SERIAL MYOGLOBIN DETERMINATIONS IN NEONATES

Abstract

Rhabdomyolysis resulting in myoglobinemia is associated with renal failure in adults. We examined the hypothesis that birth asphyxia in neonates results in rhabdomyolysis with subsequent release of myoglobin. Serial serum samples were obtained on a population of 20 neonates (9 asphyxiated and 11 non-asphyxiated) during the first four days of life. Serum samples were analyzed by radioimmunoassay for myoglobin (NMS Pharmaceuticals, Inc., Newport Beach, CA). Asphyxia (5 minute Apgar ≤ 5) predicted an elevation of myoglobin (> 200 ng/ml) at 12 and 24 hours (Chi square, p < .005). Serum values comparable to those reported in adults with myoglobinemic renal failure were seen in some neonates. High serum myoglobin values (> 1000 ng/ml) at 12 hours were associated with severe oliguria at 24 and 48 hours (24 hrs= 0.27 ± .28 cc/kg/hr, 48 hrs = 0.70 ± .46 cc/kg/hr, n = 3). Myoglobinemia may be associated with poor urine output during the neonatal period and serum myoglobin determination may have a value as a marker for birth asphyxia. This preliminary study suggests that birth asphyxia results in rhabdomyolysis with the subsequent release of myoglobin in some neonates.