Background Acute renal failure (ARF) is associated with substantial morbidity and mortality. Some trials have reported a survival advantage among patients dialyzed with biocompatible membranes (BCM) compared to bioincompatible membranes (BICM). These findings were not consistently observed in subsequent studies. Objectives To ascertain whether the use of BCM confers an advantage in either survival or recovery of renal function over the use of BICM in adult patients with ARF requiring intermittent hemodialysis. Search strategy We searched the Cochrane Central Register of Controlled Trials (CENTRAL, in The Cochrane Library- Issue 1, 2004), MEDLINE (1966 to January 2004), EMBASE (1980 to January 2004), the Mexican Index of Latin American Biomedical Journals IMBIOMED (1990 to January 2004), the Latin American and Caribbean Health Sciences Literature Database LILACS (1982 to January 2004), and reference lists of articles. Selection criteria Randomized and quasi-randomized controlled trials comparing the use of a BCM with a BICM in patients > 18 years of age with ARF requiring intermittent hemodialysis. Data collection and analysis Two authors extracted the data independently. Cellulose-derived dialysis membranes were classified as BICM, and synthetic dialyzers were considered as BCM. The main outcomes were all-cause mortality and recovery of renal function by type of dialyzer. We further explored these outcomes according to the flux properties (high-flux or low-flux) of each of these dialyzers. A meta-analysis was conducted by combining data using a random-effects model. Main results Nine studies were included in the primary analysis of mortality, with a total of 1062 patients. None of the pooled RR's reached statistical significance. The pooled relative risk (RR) for mortality was 0.93 (95% confidence interval (CI) = 0.81 to 1.07). The overall RR for recovery of renal function, inclusive of 1038 patients from nine studies was 1.09 (95% CI 0.90 to 1.31). The pooled RR for mortality by dialyzer flux property was 1.03 (95% CI 0.82 to 1.30). The RR for recovery of renal function by flux property was 0.85 (95% CI 0.55 to 1.31). A meta-analysis of mortality of kidney transplant recipients was not possible, but the analysis of recovery of renal function in this patient population was 1.09 (95% CI 0.91 to 1.31). Results of sensitivity analyses did not differ significantly from the primary analyses. Authors' conclusions There is no demonstrable clinical advantage to the use of BCM versus BICM in patients with ARF who require intermittent hemodialysis.
