Pleural effusion occurs when excess fluid accumulates in the pleural space between the lungs and chest wall. A pleural effusion is considered an exudate if fluid formation exceeds lymphatic absorption, usually due to local inflammation, infection, or malignancy. Diagnostic evaluation involves determining if the effusion is a transudate or exudate based on pleural fluid analysis and comparing values to serum. Additional tests on exudative fluid including cell count, cultures, pH, and cytology aim to identify the specific cause. Treatment focuses on resolving the underlying condition causing fluid accumulation or drainage in some exudative cases.

2. Definition
 Pleural effusion is the accumulation of fluid in
the pleural space.
 The pleural space lies between the lung and
chest wall and normally contains a very thin
layer of fluid, which serves as a coupling
system.
 A pleural effusion is present when there is an
excess quantity of fluid in the pleural space.

3. Etiology
 Normally, fluid enters the pleural space from
the capillaries in the parietal pleura and is
removed via the lymphatics situated in the
parietal pleura.
 Fluid can also enter the pleural space from
the interstitial spaces of the lung via the
visceral pleura or from the peritoneal cavity
via small holes in the diaphragm.

4.  Pleural fluid accumulates when pleural fluid formation
exceeds pleural fluid absorption.
 The lymphatics have the capacity to absorb 20 times
more fluid than is normally formed. Accordingly, a
pleural effusion may develop when there is excess
pleural fluid formation (from the interstitial spaces of
the lung, the parietal pleura, or the peritoneal cavity)
or when there is decreased fluid removal by the
lymphatics.

5. Types of pleural effusion

6. Transudative pleural effusions
result from alteration of hydrostatic and
oncotic factors that increase the formation or
decrease the absorption of pleural fluid (e.g.,
increased mean capillary pressure [heart
failure] or decreased oncotic pressure
[cirrhosis or nephrotic syndrome]).

7. Exudative pleural effusions
occur when damage or disruption of the
normal pleural membranes or vasculature
(e.g., tumor involvement of the pleural space,
infection, inflammatory conditions, or trauma)
leads to increased capillary permeability or
decreased lymphatic drainage.

8. Diagnostic Approach

9. Clinical Presentation
 The underlying cause of the effusion usually
dictates the symptoms, although patients may
be asymptomatic.
 Pleural inflammation, abnormal pulmonary
mechanics, and worsened alveolar gas
exchange produce symptoms and signs of
disease.

10. symptoms and signs
 Inflammation of the parietal pleura leads to
pain in local (intercostal) involved areas or
referred (phrenic) distributions (shoulder).
 Dyspnea is frequent and may be present
and out of proportion to the size of the
effusion.
 Cough can occur.

11. Chest examination is notable for
 dullness to percussion, decreased or
absent tactile fremitus, and decreased
breath sounds.
 Tracheal shift to the contralateral side or
an ipsilateral pleural rub may be present.

12.  The clinical setting is crucial to establishing a proper
diagnosis. A definitive diagnosis based solely upon
pleural fluid analysis is possible in the minority of
pleural effusions.
 History or physical examination findings suggestive
of congestive heart failure, malignancy, pneumonia,
pulmonary embolism, myocardial infarction, surgery,
cirrhosis, or rheumatologic arthritis provide important
clues to the underlying diagnosis.

13. Laboratory and Imaging
Studies

14. Chest Roentginogram
 Pleural effusions are typically detected by
chest radiography as blunting of the
costophrenic angle or opacification of the
base of the hemithorax without loss of volume
of the hemithorax (which would suggest
atelectasis), and may be accompanied by air
bronchograms (which would suggest an
alveolar filling process such as pneumonia).

15.  Prior to invasive diagnostic or therapeutic
procedures, the patient should undergo
imaging to confirm the presence and size of
the effusion. Preferred modalities include:

16. Decubitus chest radiography
 Showing layering fluid will confirm the
presence of pleural effusion and
demonstrates that at least a portion of the
fluid is not loculated.

17. Thoracic ultrasonography
 Is one of the best modalities to assess for
pleural fluid loculations.
 Ultrasonography can also provide real-time
guidance for pleural procedures and can
reduce both the complication and failure rate
of thoracentesis.

