Parapneumonic Effusion and Empyema Management

Diagnostic Criteria

The European Respiratory Society suggests that an exudative pleural effusion is characterized by a protein level above 3.0 g/dL, with this patient having a level of 5.9 g/dL 1, 3
The American Thoracic Society indicates that an elevated LDH (above 200 IU/L) is consistent with an exudate, and this patient has an LDH of 572 IU/L 2, 4
A cholesterol level above 55 mg/dL is indicative of an exudate, and this patient's level is 121 mg/dL 4

A low pH (less than 7.2) in pleural fluid is suggestive of a complicated parapneumonic effusion or empyema, with this patient having a pH of 6.96 5, 6
Low glucose in pleural fluid (less than 60 mg/dL) can indicate infection or inflammation, and this patient has a glucose level of 124 mg/dL, which, while not severely low, in combination with low pH suggests active inflammation 5, 6
An elevated nucleated cell count (above 5,000 cells/μL) is consistent with infection, and this patient has a count of 5,570 cells/μL 1, 5

The British Thoracic Society recommends urgent chest tube drainage for patients with a pleural fluid pH less than 7.2, which applies to this patient with a pH of 6.96 5, 2, 6
The Infectious Diseases Society of America suggests initiating broad-spectrum antibiotics with anaerobic coverage for suspected parapneumonic effusion or empyema, which should be adjusted based on Gram stain and culture results when available 6, 2
Clinical response should be assessed within 24-48 hours, and if there is no improvement, further evaluation including checking tube position and patency, considering a CT scan, and possibly using intrapleural fibrinolytics should be undertaken 2, 6

Malignancy with superimposed infection should be considered, especially if cytology results are positive, and low pH in malignant effusions correlates with poorer prognosis 5, 6, 1
Tuberculosis is a consideration if the patient has risk factors, typically presenting with lymphocyte predominance rather than neutrophil predominance, and TB testing should be considered 7
Rheumatoid pleuritis usually has very low glucose and should be considered if the patient has known rheumatoid arthritis 5, 6, 7
Esophageal rupture can present with low pH and glucose and should be considered if there is a history of vomiting, chest pain, or recent instrumentation 5, 6, 1