A Cochrane review included 42 studies with a total of 11 399 subjects. Hydroxyethyl starches (HES) are synthetic colloids commonly used for fluid resuscitation. In septic and in non-septic patients, kidney failure (author-defined) was increased in treatment with HES compared to other fluid therapies (RR 1.59, 95% CI 1.26 to 2.00; 15 studies, n=1361) as well as failure requiring renal replacement therapy (RR 1.31, 95% CI 1.16 to 1.49; 19 studies, n=9857).Only limited data was obtained for analysis of kidney outcomes by the RIFLE criteria; level of acute kidney dysfunction (Risk, Injure,Failure) as well as duration of requirement of renal replacement therapy (Loss of kidney function, End-stage kidney disease). The data about safety between different HES products are insufficient. The RR of AKI based on RIFLE-F (failure) criteria also showed an increased risk of AKI in individuals treated with HES products (RR 1.14, 95% CI 1.01 to 1.30; 15 studies, n=8402). A more robust effect was seen for the RIFLE-I (injury) outcome, with a RR of AKI of 1.22 (95% CI 1.08 to 1.37; 8338 patients). No differences between subgroups for the RRT and RIFLE-F based outcomes were seen between sepsis versus non-sepsis patients, high molecular weight (MW) and degree of substitution (DS) versus low MW and DS (≥ 200 kDa and > 0.4 DS versus 130 kDa and 0.4 DS) HES solutions, or high versus low dose treatments (i.e. ≥ 2 L versus < 2 L).
Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment and blinding in half of the studies).