Twenty RCTs (n=4,220) were included in the review. One study scored 4 on the Jadad scale, 12 scored 3, five scored 2 and two scored 1.
Postoperative acute renal injury was significantly reduced by perioperative haemodynamic optimisation compared to control (OR 0.64, 95% CI 0.50 to 0.83, I2=0%; 20 studies), as was mortality (OR 0.50, 95% CI 0.31 to 0.80, I2=54%; 19 studies).
Subgroup analyses for renal injury yielded odds ratios of similar magnitude for the 13 studies that scored 3 or more on the Jadad scale, the nine studies of high-risk patients and for the various definitions used for renal injury. In low-risk patients no difference in renal injury was found (although this analysis had low power as few events occurred). Further subgroup results were reported.