Martin Friedrich1#, Terezia B Andrasi1,2#*, Johanna Kolle1, George Awad1, Saddam MA Al-Sabri1 and Theodoros Tirilomis1
1Department of Thoracic, Cardiac and Vascular Surgery, University of Göttingen, Germany
2Department of Cardiovascular Surgery, Philipps University of Marburg, Germany
#Both authors contributed equally to this study
Background: Although continuous hemodiafiltration may protect the kidney by removing inflammatory cytokines released during Cardiopulmonary Bypass (CPB), it remains rather controversial whether renal replacement therapy could also remove end-products of hemolysis that are thought to play a central role in the development of acute kidney injury (AKI) after cardiac surgery with CPB.
Methods: The incidence of AKI has been investigated in two groups of patients undergoing coronary surgery with CPB either with (n=17) or without (n=16) continuous intraoperative and 6 h postoperative hemodiafiltration by perioperatively monitoring plasma free hemoglobin (fHb) and haptoglobin levels, retention parameters and diuresis.
Results: Plasma fHb increased in both groups during CPB (p<0.05), whereas urinary fHb was not influenced by hemodiafiltration. Plasma haptoglobin reserve was similarly depleted postoperatively in both groups without reaching a critical level. Filtration significantly improved urine output during CPB (418.07 ± 386.86 vs. 224.82 ± 130.7, p<0.05), reduced postoperative AKI score (p<0.05) and maintained creatinine levels at baseline up to the 10th postoperative day.
Conclusion: Continuous hemodiafiltration during CPB does not remove fHb, but reduces transfusion by increasing acid excretion and urine output thus indirectly diminishing the degree of intravascular hemolysis and the risk for AKI after cardiac surgery.
Acute kidney injury; Free hemoglobin; Hemodiafiltration; Cardiopulmonary bypass
Friedrich M, Andrasi TB, Kolle J, Awad G, Al-Sabri SMA, Tirilomis T. Kidney Protection by Continuous Hemodiafiltration during and Post Cardiopulmonary Bypass. Clin Surg. 2019; 4: 2470.