Procedure:
Hemochron® Response System
Clinical and Laboratory Standards
Institute (CLSI) Formatted Procedure
Approved by ___________________ Date ________________________
Created by
___________________ Date ________________________
Reviewed by ___________________ Date _________________________
Reviewed by ___________________ Date _________________________
Reviewed by ___________________ Date _________________________
Reviewed by ___________________ Date _________________________
Contact Person __________________________
Contact Number(s) _______________________
PURPOSE
The Hemochron® Response Whole Blood Coagulation System is a dual-well
microprocessor-controlled coagulation testing instrument with an integral test type
barcode reader, RS232 communication interface capability, and a printer. The system
runs coagulation tests such as: Activated Clotting Time (ACT), Activated Partial
Thromboplastin Time (APTT), Prothrombin Time (PT) and other specialty tests that are
specific to the RxDx® to include: Heparin Response Time (HRT), Protamine Response
Time (PRT), Protamine Dose Assay - O (PDAO), Thrombin Time (TT), Heparin
Neutralized Thrombin Time (HNTT)
The Hemochron RxDx® Analysis Module is a supplementary module for the Hemochron
Response Whole Blood Coagulation System that provides automated calculations for
use during cardiopulmonary bypass surgery and cardiac catheterization procedures.
These calculations are used to determine the doses of heparin to be administered before
and during these procedures, the dose of protamine needed to reverse the effects of
heparin after the procedure is completed, and the patient's clotting time and residual
heparin level after protamine has been administered.
PRINCIPLE
The Hemochron clot detection module contains two test wells into which disposable
unitized coagulation test tubes can be inserted. The test tubes contain reagents for a
particular test and a magnet. Immediately after the sample is added to the test tube, the
“START” button is pressed, the test tube is agitated, and the test tube is placed into the
test well by the operator. Once in the test well, the tube containing the sample is
automatically rotated at a controlled speed and incubated at 37 °C ± 1.0 °C.
When a fibrin clot begins to form, it causes the magnet in the test tube to be displaced.
Two magnetic detectors located in the test well continuously monitor the precise magnet
position. When a specific displacement of the magnet occurs, the elapsed time between
the beginning of the test and the clot endpoint is displayed as the coagulation time (in
seconds).
The instrument also emits an audible beep when clot formation occurs, indicating the
end of the test. The coagulation time is displayed on the LCD screen.
The Analytic Measurement Range (AMR): 22-1500 seconds
Activated Clotting Time (ACT)
The ACT is performed by adding a clotting activator such as Celite®, silica, kaolin, or
glass particles to a blood sample and then measuring the length of time required for clot
formation. The particular clotting activator that is used influences the time required for
clot formation. Celite (diatomaceous earth) is the standard ACT reagent used for high
level heparin monitoring because of its excellent activating properties.
However, serine protease inhibitors such as aprotinin that may be administered to
certain patients to decrease postoperative bleeding can prolong the Celite-activated
ACT. When aprotinin is on-board, a kaolin-activated ACT tube should be used.
Activated Partial Thromboplastin Time (APTT)
The OneStep APTT test measures the intrinsic coagulation pathway and involves all
coagulation factors except Factors VII and III (tissue factor). The APTT test improves the
earlier Partial Thromboplastin Test (PTT) test through use of a contact activating
substance (kaolin) which initiates activation of Factor XII and acts as a Platelet Factor 3
substitute to provide for low level heparin monitoring.
Prothrombin Time (PT)
The PT test measures the extrinsic coagulation pathway and is sensitive to coagulation
Factors VII, X, V, II, and fibrinogen. PT results may be abnormal in patients with liver
disease or Vitamin K deficiency, and the test is widely used to monitor warfarin
anticoagulant therapy.
RxDx Analysis Mode
Prior to administration of heparin, an Activated Clotting Time (ACT) and Heparin
Response Time (HRT) test are run on the Hemochron Response Whole Blood
Coagulation System. These tests measure the patient's baseline clotting time and
determine how the patient will respond to heparin. The patient blood volume can either
be directly entered (if available) or calculated by the system based upon the patient's
height, weight, and gender.
1. The initial heparin dose (referred to as the bolus heparin dose) necessary to reach
target time is then calculated by the system. During this process, the case is in the
heparin mode.
2. Once the patient has received heparin, additional ACT or High Dose Thrombin Time
(HiTT) tests are run to measure the coagulation status, determine the efficacy of
heparin, and calculate additional heparin doses that may be needed to maintain the
target clotting time in the patient. The case is now in the additional heparin mode.
3. After the cardiac surgery or cardiac angioplasty procedure is completed, the effects of
administered heparin can be reversed by administration of protamine.
Like heparin, protamine must be administered in the correct dose to prevent dangerous
bleeding or thrombosis. For this reason, a Protamine Response Time (PRT) test is
performed, and the results of this test and the most recent ACT test are used to
determine the dose of protamine that is required. The case is now in the protamine
mode.
Once the protamine has been administered, the patient's clotting time and residual
heparin level are measured, using an ACT and a Protamine Dose Assay - O (PDAO)
