Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
37 Cards in this Set
- Front
- Back
|
What does PT stand for?
|
Prothrombin Time
|
|
|
Which coagulation pathway does PT test measure?
|
extrinsic and common
|
|
|
What is the main reagent used in PT?
|
thromboplastin
|
|
|
What is the source of thromboplastin in PT?
|
rabbit brain
|
|
|
How are PT results reported?
|
seconds
|
|
|
What is the normal reference range for PT?
|
9.0 - 12.0 s
|
|
|
What is the temperature of the PT reagent well?
|
15 degrees
|
|
|
Why is it important to keep PT reagent at 15 degrees?
|
the reagent stays stable at this temperature
|
|
|
specimen stability at RT and 4 degrees
|
< 24 hours
|
|
|
What anticoagulant and ratio is used for coagulation tests?
|
sodium citrate, 9 blood : 1 citrate
|
|
|
What does ACL stand for?
|
Automated Coagulation Laboratory
|
|
|
INR: where does 'mean of normal range' come from?
|
from lab's patient population; labs do a statistical analysis to find the mean
|
|
|
INR: what does isi mean?
|
International Sensitivity Index
|
|
|
INR: where does INR's gold standard come from?
|
thromboplastin used by the WHO
|
|
|
What does the isi tell us about the sensitivity of the reagent?
|
the closer the isi value is to 1.0, the more sensitive it is
|
|
|
where does isi value for the PT reagent come from?
|
the manufacturer
|
|
|
which coagulation factors are monitored by the PT?
|
I, II, V, VI, X
|
|
|
how is fibrinogen reported?
|
g/L
|
|
|
what is the normal reference range for fibrinogen?
|
2.0 - 4.0 g/L
|
|
|
what pathways does the APTT monitor?
|
intrinsic and common
|
|
|
what are the 2 main ingredients of the APTT reagent?
|
colloidal silica and phospholipid
|
|
|
what temperature is the APTT reagent kept on the ACL?
|
15 degrees
|
|
|
what temperature is the APTT analysis carried out?
|
37 degrees
|
|
|
what temperature is the CaCl2 kept on the ACL?
|
RT
|
|
|
What is the molarity of the CaCl2 used?
|
0.025 M
|
|
|
What is the reference range for the APTT test?
|
28.0 - 34.0 s
|
|
|
which factors are monitored by the APTT test?
|
XII, XI, IX, VIII (intrinsic)
X, V, II, I (common) |
|
|
5 reasons for a prolonged APTT
|
1. liver disease
2. dysfunctional factor(s) 3. DIC 4. Circulating inhibitors 5. short draw |
|
|
Coagulation factors and Roman numerals that can give a prolonged PT
|
VII: Stable factor
X: Stuart-Prower factor V: Labile factor II: prothrombin I: fibrinogen |
|
|
7 coagulation related reactions in which thrombin plays a role
|
I -> fibrin
V -> Va VII -> VIIa VIII -> VIIIa XI -> XIa XIII -> XIIIa plasminogen -> plasmin |
|
|
What PT result can you expect from a patient with PV?
|
increased because plasma volume is decreased, leaving excess citrate, which binds with calcium in the APTT reagent, causing falsely prolonged clotting times
|
|
|
List Roman numerals and names of coagulation factors that can give elevated APTT results
|
I Fibrinogen
II Prothrombin V Proaccelerin VII Antihemophilic factor IX Plasma Thromboplastin Component X Stuart factor XI Plasma thromboplastin antecedent XII Hageman factor |
|
|
follow up tests to investigate elevated APTT results
|
- factor studies
- mixing studies - PT test - LFT |
|
|
List Roman numerals and names of coagulation factors that can give elevated PT results
|
I fibrinogen
II prothrombin V proaccelerin X stuart factor VII proconvertin / stable factor |
|
|
three conditions that can give prolonged PT results
|
DIC
heparin therapy oral anticoagulants e.g. warfarin |
|
|
INR low dose therapeutic range
under what clinical condition is it used? |
2.00 - 3.00
with patients on oral anticoagulants |
|
|
INR high dose therapeutic range
under what clinical condition is it used? |
2.50 - 3.50
with patients who have heart valves |
