Plural effusions Flashcards
What are the two main types of pleural effusions?
Pleural effusions occur when there is excess fluid accumulation in the pleural cavity due to increased fluid production or impaired drainage. The two types are Transudative and Exudative.
What are common causes of transudative pleural effusions?
Heart failure, cirrhosis (low albumin), nephrotic syndrome, peritoneal dialysis.
What are common causes of exudative pleural effusions?
Pneumonia, malignancy, tuberculosis, autoimmune disease (e.g., lupus, rheumatoid arthritis), trauma.
What is a chylothorax?
Pleural effusion due to rupture of the thoracic duct, leading to accumulation of lymphatic fluid rich in triglycerides.
What are the common symptoms of pleural effusion?
Dyspnea, chest pain, cough; often asymptomatic if small.
What are the key physical exam findings of pleural effusion?
Dullness to percussion, decreased tactile fremitus, and decreased breath sounds over the affected area.
What is the first-line imaging study for pleural effusion?
Chest X-ray (CXR), which shows blunting of the costophrenic angles.
What imaging modality is more sensitive for detecting small pleural effusions?
CT scan or ultrasound.
What is the role of thoracentesis in pleural effusion evaluation?
Diagnostic and therapeutic procedure used to determine the nature of the effusion unless the cause is clearly heart failure.
What are Light’s criteria for exudative pleural effusion?
Pleural protein/serum protein ratio >0.5, Pleural LDH/serum LDH ratio >0.6, Pleural LDH >2/3 of the upper limit of normal serum LDH.
What are additional pleural fluid tests used for further classification?
Glucose (low in infection and malignancy), pH (7.6 normal, 7.4-7.55 transudative, 7.3-7.45 exudative, <7.2 complicated infection), cytology (for malignancy), and amylase (for esophageal rupture).
How are transudative pleural effusions managed?
Treat the underlying condition (e.g., diuretics for heart failure).
What is the general management approach for exudative pleural effusions?
Thoracentesis, chest tube drainage if necessary, and possible surgical intervention if loculated or not draining.
What are the three types of parapneumonic effusions?
Uncomplicated, complicated, and empyema.
What characterizes an uncomplicated parapneumonic effusion?
Sterile exudate, WBC <50,000, pH >7.2, negative culture; treated with antibiotics alone.
Why are antibiotics given in uncomplicated parapneumonic effusions?
To prevent progression to complicated effusions or empyema.
What characterizes a complicated parapneumonic effusion?
Bacterial infection, WBC >50,000, pH <7.2, positive culture (~50% cases); requires antibiotics and drainage.
What characterizes an empyema?
Frank pus in the pleural space, positive Gram stain and culture; requires antibiotics and urgent drainage.
What is a hemothorax?
Pleural effusion caused by blood accumulation, often due to trauma.
What is the pleural fluid hematocrit cutoff for diagnosing hemothorax?
Pleural fluid hematocrit >50% of serum hematocrit.
What is the characteristic finding in chylothorax?
Milky white pleural fluid with high triglycerides (>110 mg/dL).
What condition is associated with low glucose in pleural effusion?
Rheumatoid arthritis, tuberculosis, empyema, malignancy.
What is the most common cause of pleural effusion worldwide?
Tuberculosis.
What is the most common cause of malignant pleural effusion?
Lung cancer.
When should a chest tube be placed for pleural effusion?
If the effusion is large, causing respiratory compromise, or if it is a complicated parapneumonic effusion or empyema.
