Blood Pressure Disorders in the Neonate: Hypotension and Hypertension

Abstract

Blood pressure (BP) disorders are an extremely common problem in neonates admitted to the neonatal intensive care unit (NICU). Direct invasive measurement (via an arterial or peripheral artery catheter) is currently considered the optimum for measuring BP. Usually, mean blood pressure rather than systolic pressure is used. Normal blood pressure in newborns varies with gestational age, birth weight, and postnatal age, increasing by 1–2 mmHg per week for the first month. The clinical features of hypotension in the neonate include tachycardia, bradycardia, tachypnea, mottling of the skin, prolonged capillary refill time, cool extremities, and decreased urine output. Normal saline is the preferred fluid for volume expansion. Dopamine and dobutamine are the most commonly used agents to treat hypotension, although norepinephrine is preferred by some clinicians. Many hypotensive pre-term infants have low cortisol levels, and corticosteroids are being used increasingly to prevent or treat hypotension. There is an association between systemic hypotension and neonatal morbidities such as intraventricular hemorrhage and poor neurodevelopmental outcomes. Hypertension, while less common, can also lead to significant short- and long-term morbidities. It is important to determine whether any renovascular anomalies were detected prior to birth. The history may include drug abuse, perinatal asphyxia, umbilical catheter placement, or medications administered to the neonate. It is important to measure the BP in all four extremities to rule out coarctation of the aorta. Some infants may require prolonged treatment with beta-blockers, angiotensin-converting enzyme inhibitors, calcium channel blockers, and/or diuretics. Blood pressure should not be decreased too quickly in hypertensive neonates as cerebral perfusion pressure may be adversely affected.