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Updated: Jul 2, 2025
Normothermic Ex Vivo Kidney Perfusion for the Preservation of Kidney Grafts prior to Transplantation
Published on: July 15, 2015
Higher perfusion pressure and pump flow during cardiopulmonary bypass are beneficial for kidney function-a
Jakub Udzik1, Jerzy Pacholewicz1, Andrzej Biskupski1
1Cardiac Surgery Department, Pomeranian Medical University, Szczecin, Poland.
Insights
Maintaining a higher mean arterial pressure (MAP) above 90 mmHg during cardiopulmonary bypass (CPB) improves kidney function and reduces renal hypoperfusion. This strategy is safe for the central nervous system and may decrease delirium post-surgery.
Area of Science:
- Cardiovascular Surgery
- Nephrology
- Critical Care Medicine
Background:
- Kidneys are vital for circulatory homeostasis, regulating blood pressure and volume.
- Cardiopulmonary bypass (CPB) can compromise renal function due to decreased blood pressure and hemoglobin.
- Acute kidney injury (AKI) is a risk during CPB, necessitating strategies to protect renal function.
Purpose of the Study:
- To investigate the impact of maintaining a higher mean arterial pressure (MAP) during CPB on renal function.
- To assess the safety of elevated MAP during CPB concerning cerebrovascular complications and postoperative delirium.
Main Methods:
- Prospective enrollment of 109 adult patients undergoing CPB.
- Intervention group: CPB pump flow adjusted to achieve MAP > 90 mmHg.
- Control group: Standard CPB pump flow of 2.4 L/min/m².
Main Results:
- Higher MAP (> 90 mmHg) during CPB increased intraoperative and postoperative diuresis.
- Elevated MAP reduced renin release associated with CPB.
- Maintaining MAP > 90 mmHg significantly reduced renal hypoperfusion compared to MAP < 70 mmHg.
- No increase in cerebrovascular complications; a trend towards lower postoperative delirium in the higher MAP group.
Conclusions:
- Maintaining MAP > 90 mmHg during CPB positively impacts intraoperative and postoperative kidney function.
- This strategy is safe for the central nervous system.
- Preliminary findings suggest a potential benefit in reducing postoperative delirium.
Abstract:
Background: Kidneys play an essential role in the circulatory system, regulating blood pressure and intravascular volume. They are also set on maintaining an adequate filtration pressure in the glomerulus. During the CPB, a decrease in systemic blood pressure and hemoglobin concentration may lead to renal ischemia and subsequent acute kidney injury. Methods: One hundred nine adult patients were prospectively enrolled in this study. The intervention in this study was increasing the flow of the CPB pump to reach the target MAP of > 90 mmHg during the procedure. The control group had a standard pump flow of 2.4 L/min/m2. Results: Standard pump flow of 2.4 L/min/m2 resulted in mean MAP < 90 mmHg during the CPB in most patients in the control group. Maintaining a higher MAP during CPB in this study population did not affect CSA-AKI incidence. However, it increased the intraoperative and postoperative diuresis and decreased renin release associated with CPB. Higher MAP during the CPB did not increase the incidence of cerebrovascular complications after the operation; patients in the highest MAP group had the lowest incidence of postoperative delirium, but the result did not obtain statistical significance. Conclusion: Maintaining MAP > 90 mmHg during the CPB positively impacts intraoperative and postoperative kidney function. It significantly reduces renal hypoperfusion during the procedure compared to MAP < 70 mmHg. MAP > 90 mmHg is safe for the central nervous system, and preliminary results suggest that it may have a beneficial impact on the incidence of postoperative delirium.
