| |
Patient Population: |
| 1. |
A sufficient number of samples must be obtained to span the entire
normal and therapeutic range. |
| 2. |
The table at the bottom of the attached data collection form indicates
the breakdown of the number of paired samples required in each sensitivity
range. |
| 3. |
The normal range samples (volunteer normal donors) should be done
first, prior to collecting specimens from anticoagulated patients. |
| |
|
| |
Material Preparation: |
| 1. |
Bring all cuvettes to room temperature. This may require up to
1 hour. |
| 2. |
Perform instrument quality control (as per the HEMOCHRON Jr. Signature/Jr
II Operator's Manual) using the HEMOCHRON Jr. EQC test cartridges,
or directCHECK® Quality Control test products. |
| |
|
| |
Test Procedure: |
| 1. |
Insert the appropriate cuvette into the HEMOCHRON® Jr. Signaturer/Jr.
II
analyzer. The instrument will display a number of messages (i.e.
pump
warming...) while performing a series of internal tests. Do not collect
any blood
sample until the analyzer display reads “ADD SAMPLE… PRESS
START”.
Once displayed, you have 5 minutes to collect the fresh whole blood
sample and
add it to the cuvette. |
| |
|
| |
Blood Collection: |
| 1. |
Collect 2 ml of fresh whole blood. (When using a 2 syringe technique, make
sure to use the second draw.) |
| 2. |
Alternatively, a single citrated tube may be used. After mixing,
a small (< 0.1 ml) sample can be removed from tube with a syringe
and tested on the JR. instrument. |
| |
Using the collection syringe, immediately add
the blood sample to the center well of the HEMOCHRON® Jr. cuvette.
Fill the center well of the cuvette flush to the top (if a large
dome forms on top of the well, push it over into the outer well).
Depress the START button on the analyzer.
Note: If the blood sample is collected and added to the cuvette prior to the
analyzer being ready, a fault message will most likely be displayed, and the
result will be invalid. If sample collection exceeds the 5 minute time limit, the
analyzer will display a “START TIMEOUT” message, and you will need to discard
the cuvette and replace it with a new cuvette, according to the package insert
instructions. |
| 3. |
Immediately fill an evacuated blue
top tube containing sodium citrate using the blood sample remaining
in the syringe. This sample is to be used in the clinical laboratory
to perform the plasma test.
Note: Either 3.2% or 3.8% sodium citrate
tubes may be employed. However, differences exist between laboratory
test results with each citrate concentration. It is therefore critical
that only one concentration be used by a single medical facility. |
| 4. |
Immediately label the citrated blood sample with “STAT CORRELATION
STUDY” and patient ID and immediately transport to the clinical laboratory. |
| 5. |
Record the HEMOCHRON® Jr. Signature/Jr II results upon completion
of the test (indicated by an audible beep). |
| 6. |
The comparative plasma test is to be performed using the standard lab
procedure.
The laboratory assay must be performed within 60 minutes of specimen collection. |
| |
|
| |
Recording Results: |
| |
Record all information on attached data sheets. |
| 1. |
Record specimen draw time and time that laboratory result was obtained. |
| 2. |
Record HEMOCHRON® Jr. Signature/Jr II results: plasma equivalent
result and INR for PT |
| 3. |
Record the corresponding laboratory plasma PT and/or INR result. |
| 4. |
Once a minimum of 30 sets of data points distributed over the desired
clinical range have been collected, call ITC Technical Service (800-631-5945)
and arrange to have the collected data faxed to them for review and
analysis. |
| 5. |
Once analysis is complete, Technical Services will contact you
to discuss whether your correlation is acceptable, or whether additional
data is required. |
| |
|
| |
Interpretation of results: |
| |
Clinical correlations demonstrate the statistical similarity of the two test systems. Data
is analyzed using a linear regression model. The correlation coefficient (r) indicates the
degree to which data points deviate from the line of best fit. A perfect correlation of 1.0
indicates each data point is matched to the “control” method, measured against a line of
best fit. The slope of the regression line indicates a bias in either test method. In order
to have two tests be identical, both the correlation coefficient (r) and the slope of the
regression line must be 1.0 Correlations of HEMOCHRON® whole blood assays to
laboratory method are generally 0.88 or greater. This indicates the tests are statistically
similar, yet actual differences of individual data points are expected. |
| |
|
| |
Please
click here for HEMOCHRON Jr. Signature/ Jr. II PT CORRELATION
PROTOCOL DATA SHEET |
