Evaluation of density area in dorsal lung region during prone position using transesophageal echocardiography

To evaluate the changes of density area in the dorsal lung regions of acute respiratory distress syndrome patients during prone position using transesophageal echocardiography.

Retrospective clinical study.

General intensive care unit in a university hospital.

Ten patients with acute respiratory distress syndrome who underwent prone position therapy.

Density areas in the left dorsal lung region were observed using transesophageal echocardiography before and after patients were in the prone position for 2 hrs. In five patients, a pediatric transesophageal echocardiography probe was left in the esophagus and used for observation during the prone procedure.

Changes of density area and PaO2/FiO2 were observed. The density areas decreased after prone position compared with those of preprone position (preprone 11.4 +/- 5.1 cm2, after prone 5.6 +/- 3.5 cm2, mean +/- sd, p <.01, respectively). There was also a significant correlation between the percentage change of density area and PaO2/FiO2 (r =.47, p <.05) after prone position. During prone position, the density area decreased; however, there was no correlation between the percent changes of density area and PaO2/FiO2.

It was possible to observe the change in density area during prone position using transesophageal echocardiography. The change of density area estimated with transesophageal echocardiography during prone position was useful to estimate the effectiveness of the procedure.