Published in:
01-07-2013 | Physiological and Technical Notes
Correlation of thermodilution-derived extravascular lung water and ventilation/perfusion-compartments in a porcine model
Published in: Intensive Care Medicine | Issue 7/2013
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Purpose
This study examines the correlation between the transpulmonary thermodilution derived extravascular lung water content (EVLW) and the ventilation/perfusion-distribution (\( \dot{V}/\dot{Q} \)) measured by multiple inert gas elimination (MIGET) in a porcine model.
Methods
\( \dot{V}/\dot{Q} \) measured by micropore membrane inlet mass spectrometry-MIGET (MMIMS-MIGET) and EVLW were simultaneously measured in twelve pigs in the heathy state, with impaired gas exchange from repetitive lung lavage and after 3 h of ventilation. The relationship between \( \dot{V}/\dot{Q} \) compartments and EVLW was analysed by linear correlation and regression.
Results
Considerable increases in EVLW and \( \dot{V}/\dot{Q} \) mismatching were induced through the lavage procedure. Significant correlations between the EVLW and the \( \dot{V}/\dot{Q} \) fractions representing pulmonary shunt and low \( \dot{V}/\dot{Q} \) were found. Perfusion to the normal \( \dot{V}/\dot{Q} \) regions was inversely correlated to the EVLW.
Conclusions
Increased EVLW is associated with increased low \( \dot{V}/\dot{Q} \) and shunt, but not equal to pulmonary shunt alone. Beneath true shunt EVLW can also be associated with low \( \dot{V}/\dot{Q} \) regions.