Lab Data-Clin Path.txt

Card Set Information

Lab Data-Clin Path.txt
2014-09-29 20:58:34
vet med
clin path
Show Answers:

  1. pre-analytical factors of error in lab tests (6)
    patient variables (age, breed, etc), lipemia, hemolysis, icterus, collection procedures, and shipping procedures
  2. lipemia is caused by...
    circulating trigycerides, causing visible latescence (fat-containing meal prior to sample collect)
  3. hemolysis is caused by...(5)
    rupture of red blood cells due to pathology, difficult venipuncture, wrong needle used, excessive suction on syringe, rough transfer of blood
  4. icterus is caused by...
    increased concentration of bilirubin (yellow discoloration)
  5. analytical factors of error in lab tests (4)
    analyzer and equipment used to process the sample, test methodology and components, quality control procedures, and operating and maintenance procedures
  6. post-analytical factors of error in lab tests (2)
    data review by the laboratory and clinician, data entry and reporting
  7. basic principals of a quality control system (3)
    standard operating procedure, calibration, daily controls prior to analyzing patient samples
  8. how do you determine if an isolated laboratory abnormality is indicative of disease or lab error/ biological variation?
    the more tests you run, the more likely you are to get normal animals with test results outside of the RI; consider the animal's age, breed, history, diet, excitement, and medications; examine possible sources of error; for some analytes, a small deviation from RI is significant, for others only large deviations are medically significant (know the difference); note possibility of interassay variation; draw a new sample and retest if results don't make sense
  9. define sensitivity
    animals with disease that have positive test results; TP/ (TP+FN)
  10. define specificity
    animals without disease that have negative test results; TN/ (TN +FP)
  11. Negative predictive value
    % of animals with negative test that are actually disease-free; TN/ (TN+FN)
  12. positive predictive value
    % of animals with positive test that actually have the disease; TP/ (TP+FP)
  13. as prevalence of a disease goes down, ____ of a test goes up.
    NPV; thus, more animals that test negative are actually healthy
  14. as prevalence of a disease goes up, _____ of a test goes up.
    PPV; more animals that test positive actually have the disease
  15. Confirmatory tests should have high ________ in order to ....
    specificity; so if it is positive, you know the animal is not healthy (low FP); used when treatment may be very harmful; DON'T WANT TO TREAT NEGATIVE ANIMALS
  16. screening tests have high ______ in order to...
    sensitivity; negative animals can be ruled out (Low FN); used when cost of FN is high-such as in a herd; DON'T WANT TO MISS POSITIVE ANIMALS
  17. reference intervals are established by sampling animals from a ________; then,.....
    healthy population; for gaussian curve, RI is + or - 2SD from the mean (therefore, ~5% of normal animals will fall outside of RI