Abstract
PURPOSE: To determine the correlations of emphysema measured by automated lung parenchyma analysis software (LAV) with pulmonary function tests(PFT); partial pressure of oxygen (Po2); partial pressure of carbon dioxide (PCO2) and the ratio between pulmonary artery diameter and aorta diameter PA:A
METHODS: 184 patients admitted to hospital for COPD exacerbation during 2014 – 2015 and 64 as control group underwent %LAV, PFT, PO2, PCO2, PA:A study. For analysis of data SPSS 20 , Pearson correlation (R), linear regression, ROC curve and Youden index were used.
RESULTS: There is good correlation between %LAV and FEV1 with R= – 0.319, P value=0.001. A correlation between %LAV and airway obstruction is more evident in the lower right pulmonary lobe with R = – 0.38, P= 0.000. Youden index and ROC curve show a sensibility of 0.84 and a specificity of 0.67 for a %LAV=24.3 with FEV1 < 70% under e ROC curve of 0.77 . Patients with FEV1 < 30 had a mean of % LAV = 36.23 std +_ 7.1. For 30 < FEV1 < 50 had a mean of %LAV = 26.6 std +_ 12.8. For FEV1 > 50 had a mean of %LAV = 23.9 std +_ 11.1. There is good correlation of %LAV and PA: A with R= - 0.21, P= 0.016. Regression analysis has shown that for 1% LAV increase there is a decrease of %FEV1 by 0.3
CONCLUSIONS: There is good correlation between %LAV with FEV1 and PA: A . There is no correlation between %LAV and PO2 and PCO2 which suggests that emphysema contributes to respiratory failure not only by destruction of alveolar capillary membrane but also with damage of pulmonary compliance and pulmonary hypertension.
CLINICAL IMPLICATIONS: The value of %LAV can predict the severity of emphysema and bronchial obstruction.
- Copyright ©the authors 2016
