Cerebral Hemodynamics in Premature Infants

Abstract

Extremely low birth weight infants remain at increased risk of intraventricular hemorr h age from the fragile vascular bed of the germinal matrix; the roles of hypotension (ische mia) and reperfusion (hyperemia) in the development of intraventricular he morrhage are still debated. Cerebrovascular pressure autoregulation protects the brain by maintaining constant cerebral blood flow despite changes in blood pres sure. The ontogeny of cerebrovascular pressure autoregulation has not been well established and uncertainty remains about the optimal arterial blood pressure required to support brain perfusion. Another important aspect of premature cerebral hemodynamics is the critical closing pressure-the arterial blood pressure at which cerebral blood flow ceases. Interestingly, in premature infants, the critical closing pressure approximates the mean arterial blood pressure. Often in this unique population, cerebral blood flow occurs only during systole when the diastolic arterial blood pressure is equal to the critical closing pressure. Moreover, the diastolic closing margin, a metric of cerebral per fusion that normalizes diastolic arterial blood pressure to the critical closing pressure, may be a better measure than arterial blood pressure for defining cerebral perfusion in premature infants. Elevated diastolic closing margin has been associated with intraven tricular hemorrhage. This review summarizes the current state of understanding of cerebral hemodynamics in premature infants.

Systemic Candidosis Diagnostic Test with Candida Score and Monocyte Count in Premature Infants with Late-Onset Sepsis: Research in Low Resources Country

“…It was previously known that the type and amount of antibiotics, such as the third generation cephalosporins, vancomycin or carbapenems, can predispose to candida infection, especially in the host with a compromised immune system. Repeated or long-term use of antibiotics will damage the normal flora balance, causing the proliferation of Candida albicans [25,26,27,28,29].…”

Effect of Kangaroo Mother Care on Cerebral Hemodynamics in Preterm Neonates Assessed by Transcranial Doppler Sonography in Middle Cerebral Artery

“…The neonatal period is the critical period of brain development and maturation [2]. Preterm neonates are especially susceptible to brain injury as they have immature cerebral vasculature and ineffective cerebral autoregulation, leading to the marked fluctuation in cerebral blood flow [3,4]. This results in cerebrovascular events like intraventricular hemorrhage and ischemic injury to periventricular white matter, which have long-term adverse neurodevelopmental problems in cognitive, motor, and behavioral domains [5].Globally, during the last two decades, there has been significant improvement in the survival of extremely preterm neonates due to advanced perinatal and neonatal intensive care practices.…”