Pleural effusions

Question 1

Uncomplicated vs complicated pleural effusion etiology

Answer 1

uncomplicated - sterile exudate in pleural space - movement of fluid from lung parenchyma to pleural space due to increased hydrostatic pressure. It will resolve after PNA resolves

Complicated - bacterial invasion of pleural space. This causes lowering of pleural fluid glucose and increased LDH (lysis from neutrophils)

Question 2

pleural fluid analysis of uncomplicated parapneumonic effusions

Answer 2

sterile exudate in pleural space

pH >7.2

WBC <50K

glucose >60

no bacteria on gram stain or culture

Question 3

Treatment of parapneumonic effusion that is uncomplicated

Answer 3

antibiotics

Question 4

Treatment of complicated parapneumonic effusions

Answer 4

antibiotics and drainage.

Question 5

Lab values for complicated parapneumonic effusion

Answer 5

bacterial invasion of pleural space

pH<7.2

glucose <60

WBC>50K

treat with antibiotics + drainage

Question 6

often do you see malignant cells on effusions

Answer 6

60% but need 3 separate thoracenteses to detect up to 90% of malignant effusions.

If concerned about cancer and first thoracentesis is unrevealing repeat thoracentesis.

if 3 negative thoracentesis then needs thorascopy performed

Question 7

causes of chylothorax?

Answer 7

post intrathoracic surgery, cancer evasion

Spontaneous cases or idiopathic cases are about 10% of all presentations.

Disruption of thoracic duct as it crosses mediastinum at level of 5th intercostal space

Question 8

Lab findings on pleural studies that indicate chylothorax?

Answer 8

white or milky and lipophilic looking

around 900-1000 TG

WBC mildly elevated with lymphocytic predominance

mean pH 7.4

can be exudative or transudative.

Question 9

Light’s criteria

Answer 9

total protein pleural / serum >0.5

LDH pleural / serum: >.6

LDH >2/3 upper limit of normal serum value

Question 10

When do we care about pleural cholesterol?

Answer 10

pleural cholesterol >45 plays a role in a 2 and 3-test rules to diagnose exudative pleural effusions based on pleural fluid LDH and total protein.

Not a definitive criteria.

Question 11

How do we treat chylothorax?

Answer 11

address the underlying cause, pleural drainage, low fat diet, thoracic duct ligation and thoracic duct embolization or pleurodesis.

Question 12

What is Empyema

Answer 12

It’s a complicated parapneumonic effusion with positive gram stain, acid pH and purulent fluid. clinical diagnosis based on physical appearance of pleural fluid in the setting of lung infection -positive Gram stain and WBC with neutrophilic predominance -PH<7.2 and low glucose and normal or mildly elevated triglyceride level

Question 13

Malignant effusion lab work on pleural studies

Answer 13

generally have positive cytology in 60-90% of cases exudative generally.

Question 14

exudative pleural effusions are driven by

Answer 14

inflammation

Question 15

transudate pleural effusions are driven by

Answer 15

hydrostatic or oncotic pressure

Question 16

common causes of exudative pleural effusions

Answer 16

infection (TB or pneumonia)

malignancy

connective tissue disease

pulmonary embolism

pancreatitis

post CABG

Question 17

common causes of transudate pleural effusions

Answer 17

cirrhosis (hepatic hydrothorax)

nephrotic syndrome

heart failure

constrictive pericarditis

peritoneal dilaysis

Question 18

low pH very low glucose levels (<30 mg/dl) extremely high LDH levels >1000

Answer 18

seen in rheumatoid pleurisy or Rheumatoid effusions - they are yellow green in color see cell counts <5000 and have high lymphocytes

Question 19

hypothyroidism pleural effusions

Answer 19

can be both transudative or exudative.

Question 20

pulmonary HTN pleural effusion

Answer 20

tend to be transudative

Question 21

what is benign asbestos related pleural effusion?