18. Computed tomography of the chest
 With contrast helps differentiate pleural fluid
from lung masses and atelectatic lung, and
 helps define the extent of pleural thickening,
pleural nodularity, and other associated
findings.

19. Pleural fluid analysis
 Thoracentesis can be performed safely at the
bedside, in the absence of disorders of hemostasis,
on effusions that extend >10 mm from the inner chest
wall on a lateral decubitus film.
 Loculated effusions can be localized with
ultrasonography or CT scan.
 Proper technique and sonographic guidance
minimize the risk of pneumothorax and other
complications.

20.  The first step is to determine whether the
effusion is a transudate or an exudate.

21.  A transudative pleural effusion occurs when
systemic factors that influence the formation
and absorption of pleural fluid are altered.
The leading causes of transudative pleural
effusions are left ventricular failure and
cirrhosis.

22.  An exudative pleural effusion occurs when
local factors that influence the formation and
absorption of pleural fluid are altered. The
leading causes of exudative pleural effusions
are bacterial pneumonia, malignancy, viral
infection, and pulmonary embolism.

23.  The primary reason to make this
differentiation is that additional diagnostic
procedures are indicated with exudative
effusions to define the cause of the local
disease.

24.  While pleural effusion occurs in a vast array
of disease states, 90% of pleural effusions
are the result of only five diseases.
 Congestive heart failure (36%)
 Pneumonia (22%)
 Malignancy (14%)
 Pulmonary embolism (11%)
 Viral disease (7%)

25. Check pleural fluid for
 Appearance,
 lactate dehydrogenase (LDH),
 protein,
 pH,
 glucose and
 albumin

26.  Serum lactate dehydrogenase (LDH), protein,
pH, glucose and albumin should be
measured within hour of the thoracentesis to
allow appropriate comparison.

27. Pleural fluid appearance
 Most transudates are clear, straw colored,
nonviscid, and without odor
 Red-tinged pleural effusions indicate the
presence of blood.
 In exudative pleural effusions,
serosanguineous fluid is usually not helpful in
narrowing the diagnosis.

28. Bloody pleural fluid
 If the blood is due to thoracentesis, the
degree of discoloration should clear during
the aspiration.
 Bloody pleural fluid usually indicates the
presence of malignancy, pulmonary
embolism (PE), or trauma.

29. Hemothorax
 The presence of gross blood should lead to
the measurement of a pleural fluid
hematocrit.
 Hemothorax is defined as a pleural fluid to
blood hematocrit ratio of >0.5, and chest tube
drainage should be considered.

30.  Exudative pleural effusions meet at least one
of the Light's criteria , whereas transudative
pleural effusions meet none:

31. Light's criteria
 (a) a pleural fluid-to-serum protein ratio of
>0.5,
 (b) a pleural fluid-to-serum LDH ratio of >0.6,
 (c) a pleural fluid LDH of more than two-thirds
of the upper limit of normal for serum LDH

32.  The above criteria misidentify ~25% of
transudates as exudates.
 If one or more of the exudative criteria are
met and the patient is clinically thought to
have a condition producing a transudative
effusion, like in whom clinical suspicion for
heart, liver, or kidney disease is high what
should be done?

33.  The difference between the protein levels in the
serum and the pleural fluid should be measured.
 If this gradient is greater than 31 g/L (3.1 g/dL), the
exudative categorization by the above criteria can be
ignored because almost all such patients have a
transudative pleural effusion.
 In some texts a gradient of >1.2 g/dL suggests that
the pleural fluid is transudate.

34. If a patient has an exudative pleural
effusion
 Description of the fluid,
 Glucose level,
 Differential cell count,
 Microbiologic studies,
 Cytology.
 Cultures,
 Triglycerides,
 Amylase, and
 pH

35. WBC differential
 The WBC differential is often not diagnostic,
although neutrophilia is suggestive of
infection.

36.  Eosinophilia (>10% of total nucleated cell
count) is suggestive of air or blood in the
pleural space. If air or blood is not present in
the pleural space, consideration should be
given to fungal and parasitic infection, drug-
induced disease, PE, asbestos-related
disease, and Churg-Strauss syndrome.

