Pleural Flashcards
Hydrostatic and oncotic pressure in pulmonary circulation favor fluid accumulation on _______ surfaces and absorption at _____ surfaces
Accumulation at parietal pleural surfaces, absorption at visceral.
Higher hydrostatic pressure in vessels does what to fluid
Pushes it out
Higher hydrostatic pressure outside vessels does what to fluid
Pushes it in
Oncotic pressure - lower causes what in vessels
Water leaves
Oncotic pressure- higher causes what in vessels
Water influx/stay
Higher oncotic pressure in insterstitial space leads to what
Water leaves vessels
Lower oncotic pressure in interstitial space leads to what
Water goes into vessels
Filtration coefficient/ permeability effect on vessel
More permeable= mild changes in starling forces have greater effect on fluid accumulation
Which vessels are more leaky pleural vessels vs lung vessels
Pleural not very leaky, lung leaky but oncotic pressures so narrow that they drive fluid resorption so hard to get fluid build up inside lung from oncotic pressure changes. More possible outside lung
When do clinical signs of fluid build up become apparent
> 60 mL/kg
What are the signs of fluid build up
Tachypnea (1st) –> inspiratory dyspnea, cyanosis, orthopnea
Why does fluid accumulation cause dyspnea
Inspiratory effort increased due to lack of ability to move negative pressure
What are the clinically auscultable signs of pleural effusion
Dull/absent lung sounds ventrally (lung sounds heard dorsally) - TAP THEM! Thoracocentesis- not radiographs
What drugs can be used in patients with respiratory distress
Anxiolytic, not sedative (unless needed for tap)
What does thoracocentesis cytology test for?
Total protein, cell count, differential cell count, cell morphology assessment - all to classify the fluid
What are the three differentials for types of pleural fluid
Transudate, modified transudate, exudate
What are the characteristics of transudate
Low protein, low cell count! Primarily low number of mononuclear cell counts (macrophages, lymphocytes, mesothelial cells) - not eos, neuts, mast
What are the characteristics of modified transudate
Fluid + protein, medium cell count, add neutrophils (non-degenerate, healthy)
Rank fluid types by amount of protein from least to most
Trans- modified - exudate
Rank fluid types by amount of cells from least to most
Trans- modified - exudate
Changes in starling forces lead to what types of fluids
Trans and modified transudate
Low oncotic pressure in blood, high hydrostatic, impermable vessels
Transudate
What conditions may lead to modified transudate fluid
More permeable vessels, significant high hydrostatic, low oncotic pressure
What are the causes of transudate and modified transudate pleural effusion in dogs and cats
Hydrostatic: Dogs- RHF, Cats- R or LHF; pericardial disease, volume overload; Severe hypoalbuminemia (oncotic); lymphatic draining, neoplasia, diaphragmatic hernia, lung lobe torsion
What kind of lymphatic drain would cause pleural effusion
Draining out of chest
Lymphatic draining into chest cause what kind of fluid
Chylous
Describe non-septic exudate
Variable cells (neuts, macrophages, eos, lymphs): non-degenerative neuts but active macs and lymphs; no organisms seen
Describe septic exudate
Exremely high cell count, degenerate neuts dominate, +/- bacteria (foul odor with anaerobes). BACTERIA IN NEUTS
What would red fluid with white or yellow granules
Sulfur granules - nocardia, actinomyces
Which neoplastic processes readily exfoliate into effusion
Lymphoma; others occasionally do
What kind of cells can give false positive for neoplasia
Reactive dysplastic mesothelial cells from inflammation
Describe chylous effusion
Moderate protein, moderate to high cell counts (with these could mistake with modified transudate or exudate); Cloudy or high lymphocytes- run serum triglycerides - if lower, chylous (lymphatic problem dumping into chest)
What would serum triglycerides lower than blood triglycerides indicate
Chylous effusion from lymphatic obstruction dumping into chest
Name differentials for chylous effusion
trauma, neoplasia, cardiac disease, dirofilariasis, lung lobe torsion, diaphragmatic hernia
