Fig. 3

Proposed effects of capillary hydrostatic pressure (P _C) on fluid flow and hydroxyethyl starch (HES) permeation across capillaries. The increase in P _C resulting from vasodilation increases fluid flow and HES permeation across capillaries (lower left panel). The use of vasopressors attenuates the increases in fluid flow and HES permeation across capillaries by normalizing P _C. When P _C is low in collapsed capillary under hypovolemia, most of the infused HES solution is retained in the intravascular space (lower right panel), whereas vasopressor worsens tissue perfusion by further lowering P _C. ESL endothelial surface layer