37.  Lymphocytosis (>50% of the total nucleated
cell count) is suggestive of malignancy or
tuberculosis.
 Mesothelial cells argues against the
diagnosis of tuberculosis.
 Plasma cells suggest a diagnosis of multiple
myeloma.

38.  Exudative effusions with normal protein but
high LDH are likely to be parapneumonic or
secondary to malignancy.
 LDH is an indicator of the degree of pleural
inflammation.

39. Glucose concentration
 A glucose concentration of <60 mg/dL is
probably due to
 tuberculosis,
 malignancy,
 rheumatoid arthritis, or
 parapneumonic effusion.
 For parapneumonic pleural effusions with a
glucose of <60 mg/dL, tube thoracostomy
should be considered.

40. Pleural fluid with a low pH
 A pH of <7.3 is seen with
 empyema,
 tuberculosis,
 malignancy,
 collagen vascular disease, or
 esophageal rupture.

41.  For parapneumonic pleural effusions with a pH of
<7.20, tube thoracostomy should be considered.
 Pleural fluid for pH testing should be collected
anaerobically in a heparinized syringe and placed on
ice.
 Pleural fluid with a low pH usually has a low glucose
and a high LDH; otherwise, the low pH may be due to
poor sample collection technique.

42. Amylase
 An elevation of amylase suggests that the
patient has pancreatic disease, malignancy,
or esophageal rupture.
 Malignancy and esophageal rupture have
salivary amylase elevations and not
pancreatic amylase elevations.

43. Turbid or milky fluid
 should be centrifuged.
 If the supernatant clears, the cloudiness is likely due
to cells and debris.
 If the supernatant remains turbid, pleural lipids should
be measured. Elevation of triglycerides (>110 mg/dL)
suggests that a chylothorax is present, usually due to
disruption of the thoracic duct from trauma, surgery,
or malignancy (i.e., lymphoma).

44. Cytology
 Cytology is positive in approximately 60% of
malignant effusions.
 Priming the fluid collection bag with
unfractionated heparin (UFH; e.g., 1,000
International Units) may increase the yield.
 The volume of pleural fluid analyzed does not
impact the yield of cytologic diagnosis.
 Repeat thoracentesis increases the
diagnostic yield.

45. Surgical diagnostic
procedures

46. Closed pleural biopsy
 Closed pleural biopsy adds little to the diagnostic
yield of thoracentesis, except in the diagnosis of
tuberculosis.
 For tuberculous effusions, pleural fluid cultures alone
are positive in only 20% to 25% of cases. However,
the combination of pleural fluid studies and pleural
biopsy (demonstrating granulomas or organisms) is
90% sensitive in establishing tuberculosis as the
etiology of the effusion.

47. Diagnostic thoracoscopy
 Diagnostic thoracoscopy has largely
replaced closed pleural biopsy. Thoracoscopy
allows directed biopsies that increase the
diagnostic yield for malignancy while
maintaining the high diagnostic yield of
closed pleural biopsy for TB.

48. Indications for diagnostic
thoracoscopy
 Pleural effusion of unknown etiology
 Mesothelioma
 Lung cancer
 Tuberculosis
 Other benign pleural disorders
 Pulmonary parenchymal disease

49. Other diagnostic
procedures

50.  Other diagnostic procedures that are useful in
establishing the etiology of a pleural effusion
when the aforementioned tests are
nondiagnostic include:
 Evaluation of liver function
 Renal function,
 Cardiac echo,
 Biopsy of other abnormal sites (e.g., a
mediastinal or lung mass), and
 Evaluation of PE.

