Hematology Lab Quiz Flashcards Preview

Med Lab Tech Fall 2016 > Hematology Lab Quiz > Flashcards

Flashcards in Hematology Lab Quiz Deck (50)
Loading flashcards...
1

What is one of the most complex areas of diagnostic laboratory testing?

Hemostasis

2

What are the 3 steps for forming a clot?

1. constrict the blood vessel in the region of the hole

2. form a platelet plug

3. seal that plug with fibrin

3

What is platelet poor plasma?

contains less than 10 x 109 platelets/L

4

What are some specimen factors affecting coagulation testing?

  • collection system
    • order of draw
  • anticoagulant
  • phlebotomy technician
  • centrifugation
  • delays in handling
  • storage conditions

5

What are some instrument factors affecting coagulation testing?

  • temperature
  • light sensor
  • detector
  • timer
  • disposables
  • reagent delivery

6

What are some reagent and control factors affecting coagulation testing?

 

  • shipping conditions
  • storage conditions
  • reconstitution
  • contamination
  • deterioration
  • lot changes

7

What must be analyzed with each assay performed within the lab?

Internal Quality Control (IQC)

8

What is the purpose of internal quality control?

To assess ongoing assay performance to ensure assays are:

  • performing according to specifications
  • results are accurate and reliable
  • ensure reproducibility of testing

9

Definition:

Peer group assessment process that allows a lab to assess individual analytes against those of other labs using either the same or different reagents or instrumentation

External Quality Assurance

10

What anticoagulant is used for routine coagulation testing?

Sodium citrate

11

True or False:

If sodium citrate anticoagulant is unavailable, you may use EDTA, heparin, or oxalate.

False, these anticoagulants are unacceptable

12

What is the ratio of blood to anticoagulant?

9:1

13

A disproportion of blood to anticoagulant is seen in a patient with what disorder?

Polycythemia

14

What is the calculation used to calculate the amount of sodium citrate that should be used?

 

  • X= (100-Hct)Vol/(595-Hct)
    • X = volume of sodium citrate required for unit volume of blood
    • Hct = hematocrit
    • Vol = blood draw volume required in the blood collection tube

15

Most clot based coagulation activity procedures are performed on what type of specimen?

Plasma

16

The addition of what to plasma is required in order to perform coagulation activity testing?

The addition of CALCIUM is required in order to perform tests

17

What pathway include factors X, V, II, and I?

Common pathway

18

Which pathway includes factor VII?

Extrinsic pathway

19

Which pathway include factors XII, XI, IX, and VIIIa?

Intrinsic pathway

20

What are some advantages of enzyme specific synthetic substrates over the traditional clot formation?

  • can be performed rapidly
  • sensitive
  • allow for a greater degree of standarization
  • require smaller sample volumes
  • well suited for automation

21

If unable to perform testing within 4 hours what should be done?

Freeze plasma at -70C

22

Immediately before testing plasma, how should you thaw it when frozen?

Rapidly thaw in a 37C water bath to prevent formation of cryoprecipitate

23

What are the 4 methods of endpoint detection?

  • Mechanical
  • Photo-optical
  • Chromogenic
  • Immunogenic

24

A fibrometer is what type of endpoint detection method?

Mechanical

25

What type of endpoint method is the following:

when a light souce of a specified wavelength is passed through a test solution (plasma), a certain amount of light is detected by a photodetector or photocell located on the other side of the solution

Photo-optical endpoint detection

26

This endpoint detection method is the most commonly utilized in coagulation instruments

Photo-optical endpoint detection

27

What is another name for photo-optical endpoint detection?

Turbidometric methodology

28

This endpoint detection method is also known as amidolytic methodology

Chromogenic Endpoint Detection

29

The color-producing substance used in chromogenic endpoint detection is known as what?

Chromophore

30

This endpoint detection method is based on antigen-antibody reactions

Immunogenic endpoint detection