Pleural Effusions
Internal Medicine AM Report
Andrew Smitherman
Wednesday May 27, 2009
Definition
Excess fluid in
space
between the
lung and
chest wall.
Pathophysiology

Fluid typically enters pleural space from
capillaries in the parietal pleura, from the
pulmonary interstitium via visceral pleura or from
peritoneal cavity via small holes in the
diaphragm.

Lymphatics are able to increase absorption 20
times that of normal if needed.

An effusion forms when the production of pleural
fluid overwhelms the ability of the lymphatics to
drain or due to decreased lymphatic drainage.
Etiologies
CAUSE
ANNUAL
INCIDENCE
TRANSUDATE /
EXUDATE?
CHF
500,000
Transudate
Pneumonia
300,000
Exudate
Malignancy
200,000
Exudate
Pulmonary Embolus
150,000
Either
Viral Disease
100,000
Exudate
Post CABG
60,000
Exudate
Cirrhosis with
Ascities
50,000
Transudate
Light, RW. Pleural Effusion. NEJM. 2002; 246: 1971-1977.
Etiologies
Transudate
Exudate
Congestive Heart Failure
Malignancy – Metastatic or Mesothelioma
Cirrhosis
Infection / Parapneumonic / Empyema
Pulmonary Embolus
Pulmonary Embolus
Nephrotic Syndrome
GI Disease – Pancreatic Disease,
Esophageal Perforation, Intraabdominal
Abscess, After Abdominal Surgery
SVC Obstruction
Collagen-Vascular Disease – SLE,
Rheumatoid Pleuritis, Wegner’s, Sjögrens
Peritoneal Dialysis
Post CABG
Urinothorax
Sarcoidosis
Uremia
Drug-Induced – Nitrofurantoin, Amiodarone
Meig’s
Radiation Therapy
Initial Evaluation with Physical
Exam
Typical findings:
Dullness to percussion, absence of tactile fremitus
Diminished or absence of breath sounds
Findings suggestive of a particular etiology:
S3, Distended Neck Veins, Peripheral Edema – CHF
RV Heave or Thrombophlebitis – Pulmonary Embolism
Lymphadenopathy or Hepatosplenomegaly – Malignancy
Ascities – Hepatic Failure / Cirrhosis
What’s My Claim to Fame?
Josef Leopold
Auenbrugger
(1722 – 1809)
What’s My Claim to Fame?
Josef Leopold
Auenbrugger
(1722 – 1809)
Developed physical exam
techniques of chest
percussion and tactile
fremitus
Indications for Thoracentesis

Diagnostic: effusion > 10mm in height on lateral
decubitus or ultrasonography

Therapeutic: patient symptomatic – dyspnea at rest,
increased O2 requirement. Removal of up to 1500mL
indicated.

If patient presents with likely CHF exacerbation, with
bilateral effusions, afebrile and reports no chest pain a
trial of diuresis is reasonable and safe.




Greater than 80% of effusions due to CHF are bilateral
75% of effusions due to CHF resolve in 48 hours of diuresis
If effusions persist for >72hrs a thoracentesis is indicated
Unilateral or Asymmetric effusions should be tapped
Shinto RA and Light RW. Effects of Diuresis on the Characteristics of Pleural Fluid in Patients with Congestive Heart
Failure. American Journal of Medicine. 1990; 88: 230-234.
Do I Need a Follow-up Chest
Radiograph?

Not needed unless air is obtained during
procedure; coughing, chest pain or
dyspnea develops; or tactile fremitus is
lost over apex of aspirated hemithorax.

