Pleural Effusion Flashcards
What is a pleural effusion?
Fluid in the pleural space
What are the symptoms of a pleural effusion?
Small pleural effusions may be asymptomatic
Larger effusions cause breathlessness (dyspnoea) and pleuritic chest pain
Note- there can also be symptoms due to the cause- e.g. infective cause- fever, malaise, rigours or malignancy- weight loss, fever, fatigue
What are the signs seen when examining a patient with a pleural effusion?
Decreased chest wall expansion
Decreased breath sounds on auscultation
Stony dull on percussion
Decreased vocal resonance (note this increases in a collapsed lobe)
What is the first investigation that should be requested if suspecting a pleural effusion?
CXR
What would be seen on a CXR of a pleural effusion?
Blunting of the costo-phrenic angles
Wide spread opacity
Meniscus
Tracheal deviation away from the effusion (due to pulling force)
What two other imaging modalities may be requested for a patient presenting with a pleural effusion?
USS- Always aspirate under USS guidance
CT- If suspecting malignancy or underlying cause not known
How much fluid should be aspirated from a pleural effusion? What is there is obvious pus when aspirating?
Depends on wether the patient is symptomatic or not
Asymptomatic- aspirate enough for diagnostic testing, around 20-50mls
Symptomatic- aspirate enough to reduce symptoms but do not completely drain as some more may be required later on
Note- If there is pus on aspiration then an ICD should be inserted urgently
Describe the process by which an aspiration is taken?
This should be done under USS guidance
Percuss upper boundary of effusion and go 1-2 ribs beneath this
Infiltrate the area with LA
Use 21g needle to aspirate some fluid
What tests may be requested on a pleural effusion aspirate?
Biochemistry- Glucose, LDH, Protein, pH, Amylase
Cytology- WCC, If suspecting malignant cells, neutrophils
Bacteriology- MC&S, ZN Stain/AFB Staining, TB Culture (if suspected)
Immunology- ANA, Anti-CCP, RF, Complement
What can blood in pleural fluid be a sign of?
Malignancy
Pulmonary Infarction
Benign asbestos pleural effusion
What can milky pleural fluid be a sign of?
Chylothroax- leakage from the thoracic duct
What colour are transudates typically?
Straw coloured
What might yellow-green pleural fluid be a sign of?
RA related effusion
What is a transudate and what level must the protein be below to be considered a transudate?
Transudates are caused by factors that increase the leakage of fluid from capillaries. This includes:
- Increased hydrdostatic pressure- CCF, Cirrhosis, Fluid Overload, Pericarditis
- Decreased osmotic pressure due to low protein content (cirrhosis, liver failure, nephrotic syndrome, malabsorption)
Protein content less than 30g/L (less than 25g/L OHCM)
What is an exudate and what level must the protein be able to be considered an exudate?
Exudates exude protein, they therefore occur often when there is an inflammatory process going on.
Causes include (Infection, Inflammation, Malignancy): SLE, RA, Infection, Malignancy, Pneumonia, TB
Protein level >30g/L
What is light’s criteria and what is it used for?
Light’s criteria is used to decide if an aspirate is an exudate and should be used for border line cases. Criteria are:
- Protein content >30g/L
- Aspirate Protein/Serum Protein>0.5
- Aspirate LDH/Serum LDH >0/.6
- Aspirate LDH >2/3 Serum LDH upper limit normal
What can a low aspirate glucose be an indicator of? (<3.3mmol/L)
Empyema
TB
RA/ SLE
Malignancy
What might a low aspirate pH be an indicator of? (pH<7.2)
Empyema
TB
RA/SLE
Malignancy
What might a high aspirate LDH be an indicator of?
Recall Light’s Criteria regarding LDH
Empyema
TB
RA/SLE
Malignancy
Aspirate LDH/Serum LDH >0.6
Aspirate LDH> 2/3 ULN for Serum LDH
What might a aspirate raised amylase be an indicator of?
Pancreatitis
Ruptured oesophagus
Carcinoma
What immunology tests may be requested for a pleural effusion and what do they indicate?
ANA- SLE
RF- RA
Complement- Low in SLE, RA, Malignancy, Infection
What is Meigs’ Syndrome?
Right sided pleural effusion seen with ovarian fibroma
What is the usual pH of pleural fluid Below what pH should you consider empyema, malignancy, TB, SLE/RA?
7.6 is normal
Below 7.2/7.3 consider empyema, TB, malignancy, RA, SLE
How do you manage a pleural effusion?
Find the cause and treat this
Symptomatic drainage
If no cause identified from aspiration (e.g. infection)- CT Thorax (and other imaging), VATS, Medical Thoracoscopy
What are the two types of parapneumonic effusion?
Simple- common and usually sterile, resolve without intervention
Complex- pH<7.2 and infection likely or gram stain/culture +Ve. Requires ICD.
Empyema- Pus on diagnostic aspirate, requires PROMPT ICD
Where should an ICD be inserted, describe the anatomical boundaries?
Safe Triangle Lateral border of pectoralis major Anterior border of trapezius Level of the 5th ICS Mid clavicular line
How might recurrent pulmonary effusions be prevented?
Pleurodesis using talc (combines the visceral and parietal pleura). Can be done by:
- Talc insertion via ICD
- Talc via medical thoracoscopy
- Talc via VATS