53. Differential Diagnoses of
Pleural Effusions

54. Transudative Pleural Effusions
1. Congestive heart failure
2. Cirrhosis
3. Pulmonary embolization
4. Nephrotic syndrome
5. Peritoneal dialysis
6. Superior vena cava obstruction
7. Myxedema
8. Urinothorax

55. Exudative Pleural Effusions
 1. Neoplastic diseases
a. Metastatic disease
b. Mesothelioma

56.  2. Infectious diseases
a. Bacterial infections
b. Tuberculosis
c. Fungal infections
d. Viral infections
e. Parasitic infections

57.  3. Pulmonary embolization
 4. Gastrointestinal disease
a. Esophageal perforation
b. Pancreatic disease
c. Intraabdominal abscesses
d. Diaphragmatic hernia
e. After abdominal surgery
f. Endoscopic variceal sclerotherapy
g. After liver transplant

58.  5. Collagen-vascular diseases
a. Rheumatoid pleuritis
b. Systemic lupus erythematosus
c. Drug-induced lupus
d. Immunoblastic lymphadenopathy
e. Sjögren's syndrome
f. Wegener's granulomatosis
g. Churg-Strauss syndrome

59.  6. Post-coronary artery bypass surgery
 7. Asbestos exposure
 8. Sarcoidosis
 9. Uremia
 10. Meigs' syndrome
 11. Yellow nail syndrome

60.  12. Drug-induced pleural disease
a. Nitrofurantoin
b. Dantrolene
c. Methysergide
d. Bromocriptine
e. Procarbazine
f. Amiodarone

61.  13. Trapped lung
 14. Radiation therapy
 15. Post-cardiac injury syndrome
 16. Hemothorax

62.  17. Iatrogenic injury
 18. Ovarian hyperstimulation syndrome
 19. Pericardial disease
 20. Chylothorax

63. "Classic" exudates that can be
transudates
Malignancy:
Due to early lymphatic obstruction, obstructive
atelectasis, or concomitant disease (CHF).
Pulmonary embolism:
23 percent incidence; due to atelectasis.
Sarcoidosis:
Stage II and III disease.
Hypothyroid pleural effusion:
From hypothyroid heart disease or hypothyroidism per
se.

64. Treatment

65. Transudates resolve with treatment of the
underlying heart, kidney, or liver disease.
Uncommonly, more aggressive approaches
including pleurodesis and shunts are
required.

66.  Parapneumonic effusions and empyema
should be managed with tube drainage when
indicated based on the size, gross
appearance, or biochemical analysis of the
pleural fluid or the presence of loculations
Multiple tubes are sometimes required to
adequately drain the pleural space.

67. Failure to adequately and quickly drain a
complicated parapneumonic effusion can
lead to organization of the pleural fluid and
formation of a thick pleural adhesions which
may necessitate surgical removal known as
decortication.

68. Indications for Tube
Thoracostomy in
Parapneumonic Effusions

69. Radiographic criteria
Pleural fluid loculations
Effusion filling more than half the hemithorax
Air fluid level

70. Microbiologic criteria
Pus in the pleural space
Positive stain for microorganisms
Positive pleural fluid cultures

71. Chemical criteria
Pleural fluid pH <7.2
Pleural fluid glucose <60 mg/dL

72. CONTRAINDICATIONS
 There are no absolute contraindications to
tube thoracostomy, particularly if the patient is
in respiratory distress.
 Anticoagulation or a bleeding diathesis is a
relative contraindication in a patient
undergoing elective chest tube placement for
pleurodesis. Blind insertion of a chest tube is
dangerous in a patient with adhesions from
infection, previous pleurodesis, or a lung
transplant; guidance by CT scan without
contrast is preferred in these patients.

73. Type of tube
 Silastic® tubes are preferred because older
rubber tubes have fewer drainage holes, are
not well visualized on chest radiographs, and
produce more pleural inflammation. Silastic
chest tubes contain a radiopaque strip with a
gap that serves to mark the most proximal
drainage hole.

74. Size of tube
 A chest tube's internal diameter and length
are the critical determinants of flow.
 Select the appropriate chest tube size to
account for the viscosity and accumulation
rate of the pleural material to be drained.
 As an example, drainage of viscous fluids
requires a larger bore chest tube than that
required for drainage of a similar volume of
air.

75.  Malignant effusion— A small-bore catheter (8
to 14 Fr) placed under ultrasound or CT
guidance is usually adequate to drain a
malignant pleural effusion and achieve
pleurodesis.
 Empyema — For a complicated
parapneumonic effusion or empyema that is
amenable to drainage with a single catheter.
Prefer initial image-guided placement of
small-bore catheters (10 to 14 Fr), with or
without intrapleural fibrinolytic agents.

