Pleural Diseases

Question 1

Pleural Effusion essentials of diagnosis

Answer 1

• May be asymptomatic; chest pain frequently seen in the setting of pleuritis, trauma, or infection; dyspnea is common with large effusions
• Dullness to percussion and decreased breath sounds over the effusion
• Radiographic evidence of pleural effusion
• Diagnostic findings on thoracentesis

Question 2

Absorption of pleural fluid occurs through

Answer 2

parietal pleural lymphaticcs

Question 3

A pleural effusion is

Answer 3

an abnormal accumulation of fluid in the pleural space

Question 4

The five pathophysiologic processes that account for most pleural effusions:

Answer 4

1) transudates
2) exudates
3) empyema
4) hemothorax
5) Parapneumonic pleural effusions

Question 5

Transudates

Answer 5

Increased production of fluid in the setting of normal capillaries due to increased hydrostatic pressures

Question 6

Exudates

Answer 6

increased production of fluid due to abnormal capillary permeability

Question 7

Empyema

Answer 7

Infection in the pleural space

Question 8

Hemothorax

Answer 8

bleeding into the pleural space

Question 9

Parapneumonic pleural effusions

Answer 9

exudates that accompany bacterial pneumonias

Question 10

Diagnostic thoracentesis should be performed when

Answer 10

• there is a new pleural effusion and no clinically apparent cause
• an atypical presentation or failure of an effusion to resolve

*sampling allows visualization of the fluid and chemical and microbiologic analyses to identify underlying dz

Question 11

Causes of transudates

Answer 11

• Heart failure (>90% of cases)
• Cirrhosis with ascites
• Nephrotic syndrome
• Peritoneal dialysis
• Myxedema
• Atelectasis (acute)
• Constrictive pericarditis
• Superior vena cava obstruction
• Pulmonary embolism

Question 12

Causes of Exudates

Answer 12

• Pneumonia (parapneumonic effusion)
• Cancer
• Pulmonary embolism
• Bacterial infection
• Tuberculosis
• Connective tissue disease
• Viral infection
• Fungal infection
• Rickettsial infection
• Parasitic infection
• Asbestos
• Meigs syndrome
• Pancreatic disease
• Uremia
• Chronic atelectasis
• Trapped lung
• Chylothorax
• Sarcoidosis
• Drug reaction
• Post-myocardial injury syndrome

Question 13

Signs and symptoms of pleural effusions

Answer 13

• Dyspnea, cough or respirophasic chest pain
• symptoms more common in patients with existing cardiopulmonary disease
• Small effusion less likely symptomatic than large one
• Large effusion=dullness on percussion and diminished or absent breath sounds over effusion
• massive effusion with increased intrapleural pressure may cause contralateral shift of trachea and bulging of intercostal space

Question 14

Compressive atelectasis PE

Answer 14

-bronchial breath sounds and egophany just above effusion

Question 15

Pleural friction rub indicates

Answer 15

infarction or pleurtitis

Question 16

Grossly purulent fluid signifies

Answer 16

empyema

Question 17

Empyema vs. chylous effusion

Answer 17

• CLear supernatant above pellet of white cells=empyema
• persistently turbid=chylous effusion–on analysis see high triglyceride (more than 100 mg/dL) often from disruption of the thoracic duct

*so need to centrifuge

Question 18

Hemorrhagic pleural effusion

Answer 18

• mixture of blood and pleural fluid

- 10,000 red cells/mL create blood tinged pleural fluid; 100,000=grossly bloody

Question 19

Hemothorax

Answer 19

presence of gross blood in the pleural space usually following chest trauma or instrumentation
-defined as a ratio of pleural fluid hematocrit to peripheral blood hematocrit greater than 0.5

Question 20

Pleural exudate (vs. transudate)

Answer 20

• effusion that has one or more of these features:
  1) ratio of pleural fluid protein to serum protein more than 0.5
  2) ratio of pleural fluid LD to serum LD greater than 0.6
  3) pleural fluid LD greater than 2/3 the upper limit of normal serum LD

Question 21

Pleural transudate (vs. exudate)

Answer 21

• occur in setting of normal capillary integrity and don’t show any of the lab features of exudates
• suggests absence of local pleural disease
• Labs: glucose=serum glucose, pH bw 7.4 and 7.55 and less than 1.0 x 10^3 white blood cells/mcL (1.0 x 10^9) with predominance of mononuclear cells

Question 22

What accounts for 90% of transudates? what are the most common causes of exudates?

Answer 22

• Transudate=Heart failure!!

- Exudate=Bacterial pneumonia and cancer

Question 23

Useful in assessing parapneumonic effusions

Answer 23

Pleural fluid pH

-pH below 7.3 suggests the need for drainage of pleural space

Question 24

An elevated amylase level in pleural fluid suggests?

Answer 24

pancreatitis, pancreatic pseudocyst, adenocarcinoma of the lung or pancreas, or esophageal rupture

Question 25

Suspected tuberculous pleural effusion should be evaluated by

Answer 25

thoracentesis with culture with pleural biopsy since pleural fluid culture positivity for M. tuberculosis is low (less than 23-58% of cases)

• closed pleural biopsy reveals granulomatous inflammation in 60% while culture of 3 pleural biopsy combined with histo exam of pleural biopsy for granulomas yields Dx in 90%
• also helpful is pleural fluid adenosine deaminase and interferon gamma

Question 26

Over 90% of malignant pleural effusions are exudative or transudative??

Answer 26

Exudative

• Any cancer can case effusions but most common causes are lung cancer and breast cancer
• In 5-10% of malignant pleural effusions, no primary tumor identified

Question 27

Paramalignant pleural effusion

Answer 27

• effusion in a patient with cancer when repeated attempts to identify tumor cells in the pleura or pleural fluid are non-diagnostic but when there is a presumptive relation to underlying malignancy
• ex: SVC syndrome with elevated systemic venous pressures causing transudative effusion is paramalignant
• if suspect cancer, send to cytology which if negative, repeat thoracentesis