Cardiovascular support of the sick neonate

Summary 

From fetal through to adult life the cardiovascular system undergoes striking developmental changes that determine cardiovascular function in health and disease. An appreciation of these changes aids our understanding of the therapeutic approaches to supporting the cardiovascular system in sick newborns. Cardiovascular assessments should include not only the blood pressure, but fluid balance, acid–base balance, electrolytes, cardiopulmonary interactions, and the potential haemodynamic contributions of a patent ductus arteriosus. As prolonged systemic hypotension may be detrimental it should be effectively managed. The major contributor to neonatal hypotension is not hypovolaemia but impaired myocardial function and regulation of peripheral vascular tone. Routine volume expansion should therefore be restricted to 10–20ml/kg and greater attention given to the pharmacological regulation of peripheral vascular tone and treating myocardial dysfunction. There is also increasing recognition of the role of glucocorticoids in modulating the cardiovascular responsiveness to catecholamines and the beneficial effects of steroid administration to infants with refractory hypotension.

Keywords: Blood pressure, Hypotension, Hypovolaemia, Peripheral vascular tone, Patent ductus arteriosus, Myocardial dysfunction, Dopamine, Dobutamine, Epinephrine, Norepinephrine