Definition
A.Result of excess fluid production or decreased absorption of fluid in the pleural space.
Incidence
A.There are an estimated 1 to 1.5 million cases annually.
B.In general, the incidence is similar in both males and females. However, certain causes are more likely in males or females.
Pathogenesis
A.Pleural effusions are a manifestation of an underlying disease process.
B.Effusions can be transudative or exudative.
1.Transudative effusions are typically due to imbalance that occurs between the hydrostatic pressure and oncotic pressure.
2.Exudative effusions are the result of an alteration of the pleural surface such as pleural or lung inflammation, impairment of lymphatic drainage, and so forth.
Predisposing Factors
A.Any disease that may lead to accumulation of pleural fluid. The most common causes of pleural effusions are heart failure, malignancy, and pneumonia.
B.Diseases that can predispose a patient to a transudative effusion.
1.Heart failure.
2.Cirrhosis.
3.Nephrotic syndrome.
C.Diseases that can predispose a patient to an exudative effusion.
1.Pneumonia (parapneumonic effusion or empyema).
2.Malignancy.
3.Pancreatitis/pancreatic disease.
4.Trauma.
Subjective Data
A.Common complaints/symptoms.
1.Patients may have complaints of cough, pleuritic chest pain, and dyspnea.
2.Patients may have additional symptoms or clinical manifestations secondary to the underlying etiology for the pleural effusion.
B.Review of systems.
1.Depending on the suspected etiology of the effusion, the provider may want to inquire about heart failure, known liver disease or chronic alcoholism, recent trauma, history of cancer, occupational exposures, recent signs and symptoms of respiratory infection, and so on.
Physical Examination
A.Typically, no physical findings when the pleural effusion is less than 300 mL.
B.Other findings.
1.Diminished breath sounds.
2.Dullness on percussion.
3.Pleural friction rub.
4.Decreased tactile fremitus.
C.Possible other findings such as fever and edema, depending on the etiology.
Diagnostic Tests
A.Chest x-ray (see Figure 2.4).
1.Blunting of costophrenic angle in upright posteroanterior x-ray when 175 mL or more is present.
B.Smaller pleural effusions observed in lateral decubitus x-rays.
C.Failure of a pleural effusion to layer on a lateral decubitus x-ray. This may indicate a loculated pleural effusion.
D.Chest CT: Possible for evaluation of a loculated pleural effusion.
E.Ultrasonography: Can be used to evaluate the size of the pleural effusion and location.
F.Diagnostic thoracentesis.
1.Should be performed in patients whose etiology is unclear and who fail to respond to therapy.
2.Pleural fluid for diagnosis. Send for glucose, lactate dehydrogenase (LDH), pH, cell count, protein, and culture to aid with a possible diagnosis. Serum blood levels of LDH, total protein, and glucose are needed for comparison.
3.Light’s criteria: Used to differentiate between transudative and exudative pleural effusions.
a.Exudative if one of the following is present.
i.Ratio of pleural fluid to serum protein is greater than 0.5.
ii.Ratio of pleural fluid to serum LDH is greater than 0.6.
iii.Pleural fluid LDH is greater than two-thirds the normal serum LDH.
4.Additional testing may be indicated when trying to identify the etiology.
Differential Diagnosis
A.First, it is important to determine if the pleural effusion is transudate or exudate using Light’s criteria in order to establish a differential diagnosis.
B.Transudate pleural effusion.
C.Congestive heart failure (CHF).
D.Cirrhosis.
E.Exudate pleural effusion.
F.Pneumonia.
G.Cancer.
H.Tuberculosis.
I.Pulmonary embolism.
Evaluation and Management Plan
A.General plan.
1.For transudative effusions, manage the underlying disease process such as diuretics for patients with effusions due to heart failure.
2.Specific interventions.
a.Monitoring of chest x-rays: As needed pending the size, symptoms associated with the effusion, and following treatment to evaluate for reaccumulating fluid.
b.Therapeutic thoracentesis: Used for patients with refractory, large pleural effusions and/or severe respiratory compromise to relieve symptoms. Diagnostic evaluation may be required if concerned for malignancy, infectious process, and so forth.
i.Patients with malignant pleural effusions may require more than one thoracentesis due to reaccumulating fluid.
ii.Patients who need frequent thoracentesis may require a pleurodesis or indwelling tunneled pleural catheter for home drainage. The patient and family will require teaching about home use of the tunneled pleural catheter.
c.Chest tube.
i.Required for a parapneumonic effusion or an empyema, but ultimately the patient will need to be treated with antibiotics and possible surgical intervention.
FIGURE 2.4 Chest x-ray of left pleural effusion.
Source: By Tomatheart/Shutterstock.
ii.Required for patients with a hemothorax (bloody pleural effusion).
B.Patient/family teaching points.
1.Teach patients that it may help to cough or take a deep breath by holding a pillow against your chest to prevent pain.
2.Practice smoking cessation and avoid secondhand smoke.
3.Keep hydrated.
4.Use an incentive spirometer for frequent deep breathing and coughing exercises.
C.Pharmacotherapy—depends on the etiology of pleural effusion.
1.Antibiotics.
a.For use in parapneumonic effusions, empyemas, and abscesses.
b.Use empiric coverage and consider the patient’s age, comorbidities, and clinical picture before tailoring the final selection of antibiotics.
c.In general, the antimicrobial coverage should cover anaerobic organisms.
2.Vasodilators and diuretics: For use in pleural effusions related to CHF and pulmonary edema.
3.Anticoagulants: For use in pleural effusions due to pulmonary emboli.
D.Discharge instructions.
1.Instruct patients to report any increased work in breathing, fevers, and pain that does not go away or gets worse. Take medications as prescribed.
Follow-Up