27. Pleural Disease

Question 1

visceral pleura on what surface? parietal?

Answer 1

visceral are directly on lung surface, cover parenchyma and interlobar fissures. parietal line the inside of the thoracic cavity.

Question 2

visceral pleura: blood supply? lymphatics? pain fibers?

Answer 2

blood: systemic circ?
rich network of lymphatics
no pain fibers

Question 3

parietal pleura: blood supply? lymphatics? pain fibers?

Answer 3

blood: systemic circ.
lymphatics have stoma with varied concentrations in diff areas
innervation from intercostal nerves and phrenic nerve

Question 4

when is pleural pressure most negative?

Answer 4

during inspiration. usually slightly sub-atmospheric at FRC.

Question 5

what is the normal situation with pleural fluid?

Answer 5

normally fluid continuously enters and is resprbed from the pleural space. accumulation will be due to disease processes.

Question 6

what equation/law governs the movement of fluid across the pleural membranes?

Answer 6

Starlings Law

Question 7

acc Starling’s law, the flow of liquid across the pleural surface depents on what 4 things?

Answer 7

1. SA of the membrane, and how easily it allows movement of water
2. hydrostatic pressures in caps and pleural space
3. oncotic pressures in cap and pleural space
4. pore size in membrane (for proteins to pass)

Question 8

what is produced by the net gradient in the parietal pleura?

Answer 8

net gradient causes fluid filtration, movement from the systemic caps into the pleural space.

Question 9

what is the net gradient between the visceral pleura and the pleural space?

Answer 9

net is ZERO: no net movement of fluid from viscera into pleural space

Question 10

what mechanism keeps the pleural space relatively free of liquid?

Answer 10

lymphatic drainage on the parietal size

Question 11

what are stoma/where are they located?

Answer 11

on the parietal side. lymphatic drainage ducts. remove proteins, cells, fluid from the pleural space

Question 12

what are some factors leading to pleural effusions?

Answer 12

• incr hydrostatic pressure in either side of the heart
• decr oncotic pressure (hypoalbuminemia)
• incr cap permeablity (pneumonia)
• incr intrapleural pressure (atelactasis)
• impaired lymph drainage (obstruction, tumor)

Question 13

what is a transudate? what are examples?

Answer 13

accumulated fluid resulitng from changed Starling forces (cap pressure or oncotic pressure). pleura are secondarily affected. fluid will be LOW in protein.

• congestive heart failure
• cirrhosis
• nephrotic syndrome
• hypoalbuminemia

Question 14

what is an exudate? what are examples?

Answer 14

increased permeability allowing for leakage of macromolecules. affects pleural surface directly. fluid will be HIGH in protein.

• malignancy
• infection
• inflammatory process below the diaphragm
• CT diseases
• asbestos exposure
• uremia

Question 15

symptoms of pleural disease?

Answer 15

• SOB is most common symptom
• pain
• cough. mech unclear
• sx due to underlying disease

Question 16

what will you find on physical exam with a pleural effusion? inspection/palp/percuss/ausc

Answer 16

ins: may be asymmetrical expansion
palp: decr tactile fremitus
percus: dullness
auscultation: decr breath sounds

Question 17

xray appearance with pleural effusion?

Answer 17

may see blunting of costophrenic angles on sides and posterior. may be hazy appearance on supine film.

Question 18

Pleural effusion: restrictive or obstructive pattern?

Answer 18

restrictive.

Question 19

how can you tell if the pleural fluid is a transudate or an exudate?

Answer 19

exudate if:

• pleural fluid/serum PROTEIN >0.5
• pleural fluid/serum LDH >0.5
• pleural fluid LDH > 2/3 upper limit normal serum value

transudate if none of the above

Question 20

testing the pleural fluid’s cell count: high WBC suggests what?

Answer 20

infection

Question 21

testing the pleural fluid’s cell count: high RBC suggests what?

Answer 21

trauma, malignancy, pulm infarction

Question 22

testing the pleural fluid’s glucose level: lowest levels seen in what situations?

Answer 22

lowest glucose seen in infection, CT disease, malignancy

Question 23

an incr amylase level in pleural fluid could suggest what?

Answer 23

pancreatitis, esophag perf/rupture

Question 24

what is the usual pH of pleural fluid? what might a low pH indicate?

Answer 24

usually 7.5. low could indicate infection, malignancy

Question 25

what happens in a pneumothorax? (lung, chest wall, 02 level?)

Answer 25

lung recoils inward, chest recoils outward, hypoxia due to shunt or low VQ

Question 26

what could cause a spontaneous pneumothorax?

Answer 26

apical blebs, congenital cause, underlying lung disease like emphysema or CF.

Question 27

sx of pneumothorax?

Answer 27

breathlessness, cough, chest pain.

Question 28

physical exam with pneumothorax: percussion, auscultation, anatomic, extremities?

Answer 28

perc: hyperresonant
ausc: low breath sounds or absent
tracheal shift away from PTX
tachycardia, hypotension, cyanosis

Question 29

tx for pneumothorax?

Answer 29

remove air with catheter, chest tube, give 02, may do pleurodesis (glue together pleurae)