Pleural effusion and empyema
Pleural effusion and empyema: Excerpt from Handbook of Diseases
Pleural effusion is an excess of fluid in the pleural space. Normally, this space contains a small amount of extracellular fluid that lubricates the pleural surfaces. Increased production or inadequate removal of this fluid results in pleural effusion. Empyema is the accumulation of pus and necrotic tissue in the pleural space. Blood (hemothorax) and lymph or chyle (chylothorax) may also collect in this space.
Causes
The balance of osmotic and hydrostatic pressures in parietal pleural capillaries normally results in fluid movement into the pleural space. Balanced pressures in visceral pleural capillaries promote reabsorption of this fluid.
Transudative pleural effusion
Excessive hydrostatic pressure or decreased osmotic pressure can cause excessive amounts of fluid to pass across intact capillaries. The result is a trans-udative pleural effusion, an ultrafiltrate of plasma containing low concentrations of protein. Such effusions commonly result from heart failure, hepatic disease with ascites, peritoneal dialysis, hypoalbuminemia, and disorders resulting in overexpanded intra-vascular volume.
Exudative pleural effusion
Exudative pleural effusions result when capillaries exhibit increased permeability with or without changes in hydrostatic and colloid osmotic pressures, allowing protein-rich fluid to leak into the pleural space.
Exudative pleural effusions occur with tuberculosis, subphrenic abscess, pancreatitis, bacterial or fungal pneumonitis or empyema, malignancy, pulmonary embolism (with or without infarction), collagen disease (lupus erythematosus and rheumatoid arthritis), myxedema, and chest trauma.
Empyema
Usually associated with infection in the pleural space, empyema may be idiopathic or may be related to pneumonitis, carcinoma, perforation, or esoph-ageal rupture.
Signs and symptoms
Patients with pleural effusion characteristically display symptoms relating to the underlying pathology. Most patients with large effusions, particularly those with underlying pulmonary disease, complain of dyspnea. Those with effusions associated with pleurisy complain of pleuritic chest pain. Other clinical features depend on the cause of the effusion. Patients with empyema also develop fever and malaise.
Diagnosis
A chest X-ray or thoracic computed tomography scan shows radiopaque fluid in dependent regions. Auscultation of the chest reveals decreased breath sounds; percussion detects dullness over the effused area, which doesn’t change with respiration. These tests verify pleural effusion. However, diagnosis also requires other tests to distinguish transudative from exudative effusions and to help pinpoint the underlying disorder.
The most useful test is thoracentesis, in which analysis of aspirated pleural fluid shows:
❑ transudative effusions: lactate dehydrogenase (LD) levels less than 200 IU and protein levels less than 3 g/dl
❑ exudative effusions: ratio of protein in pleural fluid to serum greater than or equal to 0.5, LD in pleural fluid greater than or equal to 200 IU, and ratio of LD in pleural fluid to LD in serum greater than or equal to 0.6
❑ empyema: acute inflammatory white blood cells and microorganisms
❑ empyema or rheumatoid arthritis: extremely decreased pleural fluid glucose levels.
In addition, if a pleural effusion results from esophageal rupture or pancreatitis, fluid amylase levels are usually higher than serum levels. Aspirated fluid may be tested for lupus erythematosus cells, antinuclear antibodies, and neoplastic cells. It may also be analyzed for color and consistency; acid-fast bacillus, fungal, and bacterial cultures; and triglycerides (in chylothorax). Cell analysis shows leukocytosis in empyema. Negative tuberculin skin test strongly rules against tuberculosis as the cause. With exudative pleural effusions in which thoracentesis isn’t definitive, pleural biopsy may be done; it’s particularly useful for confirming tuberculosis or malignancy.
Treatment
Depending on the amount of fluid present, symptomatic effusion may require thoracentesis to remove fluid or careful monitoring of the patient’s own reabsorption of the fluid. Hemothorax requires drainage to prevent fibrothorax formation.
Treatment of empyema requires the insertion of one or more chest tubes after thoracentesis to allow the drainage of purulent material and possibly decortication (surgical removal of the thick coating over the lung) or rib resection to allow open drainage and lung expansion. Empyema also requires parenteral antibiotics. Associated hypoxia requires oxygen adminis-tration.
Special considerations
❑ Explain thoracentesis to the patient. Before the procedure, tell the patient to expect a stinging sensation from the local anesthetic and a feeling of pressure when the needle is inserted.
❑ Instruct the patient to tell you immediately if he feels uncomfortable or has trouble breathing during the procedure.
❑ Reassure the patient during thoracentesis. Remind him to breathe normally and to avoid sudden movements, such as coughing or sighing. Monitor vital signs, and watch for syncope.
CLINICAL TIP: If fluid is removed too quickly, the patient may suffer bradycardia, hypotension, pain, pulmonary edema, or cardiac arrest. Watch for respiratory distress or pneumothorax (sudden onset of dys-pnea, cyanosis) after thoracentesis.
❑ Administer oxygen and, in empyema, antibiotics.
❑ Encourage the patient to do deep-breathing exercises to promote lung
expansion. Use an incentive spirometer to promote deep-breathing.
❑ Provide meticulous chest tube care, and use aseptic technique for changing dressings around the tube insertion site in empyema.
❑ Ensure chest tube patency and record the amount, color, and consistency of any tube drainage.
❑ Because weeks of such drainage are usually necessary to obliterate the space, make visiting nurse referrals for patients who will be discharged with the tube in place.
❑ If pleural effusion was a complication of pneumonia or influenza, advise the patient to seek prompt medical attention for chest colds.
Book Source Details
- Book Title: Handbook of Diseases
- Author(s): Springhouse
- Year of Publication: 2003
- Copyright Details: Handbook of Diseases, Copyright © 2003 Lippincott Williams & Wilkins.
More About Pleural effusion
More Medical Textbooks Online about Pleural effusion
Review other book chapters online related to Pleural effusion:
Medical Books Excerpts
- Pleural Effusion
- "The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter" (2000)
- [ read ]
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
|
|
More About This Book:
Title: Handbook of Diseases
Authors: Springhouse
Publisher: Lippincott Williams & Wilkins
Copyright: 2003
ISBN: 1-58255-266-5
|
|
» Next page: Consider a differential diagnosisbeyond empyema when managing a pleural effusion (Avoiding Common Pediatric Errors)
Rate This Website
What do you think about the features of this website?
Take our user survey and have your say:
Website User Survey
Medical Tools & Articles:
Next articles:
Tools & Services:
Medical Articles:
Forums & Message Boards
- Ask or answer a question at the Boards:
