pleural diseases - health education england · 2016-12-23 · pleural diseases dr matthew j knight...
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Pleural Diseases
Dr Matthew J Knight
Consultant Respiratory Physician
What do you need to know?
What do you need to know?
• Pleura- normal anatomy and physiology
• Pleural effusions
• Causes and investigations
• Treatment and prognosis
• Mesothelioma
• Pneumothorax
• Causes and investigations
• Treatment and prognosis
• Procedures
• Competent to perform tap (US not yet a core competency)
• Drain for pneumothorax
What we will cover
• The Pleura
• Pleural effusion
• Mesothelioma
• Pneumothorax
• Range of procedures
• How do I get US competent?
Structure
• Definition
• Pathophysiology
• Epidemiology
• History
• Clinical Examination
• Differential diagnosis
• Investigations and diagnostic criteria
• Management – INITIAL, MEDIUM AND LONG TERM
• Prognosis/ Complications
THE PLEURA
THE LUNG
Lun
g Segm
ents
Th
e Pleu
ra
Lun
g surface an
atom
y
Pleu
ra surface
mark
ings
Pleural cavity
• A small space!
• 10 ml of Pleural fluid
• Lubricant to allow smooth sliding
• 20ml is produced per day
• Lymph can resorb 0.2ml/kgbw/hr
• 14 ml per hour in a 70 Kg man
• Normal PH is 7.6
• Adhesive forces help transmit inspiratory expansive force
AT FRC
PLEURAL EFFUSION
Definition
• The accumulation of fluid in the pleural space
• This fluid can be classified as either
• Transudate
• Exudate
• Blood
• Other
Other
• Slightly more unusual causes
• Urinothorax (eg following renal biopsy)
• CSF-’o’-thorax (Duro-pleural fistula)
• Chylothorax (Chyle from the Thoracic duct)
• Food-’o’-thorax (Oesophageal rupture)
Transudate
• Pleural fluid accumulates due to either an increase in the hydrostatic pressure
within vessels or a decrease in the oncotic pressure
• The pleura is usually intact/normal
Tran
sud
ate
Tran
sud
ates
Transudates
• Congestive Cardiac Failure
• Renal failure
• Liver disease
• Malnutrition
• Urino-thorax
• Meigs syndrome (Ascites, Pleural effusion and benign Ovarian tumour)
Exudates
• Result of an inflamed/abnormal pleura
• Increased vascular permeability or decreased lymphatic drainage.
Exu
dates
Exudates
Common
• Pneumonia
• Cancer
• TB
• PE
• Rheumatoid
Less Common • Pancreatitis
• Benign asbestos effusion
• Post MI
• Post CABG
• Yellow nail
• Drugs
Drugs and pleural disease
• www.pneumotox.com
• Methotrexate
• Phenytoin
• Cloazapine
• B Blockers
• Amiodarone
• Nitrofurantoin
Epidemiology of Pleural Effusion
• Incidence is 3/1000/year
• 195,000 cases per year in the UK
Cause Percentage Number
CCF 35% 68,000
Pneumonia 30% 58,500
Cancer 14% 27,500
PE 9% 17,500
Liver Cirrhosis 6% 12,000
GI disease (UC, CD, Panc) 3.75% 7,500
Asbestos related 1.3% 2,500
Rheumatological related 0.4% 800
TB 0.2% 400
Others 0.35% 700
Approximate numbers of Pleural effusions by underlying aetiology
Features of the History
• Dyspnoea
• Pain
• Cough
• Fevers
• Weight loss
• PND, orthopnoea
Examination findings
• Dullness to percussion
• Decreased tactile fremitus
• Diminished breath sounds
• Reduced expansion on side of effusion
• Shift of trachea if large
• Pleural friction rub
• Nothing if less than 300ml
Differential
• Pleural effusion is not a diagnosis- it is the result of a pathological process
• Remember dullness on percussion
• Raised hemidiaphragm or subphrenic abscess
• Previous thoracic surgery resulting in marked pleural thickening
Investigative pathway for a pleural effusion
• Chest x-ray
What next….?
• Do you have a very high suspicion that it is a transudate and safe to leave?
• Volume overloaded dialysis patient
• CCF with pulmonary oedema
• No abnormal infection markers
• Responds well to treatment for the underlying condition
• If so- leave it and treat the cause- if it does not resolve or if you are not
certain US guided pleural tap (look at procedures later)
Why US guided?
