9.3 & 9.4 Pleural Effusions Flashcards
Define pleural effusion
Abnormal/excess fluid in pleural space
Describe the three broad mechanisms of pleural effusion
- Transudative
- Exudative
- Disruption of fluid-containing structure within thoracic cavity
List some of the most common causes of pleural effusion. Which is the most common?
- Heart failure (most common)
- Malignancy
- Infection
- Post-surgical
Is pleural effusion more common in men or women? Does this differ between aetiologies?
- Overall, same
- However, differs between aetiologies
Is pleural effusion more common in adults or children?
Adults
What % of pleural effusion cases are considered idiopathic?
25%
What symptoms do patients commonly present with when they have pleural effusion? Why?
- Shortness of breath (increased weight of fluid, mechanical strain on diaphragm and chest wall)
- Chest pain (usually due to parietal pleura inflammation)
- Cough (mechanical effects detected by airways)
True or false: pleural effusion patients never present with abnormal examination findings
- False
- Sometimes they do, sometimes they don’t
List some common examination findings for pleural effusion
- Clubbing (cancer)
- Tar staining (smoking -> cancer)
- Enlarged lymph nodes (infection)
- Chest wall scars
- Radiation burns and mastectomy (cancer?)
- JVP (heart failure)
- Evidence of arthropathy (rheumatological causes)
Chest expansion findings pleural effusion
Reduced expansion ispilateral to effusion
Percussion findings pleural effusion
“Stony” dull
Auscultation findings pleural effusion
Absent or reduced breath sounds
Investigations for suspected pleural effusion
- Observations (RR, HR, BP, SpO2)
- Blood test (WCC, CRP, Troponinin, D-Dimer)
- ECG
- CXR
- CT
Describe various pleural fluid sampling/drainage procedures for pleural effusion
Diagnostic thoracentesis: Small volume of pleural fluid aspirated
Therapeutic thoracentesis: larger volume (usually >500mL) drained
Chest drain insertion: thoracostomy
What is the recommended first line treatment approach for pleural effusion? Why?
- Large volume aspirate (don’t leave tube in) -> 1-1.5L
- It enables testing of fluid for aetiology, tests how quickly fluid will refill, gauges symptomatic benefits, and helps to identify a non-expansile lung
What type of pleural effusion does low viscosity, straw-coloured fluid often suggest?
Transudate (but it can still be paucicellular exudate)
What does serosanguinous fluid suggest in pleural effusion?
No real diagnostic value
What does frank blood fluid in pleural effusion suggest?
Usually from malignant effusion, but could have other causes as well
What does milky/turbid pleural effusion suggest?
Infection/chylothorax
What does putrid smelling pus on pleural effusion suggest?
Infection. Likely from anaerobes
What does urine-smelling pleural effusion indicate?
Urinothorax
Is the criteria for classifying pleural effusions more likely to misdiagnose transudates or exudates? Why?
- More likely to mis-classify transudates as exudates
- This is because exudates are more severe
Light’s criteria are the most common criteria used to classify pleural effusions. What are the criteria, and how many need to be fulfilled for it to be exudative?
- If pleural fluid protein > 0.5 of serum protein
- If pleural fluid LDH > 0.6 of serum LDH
- If pleural fluid LDH >2/3 of laboratory normal value
What does low pH of pleural fluid in pleural effusion suggest?
Malignancy and/or infection
Under normal circumstances, can glucose diffuse across the pleura? How does this impact glucose levels?
- Yes, it can diffuse freely
- Usually, pleural fluid glucose levels are same as blood glucose levels
Under what circumstances could pleural fluid contain low glucose?
- Increased utilization
- decreased diffusion due to pleural thickening
What is the role of cell count testing in pleural effusion?
Differentiate between infection/inflammation and malignant aetiology.
What is the role of cytology testing in pleural effusion?
Tests for malignancy
What ages are pleural infection more common in, and is it more common in men or women?
- More common in elderly and childhood.
- More common in men (twice as common)
Mortality rates of pleural infection, including normal and immunocompromised/elderly:
Overall: 20%
Elderly/immunocompromised: 30%
List the four aetiologies of pleural infection (hint: it kind of resembles those of pneumonia)
- Community-acquired
- Hospital-acquired
- Iatrogenic
- Other
List some types of pleural infection whose aetiology falls under “Other”
- Oesophageal leak/rupture
- Spontaneous bacterial empyema
- Translocation from abdominal/sub-diaphragmatic infection
Additional exam findings in pleural effusions associated with pleural infection
- Patients may look unwell
- Diaphoretic
- Fever
In what % of infective pleural effusion is fluid culturing positive?
Only 50-60%
Uncomplicated vs complicated para-penumonic effusion
- Both have no pus
- Uncomplicated has normal pH/glucse, whereas complicated has abnormal
- Complicated may also have culture positive readings and septations, uncomplicated has neither
Describe the two main pillars of pleural infection management, and what is done for both
Pillar 1: Eradicate infection
- Broad-spectrum antibiotic
Pillar 2: Removed infected fluid
- Chest tube
- Fibrinolytics + mucolytics
If these don’t work:
- Surgery
Which agent is used for lysis of pleural adhesions? What type of drug is it?
Alteplase (thrombolytic)
Which agent is used to decrease viscosity of infected pleural fluid
Pulmozyme
Roughly what percentage of pleural effusions are malignant?
22% -> 1/5 is close enough to remember
What % of cancers are complicated by malignant pleural effusion?
15%
Strictly speaking, which cancers can cause malignant pleural effusion?
Literally any of them, if they spread
List the four most common cancers that cause malignant pleural effusion, and specify the most common
- Lung cancer (most common)
- Breast cancer
- Mesothelioma
- Lymphoma
Is malignant pleural effusion more common in lung cancer or mesothelioma?
Mesothelioma (90% vs 50%)
Are the examination findings for malignant pleural effusion very consistent?
- No
- They can vary widely depending on what stage of disease the patient is in
Investigations for malignant pleural effusion
- Vitals
- Comprehensive bloods
- Imaging (CXR, Thoracic ultrasound, CT, +/- PET scan)
- Pleural fluid sampling
- Pleural biopsy
Describe pleural fluid characteristics in malignant pleural effusion
- Clear, blood-stained, or cloudy
- No smell
- pH may be normal or low
- Protein: usually high
- LDH: normal/elevated
Does malignant pleural effusion always require intervention?
- No
- Sometimes, systemic therapy will reduce the effusion
Management options for malignant pleural effusions
- Thoracentesis
- Intercostal catheter (temporary)
- Indwelling pleural catheter - long-term
- Surgical (Video-assisted surgery, decortication, pleurodesis)
Describe indwelling pleural catheters
- Stay in patient
- Intermittently, nurse can come to patient’s house and drain the fluid
What % of malignant pleural effusion cases show re-accumulation following drainage?
70-90%
What occurs during video-assisted thoracoscopy surgery (VATS)
- Drain fluid
- Take biopsies
- Administer talc
- Place a drain into patient
