Download Pleural effusion

Attending Version
Pleural Effusion Module; created by Dr. Farzana Harji
Objectives:
By the end of this module, you should be able to:
1. Identify top three most common causes of pleural effusion
2. Recognize indications for thoracentesis
3. Understand the diagnostic approach to pleural effusion and be able to differentiate transudative versus
exudative pleural effusion.
4. Understand the significance of fluid pH, glucose level, gross appearance of fluid, gram stain and culture.
References:
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Light, RW. Pleural effusions. Medical clinics of North America Nov 1977; Vol. 61, No. 6, 1339-1352.
Light, RW. Pleural effusion. N Engl J Med June 20, 2002; Vol. 346, No. 25, 1971-1977.
Uptodate: Diagnostic evaluation of a pleural effusion in adults.
Light, RW. Pleural diseases, 3rd ed, Williams Wilkins, Baltimore, 1995.
Pleural effusion

Top three most common causes of pleural effusion in the United States are congestive heart failure, pneumonia, and
cancer.
FIRST STEP: History and examination
Exam findings:
Chest exam typically reveals dullness to percussion, the absence of fremitus, and diminished breath sounds or their absence.
-Distended neck veins, and S3 gallop, or peripheral edema suggests congestive heart failure.
-Right ventricular heave or thrombophlebitis suggests pulmonary embolus.
-Presence of lymphadenopathy or hepatosplenomegaly suggests neoplastic disease or liver disease.
-Ascites may suggest hepatic cause.
Imaging studies sometimes necessary to verify pleural effusion:
-Lateral decubitus chest x-ray
-Ultrasound
-CT scan (for lung parenchyma or mediastinum)
Indications for thoracentesis:
Presence of a clinically significant pleural effusion (more than 2cm thick on ultrasound or lateral films) with no known cause (not
worked up previously). Thoracentesis is performed for diagnosis or therapeutic reasons.
SECOND STEP: Differentiate Exudates versus Transudates
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Leading causes of transudative pleural effusions: chf, cirrhosis, nephrosis, and PE
Leading causes of exudative pleural effusions: pneumonia, cancer, and PE
THIRD STEP: Additional Tests and Interpretation:
1.
Low glucose level (<60 mg/dL): complicated parapneumonic effusion, malignancy, or rheumatoid pleuritis (not SLE) or
tuberculous pleural effusion
2.
Pleural fluid pH: useful prognostic factor
<7.2 pleural fluid pH (arterial pH >7.35): strongly suggests that fluid will not resolve spontaneously in parapneumonic effusions
and will most likely need a chest tube. Low pH can also occur in malignancy, rheumatoid pleuritis and tuberculous effusion
3.
Smears and cultures
-Usually just need aerobic and anaerobic cultures and gram stain
-If chronic febrile illness or fever of unknown origin then include fungal culture
-If >50% lymphocytes, then include AFB smear and culture
4.
Amylase: elevated in pancreatic disease, or esophageal rupture, 10% with malignancy
5.
Appearance of Pleural Fluid
1. Bloody
<1% of peripheral hematocrit
1-20%
>50%
Interpretation
 nonsignificant
 cancer, PE and trauma
 hemothorax
2. White/milky/opaque
chylothorax, chyliform; pyothorax
3. Putrid odor
probably infection due to anaerobic bacteria
6.
Total and differential cell count and their values:
A. Neutrophils (limited value): (>50% of cells) parapneumonic, pancreatitis, PE, malignancy, TB
B. Lymphocytes (good value): (>50% of cells) cancer or tuberculous pleuritis
C. Eosinophils (limited value): (>10%) most common cause is trauma resulting in either blood (hemothrax) or air
(pneumothorax), or viral pleuritis, or resolving parapneumonic effusion. Unusual causes reactions to drugs or exposures
(asbestos)
D. Mesothelial cells: commonly found up to 12 or more can be normal; uncommon in tuberculous effusions; presence of
numerous mesothelial cells nearly excludes a diagnosis of tuberculosis
7.
Cytologic Exam Efficiency when cancer involving the pleura:
Metastatic adenocarcinoma
70% sensitive
Mesothelioma
10% sensitive
Squamous-cell carcinoma
20% sensitive
Lymphoma
25-50% sensitive
Sarcoma
25% sensitive
8.
Lipid analysis: if fluid is milky or opaque
-Chylous pleural effusion arises when the thoracic duct is severed or obstructed. High TG, low cholesterol.
-Chyliform pleural effusion has been present for a long time and cholesterol accumulates. High cholesterol, normal TG.
Case:
HPI: 75 yom w/ 50 pack year smoking history, and MI x2, who presents with increasing shortness of breath. He has
had increasing shortness of breath over last 2 weeks, and low grade fever, sweats, cough, and orthopnea x4 days. No
sick contacts, no recent chest pain, no hemoptysis. Productive cough w/ white sputum.
PMH:
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MI x2, first 5 years ago, most recent 1 year ago
DM, HgB A1c 8.3
Obese
Chronic bronchitis
Osteoarthritis
HTN
Past heavy alcohol abuse
Hyperlipidemia
Medications:
1. Lisinopril 10mg
2. Metformin 1000mg bid
3. Metoprolol 75mg bid
4. Albuterol/Atrovent MDI
5. ASA 81mg qd
6. Tylenol prn
7. Atorvastatin 80mg qd
8. Lasix 40mg po qd
Allergies: none
FH: father died in MVA, mother died of cancer “unknown”, one brother w/ diabetes, one sister w/ HTN.
