The aim of this study was to develop a logistic model to predict the clinical probability of liver impairment based on a series of tests of respiratory function,in order to characterize those cirrhotic patients being more hypoxemic and thus at risk for the successfull of the liver transplant.
More than 500 patients with liver cirrhosis of different degree and classifed differently according Child-Pugh (32% in A class, 48% in B class, 20% in C class) have been evaluated by measure of spirometry, lung volumes, single breath CO test, gas exchange and hyperoxia test for the evaluation of intrapulmonary shunt. Out of these, 202 patients were transplanted and their rate of mortality was around 11% in the first 6 months later on. We used logistic regression analysis to estimate the probability of having a more severe hepatic disease (B and C) based on patient’s functional characteristics according the values of the respiratory tests.
The most frequent respiratory abnormalities were hypocapnia (PaCO2<35mmHg), low TLCO (<80% pred.), increase of alveolar to arterial gradients for oxygen (A-aPO2>18mmHg) and shunt (>9%) present in more than 30%, 40%, 37% and 17% of patients, respectively. After transplant, those who died had more severe gas exchange impairment, in terms of A-aPO2, PaCO2 and shunt. FIO2 100% breathing test was able to predict a favoreable outcome after transplant mostly on 89% (predictive negative values of 94%). Abnormal values of five parameters, TLCO, A-aPO2, PaCO2, pH and hemoglobin were associated with an increased risk of more severe liver disease. With this model, when abnormal shunt was introduced, the correct classification of patient with a more severe liver damage was approximately around 86% (sensitivity 91.5).
This structured logistic model may be useful for estimating the probability of having a more severe hepatic derangement from simple functional respiratory tests and to predict the survival after the transplant by the assessment of the shunt in the complex contest of the liver-lung scenario.
Outcome of liver transplant.
G. Catapano, None.