test to determine the post-protamine clotting time and residual heparin level in the
patient's blood. Heparin Neutralized Thrombin Time (HNTT) tests can also be run after
protamine administration to identify the presence of heparin rebound or abnormal
fibrinogen function.
Since Celite® (diatomaceous earth) is sensitive to the presence of serine protease
inhibitors such as aprotinin, it is recommended that kaolin test tubes are used instead of
Celite test tubes when aprotinin
High Dose Thrombin Time (HiTT)
The Hemochron ® HiTT is a quantitative, one-stage high dose thrombin time test for the
purpose of monitoring high levels of heparin anticoagulation. The HiTT employs a
specific concentration of thrombin so that high heparin levels may be monitored. The
HiTT can be used in conjunction with, or as an alternative to, the Activated Clotting Time
(ACT) test to monitor heparinization during cardiopulmonary bypass surgery. The test
may be used in the presence of antifibrinolytic drugs, such as aprotinin (Trasylol®), which
appear to preserve platelet function and reduce post-operative bleeding.
Protamine Response Test (PRT)
The Hemochron ® PRT is designed for in vitro diagnostic protamine dose Response
evaluation. The Hemochron PRT200 and the PRT400 tubes are recommended for use
in invasive cardiology procedures requiring protamine for neutralization of heparin
anticoagulation with the PRT 400 used for extremely high heparin concentrations. The
kaolin- activated PRT assays may also be used for patients receiving aprotinin. The
PRT200 and PRT400 should be used with established Hemochron procedural guidelines
with Hemochron Response. The dose of protamine sulfate required to neutralize heparin
after cardiopulmonary bypass surgery is commonly based on a ratio of protamine to the
amount of heparin infused during the procedure, or on protamine titration.
Protamine Dose Assay-Orange (PDAO)
The Hemochron ® PDAO provides a convenient method for protamine titration using the
principles of in vitro dose-response heparin neutralization and verification of heparin
neutralization. Titration analysis performed using PDAO quantifies the milligrams of
protamine per milliliter of patient blood necessary to neutralize the patient’s residual
heparin load and return the Activated Clotting Time (ACT) to the pre-heparinized
baseline value. The PDAO test is available with either Celite® (diatomaceous earth) or
kaolin activators. The Celite-activated PDAO test is not intended for use with the
protease inhibitor aprotinin (Trasylol®, Bayer Corporation), which may be administered to
reduce post-operative bleeding, especially during cardiopulmonary bypass surgery, and
can prolong the Celite-activated PDAO. Kaolin is unaffected by moderate doses of
aprotinin. The kaolin-activated PDAO can be used as an alternative for protamine dose
response evaluation in patients receiving aprotinin.
The postsurgical patient should be monitored with the ACT and PDAO to determine the
need to infuse additional protamine to compensate for latent heparin effect, which may
possibly result in heparin rebound.
Thrombin Time (TT)
The Hemochron ® TT is designed for use as a screening assay to evaluate the level of
circulating fibrinogen and detection of heparin. The thrombin time is commonly
employed to detect suspected heparin anticoagulation and to quantify circulating
fibrinogen. The measurement of fibrinogen is useful in the diagnosis of consumptive
coagulopathy or intravascular coagulation and the monitoring of thrombolytic therapy.
Heparin Neutralized Thrombin Time (HNTT)
The Hemochron ® HNTT is designed to be solely indicative of circulating fibrinogen and
is not affected by the presence of heparin. In addition to sensitivity to fibrinogen level,
the thrombin time is sensitive to the presence of heparin. Heparin prolongs the thrombin
time through neutralization of the thrombin in the test tube. The results of a coagulation
assay, such as the thrombin time, performed on a blood specimen in which heparin has
been neutralized, reflect the hemostatic condition of the patient. Such an assay may be
referred to as the heparin-neutralized thrombin time (HNTT).
SAFETY
Universal precautions should be observed through all phases of the testing procedure.
Refer to the current versions of CLSI Document M29– Protection of Laboratory Workers
from Occupationally Acquired Infections and CLSI Document GP17 - Clinical Laboratory
Safety for Information on Laboratory Safety and Special Requirements.
SPECIMEN
A. Patient Preparation
There is no patient preparation needed prior to testing.
B. Sample Collection
The ACT test is performed using fresh whole blood collected with a syringe from the
patient. Refer to the most recent version of CLSI Document H21 - Collection, Transport,
and Preparation of Blood Specimens for Testing Plasma-Based Coagulation Assays and
Molecular Hemostasis Assays; Approved Guideline for the collection of specimens for
coagulation testing.
When sampling through indwelling blood lines, flush access port thoroughly following
institutional procedures.
1. Identify patient as directed by policy
2. Collect a blood sample from the patient by venipuncture or an indwelling catheter
line to allow for 2cc volume required for ACT testing.
3. If using a syringe with needle:
a. Use a 23 or larger gauge needle
b. Safely remove needle and discard in a sharps container.
c. Optional: attach a transfer needle no less than 23 gauge to the syringe.
d. After dispensing the sample, discard syringe and transfer needle in labeled
sharps container.
C. Sample Storage
Specimens must be processed immediately. There is no storage prior to testing.
D. Unacceptable Sample Types
Samples with any of the following characteristics should be discarded immediately, and
a fresh whole blood sample must be collected prior to performing any test on the
Hemochron instrument.

