MKSAP 5: Pleural Disease

Question 1

What are typical signs and symptoms of a pleural effusion?

Answer 1

dyspnea, cough, and pleuritic chest pain

Question 2

What other history specifics should be elicited in a patient with a pleural effusioin?

Answer 2

history of travel, prior or current occupation, medication use, prior surgery (CABG), malignancy, place of residency and prior asbestos exposure

Question 3

What are the clinical examination hallmarks?

Answer 3

Diminished breath sounds, dullness to percussion and decreased tactile fremitus over the area of the pleural effusion

Question 4

How much fluid needs to be present in a PA and a lat CXR to see an effusion?

Answer 4

PA: 200mL
Lat: 50mL

Question 5

What imaging modality has a higher sensitivity for pleural fluid

Answer 5

Thoracic ultrasound

Question 6

What are the indications for thoracentesis? In what situations can you wait?

Answer 6

Any new unexplained pleural effusion.

Observation is OK int he setting of known heart failure, small parapneumonic effusions or following CABG

Question 7

Name the Light criteria

Answer 7

An effusion is considered an exudate if any of the following are met:

1) Pleural fluid total protein/serum total protein > 0.5
2) Pleural fluid LDH/serum LDH ? 0.6
3) Pleural fluid LDH > 2/3 upper limit of normal for serum LDH

Question 8

What ratio do you use in the setting of ongoing diuresis?

Answer 8

Light criteria can occasionally misclassify transudative effusions as exudates in the setting of ongoing diuresis.
Determine serum albumin to pleural fluid albumin gradient, if greater than 1.2, the underlying process is likely transudative

Question 9

Name common causes of transudates

Answer 9

Heart failure
Hepatic hydrothorax
Nephrotic syndrome
Hypoalbuminemia
Unexpandable lung
Urinothorax
Atelectasis
Peritoneal dialysis

Question 10

Name common causes of exudates

Answer 10

Parapneumonic effusions
Malignancy
Pulmonary embolism
TB
Autoimmune diseases
Benign asbestos effusion
Post CABG
Pancreatitis
Post-MI
Yellow nail syndrome
Drugs

Question 11

Clinical significance of 5-10K erythrocytes on thoracentesis

Answer 11

Bloody appearance, hemothorax if pleural fluid hematocrit > 50% peripheral hematocrit; most commonly associated with cancer, pulmonary infarction, asbestosis related effusions or trauma

Question 12

Clinical significance of the following levels of nucleated cells on thoracentesis:
>50K
>10K
<5K

Answer 12

> 50K: complicated parapneumonic effusions and empyema
10K: Bacterial PNA, acute pancreatitis, and lupus pleuritis
<5: chronic exudates (TB pleurisy and malignancy)

Question 13

Clinical significance of >80% lymphocytes on thoracentesis

Answer 13

Suggests TB, lymphoma, chronic rheumatoid pleurisy, sarcoidosis and late post-CABG effusions, Pleural biopsy indicated if no diagnosis

Question 14

Clinical significance of > 10% eosinophils on thoracentesis

Answer 14

Suggests air or blood in the pleural space if nonspecific. Can be seen in parapneumonic effusions, drug induced pleurisy, eosinohilic granulomatosis with polyangiitis, benign asbestos effusions, malignancy, pulmonary infarction, fungal disease and parasitic disease

Question 15

What is the differential for pleural effusions with glucose level less than 60 mg/dL?

Answer 15

Rheumatoid pleurisy
Complicated parapneumonic effusion or empyema
Malignant effusion
Tuberculous pleurisy
Lupus pleuritis
Esophageal rupture

Question 16

What is the differential for pleural fluid acidosis (pH < 7.30)?

Answer 16

Complicated parapneumonic effusions, malignancy, tuberculous pleuritis, rheumatoid and lupus pleuritis and esophageal rupture
In suspected pleural infection, a pH less than 7.20 should be treated with pleural drainage

Question 17

What is the use and significance of pleural fluid amylase?