Answer 21

early pleural effusion manifestation of asbestos related lung dx that occurs 10-15 years after exposure. this predates asbestos-related pleural plaques and may be marker of future development of diffuse pleural thickening

Question 22

Benign asbestos related pleural effusion characteristics

Answer 22

small <500 ml, bloody, exudative, eosinophilic predominance >10% nucleated cells >50%

Question 23

symptoms of benign asbestos related pleural effusion

Answer 23

see dyspnea, low grade fever, pleuritic chest pain and

Question 24

what happens to benign asbestos related pleural effusion?

Answer 24

spontaneous resolution over weeks to months is normal.

Question 25

malignant pleural effusions

Answer 25

see lower glucose exudative and generally lympohcytic but can have eosinophils in it.

Question 26

eosinophilic effusion

Answer 26

asbestosis, dantrolene, bromocriptine, nitrofurantoin and valproic acid.

Question 27

RA effusions

Answer 27

low glucose and low pH

see large exudative pleural effusions.

mimics malignant or Tb pleural fluid studies.

Question 28

TB effusion

Answer 28

exudative, low pH and low glucose

needs to live in edemic area see predominantly lymphocytic effusion.

Question 29

what causes chylothorax?

Answer 29

TG>110 supports diagnosis seen in non traumatic and traumatic causes look for bulky adenopathy b’c lymphoma is a cause of chylothorax

Question 30

what are traumatic causes of thoracic duct injury?

Answer 30

CVC placement via the subclavian approach and esophageal surgery

Question 31

if chylothorax is associated with cirrhosis or CHF or nephritic syndrome

Answer 31

chylothorax can be transudative

Question 32

what are non traumatic causes of thoracic duct injury?

Answer 32

Non traumatic: thoracic duct obstruction from malignancy, sarcoidosis or retrosternal goiter and infections like TB of filariasis

Question 33

amylase levels are high in pleural effusions when

Answer 33

it’s related to esophageal rupture or pancreatitis

Question 34

cholesterol effusions are seen with

Answer 34

TB or rheumatoid pleurisy

seen with exudative effusions that remain in pleural space chronically so it becomes enriched with cholesterol.

Question 35

TB should be suspected if pleural effusion is:

Answer 35

lymphocytic effusions

get acid fast staining and culture

Question 36

indications for thoracentesis for a patient who has PNEUMONIA and has pleural effusion:

Answer 36

-free flowing and large -layers >10 mm on lateral decubitus film -demonstrates loculation -seen with thickened parietal pleura on contrast CT -clearly delineated by U/S

Question 37

in treatment of empyema what needs to be done?

Answer 37

multiple loculated collections may need multiple test tubes chest CT needs to be done within 24 hrs to make sure chest tube location is correct and assess drainage. Needs to get both chest tube drainage and antibiotics

Question 38

approach to a parapneumonic effusion

Answer 38

parapneumonic effusions can occur in the adjacent pleural space in the 40% of bacterial pneumonias

most parapneumonic effusions are minimal and resolve with antibiotics and effusions that are free flowing <10 mm on lateral decubitus film shoudl be observed in serial imaging alone as they are most likely to resolve with antibiotics.

loculations, pleural thickening, and large >1/2 hemithorax effusions are considered high risk features ars they are associated with higher rate of adverse effects.

Question 39

diagnostic thoracentesis is needed for effusions that

Answer 39

are >10 mm with no high risk features on imaging

gram stain, negative culture and pH>7.2 and glucose>60 on fluid analysis shows that this is uncomplicated.

Question 40

what to do for pleural effusion to be result of suspected CHF but has an exudative effusion?

Answer 40

calculate the serum-effusion protein difference OR serum effusion albumin gradient

if serum-effusion protein difference is >3.1 g/dl

OR

serum effusion albumin gradient >1.2 g/dl

then likely a true transudative effusion.

light criteria is 100% sensitive but only 83% specific for identifying exudates and so can have decreased specificity with diuretic use. up to 20% of pts with CHF can have exudative effusion.