1. Source: http://emedicine.medscape.com/article/299959
Pleural Effusion
Prof KR Sethuraman. MD
Source:

2. Learning Outcomes

3. It is the most common manifestation of pleural disease
Definition
A pleural effusion is
an abnormal collection of fluid
in the pleural space resulting from
excess fluid production or
decreased absorption.
It is the most common manifestation of pleural disease

4. Anatomy of The Pleural Space
bordered by the parietal and visceral pleurae
The parietal pleura covers the inner surface of the thoracic cavity, including the mediastinum, diaphragm, and ribs.
The visceral pleura envelops all lung surfaces, including the interlobar fissures.
The right and left pleural spaces are separated by the mediastinum (heart & other midline structures).

5. The Pleural space in Respiration
a relative vacuum in the space keeps the visceral and parietal pleurae in close proximity.
pleural fluid is a lubricant between the pleural surfaces rubbing against each other during respiration.
This small volume of fluid, 0.13 mL/kg of body weight, (10 ml for an average adult) is maintained through
the balance between
hydrostatic pressure and
oncotic pressure & lymphatic drainage,
any disturbance of these 3 may lead to pathology

6. Lung Recoil

7. The net result of effusion formation is
mechanical separation of the visceral and parietal pleura,
shift of the mediastinum to the opposite side and
a restrictive ventilatory defect
a flattening or inversion of the diaphragm

8. Aetiology Pleural effusion is an indicator of
an underlying disease process that is
pulmonary or
non-pulmonary in origin
may be
acute or
chronic
most pleural effusions are caused by
congestive heart failure,
pneumonia,
tuberculosis
malignancy, or
pulmonary embolism.

9. Pathophysiologic mechanisms -i
Altered permeability of the pleural membranes
e.g., inflammation,
malignancy,
pulmonary embolus
Reduction in intra-vascular oncotic pressure
e.g., hypoalbuminemia,
cirrhosis
Increased capillary permeability or vascular disruption
e.g., trauma, malignancy,
inflammation, infection,
pulmonary infarction,
drug hypersensitivity,
uremia,
pancreatitis

10. Pathophysiologic mechanisms -ii
Increased capillary hydrostatic pressure in the systemic and/or pulmonary circulation
e.g., congestive heart failure, superior vena cava syndrome
Reduction of pressure in the pleural space, preventing full lung expansion
e.g., extensive atelectasis, mesothelioma
Increased peritoneal fluid, with migration across the diaphragm via the lymphatics or structural defect
e.g., cirrhosis, peritoneal dialysis
Decreased lymphatic drainage or complete blockage, including thoracic duct obstruction or rupture
eg, malignancy, trauma

11. Classification Pleural effusions are generally classified as
Transudates (watery fluid) or
Exudates (protein-rich fluid),
based on the
mechanism of fluid formation and
pleural fluid chemistry.
Transudates result from an imbalance in oncotic and hydrostatic pressures,
whereas
Exudates are the result of inflammation of the pleura or decreased lymphatic drainage.

12. Why worry Transudate or Exudate?
differentiating between transudates and exudates is a useful first step in the study of any pleural effusion of unknown cause.
As a general rule, once an effusion has been classified as a transudate, further diagnostic procedures or studies of the pleural tissues are unnecessary

13. Transudate Exudate Tuberculosis Congestive heart failure
TB pericarditis
Para-pneumonic cause
Malignancy
lung or breast cancer, lymphoma
Pulmonary embolism
Collagen-vascular conditions (SLE)
Radiation pleuritis
Congestive heart failure
Constrictive pericarditis
Hypoalbuminemia
Cirrhosis
Nephrotic syndrome
Peritoneal dialysis
Myxedema

14. Epidemiology 320 cases per 100,000 people in industrialized countries
Estimate: 3200 x 27 = in Malaysia
About 2/3 of malignant pleural effusions occur in women
associated with breast and gynecologic malignancies.

15. Morbidity and Mortality
directly related to
the aetiology,
stage of disease
Early or late
& biochemical findings in the pleural fluid.
E.g., lower pleural fluid pH is associated with a worse prognosis
a malignant pleural effusion is associated with a very poor prognosis
median survival of 4 months and
mean survival of less than 1 year
in men: lung cancer
in women: breast cancer

16. The clinical manifestations
The most commonly associated symptoms are
progressive dyspnea,
dry cough, and
pleuritic chest pain
orthopnea with large effusion
(the inability to breathe easily unless the person is sitting up straight).
Dyspnea is related more to distortion of the diaphragm and chest wall during respiration than to hypoxemia.
Cough with purulent or bloody sputum suggests pneumonia or endobronchial tumour as the aetiology

17. Pleuritic Pain chest pain, indicates pleural irritation,
suggests an exudative etiology, such as
pleural infection,
mesothelioma, or
pulmonary infarction
Pain may be mild or severe.
It is typically described as sharp or stabbing and is exacerbated with deep inspiration.
owing to diaphragmatic involvement, pain can be referred to
the ipsilateral shoulder
(phrenic nerve root C4)
or upper abdomen

18. Physical Examination asymmetrical chest expansion
Diminished expansion on the side of the effusion
decreased tactile fremitus
Dullness to percussion
Mediastinal shift away from the effusion
Large effusion >1litre
No physical findings for effusions smaller than 300 mL
With effusions larger than 300 mL, more reliable physical findings include the following:

19. Percussion: the key to diagnosing Effusion
Pleximeter is the left middle finger used in percussion to absorb the energy generated by the strike from the Plexor finger (right middle or index finger)

20. Inventor of Percussion technique
Leopold Auenbrugger
Austrian physician who invented percussion as a diagnostic technique. On the strength of this discovery, he is considered one of the founders of modern medicine.
Leopold Auenbrugger (1722–1809) was born in Graz, the son of an innkeeper. Legend has it that his discovery of percussion was based upon observing his father tap wine casks in order to ascertain the amount of wine present in the cask.

