Abnormal cerebral haemodynamics in perinatally asphyxiated neonates related to outcome

Aim-To measure changes in cerebral haemodynamics during the first 24 hours of life following perinatal asphyxia, and relate them to outcome. Methods-Cerebral blood volume (CBV), its response (CBVR) to changes in arte rial carbon dioxide tension (PaCO2), and cerebral blood flow (CBF) were mea sured using near infrared spectroscopy (NIRS) in 27 term newborn infants wi th clinical and/or biochemical evidence consistent with perinatal asphyxia. Results-Both CBF and CBV were higher on the first day of life in the infant s with adverse outcomes, and a CBV outside the normal range had a sensitivi ty of 86% for predicting death or disability. The mean (SD) CBVR on the fir st day of life was 0.13 (0.12) ml/100 g/1/kPa, which, in 71% of infants, wa s below the lower 95% confidence Limit for normal subjects. Conclusion-An increase in CBV on the first day of life is a sensitive predi ctor of adverse outcome. A reduction in CBVR is almost universally seen fol lowing asphyxia, but is not significantly correlated with severity of adver se outcome.