Abstract
Severe heart failure patients that do not respond to conventional treatment will certainly die, unless such patients are placed on veno-arterial extracorporeal life support (VA-ELS). The VA-ELS (partially) takes over the cardiac and lung function, hereby reducing the burden on these organs. This support allows the heart and lungs to rest in order for them to recover, or serve as time to decide on next steps (transplantation, long term mechanical support, etc.). Current challenges in the management of these patients includes maintaining a proper filling status and determining when the heart and lungs are recovered sufficiently for the support to be withdrawn.
A patient specific mathematical model could help gain insight on the physical and physiological processes that take place during VA-ELS. Additionally this model could serve as a clinical decision support tool to predict the optimal support flow and cardiac function.
The project described in this report describes the first steps towards such a model. These steps can be divided in three parts: the design and start of a clinical study on measuring the cardiac function, choosing a mathematical model, and providing input on the pump, the oxygenator and on venous collapse.
Previous research showed that the dynamic filling index (DFI) gives a measure of the cardiac function by assessing the drainable volume. A protocol was developed to measure the DFI. Approval to perform this protocol was received in July of 2014 by the central medical ethical comity. Currently 5 patients have been included and a total of 55 measurements have been performed. A major problem occurring in the measured data is the drift present in the pressures measured in the last two included patients.
This drift should be investigated and solved before continuation of the measurements.
Concerning the mathematical model, a one dimensional pulse wave propagation model was chosen.
The pump and oxygenator were characterized to serve as input for this model. Additionally, in vitro measurements on venous collapse were performed as input for the model. The data measured this way raises some questions regarding the theory behind DFI measurements and warrant further investigation.
A patient specific mathematical model could help gain insight on the physical and physiological processes that take place during VA-ELS. Additionally this model could serve as a clinical decision support tool to predict the optimal support flow and cardiac function.
The project described in this report describes the first steps towards such a model. These steps can be divided in three parts: the design and start of a clinical study on measuring the cardiac function, choosing a mathematical model, and providing input on the pump, the oxygenator and on venous collapse.
Previous research showed that the dynamic filling index (DFI) gives a measure of the cardiac function by assessing the drainable volume. A protocol was developed to measure the DFI. Approval to perform this protocol was received in July of 2014 by the central medical ethical comity. Currently 5 patients have been included and a total of 55 measurements have been performed. A major problem occurring in the measured data is the drift present in the pressures measured in the last two included patients.
This drift should be investigated and solved before continuation of the measurements.
Concerning the mathematical model, a one dimensional pulse wave propagation model was chosen.
The pump and oxygenator were characterized to serve as input for this model. Additionally, in vitro measurements on venous collapse were performed as input for the model. The data measured this way raises some questions regarding the theory behind DFI measurements and warrant further investigation.
| Original language | English |
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| Award date | 23 Oct 2015 |
| Place of Publication | Eindhoven |
| Publisher | |
| Publication status | Published - 2015 |