Introduction
During hemodialysis, contact between blood and dialysis membranes leads to complement and neutrophil activation. This effect is known as bioincompatibility and is most pronounced with older, less expensive, cellulose-based membranes. However, there is considerable controversy as to whether synthetic (more biocompatible) dialysis membranes improve survival in patients with acute renal failure (ARF) compared to cellulose-based membranes. Numerous trials have been conducted but have yielded conflicting results. Although the discordant results of existing studies could be explained by the varying degrees of biocompati-bility among the different membranes used, these studies were also of low statistical power. Thus we sought to determine whether combining results from all published trials would provide a better estimate of the effect of membrane on survival in ARF.
Methods
Studies were identified through a Medline search, authors' files and bibliographies of review articles. Studies were included if they were done prospectively, compared synthetic and cellulose-based membranes, and specified mortality rates for each group. Results were expressed as the cumulative odds ratio (OR) of survival over time where a P < 0.05 was considered significant. The entire sample was then analyzed for homogeneity using a Mantel–Haenszel (M–H) test, the OR recalculated using the weights from the M–H test and final M–H combined odds ratio determined.
Results
Eight prospective studies were included (n = 857) and an improvement in survival with biocompatible membrane was demonstrated (OR = 1.37, 95% CI = 1.03–1.84, P = 0.03).
Figure.
Conclusion
Use of biocompatible membranes for dialysis in ARF is associated with improved patient survival compared to the use of bioincompatible dialysis membranes.