Exudative pleural effusion is seen in: March 2005
Ans. A: PneumoniaTransudative pleural effusions are defined as those effusions that are caused by systemic factors that alter the balance of the formation and absorption of pleural fluid (e.g., left ventricular failure, renal failure, hepatic failure, and cirrhosis). Exudative pleural effusions, by contrast, are caused by alterations in local factors that influence the formation and absorption of pleural fluid (e.g., bacterial pneumonia, cancer, pulmonary embolism, and viral infection. According to Light's criteria, a pleural effusion is likely exudative if at least one of the following exists:The ratio of pleural fluid protein to serum protein is greater than 0.5The ratio of pleural fluid LDH and serum LDH is greater than 0.6Pleural fluid LDH is greater than 0.7 times the normal upper limit for serumAdditional evaluation is needed to determine the cause of the excess fluid, and pleural fluid amylase, glucose, pH and cell counts are obtained.Pleural fluid amylase is elevated in cases of esophageal rupture, pancreatic pleural effusion, or cancer.Glucose is decreased with cancer, bacterial infections, or rheumatoid pleuritis.Pleural fluid pH is low in empyema (<7.2) and may be low in cancer.If cancer is suspected, the pleural fluid is sent for cytology.The fluid is also sent for Gram staining and culture, and, if suspicious for tuberculosisThe most common causes of exudative pleural effusions are bacterial pneumonia, cancer (with lung cancer, breast cancer, and lymphoma causing approximately 75% of all malignant pleural effusions), viral infection, and pulmonary embolism.
Pneumonia
Nephrotic syndrome
Congestive cardiac failure
Cirrhosis