21. Physical signs - ii Diminished or inaudible breath sounds
Egophony at the upper border of the pleural effusion
(vocal resonance of "aah“ sounds like “ee”)
Pleural friction rub
in inflammatory lesions with mild effusion
Other signs:
CCF, Cirrhosis of liver, nephrotic syndrome, etc

22. Chest Radiography
Effusions >175 mL are seen as blunting of the costophrenic angle on upright postero-anterior chest radiographs.

23. Erect vs Supine
On supine chest radiographs, moderate to large pleural effusions may appear as a homogenous increase in density spread over the lower lung fields.
Supine AP view
Erect PA view

24. Minimal Rt Basal Effusion
Chest CT scanning
in all patients with an undiagnosed pleural effusion
to detect thickened pleura or
signs of invasion of underlying or adjacent structures.
diagnostic imperatives in this situation are pulmonary embolism and tuberculous pleuritis
Eff
Minimal Rt Basal Effusion
Lt Effusion + Hilar Lymphadenpathy ( )

25. Ultrasonography of Effusion
Very sensitive
Non-invasive
Useful to confirm the diagnosis
Guides aspiration
Placement of needle
Depth of needle insertion
Right Lateral Decubitus (supine) view at Mid-clavicular line
of the liver, diaphragm and right hemi-thorax

26. Diagnostic Thoracentesis
performed for new & unexplained pleural effusions when sufficient fluid is present to allow a safe procedure.
gross characteristics of the fluid gives clues:
purulent fluid (pus) indicates an empyema
bloody fluid may result from
trauma or
malignancy, 

28. Normal Pleural Fluid A pH of 7.60-7.64
Clear ultrafiltrate of plasma that originates from the parietal pleura
A pH of
Protein content of less than 2% (1-2 g/dL)
Fewer than 1000 white blood cells (WBCs) per cubic millimeter
Glucose content similar to that of plasma
Lactate dehydrogenase (LDH) less than 50% of plasma

29. Transudate Exudate Tuberculosis Congestive heart failure
TB pericarditis
Para-pneumonic cause
Malignancy
lung or breast cancer, lymphoma
Pulmonary embolism
Collagen-vascular conditions (SLE)
Radiation pleuritis
Congestive heart failure
Constrictive pericarditis
Hypoalbuminemia
Cirrhosis
Nephrotic syndrome
Peritoneal dialysis
Myxedema

30. Differentiating Transudates From Exudates (Light’s criteria)
The fluid is considered an exudate if any of the following applies:
Ratio of pleural fluid to serum protein > 0.5
Ratio of pleural fluid to serum LDH > 0.6
Pleural fluid LDH > two-thirds of the upper limits of normal serum value
{ Light’s criteria }

31. Pleural Fluid pH & Glucose
A pleural fluid pH of less than 7.30 with a normal arterial blood pH correlates well with low pleural fluid glucose seen in exudates
In para-pneumonic effusion, A very low pleural glucose concentration (ie, < 30 mg/dL) & pleural fluid pH of <7.2 indicates the need for urgent drainage of the effusion & >7.3 (no drainage)

32. Pleural Fluid Cell Count - 1
If exudate, then do cytology of pleural fluid
Pleural fluid lymphocytosis, with
lymphocyte values greater than 85% of the total nucleated cells, suggests
TB, lymphoma, sarcoidosis,
chronic rheumatoid effusion, chylothorax.
Pleural lymphocyte values of 50-70% of the nucleated cells suggest malignancy.

33. TB pleural effusion Suspected in patients with
a history of exposure or a positive PPD finding and
in patients with lymphocytic exudative effusions,
Effusion results from a hypersensitivity reaction to the Mycobacterium. So,
acid-fast bacillus stains of pleural fluid are rarely diagnostic
pleural fluid cultures grow M tuberculosis in <65% of cases; pleural biopsy is + in 90% cases

34. Therapeutic Thoracentesis
to remove larger amounts of pleural fluid
to alleviate dyspnea
in parapneumonic effusions, to prevent ongoing inflammation and fibrosis
avoid producing a pneumothorax during the removal of large quantities of fluid
avoid re-expansion pulmonary oedema
The recommended limit is Liters in a single thoracentesis procedure

35. This is for self study later…

36. Thank you !

37. Pleural Fluid Cell Count - 2
Pleural fluid eosinophilia (PFE), with eosinophils >10% of nucleated cells, is seen in haemothorax, pneumothorax, pulmonary infarction, parasitic diseases, etc.
Mesothelial cells are found
in variable numbers in most effusions, but
their presence at greater than 5% of nucleated cells makes a diagnosis of TB less likely.