Low superior vena cava flow on day 1 and adverse outcome in the very low birthweight infant

Background: Superior vena cava (SVC) flow assesses blood flow from the upper body, and may provide a reliable assessment of systemic blood flow. Aim: (i) To assess the relationship between SVC flow in first 24 h and adverse outcome in very low birthweight (VLBW) infants (ii) To assess correlation between SVC flow and left and right ventricular outputs and anterior cerebral artery (ACA) velocity measurements. Methods: A prospective, observational cohort study. Neonates with birthweight <1500 g were eligible and those with congenital heart disease (excluding patent ductus arteriosus) or major congenital malformations were excluded. Echocardiographic evaluation of SVC flow, right and left ventricular outputs and ductal patency was done in the first 24 h of life. Capillary refill time, blood pressure and urine output were also measured simultaneously. The primary outcome was intraventricular haemorrhage (IVH) grade ≥ II and/or early neonatal death (<7 days). Results: 40 VLBW neonates were enrolled following parental consent. Two were excluded. 8 babies (21%) had low flow states. There was no difference between the cohorts in median birth weight (1.14 kg vs 1.17 kg; p = 0.76), gestational age (26.5 vs 28.0 weeks, respectively; p = 0.12) or hours of life at examination (18.5 h vs 21 h, respectively; p = 0.36). The incidence of primary outcome (IVH ≥ grade II and/or early neonatal death) was 50% and 6.7%, respectively (p = 0.01). There was no correlation between SVC flow and right ventricular outputs and ACA velocity and blood pressure measurements. Conclusions: 21% of our VLBW infants had low SVC flow in the first 24 h, and this was associated with early neonatal death and/or severe IVH.