Acute kidney injury in cardiac surgery patients receiving hydroxyethyl starch solutions

In a retrospective study by a Canadian team [1], pentastarch infusion was a dose-related independent risk factor for acute kidney injury (AKI) after cardiac surgery. In a new retrospective cardiac surgery study by that team [2], 83% of patients received hydroxyethyl starch (HES) 130/ 0.4. For unexplained reasons, 25 to 43% of patients received both HES 130/0.4 and pentastarch. The team 'hypothesized that both synthetic starches and albumin-containing solutions are independently associated with AKI following cardiac surgery in a dose-dependent fashion'. However, they focused on albumin and never thoroughly evaluated HES-related AKI. Although univariate analyses were reported, propensity matching according to either HES 130/0.4 or pentastarch administration was omitted. Systematic allocation of low-risk patients to HES could have masked an association with AKI in the univariate ana-