Neonatal shock frequently complicates extremely preterm delivery, severe respiratory distress, asphyxia and sepsis. Early recognition and rapid targeted treatment are essential. Echocardiographic assessment is required to differentiate between infants with high and low systemic vascular resistance. Echocardiography assesses structural normality of the heart, the presence of shunts across the adapting heart, the pulmonary circulation, cardiac filling and myocardial contractility although measures of cardiac filling and myocardial contractility are poorly validated in newborn infants. SVC flow is the best surrogate of systemic blood flow (SBF) in infants with an atrial or ductal shunt, with LVO or RVO used as a cross-check or in infants with no evidence of shunt. Hypovolaemia is infrequent but may complicate peripartum fetal blood loss or neonatal surgical conditions (eg necrotising enterocolitis) and sepsis. Volume expansion and inotropes should be selected for their desired effect on pulmonary and systemic circulations and titrated to clinical and echocardiographic evidence of response - improvements in oxygenation, BP, pulmonary and SBF. Further studies are required to determine the appropriate targets (blood pressure or SBF) of treatment and treatment thresholds.
