Background Using an age-appropriate new dobutamine formulation, the aims of the study were: to validate superior vena cava flow (SVCF) as a marker of cardiac output (CO), and to study drug-related changes in haemodynamics and oxygen metabolism in response to escalating doses of dobutamine in hypoxic neonatal piglets.
Methods 2–days-old-piglets were exposed to hypoxia (10–15% oxygen) for 2 h followed by reoxigenation with 21–30% oxygen for 6 h. After 60-min of reoxigenation, 18 piglets were randomised to: Control group, hypoxic animals without treatment, and 10–15 µg/kg/min or 15–20 µg/kg/min dose groups, each animal received two doses of dobutamine (Proveca Ltd.) during 30-min with 60-min washout period between doses. All animals were monitored for arterial blood pressure (MABP), heart-rate (HR), CO, stroke-volume-index (SVI), systemic-vascular-resistance-index (SVRI), oxygen-delivery (OD), systemic consumption (VO2) and fractional-tissue-oxygen extraction (FTOE). In three animals an ultrasonic perivascular flow probe was placed around superior vena cava to continuously measure SVCF. Statistics: Mean ± SD, ANOVA, p < 0.05.
Result A good positive correlation was observed between SVCF and CO. Hypoxia resulted in a significant decreased on CO, SVI, SVRI and MABP. All dobutamine doses improved significantly HR, CO and SVRI without changes in SVI and MABP. All doses increased OD but only 10–15 µg/kg/min increased VO2 without changes in FTOE.
Conclusion The new dobutamine formulation targeted to support neonatal cardiovascular function reveals a significant improvement of haemodynamic status, but dose-specific differences in metabolic response in hypoxic neonatal piglets. Further studies are needed to evaluate those drug effects in other vital organs. FP7-HEALTH-F5–2011 (nº282533).