Blood and plasma treatments: high-volume hemofiltration--a global view.

From the recent past, hemofiltration, particularly high-volume hemofiltration, has rapidly evolved from a somewhat experimental treatment to a potentially effective 'adjunctive' therapy in severe septic shock and especially refractory or catecholamine-resistant hypodynamic septic shock. Nonetheless, this approach lacks prospective randomized studies (PRTs) evaluating the critical role of early hemofiltration in sepsis. An important milestone, which could be called the 'big bang' in terms of hemofiltration, was the publication of a PRT in patients with acute renal failure (ARF). Before this study, nobody believed that hemofiltration could change the survival rate in intensive care. Since that big bang, many physicians consider that hemofiltration at a certain dose can change the survival rate in intensive care. We now must try to define what the exact dose in septic ARF should be. As suggested by many studies this dose might well be higher than 35 ml/kg/h in the septic ARF group. The issue of the dosage of continuous high-volume hemofiltration must be tested in future randomized studies. Since the Vicenza study has shown that 35 ml/kg/h is the best dose in terms of survival when dealing with nonseptic ARF in the intensive care unit (ICU), several studies from different groups have shown that a higher dose might be correlated with better survival in septic ARF. This has also been shown in some way by the Vicenza group but not with a statistically significant value. New PRTs have just started in Europe such as the IVOIRE (hIgh VOlume in Intensive Care) study. The RENAL study is another large study looking more basically at dose in nonseptic ARF in Australasia. The ATN study in the USA is also testing the importance of dose in the treatment for ARF. Nevertheless, 'early goal-directed hemofiltration therapy' has to be studied in our critically ill patients. Regarding this issue, fewer studies, mainly retrospective, exist; but again the IVOIRE study will address this issue by studying septic patients with acute renal injury according to the RIFLE classification. This chapter will focus on the early application and adequate dose of continuous high-volume hemofiltration in septic shock in order to improve not only the hemodynamics but also survival in this very severely ill cohort of patients. This could be called the big bang of hemofiltration as one could have never anticipated that an adequate dose of hemofiltration could markedly influence the survival rate of septic ARF patients in the ICU. Apart from the use of an early and adequate dose of Honoré/Joannes-Boyau/Gressens 372 hemofiltration in sepsis, a higher dose could also provide a better renal recovery rate and reduce the risk of associate chronic dialysis in these patients. Furthermore, this presentation will also review brand-new papers regarding the use of hemofiltration in systemic inflammatory response syndrome and out-of-hospital cardiac arrest.