Empyema - Pleural Conditions

EMPYEMA

An empyema is an accumulation of thick, purulent fluid within the pleural space, often with fibrin development and a loculated (walled-off) area where infection is located. Most empyemas occur as complications of bacterial pneumonia or lung abscess. Other causes include penetrating chest trauma, hematogenous infection of the pleural space, nonbacterial infections, or iatrogenic causes (after thoracic surgery or thoracentesis).

Pathophysiology

At first the pleural fluid is thin, with a low leukocyte count, but it frequently progresses to a fibropurulent stage and, finally, to a stage where it encloses the lung within a thick exudative mem-brane (loculated empyema)

Clinical Manifestations

With an empyema, the patient is acutely ill and has signs and symptoms similar to those of an acute respiratory infection or pneumonia (fever, night sweats, pleural pain, cough, dyspnea, anorexia, weight loss). If the patient is immunocompromised, the symptoms may be more vague. If the patient has received antimi-crobial therapy, the clinical manifestations may be less obvious.

Assessment and Diagnostic Findings

Chest auscultation demonstrates decreased or absent breath sounds over the affected area, and there is dullness on chest percussion as well as decreased fremitus. The diagnosis is established by a chest x-ray or chest CT scan. Usually a diagnostic thoracentesis is per-formed, often under ultrasound guidance.

Medical Management

The objectives of treatment are to drain the pleural cavity and to achieve full expansion of the lung. The fluid is drained and ap-propriate antibiotics, in large doses, are prescribed based on the causative organism. Sterilization of the empyema cavity requires 4 to 6 weeks of antibiotics. Drainage of the pleural fluid depends on the stage of the disease and is accomplished by one of the fol-lowing methods:

·        Needle aspiration (thoracentesis) with a thin percutaneous catheter, if the volume is small and the fluid not too puru-lent or thick

·        Tube thoracostomy with fibrinolytic agents instilled through the chest tube in patients with loculated or complicated pleural effusions

·        Open chest drainage via thoracotomy, including potential rib resection, to remove the thickened pleura, pus, and de-bris and to remove the underlying diseased pulmonary tissue

With long-standing inflammation, an exudate can form over the lung, trapping it and interfering with its normal expansion. This exudate must be removed surgically (decortication). The drainage tube is left in place until the pus-filled space is obliter-ated completely. The complete obliteration of the pleural space is monitored by serial chest x-rays, and the patient should be in-formed that treatment may be long term. Patients are frequently discharged from the hospital with a chest tube in place, with in-structions to monitor fluid drainage at home.

Nursing Management

Resolution of empyema is a prolonged process. The nurse helps the patient cope with the condition and instructs the patient in lung-expanding breathing exercises to restore normal respiratory function. The nurse also provides care specific to the method of drainage of the pleural fluid (eg, needle aspiration, closed chest drainage, or rib resection and drainage). When a patient is dis-charged to home with a drainage tube or system in place, the nurse instructs the patient and family on care of the drainage sys-tem and drain site, measurement and observation of drainage, signs and symptoms of infection, and how and when to contact the health care provider.