If a non-citrated test, citrated tube used for collection

Sample collected into a pre-heparinized syringe

Sample contamination with tissue thromboplastin

Sample contamination with indwelling intravenous (I.V.) solutions

Sample contamination with alcohol cleansing solution

Samples with visible clotting or debris accumulation
EQUIPMENT/ MATERIALS/ REAGENTS
A. Equipment
1. Hemochron ® Response Instrument
2. AC/DC Power Module ITC Part Number HR1283
B. Materials
1. Fresh whole blood sample
2. Biohazard disposal receptacle
3. Sharps disposal receptacle
C. Reagents
ACT Celite
FTCA – (Part Number FTCA510: black top tube)
 Flip-top non-evacuated glass test tube contains diatomaceous earth as an
activator.
ACT Kaolin
FTK-ACT – (Part Number FTK-ACT: gold top tube)
 Flip-top non-evacuated glass test tube contains kaolin as the activator
ACT for Low Levels of Heparin
P214 – (Part Number P214: top tube; white top tube)
 Flip-top plastic test tube with glass beads as the activator
APTT
OneStep APTT for Whole Blood
APTT – (Part Number A103: navy blue top tube)
 Each tube contains a lyophilized preparation of colloidal kaolin, a platelet
factor 3 substitute, stabilizers and buffers
 Thimerosal (0.02%) is added as a preservative.
CAUTION: Reagents containing thimerosal should be discarded in accordance with
your institutions policy concerning disposal of medical waste.
PT
PT for Fresh Whole Blood
PT – (Part Number A201: dark purple top tube)
 Each tube contains a lyophilized preparation of acetone-dried rabbit brain
thromboplastin, stabilizers, and buffers.
 Sodium azide (0.05%) added as a preservative
PT for Citrated Whole Blood
Cit PT – (Part Number A202: light purple top tube)
 Each tube contains a lyophilized preparation of acetone-dried rabbit brain,
calcium salt, stabilizers and buffers.
 Sodium azide (0.05%) added as a preservative
CAUTION: Reagents containing sodium azide should be discarded in accordance with
your institutions policy concerning disposal of medical waste.
D. Reagents – RxDx System
PRT 200 (ITC Part Number R-PRT 200: peach top tube)
 Each tube contains protamine sulfate (0.04 mg), diatomaceous earth,
stabilizers and buffers.
PRT 200K (ITC Part Number R-PRT 200K: peach top tube with Kaolin label)
 Each PRT 200K tube contains protamine sulfate (0.04 mg), kaolin, stabilizers
and buffers.
PRT 400 (ITC Part Number R-PRT 400: red top tube)

