Diseases of the pleura Flashcards
What does the visceral plura cover and form?
Covers the lungs and forms the interlobar fissures
What does the parietal plura cover?
Mediastinum, diaphragm and inner surface of the thorax
How much fluid does the plural cavity contain and what is its function?
4ml of fluid
Functions: lubrication and surface tension (sticks the lungs to the chest wall)
Where do the two layers of pleura combine and where is there no plural coverage?
The visceral and parietal plura combine around the hilar of the lungs therefore the hilar have no plural coverage
What forms the pulmonary ligament and where is it found?
Plural layers form the pulmonary ligament which runs to attach the root of the lung to the diaphragm
What is a plural effusion?
An abnormal collection of fluid in the plural space
When is a plural effusion concerning?
Large unilateral effusion
If a large unilateral plural effusion is found on a CXR what should be done next?
A plural ultrasound to confirm its fluid.
Then do a plural aspirate (thoracentesis) to send to biochemistry, cytology and microbiology
Plural aspirates: what does the following imply?
1) Straw coloured
2) Red/bloody
3) Turbid/milky
4) Foul smelling
5) Food particles
1) Straw coloured = cardiac failure, hypoalbuminaemia
2) Red/bloody = Trauma, malignancy, infection, infarction
3) Turbid/milky = Empyema, chylothorax
4) Foul smelling = Anaerobic empyema
5) Food particles = oesophageal rupture
What is a chylothorax?
Type of pleural effusion. Lymph formed in the digestive system called chyle accumulates in the pleural cavity due to either disruption or obstruction of the thoracic duct.
What can cause a bilateral plural effusion?
Left ventricular failure,
PTE (pulmonary thromboendarterectomy)
Drugs- diuretics not working
Systemic pathology
What is a PTE?
PTE (pulmonary thromboendarterectomy) an operation that removes organized clotted blood from the pulmonary arteries, which supply blood to the lungs.
Plural effusion: what is a transudates and what can cause it?
Tranudate is a fluid with a protein <30g/L
Caused by heart failure, liver cirrhosis, hypoalbumanaemia or peritoneal dialysis
Less concerning
Plural effusion: what is an exudate and what can cause it?
Exudate is a fluid with a prtein >30g/L
Caused by malignancy, infection (TB?), primary infarct, asbestosis
More concerning
If a fluid protein is >2/3 of the serum protein level it is an exudate. True or false?
True
Plural effusion: apart from protein content, what other biochemical levels should you check in an aspirate?
Fluid pH- normal is 7.6. <7.3 suggests infection and <7.2 needs draining
Glucose- low in infection, TB, rheumatoid, malignancy and oesophageal rupture
What are you looking for in cytology of plural effusions?
Malignant cells- 2 samples will diagnose 2/3 of malignant effusions
Lymphocyes inmply TB, malignancy, chronic
Neurophils imply an acute process
What are you looking for in microbiology of plural effusions?
Gram stain and microscopy
PCR, Acid fast bacilli stain and culture (trying to identify TB)
How many plural aspirates should you do for diagnostic purposes and how much fluid should you take?
Up to 2- 2 samples will increase diagnostic yield but anymore will not.
Increasing volume doesn’t increase yield
What causes of plural effusion should resolve in <2 months?
CCF, Parapneumonic effusion, Acute pancreatitis, Post CABG, Post trauma, PE, Sarcoidosis, Traumatic chylothorax
What causes of plural effusion should resolve in 2-6 months?
Post CABG, TB, Cardiac injury, Sarcoidosis, Benign asbestosis, Chronic pancreatitis
What causes of plural effusion should resolve in 6-12 months?
Rheumatoid, benign asbestosis
What can cause a benign persistent plural effusion?
Trapped lung- one of the outcomes of fibrinous or granulomatous pleuritis
Lymphangiectasia-pathologic dilation of lymph vessels
YNS- yellow nail syndrome
Plural fluid cytology will diagnose what percentage of mesotheliomas?
30%
How can you obtain a tissue biopsy of the pleura?
1) CT guided biopsy
2) Blind pericutanious plural biopsy- uncommon
3) Thoracoscopy- ultra sound the pleural space. Insert needle and pump air into the plural space s lung deflates and insert a thoracoscope to take 5 biopsys
Why are biopsies often negative?
Poor technique
Involvement of plural disease is discontinuous
The effusion is caused by a malignancy but the effusion is not malignant
What is a mesothelioma?
Malignant tumour of the lining of the lung or rarely, the lining of the abdomen.
Mesothelioma can develop from exposure to one asbestos fibre, but the length of time of exposure increase the likelihood of developing mesothelioma. True or false?
True
How long does it take for mesothilioma to develop?
30-40 years
What systemic symptoms can mesothilioma cause?
Breathless, chest pain, weight loss, fever, sweating, cough
What diseases can you claim against the government for?
1) Plural plaques
2) Asbestosis- pulmonary fibrosis
3) Mesothilioma
All caused by asbestos exposure
What investigations are required if you suspect mesothiloma?
1) Imaging- CXR and CT (pleural nodularity, circumfrential pleural thickening, Local invasion, Lung entrapment)
2) Fluid aspirate- low cytological yeild
3) Biopsy- thoracoscopy or CT guided biopsy
What can be offered as treatment for mesothilioma?
1) Pleurodese effusions
2) Chemotherapy
3) Radiotherapy
4) Palliative care
5) surgery- very unlikely
Who must mesothelioma deaths be reported to?
