Técnica de monitoreo del contenido de líquido pulmonar por espectroscopia de impedancia

Abstract

The aim of lung preservation technique is to maintain the integrity and functionality of the lung, specifically at cellular preservation level until it is grafted. Despite of technique advances the lung accessibility is still shorter than 6 hours. Therefore an easy monitoring technique of water content into the organ plays an important role to improve any method which prevents the edema time generation as an attribute of cellular integrity. Electric impedance is a simple technique used to measure body volume water which can be related with the cellular integrity when the spectroscopy concept is used. This work addresses the hypothesis that lung edema formation is highly correlated with the spectroscopy impedance changes in an organ perfusion model. Pulmonary edema was induced increasing the venous pressure and the perfusion time. Reactance, resistance and hemodynamic parameters were recorder in 13 lung dissected Wistar rats as methodology. Results showed changes in the pulmonary block weight (multiple samples, ANOVA, p<0.05) which were correlated with resistance and reactance changes giving 0.64 and 0.70, respectively (p<0.05, Pearson). In addition, analysis showed significant differences in resistance and reactance with the time of perfusion (16, 30, and 50 min) and venous pressure level from 7 to 10 mmHg (p<0.01, ANOVA)). The conclusion are: (a) experimental evidence leads impedance spectroscopy is a good technique for using as a monitor of the lung edema level, (b) the correlation coefficient weight-reactance changes is better compared with the weight-resistance changes suggesting that reactance is a better parameter to be monitored when water pulmonary changes as a consequence of the edema. However more research should be continued. © 2013 Springer.