A comparison of combination dopamine and epinephrine treatment with high-dose dopamine alone in asphyxiated newborn piglets after resuscitation.
BACKGROUND
When asphyxiated neonates require additional cardiovascular support to moderate doses of dopamine infusion, controversy exists on the differential hemodynamic effects of two approaches (adding a second inotrope vs. increasing dopamine dosage). We hypothesized that high-dose dopamine (HD) would be detrimental to systemic and regional perfusion as compared with dopamine and epinephrine (D + E) combination therapy using a swine model of neonatal hypoxia-reoxygenation (H-R).


METHODS
Twenty-seven piglets (1-4 d, 1.5-2.5 kg) were used for continuous monitoring of systemic arterial pressure (mean arterial pressure, MAP) and pulmonary arterial pressure (PAP), cardiac output (cardiac index, CI), and carotid (carotid artery flow index, CAFI), superior mesenteric (superior mesenteric artery flow index), and renal arterial flows. H-R piglets underwent 2 h of hypoxia followed by 2 h of reoxygenation before drug infusion (2 h).


RESULTS
The hemodynamics of H-R piglets deteriorated gradually after reoxygenation. HD and D + E infusions improved CI similarly (both groups vs. control; P < 0.05). Both regimens increased MAP (P < 0.05) but not PAP, with decreased PAP/MAP ratio in D + E piglets. Both regimens improved CAFI and superior mesenteric artery flow index, with decreased mesenteric vascular resistance in HD-treated piglets. No significant effect on renal perfusion was observed.


CONCLUSIONS
In H-R newborn piglets treated with a moderate dose of dopamine, adding epinephrine or further increasing dopamine improved systemic hemodynamics similarly; these treatments have differential effects on the pulmonary and mesenteric circulations.
Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
Namdar
N
Manouchehri
David L
DL
Bigam
Thomas
T
Churchill
David
D
Rayner
Chloe
C
Joynt
Po-Yin
PY
Cheung
D000818:Animals; D000831:Animals, Newborn; D062186:Arterial Pressure / Q000187:drug effects; D001238:Asphyxia Neonatorum / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D015415:Biomarkers / Q000097:blood; D002302:Cardiac Output / Q000187:drug effects; D002316:Cardiotonic Agents / Q000008:administration & dosage*; D002339:Carotid Arteries / Q000187:drug effects / Q000503:physiopathology; D004195:Disease Models, Animal; D004298:Dopamine / Q000008:administration & dosage*; D004359:Drug Therapy, Combination; D004837:Epinephrine / Q000008:administration & dosage*; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007022:Hypotension / Q000503:physiopathology / Q000628:therapy; D007231:Infant, Newborn; D010100:Oxygen / Q000097:blood; D011651:Pulmonary Artery / Q000187:drug effects / Q000503:physiopathology; D012079:Renal Circulation / Q000187:drug effects; D012151:Resuscitation; D012770:Shock, Cardiogenic / Q000503:physiopathology / Q000628:therapy; D013152:Splanchnic Circulation / Q000187:drug effects; D013552:Swine; D013997:Time Factors; D014336:Troponin / Q000097:blood; D014655:Vascular Resistance / Q000187:drug effects
D015415:Biomarkers; D002316:Cardiotonic Agents; D014336:Troponin; D010100:Oxygen; D004298:Dopamine; D004837:Epinephrine