Pleural Disease Flashcards
What causes SOB in pt with pleural effusion?
Splinting of diaphragm
Nb. approx 500ml will relieve symptoms
How much does FEV1/FVC and TLC change with 1 litre of pleural effusion removal?
FEV1/FVC - increase 0.2 litres
TLC - increase 0.4 litres
Would you expect a drop in SATS with a large pleural effusion??
Not if otherwise fit and healthy (as will get shunting of blood to healthy lung)
What radiological modality detects the smallest volume of pleural fluid?
USS - can see 5ml
Nb. 200ml needed for CT (or 50ml for lateral CXR)
If you aspirate a pleural effusion, will SATS go up?
Probably not as shunting means that blood not going to that lung. Mostly improves symptoms rather than hypoxaemia
What are lights criteria?
Exudate
Protein: fluid:serum >0.5
LDH: fluid:serum >0.6
LDH > 2/3 upper limit normal
Nb. confounder = diuretics
How many effusions due to HF are unilateral?
40% (R 30%, L 10%)
What are the causes of an transudative effusion:
- Failures: liver/renal/heart (nb. 40% of cardiac = unilateral (30% R, 10% L))
Less common
- Atelectasis
- Peritoneal dialysis
- PE (much more likely exudate)/malignancy, hypothyroid
Rare
- constrictive pericarditis
- Meig (with gynae tumour), urinothorax, ovarian hyperstimulation, subvlavian vein cannulation, duropleural fistula (ass cerebella disease)
What are causes of exudative effusions?
Common:
- Malignancy
- Parapneumonic
- TB (nb. micro only +ve in 20%)
Less common:
- Empyema (nb. micro only +ve in 50%)
- PE (contralateral in 30%)
- RA/SLE/CTD
- Chylothorax/pseudochylothorax
- post CABG/MI
- Benign asbestos
Rare
- Pancreatitis, fungal, hydatid
- Drugs: methotrexate, amiodarone, phenytoin, nitrofurantoin, beta blocker
What drugs can cause pleural effusion (exudate)?
Methotrexate, amiodarone, phenytoin, nitrofurantoin, beta blocker
Other causes of exudate:
- Malignancy
- Parapneumonic
- Empyema (nb. micro only +ve in 50%)
- PE (contralateral in 30%)
- TB (nb. micro only +ve in 20%)
- RA/SLE/CTD
- Chylothorax/pseudochylothorax
- post CABG
- Benign asbestos
- Pancreatitis, fungal, hydatid
Pt has pleural effusion with protein fluid:serum ratio >0.7. Also has raised triglycerides. What is most likely cause? And what are Light’s criteria?
Chylothorax (nb. TG>1.24 and normal cholesterol = chylo, cholesterol >5.18 and TG normal = pseudochylo)
Exudate
Protein: fluid:serum >0.5
LDH: fluid:serum >0.6
LDH > 2/3 upper limit normal
Nb. confounder = diuretics
What causes a chylothorax?
Traumatic
Malignancy (lymphoma & lung cancer)
Idiopathic
Cirrhosis (and chylous ascites)
LAM, sarcoid, filiarisis, TB, SVC obstruction
Diagnosis: TG>1.24, normal cholesterol, chylomicrons, milky fluid (may be bile-stained)
–> tend to be acute, unilateral and have normal underlying pleura
Treatment: dietary change +/- somatostatin or ocreotide
N.b aspiration only for symptomatic management
What causes pseuochylothorax?
RA & TB pleuritis
Diagnosis: cholesterol >5.18, normal TG, absent chyolmicrons
Nb. always longstanding
What can cause a lymphocytic pleural effusion?
TB
RA
Malignancy (metastatic adeno & meso)
Lymphoma
CCF
Post-cardiac bypass
Sarcoid
Chylothorax
Yellow nail
Liver/renal failure (longstanding)
What CT features of the pleura are suggestive of malignant disease?
Mediastinal thickening
Nodularity
>1cm
Circumferential (can be benign)
What might cause a pleural effusion with a low glucose? (<3.4)
Empyema (can be very low i.e. <1.6)
RA (can be very low i.e. <1.6)
TB
Malignancy
Oesophageal rupture
Nb. these are same things as for low pH
What things can cause a pleural effusion with a low pH (<7.3)?
