High level of arginine vasopressin and 7.5% NaCl/6% dextran-70 solution: cardiovascular and renal effects.

A marked diuresis has been observed following resuscitation of hypotensive hemorrhaged animals with small volume hypertonic saline/dextran (HSD), 7.5% NaCl/6% dextran-70. We tested the hypothesis that high arginine vasopressin (AVP) levels associated with severe hemorrhage may exacerbate the diuretic effect of HSD infusion in euvolemic sheep. Following AVP infusion, a significant bradycardia (55% of baseline) and decreased cardiac output (62% of baseline) was observed (p < or = .05). Urine output increased during AVP infusion (25.4 +/- 2.3 ml/20 min) compared to control group (10.5 +/- 1.0 ml/20 min) (p < or = .0001). With HSD volume expansion, urine flow in the AVP group was initially 1.7 times greater than the control group (104.8 +/- 10 ml/20 min vs. 60.2 +/- 15 ml/20 min) (p < or = .05). High serum levels of AVP (600 +/- 33 pg/ml) may contribute to the diuresis seen with HSD resuscitation and possibly contribute to the bradycardia observed with severe hemorrhage.