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Changes in cerebral blood volume and cytochrome aa3 during hypertensive peaks in preterm infants.

Publication ,  Journal Article
Brazy, JE; Lewis, DV
Published in: J Pediatr
June 1986

Relative changes in cerebral blood volume and in the oxidation/reduction state of cytochrome aa3, the terminal member of the electron transport chain in oxidative metabolism, can be simultaneously observed with near infrared spectroscopy. Using this technique, we studied movement-associated blood pressure elevations in three nonparalyzed very low birth weight infants receiving mechanical ventilation. We defined hypertensive peaks as increases in systolic and diastolic blood pressures greater than or equal to 30% over baseline and lasting at least 2 seconds. Ninety percent of monitored time, an increase in tissue blood volume (tBV) immediately followed each blood pressure elevation, with deoxygenated hemoglobin providing the sole or predominant increase in tBV. A simultaneous shift of cytochrome aa3 to a more reduced state usually accompanied the rise in tBV, probably indicating a transient imbalance between oxygen delivery and cellular oxygen utilization and a failure of mechanisms that normally regulate cerebral oxygenation. The consistent association of hypertensive peaks with body movement, coughing, and breath holding, and the predominant increase in deoxygenated hemoglobin suggest that increased intrathoracic pressure transiently impedes cerebral venous return. The repeated fluctuations in intracerebral blood volume and associated shifts to greater cytochrome aa3 reduction with hypertensive peaks provide a possible explanation for the association of fluctuating blood pressure patterns and increased risk for intraventricular hemorrhage.

Duke Scholars

Published In

J Pediatr

DOI

ISSN

0022-3476

Publication Date

June 1986

Volume

108

Issue

6

Start / End Page

983 / 987

Location

United States

Related Subject Headings

  • Pediatrics
  • Oxygen Consumption
  • Oxidation-Reduction
  • Movement
  • Infant, Premature, Diseases
  • Infant, Newborn
  • Hypertension
  • Humans
  • Electron Transport Complex IV
  • Cerebrovascular Circulation
 

Citation

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Brazy, J. E., & Lewis, D. V. (1986). Changes in cerebral blood volume and cytochrome aa3 during hypertensive peaks in preterm infants. J Pediatr, 108(6), 983–987. https://doi.org/10.1016/s0022-3476(86)80944-1
Brazy, J. E., and D. V. Lewis. “Changes in cerebral blood volume and cytochrome aa3 during hypertensive peaks in preterm infants.J Pediatr 108, no. 6 (June 1986): 983–87. https://doi.org/10.1016/s0022-3476(86)80944-1.
Brazy, J. E., and D. V. Lewis. “Changes in cerebral blood volume and cytochrome aa3 during hypertensive peaks in preterm infants.J Pediatr, vol. 108, no. 6, June 1986, pp. 983–87. Pubmed, doi:10.1016/s0022-3476(86)80944-1.
Journal cover image

Published In

J Pediatr

DOI

ISSN

0022-3476

Publication Date

June 1986

Volume

108

Issue

6

Start / End Page

983 / 987

Location

United States

Related Subject Headings

  • Pediatrics
  • Oxygen Consumption
  • Oxidation-Reduction
  • Movement
  • Infant, Premature, Diseases
  • Infant, Newborn
  • Hypertension
  • Humans
  • Electron Transport Complex IV
  • Cerebrovascular Circulation