Management of Parapneumonic Effusion or Empyema

Diagnostic Criteria

A pleural fluid total nucleated cell count of 540,000 cells/mm³ indicates empyema or complicated parapneumonic effusion requiring immediate hospitalization, intravenous antibiotics, and chest tube drainage, as recommended by the American Thoracic Society 1
The differential cell count will determine if neutrophils predominate (>50%), which confirms parapneumonic effusion/empyema, according to the American Thoracic Society 1
A pH measurement of <7.20 indicates complicated parapneumonic effusion requiring drainage, as stated by the American Thoracic Society 1
A glucose level of <60 mg/dL suggests complicated infection, as recommended by the American Thoracic Society 1

Send the pleural fluid for Gram stain and bacterial culture (including anaerobic cultures) immediately, which is critical for identifying the causative organism, as stated by the British Thoracic Society 2
Blood cultures are positive in a subset of parapneumonic effusions, as reported by the British Thoracic Society 2

Admit to hospital immediately, as all patients with parapneumonic effusion/empyema require inpatient management, according to the British Thoracic Society 3
Start IV antibiotics covering Streptococcus pneumoniae at minimum, which is the most common causative organism, as recommended by the British Thoracic Society 3 and the American Thoracic Society 1
Insert chest drain at the outset, as repeated thoracentesis is not recommended, according to the British Thoracic Society 3 and the American Thoracic Society 1
Use ultrasound guidance to minimize complications and optimize placement, as recommended by the British Thoracic Society 3
Small-bore tubes (14F or smaller) reduce complications while maintaining efficacy, according to the American Thoracic Society 1

Do not manage with antibiotics alone, as effusions this large compromising respiratory function require drainage, as stated by the British Thoracic Society 3
Do not perform repeated thoracentesis, as insert a drain at the outset rather than multiple taps, according to the British Thoracic Society 3
Do not delay drainage, as conservative treatment results in prolonged illness and hospital stay, as recommended by the British Thoracic Society 3
Do not remove >1.5L during single thoracentesis if diagnostic tap performed first, as risk of re-expansion pulmonary edema, according to the American Thoracic Society 1