Each PRT400 tube contains protamine sulfate (0.08 mg), diatomaceous
earth, stabilizers and buffers.
PRT 400K (ITC Part Number R-PRT400K: red top tube with Kaolin label)
 Each PRT400K tube (red top) contains protamine sulfate (0.08 mg), kaolin,
stabilizers and buffers.
HiTT – (ITC Part Number A501: turquoise top tube)
 Each tube contains a lyophilized preparation of human thrombin, snake
venom, protamine sulfate, calcium salts, stabilizers and buffers.
 Thimerosal (0.02%) is added as a preservative.
CAUTION: Reagents containing thimerosal should be discarded in accordance with
your institutions policy concerning disposal of medical waste.
HNTT – (ITC Part Number A401 – brown top tube)
 Each tube contains lyophilized human thrombin, calcium salts, protamine
sulfate, stabilizers and buffers.
TT – (ITC Part Number A301 – rose top tube)
 Each tube contains a lyophilized preparation of human thrombin, calcium
salts, stabilizers and buffers.
HRT- Kaolin – (ITC Part Number R-480 PK: light green top tube with Kaolin label)
 Each R-HRT480PK tube contains the equivalent of 6 USP units of porcine
mucosal heparin (3 units/ml in blood), kaolin, stabilizers and buffers.
HRT – Celite – (ITC Part Number R-HRT480P: light green top tube)
 Each R-HRT480P tube contains the equivalent of 6 USP units of porcine
mucosal heparin (3 units/ml in blood), diatomaceous earth, stabilizers and
buffers.
PDAO – (ITC Part Number PDAO: orange top tube)
 Each PDAO tube contains protamine sulfate (0.01mg), diatomaceous earth,
stabilizers and buffers.
PDAOK – (ITC Part Number PDAOK: orange top tube with Kaolin label)
 Each PDAOK tube contains protamine sulfate (0.01mg), kaolin, stabilizers
and buffers.
D. Reagent Storage
Test tubes of all types are stable when stored at room temperature (15-30°C or 59-86ºF)
and used prior to expiration date on carton and/or case.
QUALITY CONTROL
A. Self-Check
The Response instrument performs a “self-check” every time it is activated and a test
is performed. When a test is initiated by pressing START, system checks are
automatically performed and include:

Verification of adequate battery power to complete a 1500 second test.

Verification that a tube has been inserted and that the test well is functioning
properly. If any rotation or temperature parameters are not appropriate, the test is
terminated and an error message is displayed.

For barcoded tubes, the test type and expiration data are read. The test type will
be displayed on the screen. If the expiration date has passed, the test is aborted
and an error message displayed. Once a barcode is read, the user cannot
change the test type.

Verification that the test well is warmed to 37± 1.0 ºC. If this temperature is not
achieved or is exceeded, an appropriate error message will be displayed and
testing is prohibited.

Verification that the internal timers function correctly for each test. If the system
timer and assay timer disagree at the end of a test, a real-time clock error
message is displayed and the test result is not reported.
B. Electronic Quality Control (EQC)
The Electronic System Verification (ESV) should be performed once every 8 hours
while the instrument is in operation. Both wells are to be tested if both are in use.
1. A prompt is displayed if entry of an OID or PIN is required. Enter your OID or PIN
and press “YES”.
2. A prompt is displayed to enter the serial number of the ESV tube. The serial
number of the last ESV used is displayed.
NOTE: If needed, enter the ESV serial number (up to 9 characters) located on
the back of the ESV tube. Press “BACKSPACE” to undo an entry for retyping.
3. Insert the multilevel ESV tube into test well of the instrument.
4. Simultaneously press both the “START” button on the Response and the button
that corresponds to the level of testing to be performed (100, 300, or 500
seconds).
5. The green detector light on the instrument and the red light on the ESV tube will
illuminate indicating start of the test.
6. When the verification tube reaches its pre-programmed time, it will electronically
simulate a test endpoint as indicated by a “beep” tone and display the test result.
7. Record the time displayed according to institutional policy.
8. Repeat steps 2-5 with the next test level of the ESV tube.
9. Results are acceptable if within 10 seconds of the selected times.
10. The ESV may be manually tagged if the barcode label is not read.
NOTE: Contact ITC if the results are not within range.
Call toll-free in the U.S. (800) 631.5945.
If calling from outside the U.S 001.732.548.5700.
Contact ITC by e-mail: www.techsupport@itcmed.com
C. Optional Temperature Verification (TVT)
1. Select the well to be tested.
2. In the Menu program, first page select “#2- QC Selects“
3. Press “#3 – Temp Check” and insert the Temperature Probe.
4. A prompt is displayed if entry of an OID or PIN is required. Enter your OID or PIN
and press “YES”.
5. When the instrument “Beeps”, record the temperature according to policy.
6. The expected range is 37 °C ±1.0 °C
NOTE: Contact ITC Technical Support if the temperature is not within
specifications:
Call toll-free in the U.S. (800) 631.5945.
If calling from outside the U.S 001.732.548.5700.
Contact ITC by e-mail: www.techsupport@itcmed.com
D. Liquid Quality Control (LQC)
Materials
Each Whole Blood Quality Control consists of:

