Predicting Mortality in Patients with Tuberculous Destroyed Lung Receiving Mechanical Ventilation

Kim, Won-Young; Kim, Mi-Hyun; Jo, Eun-Jung; Eom, Jung Seop; Mok, Jeongha; Kim, Ki Uk; Park, Hye-Kyung; Lee, Min Ki; Lee, Kwangha

TDL was diagnosed on the basis of a history of present or past pulmonary tuberculosis and radiological evidence of parenchymal lung destruction, lung volume loss, or secondary bronchiectatic changes 1 . Active infection was defined as the presence in a blood culture or adequate sputum culture, endotracheal aspirate, or bronchoscopy sample of a pneumonia pathogen (bacteria, including tuberculosis; a virus; or a fungus). To evaluate the extent of disease involvement, baseline chest X-rays were graded on a 4-point scale (field score 1-4) using a radiographic scoring method described elsewhere 4, 9, 10 . First, four zones were demarcated by dividing each lung into two equal-sized zones (upper and lower) on a frontal radiograph. In each of the four zones, the following scoring system was then applied: (1) 0, no abnormality; (2) 1, when less than 25% of lung parenchyma showed destructive lung lesions; and (3) 2, 3, or 4, respectively, when destroyed lung lesions involved 25%-50%, 50%-75%, or >75% of lung parenchyma. The field score was then calculated as the mean disease involvement of the two lungs. Forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV 1 ) were expressed as a percentage of the predicted normal values. The FVC and FEV 1 values were calculated using Korean equations, which were based on data from a non-smoking population with normal chest radiograph findings and no history of lung disease or symptoms. In these equations, the predicted value is adjusted in accordance with age, sex, height, and weight 11 . Cor pulmonale was diagnosed on the basis of both clinical and echocardiographic findings 12 . Echocardiographic signs of cor pulmonale comprised right ventricular (RV) hypertrophy or dilation accompanying high RV systolic pressure (> 35 mm Hg) 12,13 .