Model CVVH -Continuous Veno-Venous Hemofiltration
CVVH allows to remove all the substances that would normally be cleared by the kidneys such as water, urea, creatinin or salts, as well as medium size substances which result from an injury to body cells and are often nephrotoxic.
- Fluid overload
- Congestive heart failure
- Acute renal failure
- Crush syndrome
- Lactic acidosis
This therapy is usually performed continuously 24/24 until the renal function recovers, which may take from 2-3 days and up to 2-3 weeks.
In CVVH, blood is passed through a hemofilter which allows water to be filtrated together with some other relevant substances , such as salts, urea, creatinin or other medium size substances, the resulting fluid being named ultrafiltrate. Ultrafiltrate is removed at a rate which allows the necessary clearances of desired substances. As this rate is often too important for other substances a substitution fluid is injected in the blood to compensate for undesired losses, such as that of water.