Elevated Cardiopulmonary Bypass Flow for Renal Protection in Cardiac Surgery: A Randomized Trial
Johanna Wijk, Anna Corderfeldt-Keiller, Bengt Redfors, Lukas LannemyrBACKGROUND:
Acute kidney injury (AKI) is a common and severe complication after cardiac surgery with cardiopulmonary bypass (CPB). Experimental data suggest that increasing CPB flow beyond standard targets may improve renal oxygenation, but clinical evidence is limited. We hypothesized that increasing CPB flow would attenuate renal injury and improve organ perfusion.
METHODS:
In this single-center, randomized controlled trial, 89 adults undergoing elective cardiac surgery were allocated to either high-flow (2.9 L·min·m
−2
) or standard-flow (2.4 L·min·m
−2
) during CPB. Mean arterial pressure (MAP) was maintained at 60 to 80 mm Hg by use of norepinephrine. Primary outcomes were urine biomarkers of renal injury;
RESULTS:
High-flow significantly reduced renal injury biomarkers compared to standard-flow, geometric mean ratio for NAG: 0.43; 95% confidence interval (CI), 0.26 to 0.70,
CONCLUSIONS:
Increasing CPB flow by 20% reduced renal injury biomarkers and postoperative creatinine and improved early hemodynamic stability. Further large-scale, multicenter trials are required to validate these findings and determine patient subgroups most likely to benefit.