Hepatic hydrothorax is a transudative effusion. With transudative pleural effusions, the pleural fluid pH is usually similar to or slightly higher than the simultaneous blood pH. Therefore, pleural fluid pH levels will be greater than 7.3. Urinothorax is a notable exception; it is an acidic transudate and has a pleural fluid pH less than 7.2. Measurement of the pleural pH is useful in the differential diagnosis and prognosis of exudative effusions. The following conditions will have pleural fluid pH less than 7.2: empyema, complicated parapneumonic effusion, esophageal rupture, rheumatoid pleuritis, tuberculous pleuritis, malignant pleural disease, hemothorax, systemic acidosis, paragonimiasis, and lupus pleuritis.
- Hepatic hydrothorax.
Click here to return to the questions