Pleural Disease

Question 1

How much fluid is needed within the plerua to be visible on cxr ?

Answer 1

Usually contains approx 4mls (depends on weight)
Need approx. 200ml xs fluid to be detected on plain CXR

Question 2

How do the two layers of pleura combine ?

Answer 2

Combine around the hila – so hila have no pleural coverage; forming the pulmonary ligament
-runs inferiorly and attaches the root of the lung to the diaphragm

Question 3

What is plerual effusion and when is/isn’t it concerning?

Answer 3

Abnormal collection of fluid in pleural space
-Does not always require drainage or sampling (e.g. cardiac failure)
-Large unilateral effusions should raise concern

Question 4

When should a plerual effusion be aspirated ?

Answer 4

If not convincingly cardiac failure

Question 5

How is treating a plerual effusion aspproached ?

Answer 5

1) History and examination
2) PA CXR
3) US
4) Pleural aspirate (if not convincingly cardiac failure)
5) Biochemistry (transudate or exudate?)
-Cytology for cancer
Culture for infection

Other tests
-Contrast enhanced CT chest, repeat pleural tap, pleural biopsy (blind or thoracoscopy)

Question 6

How does moving the patient affect pleural effusion ?

Answer 6

Gravity…
-fluid can move freely wthin the plerual space

Question 7

What do different appearances of plerual fluid suggest ?

Answer 7

Straw-coloured = cardiac failure, hypoalbuminaemia (e.g. due to cancer)
Bloody = trauma, malignancy, infection, infarction
Turbid/Milky = empyema, chylothorax
Foul smelling = Anaerobic empyema
Food particles = oesophageal rupture
Bilateral – LVF, PTE, drugs, systemic path

Question 8

What main types of fluid can be found within pleural effusion ?

Answer 8

Transudates and exudates

Question 9

What are transudates ?

Answer 9

Thin, watery fluid that leaks out of blood vessels due to high blood pressure or low blood protein
-Protein < 30 g/L
-e.g. due to HF usually, cirrhosis, Hypoalbuminaemia, Atelectasis (ITU or post surgery), Peritoneal dialysis

Does not always have a benign aetiology

Question 10

What are exudates ?

Answer 10

Cells and fluid that has seeped out of vessels or an organ, especially in inflammation
-Protein > 30 g/L
-e.g. due to Malignancy, Infection (inc TB), Pulmonary infarct, Asbestos
-Always look for serious pathology

TB doesnt swim so wont find it in plerual space

Question 11

What biochemistry is looked for in pleural effusion samples ?

Answer 11

pH and glucose

Question 12

What can pH of pleural effusion tell you ?

Answer 12

7.6 = normal (if plasma pH normal)
< 7.3 suggests pleural inflammation (malignancy/ RhA)
< 7.2 requires drainage in the setting of infection

Do not check pH if frank pus; empyema so needs drained

Question 13

What can glucose of pleural effusion tell you ?

Answer 13

Low in infection, TB, rheumatoid arthritis, malignancy, oesophageal rupture, SLE

Question 14

What criteria is used to determine if plerual effusion fluid is exudate ?

Answer 14

Pleural fluid is an exudate if one or more of the following criteria are met:
1) Pleural fluid protein divided by serum protein is > 0.5
2) Pleural fluid lactate dehydrogenase (LDH) divided by serum LDH is > 0.6
3) Pleural fluid LDH > 2/3 the upper limits of laboratory normal value for serum LDH.

(Also, Protein > 30 g/L)

Light’s criteria

Question 15

What can cytology of pleural effusion tell you ?

Answer 15

Mostly looking for malignant cells
-Lymphocytes; TB, malignancy although any long standing effusion will eventually become lymphocytic
-Neutrophils suggest an acute process, infection

Question 16

What does increased amylase in plerual fluid suggest ?

Answer 16

Pancreatitis

Oesophageal rupture

Sometimes malignancy

Question 17

What does increased triglycerides in plerual fluid suggest ?

Answer 17

Suggests Chylothorax

Causes:

Trauma to thoracic duct / lymphatics (e.g., surgery)

Malignancy (especially lymphoma)

Lymphangioleiomyomatosis (LAM)

Chylothorax: chyle from the thoracic duct empties into the pleural space. Chyle is a milky white fluid with a high concentration of triglycerides,

Question 18

What do cholesterol crystals in plerual fluid suggets ?

Answer 18

Suggest Pseudochylothorax

Causes:
Tuberculosis
Rheumatoid arthritis

Seen in long-standing pleural effusions.

Question 19

What does increased creatinine in pleural fluid sugget ?

Answer 19

Suggests Urinothorax

Pleural fluid creatinine higher than serum creatinine

Usually due to urinary tract obstruction or trauma

Question 20

What does raised denosine deaminase in plerual fluid suggest ?

Answer 20

Tuberculosis

Question 21

What are ancillary effusions ?

Answer 21

Indirect effusions caused by cancer
Systemic tumour effects
-embolism, hypoalbuminaemia

Local tumour effects
-postobstructive infection, lymphatic obstruction, atelectasis

Question 22

What is mesothelioma ?

Answer 22

Malignant tumour of plera or rarely peritoneum
-Likelihood increases with asbestsos exposure
-Often takes 30–40 years to develop
-May cause breathlessness, chest pain, weight loss, fever, sweating and cough.

Question 23

Which asbestos is worst ?

Answer 23

Crocidilite - blue asbestos

Question 24

Which cancers are most likely to affect the plera ?

Answer 24

Virtually all cancers may metastasize to the pleura esp.
-lung cancer
-breast cancer
-(Upper GI, lymphoma, melanoma, ovary)

Median survival 3-12 months but large variation

Question 25

What can be used to treat maligiant plerual effusions ?

