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Neuropediatrics 1988; 19(1): 27-32
DOI: 10.1055/s-2008-1052397
© Georg Thieme Verlag KG Stuttgart · New York

The Influence of Abnormal Blood Gases on Cerebral Blood Flow Velocity in the Preterm Newborn

F.  van Bel1 , Margot  van de Bor1 , J.  Baan1 , J. H. Ruys1 , T.  Stijnen2
  • 1Department of Pediatrics, University Hospital Leiden, Rijnsburgerweg 10, 2333 AA, Leiden, The Netherlands
  • 2Department of Medical Statistics, University Hospital Leiden, Rijnsburgerweg 10, 2333 AA, Leiden, The Netherlands
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Publication History

Publication Date:
19 March 2008 (online)

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Abstract

The influence of hypercarbia, combined hypercarbia and hypoxemia, and hypocarbia on cerebral blood flow of preterm infants with a gestational age of less than 34 weeks was investigated by measuring peak systolic flow velocity (PSFV), end diastolic flow velocity (EDFV), pulsatility index (PI) and area under the velocity curve (AUVC) of the anterior cerebral artery (ACA) using transcutaneous Doppler technique. Mild and moderate hypocarbia did not change cerebral blood flow velocity. During severe hypercarbia (PaCO2≥6.7 kPa) significantly lower PI-values were detected, mainly caused by an increase of EDFV, indicating a decreased cerebrovascular resistance and increased cerebral blood flow. A highly significant decrease in PI-values during combined severe hypercarbia and hypoxemia (PaO2 < 6.0 kPa) was found suggesting that hypoxemia superimposed on hypercarbia strengthens the increase of cerebral blood flow. While the increase of EDFV is thought to be due to carbon dioxide-induced vasodilation of cerebral arterioles, we assume that the accompanied increase of PSFV during combined hypercarbia and hypoxemia is caused by an increase in cardiac output due to hypoxemia which can alter the blood flow velocity wave form of the ACA.

Key words

Blood gases - Cerebral blood flow

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