Hypertonic and hyperoncotic resuscitation from severe hemorrhagic shock in dogs: a comparative study.

Single bolus injections of hypertonic (7.5%) NaCl (H), hyperoncotic (6%) dextran-70 (D), or of their combination (HD) were given to severely bled (54.2 +/- 1.3 ml/kg) anesthetized dogs. Two shock procedures (30 or 60 min at 35 mm Hg) were tested. Survival was highest (11/12) after HD, lower (9/12) after H, and lowest (7/12) after D; it was higher (15/18 vs. 12/18) after the shorter vs. longer shock procedure. Cardiac index (CI) was restored to 83%-104% of prehemorrhage levels immediately after HD or H; 3 h later it was down to 67%-71% of control; after D, CI was stable at 41% to 50% of control; no differences in the relative performances of the agents tested in the 30 or 60-min shock durations. Arterial pressure recovered to near control levels in all groups; consequently, systemic vascular resistance was reduced after H and HD, but increased after D. Plasma volume recovered to 95% of control after H, 105% of control after HD, but only to 80% after D; however, the response to H was transient. Metabolic acidosis was partially reverted by all solutions. Plasma Na+ was transiently raised by H and HD. Overall differences detected between H vs. HD tend to favor HD as a resuscitative solution.