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
Lung Segments
The Pleura
Lung surface anatomy
Pleura surface markings
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
Transudate
Transudates
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.
Exudates
Exudates Common Pneumonia Cancer TB PE Rheumatoid Less Common Pancreatitis Benign asbestos effusion Post MI Post CABG Yellow nail Drugs
www.pneumotox.com Methotrexate Phenytoin Cloazapine B Blockers Amiodarone Nitrofurantoin Drugs and pleural disease
Epidemiology of Pleural Effusion Incidence is 3/1000/year 195,000 cases per year in the UK
Approximate numbers of Pleural effusions by underlying aetiology 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
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 Pseudochylothorax Cholesterol > 5.17 Triglycerides < 1.24 No Chylomicrons Implies damage or obstruction to Thoracic Duct 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 Hospital Acquired MRSA E.Coli Enterbacter Pseudomonas Anaerobes- 10%
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