L’hémofiltration en cascade : principe, premières données expérimentales

Blood Purification Techniques for Sepsis and Septic AKI

“…Cascade hemofiltration lowered epinephrine requirements in a porcine septic shock model (44). In humans however, a recent study comparing adjunction of cascade HVHF to standard care in 60 septic shock patients did not show any beneficial effect, neither inflammatory mediators nor on clinical endpoints, except the number of RRT-free days (45).…”

“…Only middle molecules will then be cleared in the final effluent, while little ones will be re-injected as a pre-dilution before the first hemofilter, to be finally infused back to the patient. Infused volumes are much lower than those required for HVHF (44).…”

The Techniques of Blood Purification in the Treatment of Septic Shock

“…On the basis of previous investigations, it was hypothesized that a higher volume of UF produced per unit of time (Qf) could be associated with an improved survival of septic shock patients and a kind of dose-effect relationship between the Qf and the outcome was then hypothesized; however, despite some studies demonstrated encouraging results 19 -21 , a large RCT using HVHF comparing elevated (70ml/kg/hour) with normal (35ml/kg/hour) Qf failed to confirm these findings 22 and this approach has been substantially abandoned; by the way, in patients treated with higher Qf a significant loss of antibiotic was demonstrated 23 . Moreover, despite the result of an experimental study showing a reduction of the catecholamine request in a porcine model of sepsis, a recent study of cascade HVHF in septic shock patients failed to demonstrate any beneficial effect when compared with standard care 14 . The of HCO membranes has been associated with the reduction of several septic mediators in some studies but other investigation did not confirm these findings 24,25 .…”

“…The UF removed has the same electrolyte composition of the plasma. Different strategies have been developed to improve the removal of mediators, including (a) the increase of the Qf, considered as a proxy of the intensity of treatment (Table 3); (b) the use of membranes with a higher cut-off (HCO) , but their use is associated with by high albumin losses 10 ; to overcome this limitation, the HCO membranes can be used in the diffusive rather than the in convective mode or by slightly reducing the pore size and the surface 12 ; and, finally, (c) the combination of two different hemofilters with different cut-off values: the first hemofilter, with a larger cut-off, produces an ultrafiltrate containing both large and small MW molecules and flows through another one with a smaller cut-off; then, only middle MW molecules will be cleared and those with lower MW are reinfused back to the patient as predilution fluid before the first hemofilter 13 ; (d) the cascade-high-volume Hemofiltration (HVHF) which has been developed to remove middle molecules while retaining those with smaller MW, including vitamins and drugs 14 .…”

The Role of Adjunctive Therapies in Septic Shock by Gram Negative MDR/XDR Infections

“…Unfortunately, the effects of these treatments on the patient's immune response are unknown, particularly the long-term effects on the mechanisms leading to immune-paralysis. As regards impact on clinical outcome, two meta-analyses showed no benefits by the use of high volume hemofiltration [27, 28] as well as of cascade hemofiltration, despite promising results in an animal model [29, 30]. The use of hemoperfusion with polymyxin-B (PMX-B) for endotoxin blood removal showed contrasting results but a potential benefit in patients after emergency abdominal surgery seems to be plausible [31–33].…”