Vulnerability to IVH and PVL
As a protective mechanism, blood flow in the brain is regulated to maintain adequate circulation. Autoregulation is the ability to maintain cerebral blood flow despite changes in cerebral perfusion pressure; cerebral vessels constrict when pressure rises and dilate when pressures decrease. The ability of premature infants to autoregulate, however, is not clear.[13–18] Absence of autoregulation or severe changes in cerebral blood flow is hypothesized to cause central nervous system complications including cerebral white matter damage, PVL, and IVH.[2,19]
Intraventricular hemorrhage is characterized as bleeding in the germinal matrix primarily during the first week of life, and it occurs in 1 in 4 premature infants because of fluctuations in cerebral blood flow. Marked areas of necrotic cerebral tissue distinguish PVL from other neurologic diagnoses and results from episodes of ischemia often because of low blood pressure. No real-time measure exists to identify infants with impaired autoregulation. Therefore, these two neurologic diagnoses are commonly discovered via head ultrasound or magnetic resonance imaging after the first week of life when neurologic damage has already occurred. Cerebral oxygenation as a proxy to monitor changes in cerebral blood flow related to IVH or PVL may serve as a viable measure to noninvasively screen for impairment in autoregulation.
NAINR. 2011;11(3):153-159. © 2011 Elsevier Science, Inc.
Cite this: Cerebral Oxygenation Monitoring - Medscape - Sep 01, 2011.