Neonatal organ system injury in acute birth asphyxia sufficient to result in neonatal encephalopathy

OBJECTIVE: To identify the proportion of major organ system injury in cases of acute intrapartum asphyxia that result in neonatal encephalopathy. METHODS: A prospectively maintained database was cross-referenced using medical record coding to identify diagnoses of acute intrapartum asphyxia, acute birth asphyxia, or neonatal encephalopathy over a 6-year period. An acute intrapartum asphyxial antecedent was validated with emphasis on excluding long-standing or chronic conditions where injury likely occurred before presentation. Injury pattern was evaluated using routinely available laboratory and imaging tests. RESULTS: Forty-six cases of acute peripartum asphyxia sufficient to result in the diagnosis of neonatal encephalopathy were identified. Clinical central nervous system injury resulting in encephalopathy was present in 100% of cases as it was an entry criteria; of these, 49% had electroencephalogram and 40% had imaging studies diagnostic of acute injury. Liver injury based on elevated aspartate transaminase or alanine transaminase levels occurred in 80%. Heart injury, as defined by pressor or volume support beyond 2 hours of life or elevated cardiac enzymes, occurred in 78%. Renal injury, defined by an elevation of serum creatinine to greater than 1.0 mg/dL, persistent hematuria, persistent proteinuria, or clinical oliguria, occurred in 72%. An elevation in nucleated red blood cell counts exceeding 26 per 100 white blood cells occurred in 41%. CONCLUSION: Using common diagnostic tests as markers of acute asphyxial injury, we noted that multiple organs suffer damage during an acute intrapartum asphyxial event sufficient to result in a neonatal encephalopathy.