Mechanisms of blood pressure increase induced by dopamine in hypotensive preterm neonates
- aCentre for Heart and Chest Research Department of Medicine Monash Medical Centre 246 Clayton Road Clayton 3168 Victoria Australia, bDepartment of Paediatrics, cDepartment of Obstetrics and Gynaecology University of Queensland Brisbane Queensland Australia, dDepartment of Cardiology Royal Children’s Hospital Parkville Victoria Australia
- Dr J J Smolich. Email: joe.smolich{at}med.monash.edu.au
- Accepted 3 May 1999
Abstract
AIMS To compare changes in global haemodynamics as well as anterior cerebral and superior mesenteric artery perfusion after dopamine treatment.
METHODS Anterior cerebal and superior mesenteric artery perfusion was measured using Doppler ultrasonography in hypotensive preterm neonates in whom cardiac output increased (group 1, n=10) or decreased (group 2, n=40) after dopamine treatment.
RESULTS Despite a lower dopamine infusion rate, the blood pressure increase (mm Hg) in group 2 [Δ=13(1); mean(SE)] exceeded that in group 1 [Δ=8(1)], while systemic vascular resistance (mm Hg/l/min/kg) rose in group 2 [Δ=106 (37)], but was unchanged in group 1 [Δ=9 (6)]. Anterior cerebral artery blood velocity and resistance were unaffected by dopamine. However, compared with unchanged values in group 1, superior mesenteric artery blood velocity fell by 14.7(4.8) cm/s and resistance increased by 4.1(0.7) mm Hg/cm in group 2.
CONCLUSIONS These results suggest that, in a portion of hypotensive preterm neonates, the increase in blood pressure induced by dopamine is related to a predominant vasoconstrictor action and is associated with a fall in bowel perfusion.
