American Board of Cardiovascular Perfusion (ABCP) Board Practice Exam

Oncotic pressure is a type of osmotic pressure exerted by proteins, primarily albumin, in the blood plasma that helps retain water within the circulatory system. In the context of capillaries, the oncotic pressure plays a vital role in fluid exchange between the blood and the surrounding tissues.

The typical oncotic pressure of an average capillary is approximately 28 mmHg. This value is reflective of the concentration of plasma proteins which create a gradient that draws water into the capillaries, balancing the hydrostatic pressure that tends to push fluid out of the capillaries.

Understanding this value is essential for perfusionists and those in the cardiovascular field, as it informs decisions about fluid management during surgical procedures and in the treatment of various medical conditions. Maintaining proper oncotic pressure is crucial for adequate tissue perfusion and fluid balance in the body.