POSTMORTEM CONCENTRATIONS OF HYPOXANTHINE IN THE VITREOUS-HUMOR - A COMPARISON BETWEEN BABIES WITH SEVERE RESPIRATORY-FAILURE, CONGENITAL-ABNORMALITIES OF THE HEART, AND VICTIMS OF SUDDEN-INFANT-DEATH-SYNDROME

Post-mortem hypoxanthine concentrations in the vitreous humor of human infants were investigated. Hypoxanthine is formed from hypoxic degrad ation of adenosine monophosphate. The concentrations in the vitreous h umor can give information about ante-mortem hypoxia. The post-mortem l evels were corrected for the time elapsing between death and the autop sy. Four groups of infants were compared: 17 babies who died of respir atory distress syndrome (RDS), 72 infants who died of sudden infant de ath syndrome (SIDS), 23 children dying of congenital heart disease (bo th cyanotic and acyanotic), and 15 children dying acutely in accidents without any known significant time of hypoxia before death. The corre cted, median hypoxanthine levels in victims of SIDS (200 mumol/L) was significantly higher (p < 0.01) than in the accident group (0 mumol/L) , but no clear difference was found between the SIDS group and the RDS group (101 mumol/L), or the heart group (54 mumol/L). A number of chi ldren with ''normal'' hypoxanthine levels (0 to 38 mumol/L) were found in all four groups, but the numbers were significantly lower (p < 0.0 05) in the RDS, SIDS and heart groups than in the accident group. It i s concluded that SIDS is probably not a sudden event, but may be prece ded by relatively long, or repeated intermittent periods of hypoxia (o f unknown etiology).