Recognition & Analysis of Body Fluids Flashcards
what are the 3 body cavity effusions
- peritoneum (abdomen)
- pleura (thorax)
- pericardium
what are the two forces that balance
Oncotic pressure
Hydrostatic pressure
what is oncotic pressure
Oncotic pressure: form of osmotic pressure that is caused by proteins (mostly albumin) in a blood vessel’s plasma (blood/liquid) that causes water molecules to flow into the circulatory systems
what is hydrostatic pressure
Hydrostatic pressure: opposing effect with pushes water and small molecules out of the blood into the interstitial spaces within the arterial end of capillaries and interstitial colloid osmotic pressure
what would you use EDTA tube for
prevents clotting of the sample, which can affect cell counts
helps preserve cell morphology during transport to the lab
submit unstained slides as well for best cell morphology preservation
what would you use plain tube for
culture
biochemical
or PCR testing
if indicated (EDTA bacteriostatic)
how do you process the sample and fluid analysis (4)
- protein concentration
- nucleated cell count: measured with automated analyzer, microscopic counting chamber
- colour turbidity
- cytological analysis (direct smear, sediment)
what are the 3 types of body cavity effusions
- transudate
- modified transudate
- exudate
what does a transudate effusion result from (2)
- decreased plasma oncotic pressure
- increased hydrostatic pressure
what would cause decreased plasma oncotic pressure that results from a transudate
severe hypoalbuminemia
- decreased production (hepatic insufficiency)
- loss (portein-losing nephropathy or enteropathy)
what would cause increased hydrostatic pressure that results from a transudate (2)
- myocardial insufficiency
- portal hypertension
what is the appearance of a transudate
grossly range from colourless to straw coloured
what is the cell count of a transudate
<1.5 x 10^9 cells/L
what is the protein content of a transudate
<25 g/L
values towards the lower end suggest hypoalbuminemia
values at high end may be seen with CHF, portal hypertension
what other cells would you expect to see in a transudate (3)
- macrophages
- mesothelial cells
- rare non-degenerate neutrophils
exception is horse –> may have up to 10 cells x 10^9/L with up to 75-80% non-degenerate neutrophils and still be considered a transudate
how does an exudate form
Increased capillary permeability
Mediators which increase the vascular permeability —> allow cells to transit out of the blood and into the tissues or body cavity
Fluid and proteins also leak out of the spaces
Chemotaxis of leukocytosis
what is the protein content of an exudate
>25 g/L
what is the cell count of an exudate
>5 x 10^9 cells/L
what could cause an exudate (4)
- pancreatitis
- bacterial infections
- bowel perforation
- irritants (bile, urine)
what is a septic exudate
microorganisms are present, especially intracellular organisms
just because you don’t see bacteria doesn’t mean they are not there –> when in doubt culture
what would the neutrophils look like in a septic exudate
neutrophils may be non-degenerate or degenerate depending on type of infectious agent present
what is shown here
degenerate neutrophils with intracytoplasmic rods
nuclei are puffy, and starting to break apart
compare a transudate and exudate protein and cell count
what is a modified transudate
a catch all category
nucleated cell count or protein concentration is increased but doesn’t fit with exudate range
how do modified transudates form
accumulation of transudative fluid causes increased pressure that irritates mesothelial cells
mesothelial cells respond by proliferating and sloughing into the effusion
when they die they draw macrophages
what can mesoethial cells resemble
reactive mesothelial cells can resemble neoplastic cells
what cell is shown here
reactive mesothelial cell