OBJECTIVE: To investigate whether or not postasphyctic cerebral hypoperfusion and decreased cerebral metabolism occur in the perinatally asphyxiated neonate, as has been reported in adults and newborn animals. METHODS: Using near-infrared spectroscopy, we monitored changes in oxyhemoglobin (HbO2), deoxyhemoglobin (HbR), total hemoglobin (HbO2 + HbR, which represents changes in cerebral blood volume [CBV]), and cytochrome oxidase (Cytaa3, which indicates changes in oxidation level of this intracerebral mitochondrial enzyme). Thirty-one neonates (gestational age > 34 weeks), divided into three groups, were monitored between 2 and 12 hours or between 12 and 24 hours of life. Group I consisted of healthy newborns: N = 8 (2 to 12 hours) and N = 5 (12 to 24 hours). Patients in group II were moderately asphyxiated newborns but neurologically normal in the first 24 hours of life: N = 6 (2 to 12 hours) and N = 3 (12 to 24 hours). Group III consisted of severely asphyxiated newborns with an abnormal neurologic behavior within 24 hours after birth: N = 5 (2 to 12 hours) and N = 4 (12 to 24 hours). RESULTS: From 2 to 12 h, CBV levels in groups I and II were stable. In group III CBV decreased in all infants. This decrease in CBV was associated with a drop in both HbO2 and HbR. Cytaa3 was stable in groups I and II, but showed a marked decrease in two of the five infants of group III. There was a positive relationship between CBV and mean arterial blood pressure in groups II and III. Between 12 and 24 hours, all groups showed stable CBV and Cytaa3 patterns. A positive relation existed now between transcutaneous PCO2 and CBV in groups II and III. CONCLUSIONS: CBV, HbO2, HbR, and Cytaa3 decreased in the first 12 hours of life in severely asphyxiated neonates who subsequently developed neurologic abnormalities. We therefore suggest that posthypoxic-ischemic reperfusion injury of the brain during early neonatal life occurs in neonates with severe birth asphyxia.
OBJECTIVE: To investigate whether or not postasphyctic cerebral hypoperfusion and decreased cerebral metabolism occur in the perinatally asphyxiated neonate, as has been reported in adults and newborn animals. METHODS: Using near-infrared spectroscopy, we monitored changes in oxyhemoglobin (HbO2), deoxyhemoglobin (HbR), total hemoglobin (HbO2 + HbR, which represents changes in cerebral blood volume [CBV]), and cytochrome oxidase (Cytaa3, which indicates changes in oxidation level of this intracerebral mitochondrial enzyme). Thirty-one neonates (gestational age > 34 weeks), divided into three groups, were monitored between 2 and 12 hours or between 12 and 24 hours of life. Group I consisted of healthy newborns: N = 8 (2 to 12 hours) and N = 5 (12 to 24 hours). Patients in group II were moderately asphyxiated newborns but neurologically normal in the first 24 hours of life: N = 6 (2 to 12 hours) and N = 3 (12 to 24 hours). Group III consisted of severely asphyxiated newborns with an abnormal neurologic behavior within 24 hours after birth: N = 5 (2 to 12 hours) and N = 4 (12 to 24 hours). RESULTS: From 2 to 12 h, CBV levels in groups I and II were stable. In group III CBV decreased in all infants. This decrease in CBV was associated with a drop in both HbO2 and HbR. Cytaa3 was stable in groups I and II, but showed a marked decrease in two of the five infants of group III. There was a positive relationship between CBV and mean arterial blood pressure in groups II and III. Between 12 and 24 hours, all groups showed stable CBV and Cytaa3 patterns. A positive relation existed now between transcutaneous PCO2 and CBV in groups II and III. CONCLUSIONS: CBV, HbO2, HbR, and Cytaa3 decreased in the first 12 hours of life in severely asphyxiated neonates who subsequently developed neurologic abnormalities. We therefore suggest that posthypoxic-ischemic reperfusion injury of the brain during early neonatal life occurs in neonates with severe birth asphyxia.
Authors: J H Meek; C E Elwell; D C McCormick; A D Edwards; J P Townsend; A L Stewart; J S Wyatt Journal: Arch Dis Child Fetal Neonatal Ed Date: 1999-09 Impact factor: 5.747
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Authors: Paul P Drury; Joanne O Davidson; Lotte G van den Heuij; Sidhartha Tan; Richard B Silverman; Haitao Ji; Arlin B Blood; Mhoyra Fraser; Laura Bennet; Alistair Jan Gunn Journal: Exp Neurol Date: 2013-10-09 Impact factor: 5.330
Authors: A N Massaro; M Bouyssi-Kobar; T Chang; L G Vezina; A J du Plessis; C Limperopoulos Journal: AJNR Am J Neuroradiol Date: 2013-03-14 Impact factor: 3.825