Hematocrit Changes in Endotoxin Shock. ∗

Summary

Intravenous injection of Escherichia coli endotoxin (3 mg/kg) caused marked rises of arterial cell percentage in dogs with spleen bin. not in splenectomized clogs. The increase in arterial cell percentage can be divided into 2 phases. The initial phase (0 to 10 minutes after endotoxin) was seen in all dogs with spleen and is attributable to the contraction of the spleen, since the cell percentage in the portal venous blood was markedly elevated, in this initial phase, the extravasation of protein-rich fluid from the splanchnic circulation was accompanied by an influx of protein-poor fluid from the kidneys and possibly other areas, hence the circulating plasma protein concentration decreased. The second phase of increase of arterial cell percentage (20 to 60 minutes after endotoxin) was associated with a rise in arterial plasma, protein concentration and is ascribed to an extravasation of protein-poor fluid. This second phase was more marked in dogs which died within 200 minutes after endotoxin. There were no significant alterations in the cell size of the arterial blood, whereas the cells in the venous blood swelled after endotoxin when pCO₂ and acidity increased.