Pleural effusion Flashcards
What is pleural effusion?
fluid in the pleural space (>50ml
What is haemothorax?
blood in pleural space
What is empyema?
pus in pleural space
What is chylothorax?
chyle (lymph with fat) in pleural space
What is haemopneumothorax?
blood and air in pleural space
What is the clinical features of pleural effusion?
Symptoms
- Dyspnoea
- Dry cough
- Pleuritic chest pain
Signs
- Tracheal deviation (if effusion is large)
- Reduced chest expansion on affected side
- Stony dullness on percussion
- Reduced breath sounds
- Bronchial breathing above fluid level
- Decreased vocal resonance
What are the investigations required for pleural effusion?
Chest X Ray
- Ipsilateral Homogenous opacity
- Blunting of costophrenic angles
- Water-dense shadows with concave upper borders
- If flat horizontal upper border – concurrent pneumothorax
Thoracentesis/ Plural Tap aka Pleural Fluid Aspiration
- Purpose: to retrieve sample for Dx reasons (non-therapeutic!)
- The 2 commonest causes of effusion are CANCER (hence cytology, immunological analysis) or INFECTION (hence gram stain, culture)
- Important to understand Transudate or Exudate (hence Protein and LDH)
Other investigations
- For Light’s Criteria : Serum and Pleural LDH & protein levels
- For infection: Pleural fluid c/s, gram stain, WCC, protein, glucose
- For malignancy : cytology
- For AI disease: AI Markers eg: Anti-CCF, RF, Anti-dsDNA, ANA, C3, C4, Anti-Ro, Anti-La
Parietal Pleural Biopsy
- If fluid analysis inconclusive
- Thoracoscopic or CT guided
What is the Light’s criteria to diagnose an exudative effusion?
- Pleural fluid protein: serum protein > 0.5
- Pleura fluid LDH: serum LDH >0.6
- Pleura fluid LDH > 2/3 upper limit of normal for serum (105-33 IU/ L)
What is the etiology of transudative pleural effusion?
Transudate: produced through increased hydrostatic pressure or reduced osmotic pressure without capillary injury (common causes in brown)
- Congestive heart failure
- Cirrhosis (hypoalbuminemia)
- Nephrotic syndrome / ESRF
- Atelectasis
- Hypothyroidism
- Constrictive pericarditis
- Meig’s Syndrome (triad of right-sided effusion, ascites and benign ovarian tumour)
What is the etiology of exudative pleural effusion?
Exudate: fluid leaking out of damaged capillaries due to inflammatory processes and impaired pleural fluid resorption (common causes in brown)
Think of 1) Infection (TB, Parapneumonic) 2) Inflamm (AI Pleuritis) 3) Malignancy
TB (lymphocytic effusion)
Parapneumonic effusion (~40% of all bacterial pneumonias)
Malignant Effusion (Most common cause of exudative effusion in the elderly)
Mesothelioma
Pulmonary Embolism – effusion due to PE is not due to pulmonary HTN -> thrombotic material triggers inflammatory cytokine release -> increased vascular permeability
Rheumatic Diseases (typically low pleural fluid glucose), SLE
Empyema / Chylothorax
Post-MI syndrome
Other Autoimmune diseases e.g. Churg-Strauss (intensely eosinophilic fluid), Wegener’s granulomatosis
Dressler’s syndrome (autoimmune inflammatory reaction often post-AMI)
Pulmonary infarction
Pancreatitis – will contain high amylase content
Uraemia
Sarcoidosis
What does clear, straw coloured pleural fluid represent?
Transudate
What does turbid, yellow pleural fluid represent?
Empyema, parapneumonic effusion
What does bloody pleural fluid represent?
Trauma, malignancy, pulmonary infarction, pneumonia
What does white/ milky pleural fluid represent?
Chylothorax (likely secondary to thoracic duct injury)
What does viscous pleural fluid represent?
Mesothelioma
What does black coloured pleural fluid represent?
Aspergillus infection
What is the protein level in transudative pleural effusion?
<25g/L
What is the protein level in exudative pleural effusion?
> 35g/L
What is the glucose, pH, LDH levels present in empyema, TB, RA, SLE?
- Glucose <3.3mmol/L
- pH <7.2
- LDH increased; pleural:serum >0.6
If amylase is found in pleural fluid, what does it mean?
Pancreatitis (pancreatic amylase)
Carcinoma, oesophageal rupture (salivary amylase)
Exudative pleural effusion is lymphocytic. How do you differentiate between TB and malignant effusion?
If an exudative pleural effusion is lymphocytic, but initial cytology and smear and culture are negative, the main differentials to consider in the local context are
- Malignant causes
- TB
Can differentiate w/ Adenosine Deaminase
- should be >40U/L in tuberculous pleural effusions
- but <40U/L in malignant pleural effusions
What are the indications of chest drainage for pleural effusions?
(Large) Malignant pleural effusion with/without pleurodesis (Pleurex)
- Malignant effusion is insidious and hence tend to present very large
- Because will remit 🡪 definitely drain and consider pleurodesis
Traumatic haemopneumothorax
Complicated parapneumonic effusion
- Complicated = Culture +ve; pH < 7,2; Glucose < 3.3
- An uncomplicated parapneumonic effusion will not require drainage 🡪 monitor w/ serial CXR and treat pneumonia
- If non-loculated 🡪 consider chest tube drainage
- If loculated 🡪 consider VATS (Video assisted thoracoscopic surgery)
Empyema – ALWAYS drain purulent fluid! Never let the sun go down on undrained pus! 🡪 and give Abx
Post-Surgery
Tension pneumothorax whereby initial needle aspiration failed
Ventilate patient with pneumothorax: We must always drain before ventilating a pneumothorax because pneumothorax is due to leakage of air from the lung 🡪 increasing the positive pressure in the lung will increase the pneumothorax!!
What is the triangle of safety to insert the chest tube?
“triangle of safety”: anterior to mid axillary line, posterior to pectoral groove, above 5th intercostal space (aka nipple line)
