Management of Empyema
- Basil Nasir
- Najib Safieddine
Empyema, or pus in the pleural space, in its various clinical manifestations and stages is a common occurrence that thoracic surgeons are frequently asked to manage. This set of recommendations aims to provide an approach to the management of empyema based on best current evidence in the literature and established guidelines from other international bodies. The recommendations are limited to cases of acute empyema (not post-operative cases such as post lung resection empyema). Parapneumonic effusion secondary to pneumonia remains the most common precursor to empyema. Empyema remains a significant cause for hospitalization, patient morbidity and resultant health care costs. The recommendations will focus on reaffirming related definitions, necessary investigations, and appropriate interventions, with specific attention paid to the role of fibrinolytics and indications for surgical intervention (minimally invasive or via thoracotomy).
- Parapneumonic effusion (Stage 1), whereby the fluid is a free-flowing exudate characterized by a low white cell count, an LDH level less than half that in the serum, normal pH and glucose levels and bacterial organisms.
- Fibrinopurulent stage (Stage 2), whereby there is bacterial translocation across the damaged lung epithelium or direct contamination of the pleural space from an external source. This bacterial infection stimulates an immune response, creating fibrin deposition and loculations in the fluid. At this stage, fluid analysis may identify the characteristic finding of a pH < 7.1, LDH >1000, Glucose < 40 mg/dl, gram stain +/-.
- Chronic organizing stage (Stage 3), with scar tissue (pleural cortex) formation. In the later stages, a solid fibrous pleural cortex begins to form, which may encase the lung, preventing re-expansion, impairing lung function and creating a persistent pleural space with continuing potential for infection.
There are two primary objectives to treatment of empyema: (1) complete drainage and evacuation of all infected material in the pleural space and (2) liberation of the lung from the exudative peel, therefore allowing full lung expansion. While there are advantages and disadvantages to the different treatment modalities, the main goal is to achieve both objectives, as this will result in the most optimal outcomes for empyema treatment.
- In the context of pneumonia or unexplained sepsis, investigation of a pleural effusion should start with a diagnostic thoracentesis in order to differentiate between the presence of a complicated parapneumonic effusion requiring chest tube drainage and a simple parapneumonic effusion where the pneumonia may resolve with antibiotics alone.
- Tube thoracostomy:
- Chest tube insertion (image guided or otherwise) is a useful initial treatment for early stage empyema with minimal septations with or without tube flushing and on-going monitoring with CT imaging to ensure resolution of collection. Lack of resolution should prompt consideration of further intervention.
- Although the use of intrapleural fibrinolysis remains controversial in terms of clear evidence, for those patients who are at higher surgical risk and relatively earlier (Stage 1 and to some degree stage 2) fibrinolytic therapy (tPA and DNase) has been reported to have very good results in well selected patients.
- Surgical intervention:
- Surgical management with or decortication is the most definitive means of treating empyema of all stages. However, it is also the most invasive approach, and may not be necessary in early stage empyema. If complete evacuation of infected material and lung expansion can not be achieved by less invasive means, then surgical management is indicated.
- There is a role for thoracoscopy in the management of empyema. Whether performed by thoracoscopy or thoracotomy, the two objectives of empyema treatment should be sought. If this is possible with thoracoscopy, then it is reasonable to perfume the procedure in that fashion. However, if the infected material cannot be removed or the lung can not be re-expanded completely, then conversion to thoracotomy is encouraged in order to achieve these two objectives.
- Finally, if it is impossible to evacuate the pleural space of all infected material or lung expansion can not be achieved with a decortication, then one must consider prolonged drainage. This can be achieved in a closed (empyema tube) or in an open fashion (open thoracic window).
- EACTS guidelines on surgical management of thoracic empyema
- AATS Guidelines on management of empyema
- British society of cardiothoracic surgery guidelines on management of pleural infections
- MIST 2 Trial
- MIST 1 Trial
- Review Cochrane Database Syst Rev 2017 Mar 17;3(3):CD010651. doi: 10.1002/14651858.CD010651.pub2.