[Pulmonary arteriovenous fistula and lateral decubitus anoxia]

The case of a female patient with Rendu-Osler-Weber disease associated with pulmonary arterio-venous fistula localized at the apical segment of the left inferior pulmonary lobe is described. A decrease in the oxygen arterial saturation (SaO2) at adopting the left lateral decubitus position (left-lateral-decubitodeoxia) was found, as well as an increase in the anatomical venoarterial short-circuit (Qs/Qt) in the same position. The resonsible factors of such changes in SaO2 and Qs/Qt related with the body position are analyzed, and the, exceptional in these patients, finding of alteration of pulmonary mechanics is commented.