Effect of small-dose dopamine on mesenteric blood flow and renal function in a pig model of cardiopulmonary resuscitation with vasopressin.

Abstract

Vasopressin (antidiuretic hormone) seems a promising alternative to epinephrine for cardiopulmonary resuscitation (CPR) in cardiac arrest victims, mediating a pronounced blood flow shift toward vital organs. We evaluated the effects of small-dose dopamine on splanchnic blood flow and renal function after successful resuscitation with this potent vasoconstrictor in an established porcine CPR model. After 4 min of cardiac arrest and 3 min of CPR, animals received 0.4 U/kg vasopressin and were continuously infused with either dopamine 4 microg x kg(-1) x min(-1) (n = 6), or saline placebo (n = 6). Defibrillation was performed 5 min after drug administration; all animals were observed for 6 h after return of spontaneous circulation. During the postresuscitation phase, average mean +/- SD superior mesenteric artery blood flow was significantly (P = 0.002) higher in the dopamine group compared with the placebo group (1185+/-130 vs 740+/-235 mL/min), whereas renal blood flow was comparable between groups (255+/-40 vs 250+/-85 mL/min). The median calculated glomerular filtration rate had higher values in the dopamine group (70-120 mL/min) than in the placebo group (40-70 mL/min; P = 0.1 at 0 min and P = 0.08 at 360 min). We conclude that small-dose dopamine administration may be useful in improving superior mesenteric artery blood flow and renal function after successful resuscitation with vasopressin. Long-term survival after cardiac arrest may be determined by the ability to ensure adequate organ perfusion during cardiopulmonary resuscitation and in the postresuscitation phase. In this regard, small-dose dopamine improved postresuscitation blood flow to the mesenteric bed when vasopressin was used as an alternative vasopressor in an animal model of cardiac arrest.