Approach to Pleural Effusion  Dr Abdalla Elfateh Ibrahim  Consultant & Assisstant Professor of Pulmonary Medicine  King Saud University

Pleural Effusion  Pleural effusions are a common medical problem  with more than 50 recognized causes including  Local pleura disease  Underlying lung  Systemic conditions  Organ dysfunction  Drugs  It occur as a result of increased fluid formation and/or reduced fluid resorption.

Mechanism  The pathophysiology of fluid accumulation varies according to underlying aetiologies.  Increase permeability  Increase pulmonary capillary pressure  Decrease negative pleural pressure  Decrease oncotic pressure  Obstructed lymphatics

Types of pleural effusions  Transudates pleural fluid proteins < 30 OR  Exudates pleural fluid proteins >30

Causes of pleural effusion Transudates  Very Common causes  Heart failure  Liver cirrhosis

Transudates  Less Common causes  Hypoalbuminaemia  Peritoneal dialysis  Hypothyroidism  Nephrotic syndrome  Mitral Stenosis

Causes of pleural exudates Common causes  Malignancy  Parapneumonic effusions  Tuberculosis

Exudates Less Common causes  Pulmonary embolism  Rheumatoid arthritis and other autoimmune pleuritis  Benign Asbestos effusion  Pancreatitis  Post-myocardial infarction  Post CABG

Exudates  Rare causes  Yellow nail syndrome (and other lymphatic disorders )  Drugs  Fungal infections

Clinical assessment and history  Thorough history (Infection, malignancy, risk of PE, heart failure etc.)  And physical examination.

History  Drug history is important. Uncommon cause of exudative effusion (mesotruxate, Amiodarone Phenytoin, Nitrofurantoin and Beta- blockers ) >100 cases reported globally  An occupational history  Asbestos exposure and potential secondary exposure via parents or spouses should be documented.

Symptoms  Asymptomatic  Breathlessness  Chest pain  Cough  Fever

 Approximately 75% of patients with pulmonary embolism and pleural effusion have a history of pleuritic pain.  Dyspnoea is often out of proportion to the size of the effusion  Asymptomatic if it occupies less than a third of the hemithorax

Signs  Decrease expansion  Dull percusion node  Decrease vocal resonance  Decrease air entry  Signs of associated disease (for example :chronic liver disease-CCF- nephrotic syndrome -SLE-RA-Ca lung)

DIAGNOSIS  CXR  Pleural aspiration  Pleural biopsy  Medical thoracoscopy  CT scan  VAT  Bronchoscopy

CXR

Diagnostic Imaging

Pleural aspiration  The initial step in assessing a pleural effusion is to ascertain whether the effusion is a transudate or exudate  Diagnostic tap  Aspiration should not be performed for bilateral effusions in a clinical setting strongly suggestive of a transudate, unless there are atypical features or they fail to respond to therapy

Pleural aspiration  A diagnostic tap, with a fine bore (21G) needle and a 50mL syringe  Bedside ultrasound guidance is recommended for all diagnostic aspirations  Biochemistry : protein, LDH, PH, and glucose  Microbiology: Gram stain, AFB and culture  Pathology :cytology

Pleural aspiration  Aspirated fluid should immediately be drawn into a blood gas syringe for PH  Biochemical (2-5 ml)  Microbiology 5ml  50ml for cytological examination

Pleural effusion  Document in the patient file : Aseptic techique (under local Anathesia)  The amount of effusion aspirated  Appearance and odour should be noted.  (colour usually Straw colour (normal)  Smell, unpleasant aroma of anaerobic infection may guide antibiotic  The appearance may be serous blood tinged or frankly bloody -

Appearance  Milky fluid Empyaema Chylothorax PesudoChylothorax

 Centrifuging turbid or milky pleural fluid will distinguish between empyema and lipid effusions.  If the supernatant is clear then the turbid fluid was due to empyema  If it is still turbid : -Chylothorax OR - Pseudochylothorax

Appearance  Grossly bloody pleural fluid is usually due to  Malignancy  Pulmonary embolus with infarction  Trauma  Benign asbestos pleural effusions  Post-cardiac injury syndrome

