blood chemistry Flashcards
why do blood chemistry
evaluates organ system functions
vt role
know variety of testing procedures, rationale behind the analyses, know proper collection and handling
how long to fast patient
minimum 2 hours, ideal 4-6 hours
enough blood should be collected to run _______
3 tests
the organ we cannot really test for is ______
the lungs
what effects the quality of sample?
venipuncture technique (traumatic stick), transferring blood into tube, avoid hemolysis
storage of blood sample
if cannot be centrifuged within the hour, refrigerate
if cannot be run within 4 hours, plasma or serum should be separated and refrigerated
transport of blood sample
wrap ice pack with paper towels to avoid touching
red top tube
contains nothing, serum will separate after centrifuge, glucose is metabolized at 10%/hr when in contact with cells
tiger top tube
serum separator, serum cannot contact cells once centrifuged, invert tube to activate clotting
gray top
potassium oxalate and sodium fluoride, glucose determination
green top
heparin, frozen or stored overnight
how are tests performed
reagent strips, photometers, abaxis, idexx
isoenzyme
multiple organ sources
enzymes are normally _______ in blood
low
if enzymes are high
cells have ruptured and leaked enzymes into serum
indirect assays
measure enzymatic reaction
endpoint
reaction between sample and enzyme reaches a stable end-point and standard curve determines enzyme level
kinetic
do not reach end-point so reaction is measured at specific time after reaction started
liver functions
synthesis of plasma proteins, clotting factors, metabolism, detox, secretion of bile
when hepatocytes are damaged…
enzymes leak into blood causing rise in levels
Alanine Aminotransferase (ALT)
liver specific
Aspartate Aminotransferase (AST)
non organ specific
ALT
source is hepatocytes, no correlation with liver damage, steroids or anticonvulsants can elevate