Whole blood controls: consisting of dried fixed bovine red blood cells, buffered
sheep and horse plasma in individual test vials.

Diluent preparation: consisting of distilled water, sodium chloride, Tween 20,
calcium chloride, anticoagulant and preservatives in individual vials for
reconstitution of the whole blood control.
NOTE: Diluents are lot matched to the whole blood control vials. DO NOT use
diluents from one lot of control with whole blood vials from a different lot.)

Hemochron kaolin and Celite ACT: Level 1 and Level 2 Quality Control, ITC Part
Number QCACT

Hemochron APTT: Level 1 and Level 2 Quality Control,
ITC Part Number QCAPTT

Hemochron PT: Level 1 and Level 2 Quality Control,
ITC Part Number QCPT

Hemochron Citrate PT: Level 1 and Level 2 Quality Control,
ITC Part Number QCPTC

Hemochron TT and HNTT: Level 1 and Level 2 Quality Control,
ITC Part Number QCTT
.
Procedure: Hemochron FTCA510, FTK-ACT, APTT (A103), Citrate APTT (A104),
PT (A201), or Citrate PT (202)
1. Remove the appropriate Whole Blood Quality Control lyophilized vials and
diluents from the refrigerator and allow them to come to room temperature (1530°C, 59-86°F) prior to testing. This may take up to 60 minutes.
2. After the control reagents have reached room temperature, peel back the flap of
the crimp seal on the diluent vial ensuring that the Level on the diluent vial
matches the Level on the Whole Blood QC vial, but do not remove the entire
crimp seal (use this technique when opening each vial).
3. Using a 3cc syringe with needle, withdraw exactly 3cc from the diluent vial.
4. Reconstitute the QC material by transferring the diluent into the Whole Blood
lyophilized vial by using safe technique to directly puncture of stopper.
5. Remove the syringe and needle from the whole blood vial. Do not discard
syringe and needle.
6. Using moderate end-to-end inversion, mix the reconstituted Whole Blood vial for
EXACTLY 15 seconds. Avoid excessive agitation, which will cause foaming of
the reconstituted material.
OPTIONAL: The Response on-board timer may be used for the timing by
pressing the “START” button for the appropriate test well on the Response
instrument to begin the timer. The timer can be the well not undergoing LQC
testing.
7. Visually inspect the vial to ensure that the control plasma is thoroughly mixed
and has no clumps.
8. Using the same syringe, withdraw 2.0 mL of the rehydrated whole blood control.
9. Immediately transfer the 2.0 mL into the appropriate Hemochron tube.
10. As the control material first enters the tube, depress the “START” button on the
appropriate Response test well.
11. Immediately mix the tube vigorously by rapid inversion from end to end 10 times.
12. Insert the tube into the appropriate Response test well.
13. Quickly rotate the tube clockwise until the detector green light is on indicating
magnet detection.
14. Press “MENU” to display the first page of the Main Menu.
15. Press “2” to display the QC Selections menu.
16 Press “1” for Normal Control or “2” for Abnormal Control to tag the LQC being
tested.
17. Upon test completion, record results according to institutional policy.
Procedure for Hemochron TT (A301) or HNTT (A401)
Preparation of the TT or HNTT tubes:
1. Remove the appropriate Whole Blood Quality Control lyophilized vials and
diluents from the refrigerator and allow them to come to room temperature (1530°C, 59-86°F) prior to testing. This may take up to 60 minutes.
2. After reaching room temperature, peel back the flap of the crimp seal on the
distilled water vial found in the TT and HNTT test kits, but do not remove the
entire crimp seal (use this technique when opening each vial).
3. Using a 3 cc syringe with a needle, withdraw exactly 1.0 cc from the distilled
water vial.
4. Transfer the water into the rose-top TT or brown-top HNTT tube by using safe
technique to directly puncture the stopper.
5. Shake the tube gently from end-to-end until the lyophilized activator is thoroughly
dissolved.
NOTE: For optimal performance, TT or HNTT tubes should be incubated within
thirty (30) minutes after rehydration.
6. Insert the test tube into the appropriate Response test well.
7. To begin the timer for the 180 second test incubation period:
a. Depress the START button or
b. Select the PRE-WARM/SELECT button for the appropriate test well.
c. Press the MENU key of the appropriate test well.
d. Press the #3 key to select “Prewarm Well”.
e. Press the #3 key to select “180 – All” to begin pre-warm function.
8. After 180 seconds have elapsed on the Response instrument, remove the tube
from the instrument.
NOTE: It is important to remove the test tube from the Response instrument to
avoid over-incubation.
Preparation of the TT/HNTT Whole Blood Quality Control:
1. Peel back the flap of the crimp seal on the diluent vial ensuring that the Level on
