Am. J. Respir. Crit. Care Med., Vol 155, No. 1, 01 1997, 32-37.
Systemic, pulmonary and mesenteric perfusion and oxygenation effects of dopamine and epinephrine
PY Cheung, KJ Barrington, RJ Pearson, DL Bigam, NN Finer and JE Van Aerde
The Perinatal Research Centre and Department of Pediatrics, University of Alberta, Edmonton, Canada.
The response of the systemic, pulmonary, hepatic and portal circulations to
infusion of dopamine and epinephrine was studied in newborn piglets 1 to 3
d of age. Anesthetized animals were instrumented to measure cardiac index
(CI), hepatic arterial flow, and portal venous blood flow. Catheters were
inserted for measurement of systemic arterial pressure (SAP), pulmonary
arterial pressure (PAP), and for sampling of arterial, portal venous, and
mixed venous oxygen saturations and plasma lactate levels. Systemic,
pulmonary and mesenteric vascular resistance indices (SVRI, PVRI, MVRI),
and systemic and mesenteric oxygen extraction were calculated. Dopamine and
epinephrine were infused in doses of 2, 10, 32 microg/kg/min and 0.2, 1.0,
3.2 microg/kg/min respectively, given in random order. Significant
increases in SAP, PAP, and CI were demonstrated with 32 microg/kg/min of
dopamine and the two higher doses (1.0 and 3.2 microg/kg/min) of
epinephrine. There were no significant changes in SVRI and PVRI with
dopamine infusions. Epinephrine at 3.2 microg/kg/min significantly elevated
SVRI and PVRI. The SAP/PAP ratio was decreased with 32 microg/kg/min of
dopamine whereas epinephrine did not affect the ratio. Dopamine had no
significant effect on hepatic arterial flow, portal venous flow, or
mesenteric vascular resistance. Epinephrine infusion at 3.2 microg/kg/min
decreased portal venous blood flow, total hepatic blood flow, and hepatic
oxygen delivery with an increase in calculated mesenteric vascular
resistance. Systemic and mesenteric oxygen extraction were not affected by
dopamine or epinephrine infusions. Plasma lactate levels were significantly
elevated with epinephrine infusion 3.2 microg/kg/min. The differential
responses of dopamine and epinephrine on pulmonary and mesenteric
circulations may be significant in the pathophysiology and management of
persistent fetal circulation and necrotizing enterocolitis.
