Instantaneous restoration of regional organ blood flow after severe hemorrhage: effect of small-volume resuscitation with hypertonic-hyperoncotic solutions.

The acute effects of small-volume infusion of hypertonic-hyperoncotic solutions on central hemodynamics, regional organ blood flow (RBF; 15-microns-diameter radiolabeled microspheres), and respiratory function following severe hemorrhage (MAP = 40 mm Hg for 45 min, approx 50% blood loss) were analyzed in anesthetized beagles. Treatment regimens used were: 10% Dextran 60 in 7.2% NaCl (HHS); 10% Dextran 60 in 0.9% NaCl (HDS); or 7.2% NaCl (HSS) alone, administered over 2 min in a volume equivalent to 10% of the blood loss (4 ml/kg iv). Within 5 min, cardiac output reached (HSS, HDS) or even exceeded prehemorrhage values (HHS), and MAP increased to 56% (HDS)-74% (HHS) of baseline. At the same time, RBF in kidneys (all groups), pancreas (HHS, HSS) and gastric mucosa (HHS) was completely restored, while flow in myocardium, brain, skeletal muscle, adrenal glands (all groups), and small intestine and colon (HHS) rose even above baseline values (P less than 0.05). Fractional blood flow (percentage of cardiac output) favored heart and brain in all three groups. These effects tended to persist for at least 30 min. Respiratory function was not affected by either of the three solutions, and no adverse effects were noted. Small-volume resuscitation with 7.2% saline/10% Dextran 60 provides instantaneous restitution of regional organ blood flow; it appears to result in a more uniform circulatory response than 7.2% saline or 10% Dextran 60 alone and might ensure improved organ perfusion during evacuation of patients from the accident site.