Low-dose dopamine preserves renal blood flow in endotoxin shocked dogs treated with ibuprofen.

Drugs that inhibit prostaglandin (PG) biosynthesis improve hemodynamics and survival in experimental endotoxic and septic shock. The therapeutic utility of these agents in the management of septic patients may be limited, however, by their tendency to decrease renal blood flow (RBF) in animals and humans stressed by experimental manipulations or disease states that promote renal vasoconstriction. In the present study, we addressed this question: can low-dose intravenous (iv) dopamine (4 micrograms/kg/min), a known renal vasodilator, improve renal perfusion in endotoxin-shocked dogs treated with the PG synthesis inhibitor, ibuprofen. RBF was measured in pentobarbital anesthetized dogs using an electromagnetic flow meter. After obtaining baseline hemodynamics, Escherichia coli endotoxin (1.5 mg/kg) was given iv. The dogs were randomized 30 min later into three groups: Group I received saline; Group II received ibuprofen (12.5 mg/kg, iv); Group III received ibuprofen plus dopamine. Comparison of Groups I and II revealed that ibuprofen increased mean arterial pressure (MAP) and systemic vascular resistance (SVR) (P less than 0.0001 and P = 0.002, respectively) and decreased RBF (P = 0.019). Adding low-dose dopamine (Group II vs Group III) did not significantly affect MAP or SVR, but did augment RBF (P less than 0.001). We conclude that low-dose dopamine improves renal hemodynamics in ibuprofen-treated endotoxemic dogs.