How to differentiate between haemothorax & hagic effusion  Pleural fluid haematocrit is greater than 50% of the patient's peripheral blood haematocrit is diagnostic of a haemothorax

Fluid Suspected disease  Putrid odour Anaerobic empyema  Food particles Oesophageal rupture  Bile stained Cholothorax (biliary fistula)  Milky Chylothorax/Pseudochylothorax  ‘Anchovy sauce’ like fluid Ruptured amoebic abscess

Differentiating between exudate and transudate effusions  Protein of > 30g/l an exudate  Protein of <30 g/l a transudate.  When protein is close to 30g/l (25-30)

Light's criteria  Exudates if one or more of the following:  Pleural fluid protein divided by serum protein is greater than 0.5  Pleural fluid LDH divided by serum LDH is greater than 0.6  Pleural fluid LDH > 2/3 the upper limits of laboratory normal value for serum LDH.

How accurate is Light ’ s criteria ?  In CCF diuretic therapy increases the concentration of protein, LDH and lipids in pleural fluid  In this context Light's criteria is recognized to misclassify a significant proportion of effusions as exudates.  Clinical judgment should be used  Measurement of NT-pro-BNP can be useful.

Other tests  Glucose < 3.3 mmol/l ? Infection  PH <7.2 empyaema  Amylase pancreatic ca,rupture oesophagus  Rheumatoid factor RA  ANA for SLE  Complement level (reduced in SLE,RA,Ca)

Pleural fluid differential cell counts  Cell proportions are helpful in narrowing the differential diagnosis but none are disease specific  When any effusion becomes long standing it tends to be populated by lymphocytes (and neutrophils fade away)  Pleural malignancy, cardiac failure and tuberculosis are common specific causes of a lymphocytic effusion

PH  Pleural fluid pH should be measured in non- purulent effusions providing that appropriate collection technique can be observed and a blood gas analyser is available.  Inclusion of air or local anesthetic in samples may significantly alter the pH results and should be avoided.  In a parapneumonic effusion, a pH <7.2 indicates the need for tube drainage

PH  In clinical practice, the most important use for pleural fluid pH is aiding the decision to treat pleural infection with tube drainage.

Pleural effusion cells (cont)  Neutrophil (are associated with acute processes)  Parapneumonic effusions:  Pulmonary embolism  Acute TB  Benign asbestos related disease Eosinophils Pleural eosinophilia when eosinophyls are greater than 10% of cells ( eosinophilic effusion)  The most common cause eosinophilia is air or blood in the pleural space  Is a fairly non-specific

Causes of lymphocytic p. effusions  lymphocytes account for > 50% nucleated cells)  Malignancy (including metastatic adenocarcinoma and mesothelioma)  Lymphoma  Tuberculosis

Causes of lymphocytic pleural effusions  Cardiac failure  Post CABG  Rheumatoid effusion  Chylothorax  Uraemic pleuritis  Sarcoidosis  Yellow Nail Syndrome

Glucose  In the absence of pleural pathology, glucose diffuses freely across the pleural membrane and pleural fluid glucose concentration is equivalent to blood  A low pleural fluid glucose level (< 3.4 mmol/l) may be found in  Complicated parapneumonic effusions  Empyema  Rheumatoid pleuritis  Tuberculosis  Malignancy  Oesophageal rupture.

Glucose  The most common causes of a very low pleural fluid glucose level (< 1.6 mmol/l) are  Rheumatoid arthritis  Empyema  Although glucose is usually low in pleural infection and correlates to pleural fluid pH values, it is a significantly less accurate indicator for chest tube drainage when compared to pH

Cytology  The diagnostic yield for malignancy depends on  The skill and interest of the cytologist  Tumour type.  The diagnostic rate is higher for adenocarcinoma  Than for  Mesothelioma,  Squamous cell carcinoma  lymphoma and sarcoma.

Tumour markers  Pleural fluid and serum tumour markers do not have a role in the investigation of pleural effusions.

Management  Treatment of the cause  Drainage (stop drain for 1-2 hours after 1st 1500 ml) may presipitate pul oedema  Pleurodesis with - Talc - Tetracycline -Bleomycin Surgery