Vasc. and plt testing Lecture 2 (continue of 1)

Question 1

Capillary fragility test (tourniquet test)
evals…looking for
fever?

Answer 1

evals vascular integrity looking for petechiae

dengue fever

Question 2

Components of blood
adult vol?

Answer 2

liquid - water/proteins/plasma

Adult vol: 4-6 liters

Question 3

EDTA tube

Answer 3

chelates calcium
EDTA clumpers
plt satillites
cold plt ab

Question 4

Sodium Citrate

Answer 4

binds calcium
must have full tube 1:10

cold plt ab
multiple by 1.1
PPP/PRP

Question 5

Anticoag sodium citriate
HCT
>55%
>55-65%
>65%

Answer 5

HCT >55% vol of anticoag needs to be adjusted

HCT 55-65% remove .1ml of citrate and do not do calculations

HCT >65% use calculation (do not need to know)

Question 6

CBC counts
x10

Answer 6

WBC x 10 3
RBC x 10 6
PLT x 10 3

Question 7

PLT count range

Answer 7

150-400 x 103

CRITICALS:
<30 x103
>1000 x 103

Question 8

Immature Plt fraction (IPF)
measure of
reflects?
more immature?
used for?

Answer 8

Measure of immature plts in peripheral blood

reflects rna

MORE IMMATURE = more fluorescnense

used for thromobytopenia

Question 9

Low to normal IPF

Answer 9

decreased production of plts

ex: aplastic anemias, leukemia, BM suppression

Question 10

Increased IPF

Answer 10

increased destruction

ITP,TTP,DIC drug effects

Question 11

Bleeding time test
ob
evals…
NOT dependent of
time?

Answer 11

obsolete

evals plt function/# ONLY

NOT dependent of coag cascade

2-9min

Question 12

Plt function analyzer (PFA)
tests
in
whole
test cartridges…

collagen/…

Answer 12

Tests primary hemostasis in artificial vessel, stim in vivo process of plt adhesion, activation and aggregation

whole blood

tests cartridges w biochem active membranes

Collagen/ADP
Collagen/EPI

Question 13

Closure time (PFA 100)
screens for…
under capillary flow similar to?

times prolonged with
HCT
PLTs

Answer 13

screens plts for ability to adhere and aggregate under capillary flow similar to in vivo

Times may be prolonged with HCT <35% or plts <150,000

Question 14

Plts defective/WV disease PFA-100 interpretation

Answer 14

Col/ADP and Col/Epi prolonged

Question 15

Aspirin/drug PA-100 interpretatations

Answer 15

Col/ADP normal

Col/Epi prolonged

Question 16

Optical aggregometry (light transmittence)
method
add
blank?
plts…and become… decreases, increases

Answer 16

referance method

add aggreg to PRP

PPP is blank

Plts aggregate and become clearer, decreasing turbidity and increasing light transmittence

Question 17

Overview of optical aggregometry
what changes?
primary aggregation
re
secondary aggregation

Answer 17

shape changes

primary aggregation - direct aggreg by agent

release rxn

Secondary aggregation mediated bu release rxn

Question 18

Aggregating agents (plt agonsits)

Answer 18

response varies dependent on agent and concentration

Question 19

ADP

Answer 19

Biphasic
30% norm subjects show only primary with any concentration

ASPRIN reduces aggregation (see only primary phase)

Question 20

EPI/NOREPI

Answer 20

Biphasic
30% norm sub only show primary with any conc.

ASPIRIN reduces aggregation (only see primary phase)

Question 21

Collagen

Answer 21

single phase with a lag phase

Question 22

Thrombin

Answer 22

biphasic
often only one phase

Question 23

Arachidonic Acid

Answer 23

Biphasic

Question 24

Ristocetin
bi…often
primary? no….only slight

Needs what two things to agglutinate

Answer 24

Biphasic often only one phase

primary agglutination no shape change and only slight release rxn

needs VWF in pt plasma/plt need GP IB to agglutinate

Question 25

Factors affecting plt aggregation
pH
temp
const
time
cuv

Answer 25

pH (8 optimal)
Temp 37
Constant stirring
Time 30 min
Cuvette/stir bar size/shape

Question 26

patient facotrs affecting plt aggregation

Answer 26

Excersise,stress,obesity,high fat, smoking, diabetes (INCREASE)

Alcohol/aspirin (DESCREASE)

Question 27

Whole blood aggregometry (impedence)
inc proportional to?

Answer 27

Increase impedence proportional to plt aggregation

Question 28

Plt luminaggregometry

Answer 28

Cleaver measure of plt secretion, biphasic curve not needed

firefly derived

luminescence proportional to ATP