Date of this Version
Hatoum, Liana. "Diffusion Modeling and Device Development for Peritoneal Membrane Oxygenation." Thesis, University of Nebraska - Lincoln, 2016.
Acute respiratory distress syndrome (ARDS) is a pulmonary disease that causes hypoxemia and respiratory failure. The mortality rate for ARDS ranges between 27% and 45%. Current treatments including mechanical ventilation and extracorporeal membrane oxygenation (ECMO) are often associated with high risk complications including barotrauma, infection, thrombosis, and hemorrhage. Alternative pulmonary support techniques are needed to improve the survival rate of patients suffering from ARDS. Previous studies introducing pure O2 gas, perfluorocarbons and red blood cells into the intraperitoneal (IP) cavity have reported no effect or only a mild increase in oxygenation. Here we report peritoneal membrane oxygenation (PMO) using phospholipid-coated oxygen microbubbles (OMBs). OMBs are oxygen carriers that have unique physical and chemical properties. We hypothesize that IP infusion of OMBs can provide supplementary oxygenation for rats with ARDS and hypoxemia, thus allowing time for essential recovery of the lungs.
We designed a bolus delivery device that automatically and periodically infuses OMBs to the rat’s IP cavity. In addition, the device flushes the cavity with saline, scavenges the perfusate, maintains safe intra-abdominal pressure, and regulates perfusate temperatures to body temperature.
In order to understand the mechanism by which intraperitoneal OMB infusion improves systemic oxygenation, we examined, both in theory and in vivo, the kinetics of oxygen transport from OMBs to blood capillaries of healthy rats.A 1D mathematical model was developed using Fick’s laws to predict the oxygen diffusion rate across the peritoneum. In vivo measurements of the gas content of OMBs after 20 minutes of dwell time in the IP cavity of rats were further used to determine the oxygen diffusion rate, which was found to be within the predicted range. Also, we are able to demonstrate in vivo that OMBs not only can provide O2 to the body, but also can absorb CO2 and possibly other gases, such as N2, from the body. PMO represents an alternative extrapulmonary technique of oxygenation and ventilation that is a potential treatment for acute respiratory failure in the future.
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