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Citrate anticoagulation has risen in interest so it is now a real alternative to heparin in the ICUs practice. Citrate provides a regional anticoagulation virtually restricted to extracorporeal circuit, where it acts by chelating ionized calcium. This issue is particularly true in patients ongoing CRRT, when the “continuous” systemic anticoagulation treatment is per se a relevant risk of bleeding. When compared with heparin most of studies with citrate reported a longer circuit survival, a lower rate of bleeding complications, and transfused packed red cell requirements. As anticoagulant for CRRT, the infusion of citrate is prolonged and it could potentially have some adverse effects. When citrate is metabolized to bicarbonate, metabolic alkalosis may occur, or for impaired metabolism citrate accumulation leads to acidosis. However, large studies with dedicated machines have indeed demonstrated that citrate anticoagulation is well tolerated, safe, and an easy to handle even in septic shock critically ill patients.

Background. As removal of pro-inflammatory cytokines is limited in conventional diffusive or convective extracorporeal therapies, we studied in two polysulphone membranes with an industrial albumin sieving coefficient of 0.05 (Type A) and 0.13 (Type B) cytokine (IL-6, IL-8, IL-1, IL-1ra, TNF-a) and plasma protein (albumin, cystatin C, total proteins) permeability profiles. Based on the convective membrane permeability, we evaluated in vitro the dialytic modality that could provide an acceptable balance between high cytokine and low albumin clearances.Methods. Cytokine and plasma protein sieving coefficient (SC) and clearance were studied in (i) post-dilutional haemofiltration mode at 20% fixed ultrafiltration rate; (ii) haemodialysis mode (dialysate flow rate of 3 and 5?l/h); and (iii) haemodiafiltration mode (dialysate flow rate of 3 or 5?l/h with 0.5?l/h of ultrafiltrate).Results. In haemofiltration mode both Type A and Type B haemodialysers at QB 150?ml/min exhibited similar median SC nearly up to 1 for IL-1 and IL-1ra, at about 0.6 for IL-6, 0.4 for IL-8 and 0.7 for TNF-a, with clearance values ranging from 15 to 30?ml/min. SC were independent of blood flow and were stable throughout the whole experiment. Albumin SC was higher in Type B than in Type A and rapidly decreased from 0.2 to 0.02 and from 0.5 to 0.04 within 3?h for haemodialyser Types A and B, respectively. Cytokine SC was lower in haemodialysis than in haemodiafiltration and haemofiltration mode, and by increasing dialysate flow from 3 up to 5?l/h in both haemodialysis and haemodiafiltration mode, SC for all tested cytokines decreased. However, at 5?l/h clearances were not different or were higher, since increased amounts of dialysate outlet compensated for the decreased SC. Albumin clearances in haemodialysis and haemodiafiltration mode after 360?min at 5?l/h were 0.81 and 0.91?ml/min, respectively.Conclusions. Our studies show that a mixed convective and diffusive technique ensures high cytokine clearances with an acceptable loss of albumin. [ABSTRACT FROM AUTHOR]