Effect of biocompatibility of hemodialysis membranes on mortality in acute renal failure: a meta-analysis.

BACKGROUND

The effect of biocompatibility of hemodialysis membranes on mortality in acute renal failure (ARF) has been a subject of intense debate, with some, but not all studies reporting a lower risk of death among patients with ARF dialyzed with biocompatible membranes (BCM) compared to bioincompatible membranes (BICM).

OBJECTIVES

We performed a meta-analysis of group data extracted from previously published studies of controlled clinical trials to assess the impact of BCM on the mortality among patients with ARF who required intermittent hemodialysis (IHD).

METHODS

BCM and BICM were defined as synthetic and cellulose-derived membranes (cuprophan and cellulose acetate), respectively. All controlled clinical trials comparing the effect of BCM to BICM on clinical outcomes in the setting of ARF were included. Original articles as well as abstracts were included. Data in Tables, Figures, and text were independently extracted by 2 of the authors. Risk ratios (RR) for mortality were combined using the random-effects model.

RESULTS

Seven studies with a total of 722 patients met the inclusion criteria. One hundred seventy-two (45%) of 384 patients died in the BCM group, compared with 156 (46%) of 338 patients in the BICM group. The RRs for mortality ranged from 0.56-1.28. Overall, the pooled RR for mortality was 0.92 (95% CI = 0.76-1.13) in favor of the BCM group. However, the test for heterogeneity in RR among studies was significant (chi2 = 8.6, p < 0.05). One study accounted for this significance, and once removed from the model, the RR for mortality was 0.94 (95% CI = 0.79-1.12), and the test for heterogeneity among studies lost its significance. Subgroup analyses comparing BCM to cuprophan membranes revealed that the RR for mortality was 0.82 (95% CI = 0.62 - 1.08) in favor of the BCM group, whereas in the subgroup of studies comparing BCM to cellulose acetate, the RR for mortality was 1.11 (95% CI = 0.87-1.44) in favor of the BCM group.

CONCLUSION

This metaanalysis demonstrates that the use of BCM does not significantly affect mortality among patients with ARF who require IHD. However, subgroup analyses suggest that cellulose acetate membranes may offer a survival advantage when compared with synthetic membranes, which, in turn, may be more beneficial than cuprophan membranes. Available evidence does not permit a recommendation for or against the use of BCM in ARF. Large trials and pooled analyses of individual patient-level data will be required to assess sources of variability among studies and non-fatal outcomes of ARF.