References:
- Brunner & Suddarth’s Textbook of Medical-Surgical Nursing, 15th Edition, ISBN 978-197-51-6103-3, by Janice L. Hinkle, Kerry H. Cheever, and Kristen J. Overbaugh (Ch. 19)
A pleural effusion is a collection of fluid in the pleural space, usually secondary to other diseases (heart failure, tuberculosis, pneumonia, pulmonary infections, nephrotic syndrome, connective tissue disease, pulmonary embolism, and neoplastic tumors). Normally, the pleural space contains a small amount of fluid (5 to 15 mL), which acts as a lubricant that allows the pleural spaces to move without friction.
Pathophysiology
In certain disorders, fluids may accumulate in the pleural space to a point at which it becomes clinically evident. This almost always has a pathologic significance.
- The effusion can be (a) a relatively clear fluid—transudate (filtrate of plasma that moves across intact capillary walls) or (b) an exudate (extravasation of fluid into tissues or a cavity).
- Transudates may be due to pathologies in the formation and reabsorption of pleural fluid, usually by an imbalance in hydrostatic or oncotic pressures. Transudative pleural effusions are most commonly due to heart failure.
- Exudates usually result from inflammation by bacterial products or tumors involving the pleural surfaces. The most common malignancy associated with a pleural effusion is a bronchogenic carcinoma.
- The effusion can also be bloody or purulent.
Clinical Manifestations
The accompanying clinical manifestations of a pleural effusion is often due to the etiologic cause of the effusion rather than the effusion itself. For example, a pleural effusion caused by pneumonia will be accompanied by fever, chills, and pleuritic chest pain, whereas a malignant effusion may result in dyspnea, difficulty lying flat, and coughing.
The severity of symptoms is determined by the size of the effusion, the speed of its formation, and the underlying lung disease. A large pleural effusion causes dyspnea. A small-to-moderate pleural effusion causes minimal or no dyspnea.
Assessment and Diagnostic Findings
Assessment of the area of the pleural effusion reveals decreased or absent breath sounds; decreased fremitus; and a dull, flat sound on percussion. These all occur because fluids don’t transmit sound very well. In the case of an extremely large pleural effusion, the assessment reveals a patient in acute respiratory distress. A large effusion places pressure on the lungs, disallowing it from expanding and filling with air. Tracheal deviation away from the affected side may also be apparent, as the effusion physically pushes the lungs to the opposite side.
- Physical examination, chest x-ray, chest CT, and thoracentesis confirms the presence of fluid. In some instances, a lateral decubitus x-ray is obtained with the patient lying on the affected side in a side-lying position. This position allows fluid to separate from air in a clear visible line, allowing for diagnosis.
- Pleural fluid is analyzed by bacterial culture, Gram stain, AFB stain (for TB), red and white blood cell counts, chemistry studies (glucose, amylase, LDH, and protein), cytologic analysis for malignant cells, and pH. A pleural biopsy also may be performed as a diagnostic tool.
Medical Management
The objectives of treatment are to discover the underlying cause of the pleural effusion; to prevent reaccumulation of fluid; and to relieve discomfort, dyspnea, and respiratory compromise.
- Specific treatment is directed at the underlying cause (e.g., heart failure, pneumonia, cirrhosis).
- Thoracentesis is performed to remove fluid, to obtain a specimen for analysis, and to relieve dyspnea and respiratory compromise. Thoracentesis may be performed under ultrasound guidance.
- Depending on the size of the pleural effusion, the patient may be treated by removing the fluid during the thoracentesis procedure or by inserting a chest tube connected to a water-seal drainage system or suction to evacuate the pleural space and re-expand the lung.
- If the underlying cause is a malignancy, effusions that are relieved via thoracentesis will often re-appear in days or weeks. Repeated thoracenteses results in pain, depletion of protein and electrolytes, and sometimes pneumothorax. Once the pleural space is adequately drained, a chemical pleurodesis may be performed to obliterate the pleural space and prevent reaccumulation of fluid.
Pleurodesis
Pleurodesis may be performed using either a thoracoscopic approach or a chest tube. A chemically irritating agent (e.g., talc or another chemical irritant) is instilled or aerosolized into the pleural space. With the chest tube approach, after the agent is instilled, the chest tube is clamped for 60 to 90 minutes and the patient is assisted to assume various positions to promote uniform distribution of the agent and to maximize its contact with the pleural surfaces. The tube is unclamped as prescribed, and chest drainage may be continued several days longer to prevent reaccumulation of fluid and to promote the formation of adhesions between the visceral and parietal pleurae.
- Other treatments for pleural effusions caused by malignancy include surgical pleurectomy, insertion of a small catheter attached to a drainage bottle for outpatient management (e.g., PleurX® catheter), or implantation of a pleuroperitoneal shunt.
- A pleuroperitoneal shunt consists of two catheters connected by a pump chamber containing two one-way valves. Fluid moves from the pleural space to the pump chamber and then to the peritoneal cavity. The patient manually pumps on the reservoir daily to move fluid from the pleural space to the peritoneal space.
Nursing Management
The nurse’s role in the care of a patient with a pleural effusion includes supporting the medical regimen. The nurse prepares and positions the patient for thoracentesis and offers support throughout the procedure. The nurse ensures the thoracentesis fluid amount is recorded and sent for appropriate laboratory testing. If a chest tube drainage and water-seal system is used, the system’s function is monitored and the amount of drainage is recorded at prescribed intervals.
- Pain management is a priority, and the nurse helps the patient assume positions that are the least painful.
- If the patient is to be managed as an outpatient with a pleural catheter for drainage, the nurse educates the patient and family about management and care of the catheter and drainage system.