الفهرس 
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Abstract
Early postnatal preterm hemodynamic pathophysiology is characterized by low systemic blood flow (SBF) (Evans, 2009). Systemic hypotension is a relatively common complication of preterm birth and is associated with many complications such as peri-ventricular hemorrhage, peri-ventricular white matter injury and adverse neurodevelopmental outcome.
In the vast majority of pediatric patients, absolute hypovolemia is the primary cause of hypotension. However, especially during the immediate postnatal period, abnormal peripheral vaso-regulation and myocardial dysfunction are the most frequently encountered primary etiological factors of
hypotension in the preterm infant
There are no uniform criteria for the diagnosis of hypotension in the very low birth weight (VLBW) infant. A number of statistically defined normative blood pressure ranges do exist, which are gestational age, birth weight and postnatal age. These absolute values are frequently relied on for intervention.
However, although blood pressure is only one aspect of cardiovascular status and may not directly correlate with tissue perfusion, it is frequently relied on because cardiac output and vascular resistance are very difficult to measure in the newborn
One way of trying to increase the blood pressure and flow of blood is to increase the amount of fluid in the blood stream (volume expansion). This can be done with products such as albumin and salt solutions.
Dopamine and dobutamine are the inotropes most commonly used in neonatal intensive care. Dopamine, a naturally occurring precursor of noradrenaline, may have specific dopaminergic actions in addition to well recognized alpha and beta adrenergic effects. It is generally accepted that the inotropic and peripheral vasoconstrictor effects of dopamine predominate in the newborn period, although there is considerable controversy surrounding the existence of any vasodilator effects in renal, coronary and cerebral circulations. Dobutamine is a synthetic catecholamine with principally beta adrenergic actions. It has been suggested that it may offer the same beneficial inotropic effects as dopamine without the tendency for peripheral vasoconstriction
Several lines of evidence support a role for corticosteroids in the treatment of hypotension in preterm infants. Relative or absolute adrenocortical insufficiency is increasingly recognized as a cause of hypotension in the preterm infant.