Pleural Empyema

Pleural empyema is defined as frank pus or culture-positive purulent pleural fluid. It progresses through three stages: exudative (free-flowing low-viscosity fluid), fibrinopurulent (loculations from fibrin deposition), and organizing (thick fibrous peel restricting lung expansion). Causes include parapneumonic effusion (most common; Streptococcus pneumoniae, Streptococcus anginosus group, Staphylococcus aureus, anaerobes), thoracic surgery, esophageal rupture, hematogenous spread, and trauma.

Patients present with persistent fever, chest pain, productive cough, weight loss, and dyspnea despite antibiotic treatment for pneumonia. Examination reveals dullness to percussion, decreased breath sounds, and pleural friction rub. Diagnostic thoracentesis criteria for empyema include pus, positive Gram stain or culture, pH <7.2, glucose <40 mg/dL, and LDH >1000 IU/L. Imaging includes chest radiograph, contrast-enhanced CT (to define loculations and pleural enhancement), and ultrasound (sensitive for septations and guidance).

Treatment requires complete drainage and antimicrobial therapy. Small-bore (10-14 Fr) image-guided chest tube is first-line for free-flowing or early loculated empyema; large-bore tubes are needed for thick pus. Intrapleural tissue plasminogen activator (tPA) plus DNase improves drainage in loculated disease (MIST-2 trial). Video-assisted thoracoscopic surgery (VATS) decortication is indicated for failed tube drainage, organized empyema, or thick pleural peel; thoracotomy decortication for advanced fibrothorax. Antibiotic duration is typically 3-6 weeks, guided by culture and clinical response.