the diluent vial matches the Level on the Whole Blood QC vial, but do not remove
the entire crimp seal.
2. Using a 3 cc syringe with a needle, withdraw exactly 3.0 cc from the diluent vial
(this can be the same syringe used to reconstitute the TT or HNTT tube).
3. Transfer the diluent into the whole blood vial by using safe technique to directly
puncture the stopper.
4. Remove the syringe and needle from the whole blood vial.
5. Do not discard syringe and needle.
6. Using moderate end-to-end inversion, mix the control vial for EXACTLY 15
seconds.
7. Using the same syringe, withdraw 1.5 cc of the rehydrated whole blood control.
8.
Immediately transfer the 1.5 cc into the tube.
9. As the control material first enters the tube, depress the START button on the
appropriate Response test well.
10. Immediately agitate the tube vigorously from end to end 10 times.
11. Insert the tube into the appropriate Response test well.
12. Quickly rotate the tube clockwise until the detector green light is on.
13. See the appropriate Package Insert for additional information.
E. Out-of Range QC Results
1. In cases where liquid quality control results are outside of an acceptable range,
the cause is likely attributable to one of the following categories:
a. Test Technique – check for correct technique
b. Control Material – assure the material has not expired, has been correctly
mixed and has been stored in accordance with requirements prior to use.
c. Test Tubes – check all expiration dates and storage conditions.
d. Instrument – verify the instrument is operating at the correct temperature by
testing with the Temperature Verification Tube (TVT).
2. Repeat the test and if the test does not fall within the expected range, verify the
above (section 1. a-d) parameters again, obtain a tube from a different lot
number and repeat the test using a control with the same lot number.
3. Obtain control material with a different lot number, and repeat the controls again.
4. If the repeated tests still do not fall within the expected range, remove the
instrument from use and notify the person as designated according to policy.
5. Document any “Out-of-Range” results on the Quality Control worksheet.
6. The instrument/test tube combination must not be used for clinical samples until
QC results are within the specified range
PATIENT TESTING
A. Patient Identification
The Response instrument can be programmed to require the Patient ID number
(PID) if the site policy specifies the sample identification is mandatory.
B. Procedure
1. Collect sample as previously described (Section “SPECIMEN”: B. Sample
Collection)
2. Depending on test method: open the plastic flip top cap or safely pierce stoppers.
3. Depending on test method: dispense the required amount of fresh blood from the
collection syringe.
4. At the same time, depress the “Start” button of the Response test well to be used
for testing.
5. With thumb or finger holding the tube top, immediately mix the test tube
vigorously by tilting from end-to-end ten times to disperse the activator.
6. Insert test tube into the Response test well and rotate the tube clockwise until the
green “Detector” light is illuminated.
7. Turn one additional revolution to assure that the green light remains on.
8. If required, enter the PID when prompted.
9. Record the result after testing has reached the end point according to institutional
policy.
RESULTS
A. Expected Results
Normal ranges and therapeutic values are assigned by the institution
B. Reporting Results
Upon test completion, report all test results according to institutional policy.
C. Procedures for Abnormal Results
Test results less than 22 seconds may indicate excessive blood coagulation activation
and should be repeated to confirm the result.
Results greater than 1500 seconds will give an “>1500” error message.
Results that appear to be inconsistent with patient therapy should be viewed as
questionable and the test should be immediately repeated.
D. Calculations
There are no extraneous calculations required for any assay. However, manual plotting
of the heparin dose or the protamine dose can be accomplished by using the materials
enclosed in each package insert for HRT tubes and PRT tubes.
E. Result Review
All Quality Control results (EQC and LQC) and Patient results will be reviewed as
directed by policy at each site.
PROFICIENCY TESTING
Each institution must be enrolled in a Proficiency Testing (PT) program as mandated by
each regulatory agency.
Receiving, distribution, handling and preparing of the PT material, and reporting results
to the issuing agency will be directed by the institutional policy.
Under no circumstances will any PT samples be referred to another facility for testing or
confirmation of the results.
Notify the issuing agency if there is a delay in receipt or damage to the testing material.
PROCEDURAL NOTES

