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Biocompatibility and acute renal failure

2000; Elsevier BV; Volume: 355; Issue: 9200 Linguagem: Inglês

10.1016/s0140-6736(00)00011-8

1474-547X

Helmut Schiffl,

Chronic Kidney Disease and Diabetes

Undoubtedly the manufacturers of the Cuprophan membrane supported and coordinated Achim Jorres and colleagues' (Oct 16, p 1337)1Jörres A Gahl GM Dobis C et al.Haemodialysis-membrane biocompatibility and mortality of patients with dialysis-dependent acute renal failure: a prospective randomised multicentre trial.Lancet. 1999; 354: 1337-1341Summary Full Text Full Text PDF PubMed Scopus (126) Google Scholar study with the intention of proving that the biocompatibility of dialyser membranes has no negative impact on the outcome of acute renal failure (ARF) and that the Cuprophan membrane is equivalent to more expensive synthetic membranes. However, this attempt is not substantiated by the data Jorres and colleagues provide. The first important weakness of the study design is the choice of membrane. The polymethyl-methacrylate membrane has intermediate biocompatibility in patients with end-stage renal disease who receive regular haemodialysis. However, in patients with ARF requiring haemodialysis the differences between the Cuprophan and polymethyl-methacrylate membranes in the potential to activate complement and leucocytes may be even less pronounced than in chronic renal failure. We did a crossover comparison of these two membranes in eight non-septic patients with ARF (two dialysis sessions with each membrane) and showed that both membranes caused substantial complement activation, leucocyte activation, and release of elastase and leukotriene B4 (table). Jorres and colleagues did not study a third (ie, high flux), highly bio-compatible synthetic membrane.TableCrossover comparison in eight non-septic patients with ARFCuprophanPolymethyl-methacrylateComplement activation at 15 minC3a desarg (μg/L)1623989Terminal complement complex (μg/L)68983853Leucocyte activation at 15 minFall in leucocyte count64%48%Elastane release (μg/L) at 4 h681783Leukotriene B4 (μg/L) at 15 min21481689 Open table in a new tab Furthermore, the investigators should have been aware that the effects of bioincompatibility are not only related to the intensity of the reactions caused, but also to the number of exposures of patient's blood to the artificial membrane. A substantial proportion of their patients received only one or two dialysis treatments and the ensuing bioincompatibility reactions can be expected to be weaker in these patients. By comparison, Himmelfarb and colleagues2Himmelfarb J Tolkoff Rubin N Chandran P Parker RA Wingard RL Hakim R A multicenter comparison of dialysis membranes in the treatment of acute renal failure requiring dialysis.J Am Soc Nephrol. 1998; 9: 257-266PubMed Google Scholar reached a mean of 15 dialysis treatments (range 8–24). Jörres and co-workers' patients had an extremely low incidence of septicaemia (three of 160, one of whom died). Infection as cause of death was given in only 17 of 66 deaths (about 26% of patients), although 36 patients already had sepsis when they entered the study (cause of ARF). Most studies report an incidence of septicaemia of 30–70% of cases, which accounts for most deaths. Prospective studies comparing cellulose membranes with highly permeable and biocompatible membranes in the setting of ARF show either a reduction of de-novo sepsis or lower mortality in septic patients.3Schiffl H Lang SM König A Strasser T Haider MC Held E Biocompatibility membranes in acute renal failure: prospective case-controlled study.Lancet. 1994; 344: 570-572Summary PubMed Scopus (298) Google Scholar, 4Neveu H Kleinknecht D Brivet F Loirat P Landais P Prognostic factors in acute renal failure due to sepsis. Results of a prospective multicentre study.Nephrol Dial Transplant. 1996; 11: 293-296Crossref PubMed Scopus (300) Google Scholar, 5Gasparovic V Dakovic K Gasparovic H et al.Do biocompatible membranes make a difference in the treatment of acute renal failure?.Dial Transplant. 1998; 27 (626,674): 621-622Google Scholar Despite overwhelming evidence that the prognosis of ARF depends on the cause of ARF, patients were not stratified according to this determinant, nor was this factor analysed in a multiple regression analysis. Curiously, the four groups of cause of ARF had striking differences in mortality. Patients with multiorgan failure, which has a mortality risk of 80–90%, were combined with patients with isolated ARF, which has a less than 10% mortality risk. This heterogeneity may have masked a beneficial effect of the more biocompatible polymethyl-methacrylate membrane on recovery of renal function and mortality. We agree with Jörres and co-workers that the skills of the medical staff are essential for the early identification of patients with ARF, for timely initiation of renal replacement therapy, for adequate performance of haemodialysis, and for prevention of lethal complications associated with ARF. The investigators recruited three patients who did not have ARF, the initiation of dialysis came too late for another three patients, who died before their first scheduled dialysis session, 19 patients could not be treated with intermittent haemodialysis, one patient received a dialysis session of 30 min duration, and among the high incidence of dialysis-related complications were two deaths from hyperkalaemia. Biocompatibility and acute renal failureAuthors' reply Full-Text PDF