The controversy over a policy of "scoop and run" or stabilizing hemorrhagic shock when evacuation time is short has not yet been settled. Small volumes of hypertonic saline have been suggested as effective therapy when the scoop-and-run policy is adopted. In the present study small-volume hypertonic saline treatment and normal saline treatment of "uncontrolled" hemorrhagic shock (UCHS) in rats were compared with no treatment, which best simulates the scoop-and-run policy. The rats were randomly assigned to three groups. Uncontrolled hemorrhagic shock was induced by 12% resection of the terminal portion of the rats' tails. In group I (n = 13) the animals were untreated. In group II (n = 6) UCHS was treated by administering 41.5 mL/kg 0.9% NaCl (NS). In group III (n = 6) UCHS was treated by administering 5 mL/kg 7.5% NaCl (HTS). Resection of the rats' tails in group I was followed by bleeding of 3.3 +/- 0.3 mL in 15 minutes with a fall in mean arterial pressure (MAP) from 100.9 +/- 7 to 63.5 +/- 5 mm Hg (p less than 0.001). The early bleeding and hemodynamic responses were similar in all three groups. Further blood loss in the first hour in group I was 0.5 +/- 0.2 mL, and MAP rose spontaneously to 73.2 +/- 6 mm Hg (p less than 0.05). The NS infusion in group II was followed by further bleeding of 4.1 +/- 0.9 mL (p less than 0.01) and a further fall in MAP to 53.8 +/- 7 mm Hg (p less than 0.01) after 60 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)