Venous congestion and cerebral perfusion in cardiopulmonary bypass
Venous congestion is a threat to perfusion during cardiopulmonary bypass (CPB), and occasionally venous drainage cannot be adequately ensured in the clinical setting. There are cases of severe hypoperfusion related to impaired drainage, and there is a risk of cerebral hypoperfusion. In rare cases, venous congestions may escape detection despite severe reduction of the cerebral perfusion . However, the experimental and clinical literature data are scarce, and it was desirable to approach the problem from an experimental angle.
We have described the effects of progressive venous congestion on cerebral non-invasive monitoring with near-infrared light spectroscopy (NIRS) and invasive metabolic measures with microdialysis. Measurable signs of ischemia were found with venous congestion, with a notable inter-individual variation. Furthermore, we were able to demonstrate that standard flow monitoring of the CPB circuit may allow undetected flow changes between the venous cannulas, a novel piece of information of large clinical importance since this challenges the current methods of ensuring SVC drainage in practice . We have also compared different strategies to preserve cerebral perfusion pressure during venous obstruction and found that vasopressor treatment can be useful to increase the perfusion margins .
Further research on organ perfusion and monitoring during CPB is warranted and the project is suitable to both physicians and perfusionists. In the future, we aim to facilitate clinical research on cardiothoracic patients operated with CPB, and hope to be able to translate the experimental findings into clinical practice.
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- Tovedal T, Jonsson O, Zemgulis V, Myrdal G, Thelin S, Lennmyr F: Venous obstruction and cerebral perfusion during experimental cardiopulmonary bypass. Interact Cardiovasc Thorac Surg 2010, 11(5):561-566.
- Tovedal T, Myrdal G, Jonsson O, Bergquist M, Zemgulis V, Thelin S, Lennmyr F. Experimental treatment of superior venous congestion during cardiopulmonary bypass. Eur J Cardiothorac Surg. 2013 Sep;44(3):e239-44
Thomas Tovedal, Ove Jonsson, Gunnar Myrdal, Vitas Zemgulis, Stefan Thelin, Fredrik Lennmyr