Fiscal
What are the most common cancers to metastasise to the pleura?
Lung and breast cancer
Upper GI, lymphoma, melanoma and ovarian cancer
What is pleurodesis?
Pleurodesis is a medical procedure in which the pleural space is artificially obliterated. It involves the adhesion of the two pleurae. In hospital for 4 days
What are the 2 different types of pleurodesis and what do they involve?
Talc slurry = talc in a suspension with NaCl and Lidocaine. Inserted through a chest drain
Talc poudrage = talc in an aerosol. Cannot go through a chest drain
What is the success rate of pleurodesis?
60%
What are the complications of pleurodesis?
Common: Minor pleuritic pain and fever
Rare: Pneumonia, Respiratory failure, ARDS, talc pneumonitis, secondary empyema
When does pleurodesis work well and when is it less successful?
Works well if its clean
Doesn’t work well if there are lots of protein fibres/pockets
Why are long term pleural catherters used and what is the maximum volume of fluid they can drain?
To allow patients to control effusion symptoms and stay out of hospital. Only 1 overnight stay required. Drain is designed to stay in place for life but can only drain 1L of fluid a day
What are the complications of a long term pleural catheter?
Incorrect placement, bleeding and infection
But patients can bath/shower and even fly if they don’t have a pneumothorax
What is the lent score used for and what does it stand for?
LENT score is used to determine survival in malignant pleural effusions. 0-7.
L = LDH- hw much protein in the plural space?
E = ECOG performance score
N = Neutrophil to lymphocyte ratio in serum
T = Tumour type
If the pleural effusion is due to left ventricular failure, what is the treatment?
Diuretics
If the plural effusion is due to infection, what is the treatment?
Antibiotics, possible drainage and possible surgery
What is the stereotypical person to suffer a pneumothorax?
Tall, thin men who smoke cannabis with underlying lung disease
What is the difference between a primary and secondary pneumothorax?
Primary = normal lungs. Apical bullae rupture Secondary = underlying lung disease. Eg COPD
What is the presentation of a pneumothorax?
Primary may be assymptomatic even if large Acute onset pleuritic chest pain SOB, hypoxia Tachycardia Hyperresonant percussion- unilateral Reduced expansion- unilateral Quiet breath sounds- unilateral Hammans sound (click)
What investigations are needed if you suspect a pneumothorax?
CXR
CT chest is useful to distinguish bullous lung disease or small pneumothorax
How is a small and large pneumothorax classified?
Small = <2cm air at the hylum
Large = >2cm air at the hylum
A 2cm rim is approximately 50% of the thoracic volume
How is a pneumothorax managed?
Oxygen No treatment if asymptomatic and small Aspiration (aviods chest drain but time consuming) Primary pneumothorax Chest drain- secondary pneumothorax Suction or surgical intervention
When would surgical intervention be needed in pneumothorax?
Second ipsilateral pneumothorax or first contralateral pneumothorax
Bilateral spontaneous pneumothorax
High risk professions- pilots/divers after first pneumothorax
What is required in pneumothorax follow up?
CXR until resolution
Risk of recurrence- flying/diving advice
Smoking cessation
What is a tension pneumothorax?
Emergency!
One way valve progressively increasing the pressure in the plural space.
What are the signs of a tension pneumothorax?
Mediastinal shift and compression of the opposite lung Acute respiratory distress Tracheal deviation Hypotention Raised JVP Reduced unilateral air entry
What are the risk factors for tension pneumothorax?
Ventilated patient Trauma CPR Blocked/ misplaced drain Airway disease Hyperbaric treatment
What is the management for tension pneumothorax?
Needle decompression with a large bore venflon
2nd intercostal space anteriorally mid clavicular line
What is the mortality for pleural infection and does it necessarily follow pneumonia?
20%
It doesn’t always follow pneumonia
What are the risk factors for plural infection?
Diabetes, Immunosupression (inc. steroids), Gastero-oesophageal reflux, Alcohol misuse/PWID
How does plural infection progress?
Rapid coagulation ad organization to form fibrous peals even with antibiotics
What are the presentations of plural infections?
Simple paraneumonic effusion
Complicated paraneumonic effusion
Empyema (collection of pus in the plural cavity)
What is an empyema?
A collection of pus in the pleural cavity
What is the difference between a simple and complicated paraneumonic effusion
Complicated = gram +ve stain. pH <7.2, low glucose, septations and loculations Simple = none of above
What is the treatment for plural infection?
Simple effusion = antibiotics if small, drainage and antibiotics if large
Complicated effusion = drainage and antibiotics
Empyema = urgent drainage and antibiotics, surgery maybe required
*Venous thromboembolism prophylactics.
*Fibrinolytics are rarely used
What type of antibiotics should be given for pleural infection?
Gentamycin does NOT enter the plural space. Use vancamycin (covers S.aureus) instead.
Coammoxiclav and augmenting can be used but increased risk of C. diff
What is the function of mesothilial cells?
Linked: what is the hallmark of mesothilial disease?
Fluid absorbtion
Effusion
It is possible for plural effusion and pulmonary oedema to develop together?
Yes
What are the common causes of pneumothorax?
Trauma: fractured ribs
Iatrogenic: CT guided biopsies
Rupture of bulla
What cell type of cancer commonly metastasises to the pleura?
Adenocarcinoma