Of 506 thoracenteses, pneumothorax
found in 13 of 18 (72%) with one or more
of the above findings but only in 5 of 488
(1%) with none of the above.
Aleman C, Alegre J, Armadans L. The Value of the Chest Roentgenography in the Diagnosis of Pneumothorax After
Thoracentesis. American Journal of Medicine. 1999; 107: 340-343.
Transudate v. Exudate

Transudate: usually due to systemic
changes and an imbalance between
hydrostatic and oncotic forces.
 CHF,

Cirrhosis, Pulmonary Embolism
Exudate: due to local changes that lead to
fluid accumulation.
 Pneumonia,
Malignancy, Pulmonary Embolism
Transudate v. Exudate
Transudate
v. Exudate

By the Light’s Criteria alone, 17 of 100 samples tested
will falsely be categorized as an exudate.

If you have a clinical situation where transudate seems
more plausible, compare pleural fluid and serum
albumin. If Alb(serum) – Alb(PF) > 1.2 g/dL a transudative
process is more likely.

An albumin difference of ≤ 1.2g/dL will incorrectly
identify an effusion as exudative in 8% of cases.
Algorithm
for
Evaluation
of Pleural
Effusions
Cell Count and Differential

Neutrophilic:
 Seen
when acute process is involving pleura
 Parapneumonic, PE, Pancreatitis

Lymphocytic
 Malignancy
or Tuberculosis
Glucose

Low glucose (<60mg/dL) in pleural fluid is
an indication of:
 Parapneumonic
 Less
or Malignant Effusion
commonly hemothorax, Tuberculosis,
rheumatoid pleuritis
LDH

Correlates to degree of pleural
inflammation.

An increasing LDH level on subsequent
thoracenteses is suggestive of worsening
inflammation.
Cytology and Malignant Effusions

75% of malignant effusions are associated with
lung carcinoma, breast carcinoma or lymphoma.

Reported sensitivity of cytology for diagnosing
the following:




Lymphoma (25-50%)
Sarcoma Involving Pleura (25%)
Squamous Cell Carcinoma (20%)
Mesothelioma (10%)
Light, RW. Pleural Effusion. NEJM. 2002; 246: 1971-1977.
Parapneumonic

Features of pleural effusion that is
suggestive of needing more invasive
procedure than thoracentesis:
 Loculated
Pleural Fluid
 Pleural Fluid pH < 7.2
 Pleural Fluid Glucose < 60mg/dL
 Positive Gram Stain or Culture
 Gross pus in Pleural Space
Tuberculous Pleuritis

Suspected based on History and a lymphocytic
predominance on cell differentiation.

Less than 40% of tuberculous effusions will have
positive pleural-fluid culture.

Adenosine Deaminase is sensitive (99.6%) and
specific (97.1%) when a cut-off of 40U/L is used.
Lee YCG, Rogers JT, Rodriguez RM, Miller KD and Light RW. Adenosine Deaminase Levels in Nontuberculous
Lymphocytic Pleural Effusions. Chest 2001; 120: 356-361.
Miscellaneous Pearls

Elevated Amylase: suggestive of
esophageal rupture or pancreatic disease

Eosinophilia: associated with DrugInduced Effusions

Fever, PMN predominance, no lung
parenchymal lesion – intraabdominal
abscess
References

Aleman C, Alegre J, Armadans L. The Value of the Chest Roentgenography
in the Diagnosis of Pneumothorax After Thoracentesis. American Journal of
Medicine. 1999; 107: 340-343.

Kasper DL, Braunwald E, Fauci AS, Hauser SL, Longo DL, Jameson LJ
eds. Harrison’s Principles of Internal Medicine. 16th ed. New York: McGrawHill, 2005.

Lee YCG, Rogers JT, Rodriguez RM, Miller KD and Light RW. Adenosine
Deaminase Levels in Nontuberculous Lymphocytic Pleural Effusions. Chest
2001; 120: 356-361.

Light, RW. Pleural Effusion. NEJM. 2002; 246: 1971-1977.

Shinto RA and Light RW. Effects of Diuresis on the Characteristics of
Pleural Fluid in Patients with Congestive Heart Failure. American Journal of
Medicine. 1990; 88: 230-234.