Conditions that Affect the Pleura Covered on the Physician
Assistant Exam You may see questions on the Physician Assistant
Exam about conditions that affect the pleura. You will need to
review the evaluation and management of pleural effusions, the
pneumothorax, and pleurisy. Fluid around the lungs: Pleural
effusion Normally, the pleura is an empty space; a pleural
effusion is simply fluid that occupies that space. Pleural
effusions can be unilateral or bilateral. In evaluating pleural
effusions, a thoracentesis helps you determine the etiology. The
fluid is sent for LDH, protein, Gram stain and culture, cell
count with differential, cytology, glucose, and pH tests.
Measuring protein and LDH: Transudative and exudative pleural
effusions Light’s criteria say that if an effusion meets any one
of three characteristics, then it meets criteria to be an
exudate: The ratio of pleural fluid total protein to serum total
protein is > 0.5. The ratio of pleural fluid LDH level to serum
LDH level is > 0.6. The pleural LDH