalography (EEG), magnetic resonance imaging (MRI) including diffusion weighted imaging (DWI) and cranial ultrasound (cUS), and mortality were retrospectively recorded. Of the 81 cases, we followed up with a diagnosis of HIE. When the patients were divided into groups and evaluated according to the Sarnat & Sarnat staging system, it was observed that 22 (27.2%) of the patients had mild HIE, 49 (60.5%) of the patients had moderate HIE, and 10 (12.3%) of the patients had severe HIE. The aEEG, EEG, DWI, and renal pathology of patients with seizures were statistically significantly higher than those of patients without seizures (<i>p</i> = 0.004, <i>p</i> = 0.002, <i>p</i> = 0.014, <i>p</i> = 0.025). MRI was performed in 66 patients within the first 7 days of life, and diffusional restriction was found in 22 of them. We found that DWI is superior to cUS in determining the severity of hypoxic injury and that renal involvement may be associated with poor neurodevelopmental outcomes. Due to the abnormal prognostic findings detected in infants with mild HIE, the existence of a standard definition of mild HIE that will determine the efficacy and reliability of therapeutic hypothermia will enable at risk infants to benefit from neuroprotective strategies.