• More accurate
• Reduces risk of complciations from 8.6% to 1.1% (by experienced
operatives)
• Helps pick up other diagnosis
What should I send the fluid for?
• PH (in a normal gas syringe)- unless pus
• MCS and AFB – both in a universal container and also culture bottles
• Cytology (and flow cytometry if suspecting lymphoma)
• Protein, LDH, Glucose
Other tests on fluid
• Adenosine Deaminase and TB PCR if suspecting TB
• Cholesterol, Triglycerides and Chylomicrons if suspecting Chylothorax
• Mesothelin (prognostic marker) in mesothelioma
• Amylase – if considering pancreatitis
• B Transferin if considering CSF
• RF, ANA, BNP no more sensitive in pleural fluid than in the blood.
Evaluation- arriving at a diagnosis
• Starts with US
• Is there fluid- Yes or no?
• How much- depth and extent (Ant, Medial, posterior)?
• Simple or complex?
• Septated?
• Unilateral or bilateral?
• Any abnormalities on the pleural, liver, spleen, kidney, pericardium?
• Normal diaphragmatic movement?
US characteristic of effusions
• Simple (anechoic)
• Echogenic (suggestive of an exudate)
• Septated (empyema = activation of clotting/fibrin cascade)
Anechoic simple effusion
Echogenic effusion
Septated effusion
Look at the fluid
• Clear/ straw coloured -
• Heavily proteinaceous – more likely exudate
• Blood stained
• Pus - empyema
• Milky (café-au-lait) – Chylothorax or Pseudochylothorax
PH
• <7.2 very sensitive marker for
• Empyema
• Rheumatoid effusion
• TB
• Oesophageal rupture
• Note that serial measures of pleural effusion from chronic maligant effusions become progressively more acidotic
• A low glucose is also found in empyema, RA and TB
Light’s criteria
• Any one of the following criteria to class as an exudate
• Pleural fluid to serum protein ratio > 0.5
• Pleural fluid to serum LDH ration > 0.6
• Pleural fluid LDH > 66% upper end of normal serum LDH
• Be careful if on diuretics
Cell differential
• Predominantly neutrophils
• Para-pneumonic
• Cancer
• PE
• Predominantly Eosinophils
• Pneumothorax and trauma (eg surgery)
• Drug induced
• Churg Strauss
• Predominantly Lymphocytes
• Chronic effusion
• TB
• Lymphoma (flow)
• Sarcoid
• Rheumatoid
• Yellow Nail syndrome (Lymphoedema,
effusion, bronchiectasis and yellow nail)
Cholesterol, Triglycerides and Chylomicrons
• Chylothorax
• Cholesterol > 5.17 mmol/L
• Triglycerides > 1.24 mmol/L
• Chylomicrons on electrophoresis
• Implies damage or obstruction to
Thoracic Duct
• Pseudochylothorax
• Cholesterol > 5.17
• Triglycerides < 1.24
• No Chylomicrons
• Can happen with any chronic
effusion
Microbiology
• Community Acquired
• Strep milleri group – 24%
• Strep pneumoniae- 21%
• Staph aureus – 10%
• H.influenzae, E.Coli, Pseudomonas,
Klebsiella- 10% but more in patients
with comorbidities
• Anaerobes- 10%
• Hospital Acquired
• MRSA
• E.Coli
• Enterbacter
• Pseudomonas
Next step
• Treat what you have diagnosed (CCF, infection)
• Or
• Investigate further
Further imaging
• CT chest
• Best done with pleural fluid present (although partial drainage if a massive effusion)
• So can visualise the pleura better
• Ask for a pleural protocol (delayed contrast) to better visualise the pleura
What about MRI and PET in pleural imaging?
• MRI
• Not much routine use (although good for deciding on surgical margins)
• CT-PET
• Not sensitive for malignancy, but can help focus location for biopsy
• Track progress for chemotherapy in Mesothelioma
Options for tissue diagnosis
• Blind pleural (Abrams) biopsy
• Good for TB in high incidence areas
• CT or US guided biopsy – v sensitive
• Medical Thoracoscopy
• Sensitive- multiple biopsies, and can drain effusion and perform pleurodesis
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