27. Pleural Disease Flashcards
visceral pleura on what surface? parietal?
visceral are directly on lung surface, cover parenchyma and interlobar fissures. parietal line the inside of the thoracic cavity.
visceral pleura: blood supply? lymphatics? pain fibers?
blood: systemic circ?
rich network of lymphatics
no pain fibers
parietal pleura: blood supply? lymphatics? pain fibers?
blood: systemic circ.
lymphatics have stoma with varied concentrations in diff areas
innervation from intercostal nerves and phrenic nerve
when is pleural pressure most negative?
during inspiration. usually slightly sub-atmospheric at FRC.
what is the normal situation with pleural fluid?
normally fluid continuously enters and is resprbed from the pleural space. accumulation will be due to disease processes.
what equation/law governs the movement of fluid across the pleural membranes?
Starlings Law
acc Starling’s law, the flow of liquid across the pleural surface depents on what 4 things?
- SA of the membrane, and how easily it allows movement of water
- hydrostatic pressures in caps and pleural space
- oncotic pressures in cap and pleural space
- pore size in membrane (for proteins to pass)
what is produced by the net gradient in the parietal pleura?
net gradient causes fluid filtration, movement from the systemic caps into the pleural space.
what is the net gradient between the visceral pleura and the pleural space?
net is ZERO: no net movement of fluid from viscera into pleural space
what mechanism keeps the pleural space relatively free of liquid?
lymphatic drainage on the parietal size
what are stoma/where are they located?
on the parietal side. lymphatic drainage ducts. remove proteins, cells, fluid from the pleural space
what are some factors leading to pleural effusions?
- 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)
what is a transudate? what are examples?
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
what is an exudate? what are examples?
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
symptoms of pleural disease?
- SOB is most common symptom
- pain
- cough. mech unclear
- sx due to underlying disease
what will you find on physical exam with a pleural effusion? inspection/palp/percuss/ausc
ins: may be asymmetrical expansion
palp: decr tactile fremitus
percus: dullness
auscultation: decr breath sounds
xray appearance with pleural effusion?
may see blunting of costophrenic angles on sides and posterior. may be hazy appearance on supine film.
Pleural effusion: restrictive or obstructive pattern?
restrictive.
how can you tell if the pleural fluid is a transudate or an exudate?
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
testing the pleural fluid’s cell count: high WBC suggests what?
infection
testing the pleural fluid’s cell count: high RBC suggests what?
trauma, malignancy, pulm infarction
testing the pleural fluid’s glucose level: lowest levels seen in what situations?
lowest glucose seen in infection, CT disease, malignancy
an incr amylase level in pleural fluid could suggest what?
pancreatitis, esophag perf/rupture
what is the usual pH of pleural fluid? what might a low pH indicate?
usually 7.5. low could indicate infection, malignancy
what happens in a pneumothorax? (lung, chest wall, 02 level?)
lung recoils inward, chest recoils outward, hypoxia due to shunt or low VQ
what could cause a spontaneous pneumothorax?
apical blebs, congenital cause, underlying lung disease like emphysema or CF.
sx of pneumothorax?
breathlessness, cough, chest pain.
physical exam with pneumothorax: percussion, auscultation, anatomic, extremities?
perc: hyperresonant
ausc: low breath sounds or absent
tracheal shift away from PTX
tachycardia, hypotension, cyanosis
tx for pneumothorax?
remove air with catheter, chest tube, give 02, may do pleurodesis (glue together pleurae)