Empyema
RA
TB
Malignancy
Oesophageal rupture
Nb. these are same things as for low glucose<3.4 (and the top 2 for very low glucose (<1.6)
What can cause pleural fluid with elevated amylase?
Pancreatitis
Malignancy (esp. adenoca)
Oesophageal rupture
What can cause black pleural fluid?
Malignant melanoma
Aspergillus niger
Haemorrhage secondary to SCLC
Pt has unilateral pleural effusion on CXR. They have bilateral pitting oedema to knees. No other examination findings. What investigations should be done?
Treat for HF and monitor for resolution (nb. also the case if suspect other causes of transudate e.g. dialysis pt)
What tests should be sent on pleural fluid?
Cytology
Protein, LDH, pH
Gram stain
+/- others
Pt has a unilateral pleural effusion. Aspirate shows an exudate but no diagnosis obtained from fluid results. What is next step?
Contrast CT (nb. need late venous phase to see pleura well)
+ consider VATS or radiology guided pleural biopsy
Pt has a unilateral pleural effusion. Aspirate shows an exudate but no diagnosis obtained from fluid results. CT and pleural biopsy also not helpful. What is next step?
Re-think re PE, TB, CCF and lymphoma.
Can consider watchful wait.
How much fluid is needed for a pleural aspirate?
50ml
5ml for micro
2-5ml for biochem
20-40ml for cytology
How should you prepare pleural fluid samples to get maximum yield for infection?
Use blood culture bottles (i.e. use if suspect infection)
What is the most likely cause of pleural fluid with a putrid odour?
Anaerobic bacteria
What causes a bloody pleural effusion?
Malignancy
PE with infarction
Trauma
Benign asbestos effusion
Post-cardiac injury
Nb. haematocrit >50% of patient’s peripheral blood = haemothorax
Pt has a chest drain in for a parapneumonic effusion. They aren’t getting better therefore you test the fluid again. The pH is 7.1. What should you do?
Change the tube (change any with pH<7.2)
What is the yield for malignancy on pleural fluid?
60%
Increases 15% on repeat
Pt suspected for malignancy. Pleural fluid is sent and comes back negative. What is next step?
CT +/- Biopsy of pleura (repeat pleural fluid not helpful) nb. do image guided biopsy first, and if inconclusive then thoracoscopy (under local or VATS)
Are serum tumour markers helpful in the context of pleural fluid?
No
What features might help you tell if effusion related to RA?
Very low glucose (<1.6), low pH, increased LDH
Painless. May be pseudochylothorax.
What features might help you tell if effusion is post-CABG?
<30 days
L>R
Usually small and asymptomatic
Exudate, bloody (but low haematocrit), may have elevated eosinophils
Tend to resolve w/o intervention in 3 months.
What is ovarian hyperstimulation syndrome in context of pleural effusions?
Life threatening reaction to ovulation induction - get R pleural effusion with massive ascites/renal & liver failure/ARDS/emboli. Exudate with elevated protein and LDH.
How can you diagnose a benign asbestos pleural effusion?
Need exposure to asbestos
Effusion usually small & asymptomatic
Blood-stained, often predominately neutrophils (polymorphs)
May resolve and leave diffuse pleural thickening
No definitive test therefore often need biopsy etc to r/o malignancy
In pt with empyema, how often will you get positive micro?
50% (nb. only 30% for TB)
What pleural fluid markers are in keeping with mesothelioma?
Positive cytokeratin & calretinin
Negative TTF1 and CEA
What treatment is available for mesothelioma?
Pemetrexed + cisplatin
–> only treatments that prolong life
Pt with known malignancy has a pleural effusion. How should it be managed?
No symptoms = observe
Symptoms = aspirate 500-1000ml
–> if prognosis <1month: aspirate to control symptoms
–> if >1month
+ trapped lung (<50% pleural apposition): IPC
+ partial or no trapped lung: drain +/- pleurodesis
–> if pleurodesis fails, do IPC
How successful is TALC pleurodesis?