Answer 25

Repeated pleural taps Pleurodesis

Question 26

What is pleruodesis ?

Answer 26

Talcum used as sclerosing agent after drainage to keep lung stuck to chest wall after lung reinflation following drainage -Success about 60%.

Question 27

What are complications of pleruodesis ?

Answer 27

Minor pleuritic pain and fever (Common). Pneumonia (Rare) Respiratory failure (Rare) Talc pneumonitis/ARDS ( Rare) Secondary empyema (Rare) Local tumor implantation at port site in mesothelioma.

Question 28

What are long term pleural catheters ?

Answer 28

Long term cathers of the pleura... -Used mostly for malignant effusions -Vacuum in drainage bottle that provides suction to drain pleural fluid

Question 29

What are complications of long term pleural catheters ?

Answer 29

Incorrect placement, bleeding, infection

Question 30

How are effusions treated ?

Answer 30

Depends on underlying cause: LVF – diuretics Infection – drain, antibiotics, may require surgery Malignancy – drain, pleurodesis, long term pleural catheter

Question 31

In which person are pneumothoraces more common ?

Answer 31

Tall thin men Smokers Cannabis Underlying lung disease

Question 32

What are primary and secondary ptx ?

Answer 32

Primary -Normal lungs -due to apical bullae rupture Secondary are those occuring in those over 50 years old with significant smoking history or underlying lung disease. -Underlying lung disease (e.g. COPD) -rupture occurs are lung already damaged

Question 33

What are differences in the symptoms caused by primary and secondary pneumothoraces ?

Answer 33

Priamary may be asymptomatic even if moderately sized Secondary usually symptomatic even if small

Question 34

What are symptoms of a pneumothorax ?

Answer 34

Acute onset pleuritic chest pain SOB, hypoxia Signs -Tachycardia -Hyper-resonant percussion note -Reduced expansion -Quiet breath sounds on auscultation -Hamman’s sign (‘Click’ on auscultation left side)

Question 35

How are pneumotharaces classified by size on cxr ?

Answer 35

Measured at hilar level not apex Small = <2cm rim of air Large = >2cm rim of air 2cm rim is approx = 50% pneumothorax by volume Chest x-ray usally enough for ptx | Rim = outer lung border to chest wall

Question 36

How is a small, primary ptx managed ?

Answer 36

<2cm with no breathlessness High flow oxygen Discharge with early OPC | Small = <2cm rim of air

Question 37

How is a large, primary ptx managed ?

Answer 37

>2cm and or breathless High flow oxygen Aspirate via 16-18g cannula , do not exceed 2.5L total aspirate If sucessful discharge If persistent and >2cm – drain | Large = >2cm rim of air

Question 38

How are secondary pneumothacres treated ?

Answer 38

Admit all patients with secondary pneumothorax for 24 hours Generally all patients with secondary pneumothorax will need a chest drain.

Question 39

How is removal of a drain approached following a ptx ?

Answer 39

24 hours after re-expansion without clamping Clamping generally unnecessary; consider only if concern persistent air leak (clamp with caution though) Never clamp a bubbling drain; wait until bubbling in drain stopped before removal. | Drain clamped to test lung inflation dpendency on it

Question 40

When should suction be considered ?

Answer 40

Consider high-volume , low pressure (10-20cm H2O) suction after 48 hours if there is a persistent air leak or failure of re-expansion. | Suction applied through drain

Question 41

What are indications for surgical treatment of a ptx ?

Answer 41

-Second ipsilateral ptx -First contralateral ptx -Bilateral spontaneous ptx -Persistent air leak -Risk professions (pilots, divers) after first ptx

Question 42

What is a tension pneumothorax ?

Answer 42

One-way valve, progressively increasing pressure in pleural space Pushes other chest organs to opposite side to affected side Emergency – can lead to cardiac arrest

Question 43

What are specific signs of a tension ptx ?

Answer 43

Acute respiratory distress Signs -Trachea deviated to opposite side -Hypotension -Raised JVP -Reduced air entry on affected side

Question 44

What is this ?

Answer 44

Tension ptx

Question 45

How is a tension ptx treated ?

Answer 45

Needle decompression in second intercostal space anteriorly, mid-clavicular line -Usually with large bore

Question 46

What is this ?

Answer 46

Ptx

Question 47

What does this show ?

Answer 47

Pleural infection -Effusion siting on side of chest and is not meniscus; pus -Pleural infections can rapidly coagulate and organize to form fibrous peels even with antibiotics. | Pleural effusion would gather at the bottom

Question 48

What are risk factors for a plerual infection ?

Answer 48

Extremes of age Following pneumonia (not always tho) diabetes mellitus immunosuppression including corticosteroids gastro-oesophageal reflux alcohol misuse intravenous drug abuse | Significant mortality (up to 20%)

Question 49

What are the main types of plerual infection ?

Answer 49

1) Simple parapneumonic effusion -none of below, treated with antibiotics alone, may need drainage later on if things change 2) Complicated parapneumonic effusion -+ve G stain, pH <7.2, low glucose, septations, loculations. 3) Empyema -pus ## Footnote Quickly sample pleural fluid to identify parapneumonic effusions that require urgent tube drainage

Question 50

How are antibtioics used to treat pleural infection ?

Answer 50

Usually 6 weeks of Co-amoxiclav -Avoid aminoglycosides (e.g. gent) which have poor pleural penetration -Intra-pleural antibiotics not recommended (Also treated with draining as appropriate) | If CRP hasn’t halfed within 3 days = treatment not wokring

Question 51

What is Intra-pleural tPA & Dnase ?

Answer 51

Used for complicated pleural effusions or empyema -Improves fluid drainage and reduces surgical referral and duration of hospital stay.