Disadvantages
In cases of parenteral nutrition, 2–10% of amino acids are lost
by ultrafiltration. CAVH also can remove pharmacological
agents from the blood; however, only the nonprotein-bound
fraction of the drug has the potential to be cleared from the
blood stream by CAVH. To prevent blood from clotting in
the haemofilter, most patients will require administration
of heparin, which in some patients may increase the possibility of
haemorrhage. Important clinical problems are: blood clotting
of the small-size haemofilters with their large number of hollow
fibre membranes and low clearances of small molecular
substances (Bellomo & Ronco 2000).