The main benefit described with high volume hemofiltration is a hemodynamic improvement (e.g reduction in catecholamines' requirement). This improvement seems to be due to the removal of a badly defined network of middle molecular weight peptides. To remove efficiently these middle molecular peptides, a high filtration rate is needed. However, with high filtration rates, there is also a high clearance for smaller molecules, including antibiotics, electrolytes, vitamins, trace elements and amino acids.