Volume of circulatory blood

The volume of circulatory blood. The volume of circulatory blood is a genetic value and makes up 68-70 ml/kg for men and 65-69 ml/kg for women. The changes of these values are attributed to water and electrolyte imbalance, as well as to the diseases of intestinal tract and kidneys.

Hypovolaemia is a reduced circulating blood volume, and if not treated can contribute to delayed recovery following surgery.

The consequence of an impaired circulating blood volume and subsequent oxygen debt across the perioperative period was first identified by Shoemaker et al. [1] in the early 1990s. The authors demonstrated that patients who maintained higher oxygen delivery across the perioperative period, were more likely to survive when compared to those with impaired oxygen delivery. This has been further established in the many studies published since (see Outcome studies).

The poorer patient outcome associated with hypovolaemia can be attributed to the following physiological changes [2, 3]:

Splanchnic bed vessels vasoconstrict to ensure adequate flow is directed towards the ‘vital’ organs (i.e., the heart and brain).

This hypoperfusion and resulting hypoxia can cause necrosis of the gut mucosa.

Damage to the mucosa allows bacteria and endotoxins to ‘leak’ from the gut lumen into the bloodstream.

Toxins unable to be broken down by the liver may enter the systemic circulation, potentially resulting in multiple organ dysfunction syndrome.

1.    Shoemaker, W.C., P.L. Appel, and H.B. Kram, Role of oxygen debt in the development of organ failure sepsis, and death in high-risk surgical patients. Chest, 1992. 102(1): p. 208-15.

2.    Fiddian-Green, R.G., Splanchnic ischaemia and multiple organ failure in the critically ill. Ann R Coll Surg Engl, 1988. 70(3): p. 128-34.

3.    Deitch, E.A., The role of intestinal barrier failure and bacterial translocation in the development of systemic infection and multiple organ failure. Arch Surg, 1990. 125(3): p. 403-4.

4.    https://www.deltexmedical.com/decision_tree/circulating-blood-volume/