Quantitative measurement of bleeding following hypertonic saline therapy in 'uncontrolled' hemorrhagic shock

The effect of small volume hypertonic saline in "uncontrolled" hemorrhagic shock (UCHS) induced by partial resection of the tail was studied in rats. The rats were divided into three groups: in group 1 (n = 15) 10% of the terminal portion of the animal's tail was resected to induce UCHS. In group 2 (n = 14) UCHS was induced as in group 1 and after 5 min 5 ml/kg NaCl 0.9% (NS) was infused intravenously. In group 3 (n = 22) UCHS was induced as in group 1 and after 5 min, 5 ml/kg NaCl 7.5% (HTS) was infused intravenously. Resection of the animal's tail was followed by bleeding of 3.5 +/- 0.3 ml within 5 min, fall in MAP to 63 +/- 4 torr (p less than 0.001) and pulse to 300 +/- 18 per min (p less than 0.05). The amount of bleeding, fall in MAP, and pulse after 5 min were similar in the three groups. Further blood loss after 60 min in group 1 was 3.7 +/- 0.8 ml, in group 2, 2.9 +/- 0.5 ml, and in group 3, 6.5 +/- 0.8 (p less than 0.01). Increased bleeding in group 3 showed two peaks: an early peak of 1.3 +/- 0.2 ml after 15 min (p less than 0.05) and a late peak of 1.2 +/- 0.4 ml at 45 min (p less than 0.05) and 1.7 +/- 0.5 ml at 60 min (p less than 0.01). MAP fell after 60 min to 54 +/- 7 torr in group 1 (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)