Systemic and regional oxygen uptake and lactate flux in endotoxic dogs resuscitated with dextran and dopexamine or dextran alone.

: We examined how volume resuscitation with and without dopexamine, a potent beta 2-adrenergic and dopaminergic agonist, would affect O2 uptake (VO2), O2 delivery (DO2), and lactate metabolism in whole body, skeletal muscle, and gut of 18 anesthetized dogs after they were infused for 1 hr with 2 mg/kg endotoxin. Six dogs were then infused with dextran for 2 hr at 0.5 ml/kg/min (DEX); another six were given the same volume with 12 micrograms/kg/min dopexamine (DPX); and a third group received no treatment (NT). After endotoxin, all animals were hypotensive; cardiac output decreased 30%; and DO2 to whole body, skeletal muscle, and gut were at or below critical for VO2. DO2 was raised above critical in whole body and gut of DEX and DPX but not in muscle of DPX, which produced lactate. Whole body DO2 approached preendotoxin level by 2 hr in DEX and DPX but stayed near critical in NT. At that time, gut VO2 was higher in DPX than in DEX or NT, and lactate efflux became less than in DEX. Vascular reactivity was present in the gut at the end of the experiment in six of six DPX studies, in four of six DEX studies, and in none of the NT studies. These results suggest that resuscitation with dopexamine + dextran after induction of endotoxic shock may be more beneficial than dextran alone, particularly for the gut mucosa.