Pleural Effusion Flashcards
Define pleural effusion
Defined as pathological collection of fluid within the pleural space
What is the pleural space
Potential space between the visceral (inner layer) and parietal (outer layer) pleura
Pleural effusion is a pathological collection of fluid within the pleural space.
What can this fluid be?
Blood, lymph, pus etc
Pleural effusion can be classified into two groups according to the protein concentration.
Name these groups
Transudate
Exudate
Pleural effusion can be classified into two groups according to the protein concentration: transudate and exadute.
Which one is associated with a high protein count?
Exudate (remember it as Exudate - Extra protein)
protein count >30g/L
Pleural effusion can be classified into two groups according to the protein concentration: transudate and exadute.
Which one is associated with a low protein count?
Transudative
Protein count <30g/L
Exudative is a classification of pleural effusion.
Define exudative pleural effusion?
Pleural effusion with a high protein count (>30g/L)
Remember it as Exudate = Extra protein
Transudate is a classification of pleural effusion.
Define transudate pleural effusion?
Pleural effusion with lower protein count (<30g/L)
Describe the pathogenesis of transudate pleural effusion
Occurs due to alteration in Starling forces i.e. hydrostatic and oncotic pressures leading to the fluid being ‘squeezed’ into the pleural space
Remember as Transudate – Transfers/moves across into the pleural space
Describe the pathogenesis of exudate pleural effusion
Occurs due to a variety of inflammatory conditions that affect vessel permeability and/or lymphatic drainage and thus the fluid exits into the pleural space
Exudate – Exits/moving out of the vessels into the pleural space
What is the most common cause of transudate pleural effusion
Heart failure
Name some of the causes of transudate pleural effusion
Heart failure (most common transudate cause)
Hypoalbuminaemia (low serum albumin) e.g. liver disease, nephrotic syndrome, malabsorption
Hypothyroidism
Meigs’ syndrome
What is the most common cause of exudate pleural effusion
Pneumonia
Name some of the causes of exudate pleural effusion
Infection: pneumonia (most common exudate cause), TB, subphrenic abscess
Malignancy: commonly lung and breast
Connective tissue disease: RA, SLE
Neoplasia: lung cancer, mesothelioma, metastases
Pancreatitis
Pulmonary embolism (PE)
Describe the percussion in the respiratory examination in a patient with a pleural effusion
Stony dull percussion at the bases (where the effusion is)
What is the key clinical feature of a pleural effusion
Dyspnoea (SoB)
Describe some of the signs of a pleural effusion on examination
Reduced chest wall movements on the affected side
Stony dull percussion note
Diminished or absent breath sounds
Decreased tactile vocal fremitus/vocal resonance
If the pleural effusion is large, the trachea may deviate away from the effusion
If the pleural effusion is large, the trachea may deviate ___ the effusion
a) away from
b) towards
a) away from
What is the first-line imaging investigation in all patients with a suspected pleural effusion
Chest x-ray
What are the chest x-ray features of a pleural effusion
Blunting of the costophrenic angle
Fluid in the lung fissures
If large, white out or meniscus
Tracheal and mediastinal deviation away from the effusion if it is a massive effusion
What are the two key investigations used in pleural effusion
Chest X-Ray - to confirm diagnosis
Diagnostic ultrasound-guided thoracentesis for pleural fluid analysis - to determine if it is transudate or exudate (required in all patients except those with clear evidence of heart failure)
What are some of the signs suggestive of heart failure
Past history of ischaemic or other heart disease
Raised jugular venous pressure
Pitting oedema of the legs
ECG evidence
Raised serum brain natriuretic peptide [BNP]
What are the features of Empyema pleural effusion (infective pleural effusion) on pleural fluid analysis
Presence of pus
Acidic pH (pH < 7.2)
Low glucose
High LDH
What criteria is used to distinguish exudative and transudative pleural effusion if the protein content is equivocal (25-35 g/L)
Light’s criteria
What is the use of the light criteria in pleural effusion
Useful to distinguish exudative and transudative if the protein content is equivocal (25-35 g/L)
When is Conservative management appropriate as the treatment choice in pleural effusions?
For small effusions will resolve with treatment of the underlying cause
Pleural effusions can be drained for symptomatic relief, but treatment should be directed towards the underlying cause.
By what two ways can a pleural effusion be drained
Pleural aspiration
Chest drain
What is a potential limitation of aspirating a pleural effusion
Temporarily relieve the pressure but the effusion may recur and repeated aspiration may be required.
What is the advantages of a chest drain in managing pleural effusion
Involves insertion of a tube into the pleural space to allow drainage over hours to days.
Drains are connected to an underwater seal to prevent backflow of air or fluid into the pleural space.
Prevents a pleural effusion from recurring
How is Empyema pleural effusion treated?
Insertion of a chest drain to remove pus
Antibiotics to treat the causative infection
