HIGH-LEVEL OF ARGININE-VASOPRESSIN AND 7.5-PERCENT NACL 6-PERCENT DEXTRAN-70 SOLUTION - CARDIOVASCULAR AND RENAL EFFECTS

A marked diuresis has been observed following resuscitation of hypoten sive hemorrhaged animals with small volume hypertonic saline/dextran ( HSD), 7.5% NaCl/6% dextran-70. We tested the hypothesis that high argi nine vasopressin (AVP) levels associated with severe hemorrhage may ex acerbate the diuretic effect of HSD infusion in euvolemic sheep. Follo wing AVP infusion, a significant bradycardia (55% of baseline) and dec reased cardiac output (62% of baseline) was observed (p less-than-or-e qual-to .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 less -than-or-equal-to .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 less-than-or-equal-t o .05). High serum levels of AVP (600 +/- 33 pg/ml) may contribute to the diuresis seen with HSD resuscitation and possibly contribute to th e bradycardia observed with severe hemorrhage.