Intrinsic or intermediate response
An intrinsic or intermediate response occurs over a
period of hours. The reduced capillary pressure provides
a movement of fluid from the interstitium to the vascular
compartment at a rate which can exceed 1 litre in the
first hour. Protein (mainly albumin) then moves fromthe interstitium to the plasma and, in the adult, up to a Clinical features
total of 2 L of fluid in 24-48 h may move from the
interstitial and intracellular compartments to the
intravascular compartment, to replace the intra-vascular
volume lost.10 Blood volume may also be replaced in
part by the osmotic effect of the elevation of blood
glucose during shock,11 increasing the vascular
compartment in an adult by approximately 17 mL for
each 1 mmol/L increase in blood glucose.