Impact of mean perfusion pressure and vasoactive drugs on occurrence and reversal of cardiac surgery-associate acute kidney injury: A cohort study

Purpose: Low cardiac output and kidney congestion are associated with acute kidney injury after cardiac surgery (CSA-AKI). This study investigates hemodynamics on CSA-AKI development and reversal.

Materials and methods: Adult patients undergoing cardiac surgery were retrospectively included. Hemodynamic support was quantified using a new time-weighted vaso-inotropic score (VIS_AUC), and hemodynamic variables expressed by mean perfusion pressure and its components. The primary outcome was AKI stage ≥2 (CSA-AKI ≥2) and secondary outcome full AKI reversal before ICU discharge.

Results: 3415 patients were included. CSA-AKI ≥2 occurred in 37.4%. Mean perfusion pressure (MPP) (OR 0.95,95%CI 0.94-0.96, p < 0.001); and central venous pressure (CVP) (OR 1.17, 95%CI 1.13-1.22, p < 0.001) are associated with CSA-AKI ≥2 development, while VIS_AUC/h was not (p = 0.104). Out of 1085 CSA-AKI ≥2 patients not requiring kidney replacement therapy, 76.3% fully recovered of AKI. Full CSA-AKI reversal was associated with MPP (OR 1.02 per mmHg (95%CI 1.01-1.03, p = 0.003), and MAP (OR = 1.01 per mmHg (95%CI 1.00-1.02), p = 0.047), but not with VIS_AUC/h (p = 0.461).

Conclusion: Development and full recovery of CSA-AKI ≥2 are affected by mean perfusion pressure, independent of vaso-inotropic use. CVP had a significant effect on AKI development, while MAP on full AKI reversal.