80%
What is most common cause of metastatic tumour to the pleura?
Men - lung cancer
Women - breast
Pleural effusion is massive. What is most likely cause?
Malignancy
What is the max amount of fluid that should be taken on pleural aspiration?
1500ml (caution above this)
What size drain do you need for talc pleurodesis?
10 - 14 is fine (i.e. small is fine)
How much lidocaine should be used for talc pleurodesis?
Max dose 3mg/kg to a max of 250mg
1% lidocaine = 1g/100ml = 10mg/1ml = max dose 21ml for 70kg person
Is there a difference between talc slurry and poudrage with respect to pleurodesis?
No - same success
nb. Bleomycin = alterantive scleroscant
What are most common SEs of pleurodesis?
Pain and fever
Do you need to rotate pt during pleurodesis?
No
How long should chest drain be clamped for after talc administration for pleurodesis?
1hr
When can chest drain be removed after pleurodesis?
<250ml fluid in 24hrs and lung re-exapnded on CXXR
Pt has proven mesothelioma. Having chest drain inserted. What else should you do?
Prophylactic radiotherapy due to risk of seeding (also do if have thoracoscapy)
Nb. don’t need for aspiration or biopsy
Pt has malignant effusion with multiple locules. Drain inserted but not working well. What should you try next?
Fibronolytics (streptokinase)
When should you do thorascopic pleurodesis in context of malignancy pleural effusion?
Good performace status - consider thoracoscopy for diagnosis of suspected malignancy, or drainage/pleurodesis of known malignancy
Or, consider for recurrent malignant effusion
What are independent RFs for empyema?
Age
Diabetes
Immunosuppression inc steroirds
GORD
Alcohol misuse
IV drug use
What is the pH of normal pleural fluid?
7.6
What are the 3 stages of empyema development?
1) Simple exudate (parapneumonic effusion)
- pH>7.2, LDH<1000, Glu>2.2, micro -ve
2) Fibrinopurulent (complicated parapn.)
- pH<7.2, LDH>1000, Glu<2.2, +/- micro
3) Organising (empyema)
- frank pus
What is the difference between a simple and complicated parapneumonic effusion?
Complicated: pH>7.2, LDH<1000, Glu>2.2, micro -ve
Simple = opposite (and micro -ve)
What is the most common cause of communicated acquired pleural infection?
Strep milleri (angiosus) > strep pneumonia > anaerobes (fusobacterium/bacteriodes) & staph aureus
Hospital: MRSA > gram -ves (enterobacter/E.coli/pseud)
What ancilliary factors should be considered in treatment of pleural infection?
Nutrition (hypo alb ass wiith poor outcome)
VTE
When assessing non-purulent pleural fluid for infection, what test should always be done?
pH, and if not available, glucose
pH>7.2 (glu>2.2) = simple
pH<7.2 (glu<2.2) = complex
However, glucose <3.4 may suggest drainage needed
What is the cause of an alkaline effusion?
Proteus spp
What are the indications for chest drain?
Empyema
Positive gram stain from pleural fluid
pH<7.2
Poor clinical progress following treatment with abx alone
Loculated effusion
If needed for symptom benefit (consider aspiration)
What size drain is required for drainage of an empyema?
10-14 fine (i.e. small bore is fine)
What abx should be given for community acquired empyema? (no bug known)
Co-Amox and Metro (as covering for Strep milleri, pneumonia and anaerobes)
What abx should be given for hospital acquired empyema?
Tazocin +/- Vanc (if MRSA)
What abx should be avoided in pleural infection?
Aminoglycosides (poor pleural penetration)
Macrolides (unless high suspicion of atypical pathogen)
How long should abx be continued in pleural infection?
3 weeks at least
Should fibronolytics be used in pleural infection?
No - refer for VATS
However if VATS contraindicated may consider tissue plasminogen activator and DNAase
When should pt with empyema be referred for VATS?
Failure to improve after 5-7 days
Residual pleural collection despite treatment with drain and abx
When should pt with empyema be followed up?
