Hypotension in the Neonate

Abstract

After completing this article, readers should be able to: 1. Describe the relationship between blood pressure and birthweight, gestational age, and postnatal age. 2. Delineate potential negative consequences of treating hypotension in the neonate. 3. Characterize the evaluation of a neonate prior to treating suspected hypotension. 4. Describe current and potential future therapeutic options for treatment of neonatal hypotension. Deciding which neonates require treatment for a low arterial blood pressure (BP) often is difficult. To some extent, this has been due to a lack of normative BP data, particularly among preterm neonates. However, we now have reliable data relating birthweight, gestational age, and postnatal age to BP in term and preterm neonates. Nevertheless, the management of suspected hypotension in various neonatal intensive care units differs. Although there are good studies comparing various modes of therapy, prospective trials relating long-term outcome to treatment versus no treatment at various BP values have not been performed. Concern about the deleterious effects of hypotension is greater for preterm neonates primarily because of the relative inability to regulate cerebral blood flow in preterm neonates compared with infants who are born at term. ### Preterm Neonates Clearly, the primary issue surrounding possible hypotension in preterm neonates is the concern that these infants may experience impaired central nervous system perfusion, leading to ischemic damage. Low arterial BP has been associated with a decrease in cerebral blood flow, and the apparent impairment of autoregulation of cerebral blood flow in distressed infants emphasizes the importance of preventing both hypotension and rapid increases in BP in preterm neonates. Impaired autoregulation, demonstrated by near-infrared spectroscopy, and BP have been shown to be predictive of germinal matrix-intraventricular hemorrhage, periventricular leukomalacia, or both. When mean blood pressure (MBP) was measured continuously in neonates at gestational ages 26 to 30 weeks, a highly significant relationship was demonstrated between MBP less than …