Hemostasis Assessment Questionnaire

Hemostasis Assessment Questionnaire
Hemostasis Assessment questionnaire
Answer to question 1
Principle : A prothrombin time (PT) test is generally conducted to detect as well
as diagnose a disorder due to bleeding or disorder due to excessive clotting. The
international normalized ratio (INR) is calculated from the result arrived for PT
and it is used to monitor how well medication used for blood-thinning
(anticoagulant) is effective to prevent blood clotting. The common reasons of
INR test are among many
a. In addition to lever function test INR test is also done since liver malfunction may
lead to decreased production of certain clotting factors. (Thachil, 2008)
b. A clot observed in a deep vein , commonly of the leg
c. A clot in lung, that travelled through veins
d. Used for hypertension patients (Ali Jiskani, 2017)
e. Used before surgery (Fralick and Sholzberg, 2017)
1. For standardization of PT INR was introduced. Initially, values of PT used to vary
because of the fact that different thromboplastins were non-standard as they
were derived from different sources. Even PT performed using identical
specimen in different laboratories were not consistent. INR can be calculation by
using the formula
INR = [PTpatient / MNPT]ISI
Here PT is the value in seconds for the sample taken from two patients as well as
for quality control samples. The value of MNPT for manual method is 17seconds
whereas NR should be within the range 13 to 19 seconds. Normal range of INR
should be within the range 0.8 to 1.2
In the second step, this ratio is raised to a power designated the ISI, or
international sensitivity index. The ISI is a function of the thromboplastin reagent.
Its value will be taken as 1.22.
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Hemostasis Assessment Questionnaire
2. APTT measures the activity of the common and intrinsic pathways of
coagulation.
The APTT ratio = NR in seconds/MNAPTT in seconds where MNAPTT should
be 41 seconds and NR is 38 to 44 seconds. The normal range of APTT should be
0.8 to 1.2.
Answer to question 2
Quality Assurance in the laboratory ensures that the result a laboratory generates
and reports is accurate, precise and specific.
Value OF INR arrived at using quality control sample of PT and PT of two
patients
1. Mean value of Prothrombin Time (MNPT) = 17 Seconds
2. Average value of PT for patient sample 1 = 26 Seconds
3. Average value of PT for patient Sample 2 = 17 Seconds
4. Average value of PT for quality control sample = 18 Seconds
INR = (PT patient /MNPT)ISI where ISI = 1.22
Value of INR for patient 1 = 1.56
Value of INR for patient 2 = 0.93
Value of INR for quality control sample = 1.07
The value of INR for first patient is on the higher side whereas that of second
patient is within the range. The value of INR using quality control sample is
within the range.
Average APTT of quality control sample = 42 seconds
MNAPTT = 41 Seconds
Average APTT of patient 1 = 52 Seconds
Average APTT of patient 2 = 43 Seconds
APTT ratio for patient 1 = 52/41 = 1.27
APTT ratio for patient 2 = 43/41 = 1.04
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