Blood volume, bleeding volume and tolerance to hemorrhage in the splenectomized dog

Abstract

The relation between blood volume reduction and survival was studied in 28 experiments on 20 splenectomized dogs using Walcott's bleed-out and replacement procedure for adjusting the blood volume to the critical range. Plasma volume was measured with T-1824 and blood volume calculated using the Fcells factor of 0.87. Control blood volumes averaged 95 ml/kg in the lean dogs and 78 ml/kg in medium fat dogs. However, the bleeding percentage (bleeding volume as percentage of blood volume) was nearly the same in both groups with an over-all average of 57%. Fifty per cent survival was computed to occur at 66% of the initial blood volume, the critical range extending from 62 to 74%. The volume of fluid replaced by compensatory dilution averaged 10% of the control blood volume.