Pleural Effusion Flashcards
What are the clinical signs of a pleural effusion?
- Primary features and associated conditions
Primary Features of Pleural Effusion
- Asymmetrically vs symmetrically reduced expansion (depends on unilateral vs bilateral effusion)
- Trachea deviated away from effusion
- Stony dull percussion at/below level of effusion
- Absent tactile vocal fremitus at/below level of effusion
- Reduced breath sounds below effusion
(Bronchial breathing above effusion)
Identifying Etiologies
1. Chronic liver disease
2. Nephrotic syndrome
3. Congestive heart failure
4. Hypothyroidism
5. PTB
6. Malignancy
7. Connective tissue/autoimmune diseases
How do you categorise the causes of pleural effusion?
Serous: transudative vs exudative
Non-serous: empyema, haemothorax, chylothorax
How would you differentiate between a transudative and an exudative effusion?
Gross appearance
Transudative: straw to clear coloured
Exudative: yellow turbid or bloody (trauma, malignancy, TB, PE)
Cytology
Transudate: normal
Exudate: presence of cells
Light’s criteria for exudative pleural effusion
Fluid:serum protein > 0.5
- Transudate protein count < 30, exudate protein count > 30
Fluid:serum LDH > 0.6
Fluid LDH > 2/3 upper limit of serum LDH
Serum to pleural albumin gradient: > 1.2g/dL is transudate
(less sensitive for exudates)
What would you look for in pleural aspiration?
- Appearance - straw vs pus vs bloody
- Cell count/cytospin - total cells and cell line predominance
- Biochemical:
- Protein (compare effusion albumin and plasma albumin)
- LDH
- Glucose
- pH
- Amylase
- Cholesterol (high in malignancy, chylothorax) - Microbiological
- Gram stain, culture
- AFB smear, PTB culture, MTB PCR, gamma interferon
- ADA (adenosine deaminase) > 40 IU/L - Cytology - malignant calls
What is an empyema?
Collection of pus within the pleural space
Anaerobes, staphylococci and gram negative organisms most commonly
Associated with bronchial obstruction (cancer) and recurrent aspiration
What is the appearance and composition of normal pleural fluid?
Clear ultrafiltrate of plasma
pH 7.6-7.64
Protein <1-2g/L
WCC <1000
LDH <50% of plasma concentration
Glucose similar to plasma concentration
What are the causes of high LDH in pleural fluid?
Empyema
Malignant effusion
Rheumatoid effusion
Paragonimus infection
What are the causes of low glucose in a pleural effusion?
Malignancy
Empyema
Tuberculosis
Oesophageal rupture
Rheumatoid arthritis
SLE
What are the indications for pleurodesis?
Recurrent malignant pleural effusion
Recurrent pneumothoraces
What agents can be used for chemical pleurodesis?
Talc
Doxycycline
Bleomycin
Zinc sulphate
Quinacrine hydrochloride
What are the differential diagnoses for dullness on percussion of right lower zone?
- Pleural effusion
- Pleural thickening: old TB, old empyema, mesothelioma, asbestosis, haemothorax
- Basal consolidation
- Lower lobe collapse
- Raised hemidiaphragm
- Phrenic nerve palsy in cancer or phrenic nerve crush (old TB treatment, presence of supraclavicular fossa scar)
- Hepatomegaly - Mitotic mass
- Lobectomy
What is the minimum volume of pleural effusion to be detected clinically as well as radiologically?
Clinically > 500mL
CXR > 300mL (some as low as 180mL)
Blunting of costophrenic angle on AP view
What are the pathophysiology and causes of transudative pleural effusion?
A. Hypoalbuminaemia - reduced oncotic pressure
- Nephrotic syndrome
- Chronic liver disease (hepatic hydrothorax)
- Protein losing enteropathy
- Malnutrition
B. Increased hydrostatic pressure
- Cardiac: congestive cardiac failure, constrictive pericarditis
- Renal: AKI, CKD, nephritic syndrome
C. Lymphatic obstruction
- Tumour compression
- Post-radiotherapy
- SVCO
D. Others
- Hypothyroidism (myxedema)
- Peritoneal dialysis
- Atelectasis
What are the causes of exudative pleural effusion based on predominant cell types?
