Novel predictors of intrapulmonary vascular dilatations in cirrhosis : extending the role of pulse oximetry and echocardiography

Background and study aims : Intrapulmonary vascular dilatations (IPVDs) are a criterion for the diagnosis of hepatopulmonary syndrome in patients with liver cirrhosis. We aimed to show that IPVDs are more common than suspected in a heterogenous cirrhotic population and to identify new diagnostic parameters. Patients and methods : Forty-three consecutive patients with cirrhosis admitted to our Gastroenterology department were included in this prospective study. History, physical examination, ECG and, when warranted, pulmonary function tests and chest radiograph were used to exclude patients with significant cardiac or pulmonary disease. Contrast enhanced transthoracic echocardiography (CEE) was used to determine the presence of IPVDs. Pulse oximetry readings were taken in the supine and standing positions. Results : We found 12 patients with IPVDs. Statistical analysis proved the correlation between IPVDs and systolic pulmonary artery pressure (sPAP) (p = .049), right ventricle wall width (RVW) (p = .013) and E/A ratio (p = .034) but not left atrial or ventricular diameter. Orthodeoxia was also present more frequently in patients with positive CEE. The difference between supine and standing oxygen saturation (Delta Sat) proved a fair diagnostic test for detecting IPVDs, with an area under the receiver operated curve (AUROC) of 0.823. Conclusions : Our study shows that RVW, sPAP, E/A and orthodeoxia determined by pulse oximetry are valuable novel predictors of IPVDs, encouraging the routine use of pulse oximetry and echocardiography in cirrhotic patients.