presence of unilateral pleural effusion occupying more
than one-half of the hemithorax with an indication for therapeutic
thoracentesis, good clinical condition (Karnofsky index 70), and
physically able to perform the 6MWT. Initially, we evaluated
42 patients; however, 17 were excluded as follows: 10 refused to
perform the 6MWT after thoracentesis, and seven had loculated
effusions, with a small amount of drained pleural fl uid ( , 300 mL).