Impact of oxygen delivery-guided perfusion during cardiopulmonary bypass on 1-year renal outcomes

To evaluate whether an oxygen delivery (DO₂)-guided perfusion strategy during cardiopulmonary bypass, previously shown to reduce postoperative acute kidney injury, affects renal outcomes during the first postoperative year.

This longitudinal follow-up of a randomized trial compared DO₂-guided perfusion (indexed DO₂ >300 mL/min/m²) with conventional fixed-flow perfusion in adult cardiac surgery. Patients with renal follow-up data at 3, 6, and 12 months postoperatively were included. The primary outcome was absolute estimated glomerular filtration rate (eGFR) over time, analyzed using linear mixed-effects models. Secondary outcomes included serum creatinine and ΔeGFR.

Of 275 patients included in the original trial, 199 (96 DO₂-guided; 103 conventional) comprised the follow-up cohort. For absolute eGFR, linear mixed-effects models showed no overall difference between groups (P = .256) but showed significant time (P < .001) and intervention-by-time interaction (P = .043) effects. Similarly, ΔeGFR showed significant time (P = .031) and interaction (P = .014) effects, indicating different postoperative renal trajectories. In the conventional group, eGFR declined more markedly by 6 months with only partial recovery at 12 months, whereas in the DO₂-guided group it remained relatively stable. Serum creatinine showed a time effect (P < .001) but no interaction (P = .093). Chronic kidney disease stage at 12 months did not differ between groups.

A DO₂-guided perfusion strategy was associated with a different renal trajectory during the first postoperative year. Although cross-sectional comparisons at 12 months showed no significant differences, intraoperative oxygen delivery optimization may influence the postoperative course of renal function after cardiac surgery.