4 weeks after d/c with CXR & inflammatory markers
What factors are associated with a risk of recurrence of primary pnx?
Age >60, Smoking, height
What factors are associated with a risk of recurrence of secondary pnx?
Age, pulmonary fibrosis, emphysema
What is the definition of large vs small pneumothorax?
large = >2cm between lung margin and hilum
What is the definition of primary and secondary pnx?
Age >50 + significant smoking hx OR evidence of underlying lung disease
Pt with primary spont pnx. 1.9cm and no symptoms. How should you manage?
Consider d/c and r/v in 2-4wks
Nb. if >2cm or SOB, aspirate (16-18G cannula, <2.5L) –> if successful (<2cm and SOB improved) then consider d/c + r/v in 2-4 wks, otherwise drain
Nb2. If minimal symptoms, can consider conservative management even if large PNX
How do you manage pt with secondary spont pnx 1.9cm + no symptoms?
Aspirate (16-18G cannula, <2.5L) –> if successful (<1cm) then admit for high flow oxygen (unless sensitive) and observe for 24hrs
Nb. if >2cm or SOB then drain
Nb2. if <1cm then admit for high flow oxygen (unless sensitive) and observe for 24hrs
Can a pt with secondary spont pnx be d/c at the door w/o any treatment?
No - will need at least 24hrs monitoring
If <1cm: high flow oxygen (unless sensitive) and observe
1-2cm + no symptoms: aspirate
>2cm OR symptoms: drain
When should consideration of referral to surgeons be done in context of pnx?
IP: Secondary spontaneous with persistent air leak >48hr
–> If unfit for surgery, consider medical pleurodesis or Heimlich valve
Ongoing airleak 3-5 days
Tension
Pregnancy (do elective assisted delivery + VATS after deliver)
Spontaenous haemothorax
OP: single pnx and pt choice, 2xipsi or 1xcontra, bilateral disease, professions at risk
What is the best surgical approach for managing recurrent pneumothoraces?
Open thoracotomy + pleurectomy = lowest recurrence
VATS = best tolerated
What is a catamenial pnx?
PNx with period
Should suction be used in pnx?
Not for primary
Secondary can try in ongoing leak (alongside larger or second drain or surgical referral)
When can pt fly after pnx?
1 week after full resolution on cxr
Nb. ideally 2 after traumatic pnx
What can pt dive after pnx?
After bilateral surgical pleurectomy (or VATS pleuordesis) + normal lung function and CT scan post-op
Nb. if traumatic pnx, then just normal lung function and CT needed
How should you manage iatrogenic pnx?
Conservative unless symptomatic/compromised
What are some causes of pnx that might come up in the exam?
Burt-Hogg-Dube
LAM (woman child-bearing age, ass with tuberous sclerosis, thin walled cysts)
Catamenial (female during period)
Marfan (aortic root dilation, skeletal problems, high arch palate, lens dislocation)
Langerhans histiocytosis
What are contraindications for local anaesthetic thoracoscopy?
Lung adherent to chest wall throughout hemithorax
Hypercapnia or severe resp distress
Uncontrollable cough
Relative: obesity, ongoing reversible process e.g. infection, high likelyhood of trapped lung, known obstruction central airway tumour
Apart from asbestos, what can cause plural plaques?
Single plaque may occur with TB trauma and haemothorax.
No evidence plaques are premalignant.
Found in 50% of workers with >30 years asbestos exposure.
What is the median survival of lung cancer (adenocarcinoma) presenting with malignant effusion?
74 days.
Mesothelioma is > 300 days
What can you use to identify effusions misclassified by lights criteria? E.g. due to diuretics
Serum/pleural album gradient
>12g/L = transudate
What features on imaging might suggest trapped lung, and therefore use of IPC may be better than pleurodesis?
Hydropneumothorax
< 50% pleural apposition
What is the likely diagnosis in turbid fluid that doesn’t clear on centrifugation?
Chylothorax or pseudochylothorax
When should CT be done in PNX?
Help determine PNX in bullous disease or drain placement in surgical emphysema
Or best way of seeing size or detecting small pnx