SH: lives in Albuquerque w/ wife. Denies recent alcohol in past month, denies illicit drug use.
ROS: denies n/v/d, admits to decreased appetite x 2 weeks, weight fluctuates – sometimes pants are tight, sometimes
they are loose. Denies melena/hematuria. Has occasional LEE – resolves when legs elevated.
PE: T 100.3 BP 150/85 HR 82 RR 28 O2Sat 86% RA  94% 2L
Gen: A&Ox3, mild respiratory discomfort,
HEENT: mild temporal wasting, otherwise normal
CV: rrr, no m/r/g, JVP 13cm, no carotid bruits
Lungs: diminished BS lower 2/3 of L lung, lower ½ of R lung, no egophony, decreased tactile fremitus bilaterally
lower regions, + dullness to percussion over same area, normal chest excursion bilaterally
Abd: Obese, NABS, s/nt, mild hepatomegaly, no splenomegaly
Ext: 1+ edema BLE, brownish discoloration of skin on BLE, + varicose veins, 2+ pulses throughout, warm
Skin: few telangiectasias over upper chest and shoulders, no rashes
Labs:
CBC: WBC 10.0, Hbg 14, Hct 40, Plts 120
Chem 10: Na 131, K 3.7, Cl 105, CO2 18, BUN 37, Cr 1.6, Glucose 225
Ca 7.1, Mg 2.1, Po4 2.1
LFT’s: TP 7.0, Alb 2.5, AST 49, ALT 45, Alk Phos 190, T Bili 1.5, D Bili .8, I Bili .7
Imaging: pCXR – Bilateral pleural effusions L>R, mild cardiomegaly, prominent pulmonary vasculature,
consolidation vs. atelectasis in LLL, clinical correlation recommended.
47. A 43 year-old male nurse presents to your office for evaluation. For the past 2 months, he has experienced intermittent
fever, night sweats, and a 20-lb weight loss. He denies having any cough or sputum production. The patient states that
about 3 months ago, he tested positive on purified protein derivative (PPD) screening. He denies any drug abuse, nor
does he report any HIV risk factors. The patient states that he was prescribed isoniazid, but he chose not to follow this
regimen. His chest x-ray is remarkable only for a moderate left pleural effusion.
Which of the following statements regarding tuberculous pleuritis is true?
A. Pleural effusion is more often a manifestation of reactivation tuberculosis than of primary tuberculosis.
B. Without therapy, this patient’s pleural effusion will likely persist for many years.
C. In most cases of this illness, pleural fluid cell differential will reveal greater than 85% neutrophils.
D. Acid-fast bacilli are rarely seen in pleural liquid, and cultures are positive in only 20% to 40% of patients.
Key concept/Objectives: to understand the clinical features of tuberculous pleuritis and pleural effusion.
Pleural effusion is more often a manifestation of primary tuberculosis than of reactivation tuberculosis. In patients with
primary tuberculosis, untreated pleural effusions resolve spontaneously in approximately 2 to 4 months. However, active
tuberculosis develops in two thirds of such patients during the ensuing 5 years. The pleural liquid is usually serous or
serosanguinous. In most cases, the differential white cell count reveals lymphocytosis. Acid-fast bacilli are rarely seen
in pleural liquid, and cultures are positive in only 20% to 40% of patients. However, closed-needle biopsy of the pleural
reveals caseating or noncaseating granulomas in approximately 70% of cases and provides material that is culture
positive in approximately 75% of cases. Thus, the total diagnostic yield, as determined on the basis of histopathology
and culture, is 90% to 95%.
Answer: D
48. A 55-year-old man visits your office with a complaint of fatigue and increasing dyspnea on exertion. He has been
experiencing these symptoms for 2 weeks. He denies having fever, chills, cough, or weight loss, and he has no
significant cardiac history. He denies having been in contact with anyone who was ill. He recently quit smoking, after
having smoked cigarettes for 35 years. He does have a history of alcoholism and chronic pancreatitis; the pancreatitis
has been well controlled with analgesics and pancreatic enzyme replacement therapy. His serum chemistries and
complete blood count are unremarkable. A chest x-ray reveals a large left pleural effusion. A diagnostic thoracentesis is
performed.
Which of the following statements regarding laboratory studies of pleural fluid is true?
A. An elevated pleural fluid amylase level is uncommon in patients with a malignant pleural effusion
B. Pleural fluid eosinophilia is diagnostic of a pulmonary parasitic infection.
C. A pleural liquid hematocrit that exceeds half of the simultaneous peripheral blood hematocrit indicates frank
bleeding into the pleural space and is diagnostic of a hemothorax.
D. A pleural effusion with a pH of 5.8 is suggestive of empyema
Key concept/Objective: To understand the clinical correlations of pleural fluid laboratory abnormalities
Determination of the pleural liquid amylase level is warranted in patients with unexplained left-sided pleural effusions,
particularly in the presence of coexistent abdominal disease. Elevated amylase levels are also commonly seen in patients
with malignancy. Pleural liquid eosinophilia is rarely the result of a fungal or parasitic infection. Much more
commonly, the eosinophilia is a nonspecific finding; in some cases, it is thought to result from the previous introduction
of air or blood into the pleural space. A pleural liquid hematocrit that exceeds half the simultaneous peripheral blood
hematocrit indicates frank bleeding into the pleural space and is diagnostic of a hemothorax. In patients who have a
pleural effusion associated with bacterial pneumonia (parapneumonic effusion), a pleural liquid pH of less than 7.0 is
suggestive of an infected pleural space (empyema). A pH of 6.0 or less suggests esophageal rupture.
Answer: C