76.  It is preferred to use the smaller tube size as
this is generally more comfortable for
patients, particularly if more than one tube is
needed. Alternatively, when the fluid appears
viscous, a larger bore tube (16-24 Fr) may be
used.

77.  Unsuccessful drainage with a small-bore
catheter either indicates the presence of
multiple loculations or very viscous material.
Multiple small-bore catheters may be used in
multiloculated effusions or large bore
catheters in case of very viscous material.
Failure to drain with a single small-bore tube
should also lead to thoracic surgery
consultation to avoid delays in case video
assisted thoracoscopy (VATS) becomes
necessary.

78.  Hemothorax — The goals of tube
thoracostomy in acute hemothorax are
drainage of fresh blood, quantification of the
rate of bleeding, evacuation of any coexisting
pneumothorax, and tamponade of the
bleeding site. Large bore catheters (32 to 40
Fr) are required to reliably achieve these
goals.

79.  Once a hemothorax is defibrinated in situ,
that is after the acute phase, success of
drainage is less dependent on the size of the
tube, than on the degree and mode of clot
formation. Large amounts of clotted blood
should be evacuated via video assisted
thoracoscopy.

80.  Occasionally, a hemothorax may result in a
sonographically complex septate pattern and
may be treated with small-bore catheters.
Treatment of hemothorax should be
individualized and done in consultation with
thoracic surgery.

81. Malignant pleural effusions
 Observation without invasive interventions
may be appropriate for some patients with
malignant pleural effusions.
 Therapeutic thoracentesis may improve
patient comfort and relieve dyspnea. The
rapid removal of more than 1 L of pleural fluid
may rarely result in re-expansion pulmonary
edema, especially if the lung is unable to re-
expand.

82.  Repeated thoracenteses are reasonable if
they achieve symptomatic relief and if fluid
reaccumulation is slow. Unfortunately, 95% of
malignant effusions will recur with a median
time to recurrence of less than a week. When
frequent or repeated thoracentesis is required
for effusions that reaccumulate, early
consideration should be given to tube
drainage with pleurodesis or placement of a
chronic indwelling pleural catheter.

83. Chemical pleurodesis
 Chemical pleurodesis is an effective therapy
for recurrent effusions. This treatment is
recommended in patients whose symptoms
are relieved with initial drainage but who have
rapid reaccumulation of fluid.

84. Talc pleurodesis
Effective and inexpensive.
Fever and hypoxia are common following
instillation of talc into the pleural space, and
respiratory failure has been described on
occasion.
Overall efficacy is similar for talc slurry
delivered via chest tube versus dry talc
insufflated during thoracoscopy.

85. Doxycycline or minocycline
 Doxycycline or minocycline can also be
instilled into the pleural space via a chest
tube.
 Pain is more prevalent and severe following
doxycycline and minocycline than following
talc.

86. Bleomycin
 Bleomycin appears to be less effective and
more expensive than other drugs.

87.  Systemic analgesics and the administration of
lidocaine in the sclerosing agent solution help
to decrease the appreciable discomfort
associated with the procedure.
 If the chest tube drainage remains high (>100
mL/d) more than 2 days after the initial
pleurodesis, a second dose of the sclerosing
agent can be administered.

88. Chronic indwelling pleural catheters
 Provide good control of effusion-related
symptoms via intermittent drainage.
 The Pleurx catheter is better at controlling
symptoms than doxycycline administered via a
chest tube. Furthermore, repeated drainage via
a Pleurx catheter leads to pleurodesis in roughly
50% of patients, allowing the catheter to be
removed.

89. Pleurectomy or pleural abrasion
 Requires thoracic surgery and should be
reserved for patients with a good prognosis who
have had ineffective pleurodesis or inadequate
response to chronic pleural drainage.

90. Chemotherapy and mediastinal
radiotherapy
 May control effusions in responsive tumors, such
as lymphoma or small-cell bronchogenic
carcinoma, although it has poor efficacy in
metastatic carcinoma.

91. Thank you very much