Lung water assessment in isolated lung perfusion model via reactance monitoring

The aim of this work was to build up a new monitoring technique for the lung preservation. The medical aside problem is to measure the integrity and functionality of the lung tissue, specifically at cellular preservation level in order to improve the survival time until it is grafted. The Impedance monitoring technique for diagnosis edema development is the key in this new technique. The hypothesis was that lung edema formation is highly correlated with the reactance changes so that a rat lung perfusion model was considered as a good model to produce edema in vitro. To prove that pulmonary edema can be induced increasing the venous pressure and the perfusion time, the reactance and hemodynamic parameters were recorder in 16 pulmonary blocks of Wistar rats as methodology. Results showed statistical changes in each pulmonary block weight as a consequence to apply 7.5 ± 1.2 and 10.2 ± 1.7 mmHg venous pressure (multiple samples, Anova, p<0.05). These edema weights were correlated with the reactance changes giving 0.6 (p<0.05, Pearson). Also, data analysis showed significant differences in reactance with the time of perfusion at 16, 30, and 50 min when venous pressure level were intermittent switched from 7.5 to 10.2 mmHg. The conclusion was this preliminary evidence sustains that reactance measurement is a good technique for monitoring the lung edema level in rats. However, more research should be continuing in bigger animal models in order to prove the validity and application of this monitoring technique in human lungs.