Benefit of slow infusion of hypertonic saline/dextran in swine with uncontrolled aortotomy hemorrhage.

In laboratory models of uncontrolled hemorrhage, immediate resuscitation from hemorrhage is associated with high mortality. However, in clinical practice, resuscitation is often delayed and the rate of fluid administration is limited. We hypothesized that a slow rate of infusion after delayed resuscitation, reflecting the clinical environment, might improve survival in the presence of uncontrolled hemorrhage. To investigate the rate of administration in the presence of delayed resuscitation, we subjected anesthetized swine weighing 35 to 45 kg to wire suture abdominal aortotomy that resulted in an uncontrolled hemorrhage. After a 30-min delay, hemorrhaged swine were infused i.v. with 4 mL/kg hypertonic saline/Dextran solution (7.5% saline in 6% Dextran 70) administered as a bolus over 1 min or as a slow infusion over 12 min (the time period to administer a similar volume to a human with a gravity feed i.v. and an 18-gauge needle) and were then monitored for another 90 min. Survival increased to 78% (seven of nine) in the slow infusion group compared with a survival rate of 56% (five of nine) in the bolus group and 50% (7/14) in the untreated controls. Blood loss was significantly higher in the bolus group (926 +/- 77 mL) compared with the slow infusion (714 +/- 83 mL) and control groups (604 +/- 46 mL). Hypertonic saline/Dextran administered slowly significantly increased cardiac output and blood pressure. Taken together, these results are consistent with the hypothesis that resuscitation solutions can be effective for treatment of uncontrolled hemorrhage when administered at a slow infusion rate 30 min after the insult.