Answer 17

Pleural fluid amylase is elevated if the pleural fluid to serum amylase ratio is greater than 1.0 and suggests pancreatic disease, esophageal rupture and malignant effusions

Question 18

What diagnoses a chylothorax?

Answer 18

A pleural fluid triglyceride level greater than 110 mg/dL

Question 19

What test should be ordered in a lymphocyte predominant pleural effuion to rule out tuberculous effusions?

Answer 19

adenosine deaminase

Question 20

What is the test most likely to yield a positive mycobacterial culture?

Answer 20

Pleural biopsy (>70%)

Question 21

What is the appropriate workup for a pleural effusion you suspect to be malignant?

Answer 21

Cytology should be perfomred on any effusion in which malignancy is suspected. If the first specimen is negative, you should repeat cytology. Increase yield of 27% on second specimen but yield drops on third attempt. Thoracoscopy is the next step in evaluation of an exudative pleural effusion that is indeterminate and malignancy suspected

Question 22

Name the 3 types of parapneumonic effusions

Answer 22

Uncomplicated
Complicated
Empyema

Question 23

Define parapneumonic effusions

Answer 23

Exudative pleural effusions that occur adjacent to a bacterial pneumonia and result from migration of excess interstitial lung fluid across the visceral pleura

Question 24

What are the characteristics of an uncomplicated parapneumonic effusion?

Answer 24

Small (<10mm on lat decubitus) with inflammatory cells present but sterile culture. Typically resolve spontaneously with PNA

Question 25

What are the characteristics of an complicated parapneumonic effusion?

Answer 25

Involves persistent invasion of bacteria resulting in an increase in inflammatory cells and decreased pH and glucose levels but cultures still sterile. Consider antibitoics then thoracostomy tube drainage , serial follow up, may require thorascopic debridement

Question 26

What are the characteristics of an empyema?

Answer 26

Clear infection of the pleural space with presence of pus, positive Gram stain or culture in the pleural fluid. When pH less than 7.2 or glucose < 60, requires chest tube drainage

Question 27

What are the recommendations for antibiotics for pleural space infection?

Answer 27

Empiric antimicrobial coverage should include anaerobic coverage

Question 28

What are the 3 causes of pneumothorax?

Answer 28

Spontaneously, result of trauma or iatrogenically

Question 29

How is spontaneous pneumothorax further classified?

Answer 29

Primary spontaneous PTX

Secondary spontaneous PTX

Question 30

Define primary vs secondary spontaneous PTX

Answer 30

Primary - in person without underlying lung disease

Secondary - in person with underlying lung disease

Question 31

Risk factors for PSP vs SSP

Answer 31

PSP: smoking, tall stature, family hx, Marfan syndrome and thoracic endometriosis
SSP: COPD

Question 32

How are PTX measured and what is considered large?

Answer 32

measuring the distance between the lung margin and the inner chest wall at the level of the hilum. Greater than 2cm

Question 33

Which type of PTX is at higher risk for persistent leak?

Answer 33

SSP or further expansion of PTX due to their underlying lung disease, thus best managed with small bore pleural drain

Question 34

What is the management for PSP with following scenarios:

• <2cm, minimal symptoms
• > 2cm, breathlessness and CP
• Clinical instability regardless of size

Answer 34

• observation alone; may be managed as outpatient
• needle aspiration; if reaccumulates then small bore CT
• emergent needle decompression followed by chest tube

Question 35

What is the management for SSP with following scenarios:

• <2cm, minimal symptoms
• > 2cm, breathlessness and chest pain
• clinical instability regardless of size

Answer 35

• admit to hospital for observation and supplemental oxygen
• insertion of small bore chest tube
• emergent needle decompression followed by chest tube insertion

Question 36

What is the recommendation for intervention to prevent occurrence with SSP and PSP?

Answer 36

Intervention is recommended in all SSP and after the 2nd PSP