Questions and Answers
What is a pleural effusion?
What primarily influences the accumulation of pleural fluid?
What method has replaced lateral decubitus x-ray for evaluating suspected pleural effusions?
Through which structure is pleural fluid primarily absorbed under normal conditions?
Signup and view all the answers
What two factors can lead to the development of pleural effusion?
Signup and view all the answers
Which of the following is a characteristic of a transudative pleural effusion?
Signup and view all the answers
What is the primary role of the thin layer of fluid in the pleural space?
Signup and view all the answers
Where can pleural fluid enter into the pleural space from aside from the capillaries?
Signup and view all the answers
What is the LDH level in pleural fluid that suggests it is exudative when compared to serum?
Signup and view all the answers
What can be ignored if the gradient between serum and pleural fluid protein levels is greater than 31 g/L?
Signup and view all the answers
When is it likely for transudates to be misidentified as exudates?
Signup and view all the answers
What is the suggested pleural fluid protein/serum protein ratio to indicate an exudative effusion?
Signup and view all the answers
If a patient is suspected of having a transudative effusion, what should be done if exudative criteria are met?
Signup and view all the answers
Which criterion is NOT part of the exudative criteria for pleural fluid analysis?
Signup and view all the answers
What problem arises if the exudative criteria are applied incorrectly?
Signup and view all the answers
What is the expected condition of patients with a gradient greater than 31 g/L?
Signup and view all the answers
What tests are indicated for a patient with an exudative pleural effusion?
Signup and view all the answers
In heart failure patients, when is a diagnostic thoracentesis required?
Signup and view all the answers
What indicates that a pleural effusion is likely due to congestive heart failure?
Signup and view all the answers
What is the most common cause of exudative pleural effusion in the United States?
Signup and view all the answers
Why does hepatic hydrothorax predominately occur on the right side?
Signup and view all the answers
What symptoms do patients with aerobic bacterial pneumonia and pleural effusion typically present with?
Signup and view all the answers
What complication may arise if pleural effusions persist despite heart failure therapy?
Signup and view all the answers
What is the predominant mechanism causing pleural effusions in patients with cirrhosis?
Signup and view all the answers
What is a leading cause of transudative pleural effusions in the United States?
Signup and view all the answers
Which of the following conditions is NOT a leading cause of exudative pleural effusions?
Signup and view all the answers
What is the primary reason for distinguishing between transudative and exudative pleural effusions?
Signup and view all the answers
Which of the following criteria is used to classify exudative pleural effusions?
Signup and view all the answers
Which condition is typically associated with high protein levels in pleural fluid?
Signup and view all the answers
What type of pleural effusion would likely require additional diagnostic testing?
Signup and view all the answers
Which of the following factors is NOT typically altered in transudative pleural effusions?
Signup and view all the answers
What is one of the leading causes of exudative pleural effusions?
Signup and view all the answers
Study Notes
Pleural Effusion Overview
- The pleural space is between the lung and chest wall and contains a thin layer of fluid for lubrication.
- An excess of fluid in this space is termed pleural effusion.
Etiology of Pleural Effusion
- Accumulation occurs when fluid formation surpasses absorption by lymphatics.
- Fluid enters the pleural space via capillaries in the parietal pleura and interstitial lung spaces.
- The lymphatics can absorb 20 times more fluid than is normally formed.
- Pleural effusions can result from increased fluid formation or decreased fluid removal.
Diagnostic Approach
- Chest imaging (preferably ultrasound) is essential for diagnosing pleural effusions.
- Classification into transudative or exudative effusions is crucial for further diagnostic steps.
Transudative Pleural Effusions
- Caused by systemic factors affecting fluid dynamics.
- Leading causes include left ventricular failure and cirrhosis.
Exudative Pleural Effusions
- Occur due to local factors altering fluid dynamics.
- Major causes include bacterial pneumonia, malignancy, viral infections, and pulmonary embolism.
- Requires additional diagnostic procedures to identify underlying local disease.
Differentiation Criteria
- Distinguish between transudative and exudative effusions based on:
- Pleural fluid protein/serum protein >0.5
- Pleural fluid LDH/serum LDH >0.6
- Pleural fluid LDH over two-thirds of the serum upper limit.
- Misidentification occurs in ~25% of cases using these criteria.
- If suspected transudate shows exudative criteria, measure serum-pleural fluid protein gradient:
- A gradient >31 g/L (3.1 g/dL) indicates a transudate.
Further Testing for Exudative Effusions
- If exudative fluid is confirmed, analyze:
- Appearance of the fluid
- Glucose level
- Differential cell count
- Microbiologic studies
- Cytology
Common Causes of Pleural Effusions
-
Heart Failure:
- Most frequent cause; linked to left ventricular failure.
- Effusion often occurs when interstitial lung fluid overwhelms lymphatic removal.
- Thoracentesis is advised if effusions are asymmetric or if the patient shows fever or pleuritic pain.
- NT-proBNP level >1500 pg/mL suggests effusion from heart failure.
-
Hepatic Hydrothorax:
- Occurs in ~5% of cirrhosis patients with ascites.
- Primarily right-sided, fluid moves through diaphragm openings, potentially causing severe dyspnea.
-
Parapneumonic Effusion:
- Associated with bacterial pneumonia, lung abscess, or bronchiectasis.
- Most common exudative effusion in the U.S.
- Empyema refers to purulent effusion. Presenting symptoms include fever, chest pain, and increased sputum production.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the crucial details regarding pleural disorders in Chapter 294 of Harrison's Principles of Internal Medicine. This quiz covers the mechanisms, causes, and implications of pleural effusion, offering insights into the pleural space and its function within respiratory health.