A. Lymphocyte predominant (85-95% of total nucleated cells)
- Malignancy (>50%, 50-70% nucleated cells)
> Primary: bronchial or pleural (mesothelioma)
> Secondary: breast, pancreas, kidneys, ovaries, lymphomas
- TB
- Connective tissue disease - SLE, RA
B. Neutrophils predominant (>50%) (parapneumonic)
- Parapneumonic effusion (bacterial pneumonia)
- Bronchiectasis
C. Mononuclear predominant - chronic
- TB
- PE (also transudative but less common)
- Sarcoidosis
- CTD
D. Eosinophils predominant
- Blood or air in pleural space
- Drug induced: nitrofurantoin, bromocriptine, ergotamine, carbegoline, methotrexate, amiodarone, dantrolene
- Churg-Strauss disease
- Paragonimiasis
- Asbestosis
E. Others
- Pancreatitis (left sided)
- Meig’s syndrome (benign ovarian fibroma with ascites and right pleural effusion)
- Yellow nail syndrome (yellow nails/onycholysis, pleural effusion/bronchiectasis, lymphedema)
- Radiation
What are the causes of non-serous pleural effusion?
(Every details are important)
A. Empyema - frank pus or positive fluid culture, may form loculated effusion
- Pneumonia
- Abscess
- Bronchiectasis
- TB
B. Haemothorax
- Trauma
- Rupture of pleural adhesion containing blood vessel
- Carcinoma
C. Chylothorax
- Trauma or surgery to thoracic duct
- Carcinoma or lymphoma affecting thoracic duct
How do you confirm the diagnosis of pleural effusion?
- Lateral decubitus CXR - look for layering in very small effusion
(Layering >10mm before safe blind thoracocentesis) - Ultrasound
When must CXR be repeated post-pleural aspiration/drain?
When suspect complications - pneumothorax
1. Air is aspirated
2. Development of new cough, chest pain or dyspnoea
3. Loss of tactile fremitus over superior part of aspirated hemithorax
Monitoring progress and/or complications of drain
1. Reduced or minimal output
2. Loss of chest tube oscillation / bubbling
How would you investigate the cause of pleural effusion?
- Bloods
- FBC, RP, coag, LFT and protein, albumin
- GXM in haemothorax
- LDH, glucose
- RF, autoimmune profile - Baseline ECG
- CXR
- PA: blunting of costophrenic angle, meniscus sign
- Lateral: obliteration of posterior costophrenic angle or hemidiaphragm
- Raised hemidiaphragm
- Loculation (along lateral chest wall or between fissures) - Sputum - gram stain+culture; AFM smear+culture; cytology
- Diagnostic pleural tap
(Refer to question: what investigations to look for in tap) - Mantoux test or MTB (GeneXpert) PCR
- Bronchoscopy
- CT thorax - visualise underlying lung parenchyma obscured by effusion
- Pleural biopsy (CT/US guided) - malignancy, PTB pleurisy, pleural tap inconclusive
- Video assisted thoracoscopy (VATS)
- Indications: unkown etiology, malignancy, mesothelioma, pleural malignancy, PTB
How do you manage pleural effusion?
- Stabilise patient, sats monitoring, oxygen support
- Treat underlying cause and symptoms
- Therapeutic thoracocentesis (pleural drain)
- Alleviates SOB in symptomatic effusion, reduces ongoing inflammation and fibrosis in exudative effusion
- Daily up to 1.5L (500mL per shift) - Pleurodesis for recurrent effusion (malignant effusion)
- Agents: tetracycline, bleomycin, talc - Surgical indications - persistent effusion, increasing pleural thickness on US
What are the indications for urgent drainage of parapneumonic effusions?
- Frank pus on diagnostic tap
- Pleural fluid pH < 7.2
- Loculated effusions
- Positive bacterial cultures
What are the causes of raised ADA? (>43 U/mL)
- Tuberculosis
- Lymphoma
- Malignancy - leukaemia, adenocarcinoma
- Empyema
- Parapneumonic effusion from pneumonia
- SLE, RA
- Infectious mononucleosis
- Typhoid fever
What is Meig’s syndrome?
Triad of: right hydrothorax, ascites, ovarian fibroma
Ultrasound in pleural effusion
- Detection of small pleural effusion
- Diagnosis of loculated pleural effusion
- Guiding aspiration or drainage, pleural biopsy
- Differentiating pleural fluid from pleural thickening
What are the causes of raised amylase in pleural fluid?
- Pancreatitis
- Malignancy
- Bacterial pneumonia
- Oesophageal rupture
