Pleural Disease

Question 1

What is the compositionof parietal and visveral pleura?

Answer 1

layers of collagen and elastin covered by a single cell layer of mesothelium

Question 2

What does peluritic chest pain indicate?

Answer 2

involvement of the parietal pleura because

Question 3

How much fluid is usually in the pleural space?

Answer 3

3.5 mL

Question 4

What are reasons why there would be excess fluid in the pleural space?

Answer 4

excess fluid in the lungs

cancer blocking drainage system

something disrupting the integrity of the membrane

Question 5

What are the hypothesized roles for the visceral pleura?

Answer 5

provide mechanical support for the lung

function as a “reservoir” for lung water preventing the development of pulmonary edema

Question 6

factors favoring the formation of pleural effusions

Answer 6

increased Pcap

decrease Ppleura

decreased πcap

increased K or decreased R

Question 7

transudates

Answer 7

accumulation of fluid from alterations of Starling forces across a normal membrane

Question 8

exudates

Answer 8

protein-rich contents spilling into the pleural space resulting from alterations in the permeability of the membrane

Question 9

Light’s Criteria

Answer 9

1) pleural fluid total protein/serum toal protein > 0.5
2) pleural fluid LDH/serum LDH > 0.6
3) pleural fluid LDH > 2/3 of the upper normal value of serum LDH

an effusion is classified as an exudate if ANY ONE of these criteria are et

Question 10

What are the top five causes of transudates?

Answer 10

congestive heart failure (increase Pcap)

liver cirrhosis (decreased πcap)

nephrotic syndrome (decreased πcap)

atelectasis (decreased Ppleural)

atelectasis (decreased Ppleura)

Question 11

What are the three mechanistic causes of exudates?

Answer 11

altered membrane permeability

grossly altered membrane

decreased lymph clearance

Question 12

What are some common causes of exudates through altered membrane permeability?

Answer 12

pulmonary infections

pleural malignancy

pulmonary embolism

subdiaphragmatic inflammation

collagen vascular diseases

occupational or drug induced pleural diseases

Question 13

What are some common causes of exudates through grossly altered membrane?

Answer 13

esophageal rupture

thoracic duct rupture

bleeding

Question 14

What are some common causes of exudates through decreased lymph clearance?

Answer 14

malignant obstruction of the lymphatics

lymphangioleiomyomatosis (LAM)

primary lymphatic diseases (yellow nail syndrome)

Question 15

common symptoms of pleural effusions

Answer 15

asymptomatic

large effusion can cause:

nonproduct cough

chest discomfort

pleuritic chest pain - indicates inflammation

dyspnea from displacement of respiratory muscles

atelectasis

Question 16

signs of pleural effusions

Answer 16

dullness to percussion

decreased tactile fremitus

tracheal devation away from the effusion

decreased breath sounds

pleural rub

Question 17

What is the treatment for pleural effusion?

Answer 17

require drainage when they are large and symptomatic or when they are infected

if not large, a small aliquot is removed and analyzed in order to help establish a diagnosis of a systemic disease (thoracentesis)

Question 18

causes of low pH effusions

Answer 18

parapneuonic effusions (main cause)

malignancy

esophageal rupture

urinothorax

pH of less than 7.15 is an indication for drainage

Question 19

causes of low glucose effusions

Answer 19

complicated parapneumonic effusions

malignancy wiht extensive pleural involvement

rheumatoid arthritis

empyema

tuberculosis

malignancy

Question 20

causes of high amylase effusions

Answer 20

pancreatitis

esophageal rupture

malignancy

other intrabdominal processes

Question 21

How does cytology help the diagnosis of pleural effusions?

Answer 21

helps identify malignancies

up to 90% sensitivity with 2 thoracenteses

Question 22

How does cell counts help the diagnosis of pleural effusions?

Answer 22

high cell counts with mostly PMNs indicate infection

mostly lymphocytes indicates malignancy, TB, or fungal effusions

presence of >5% mesothelial cells speaks against diagnosis of TB

RBC count of >/= 50% of that in peripheral blood indicates hemothorax

Question 23

tuberculous effusions

Answer 23

lymphocyte predominant

less than 5% mesothelial cells

adenosine deaminase > 47 IU/L

(deaminase < 47 means no TB) high sensitivity

Question 24

causes of pneumothorax

Answer 24

iatrogenic

traumatic

bullous disease

infection

lung hyperinflation

Question 25

signs of tension pneumothorax

Answer 25

tracheal shift

progressive dyspnea

tachycardia/hypotension

increased ypmani of same side

requires immediate decompression