Objective: To determine the dose related effects of continuous epinephrine (Epi) infusion on renal and mesenteric blood flow in both healthy and shocked newborn piglets. Methods: Superior mesenteric artery(SMA) and left renal artery (RA) ultrasonic flow probes were implanted into 16, 1-3 day old piglets. 2 d later, the effects of Epi on SMA and RA flow (f), mean arterial pressure (MAP) and CVP were measured in awake animals. Vascular resistances (vr) were calculated. Epi doses of 0.2, 0.4, 0.8, 1.6 and 3.2μg/kg/min were infused in random order for 20 minutes, with 15 minute recovery periods. Piglets were then hemorrhaged to mild hypotension (20 ml/kg) and Epi was repeated. Results: Percentage change from baseline is shown, Mean (SD).*=p<0.05 ANOVA. Conclusion: Low to moderate dose Epi does not cause renal or mesenteric ischemia either in the normovolemic or hypovolemic neonatal piglet. Hypovolemic shock has only minor effects on circulatory Epi responses, with a slight decrease in vasoconstriction.Table

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