Used Hemochron test tubes should be considered as potentially infectious. They
should be handled according to individual institutional policies concerning the
disposal of potentially infectious materials.

The flip top stoppers (FTK-ACT, FTCA510, and P214/P215 tubes) should never be
pierced by a needle or sharp object, due to the danger of slipping off the flip top and
piercing the finger.

The flip top stoppers (FTK-ACT, FTCA510, and P214/P215 tubes) should be opened
completely to dispense the blood specimen and closed completely before shaking.

Always use a two-hand technique to transfer blood. One hand securely holds the
tube while the second hand dispenses the blood specimen.

The FTK-ACT and FTCA510 are made of glass. They can be broken or cracked if
mishandled or dropped.

The FTK-ACT, FTCA510, and P214/P215 tubes contain a particulate activator
(Celite, Kaolin or glass beads). Do not handle, aerosolize, or ingest.

Use the appropriate technique when piercing stoppers to prevent any accidental
needle injury.

DO NOT remove the plug from the outlet by pulling on the cord.

Do not use tubes past their expiration date or tubes that have been stored
improperly. Test tubes must be properly stored according to the package insert.

Do not force a tube into the instrument. If resistance to insertion is encountered,
gently remove the tube and examine the test well. Remove any obstruction before
attempting further use of the instrument. Refer to the Operators Manual for further
instruction.

Protect the Response instrument from dropping.

DO NOT expose Response instruments to extremes in temperature (above 37°C) as
this type of exposure could affect the performance of any type of electronic
equipment.

Response instruments are designed for use only with Hemochron test tubes.

Response instruments are not rated for use in explosion proof areas.

Automatic Shutdown: When operating from the battery, the system shuts down
automatically after 15 minutes of inactivity. This15 minute interval cannot be
changed. When operating from the AC/DC Power Module, the system automatically
shuts down after an interval of inactivity defined by the supervisor with the factory
default setting is 60 minutes.

All stored data is retained after an automatic shutdown.

A test is automatically terminated if after pressing “START” and a test tube is not
inserted into that well within 60 seconds or if a stable magnet is not detected in that
well within 75 seconds.
LIMITATIONS
Testing may be affected by any of the following conditions:

Hemodilution

Cardioplegic solution composition

Hypothermia

Platelet dysfunction

Hypofibrinogenemia and other coagulopathies

Clotted or partially clotted blood

Unsuspected anticoagulation with either heparin or warfarin
MAINTENANCE
A. Battery
The battery must be charged initially before the system can be operated on battery
power.
CAUTION: Ensure that the input voltage requirements of the AC/DC Power Module
match the voltage used in the laboratory.
1. Connect the AC/DC Power Module cord to the Power connector.
2.
Allow the battery to charge for at least 16 hours.
3. The battery supplies power whenever the system is operated without the AC/DC
Power Module.
4. The system will operate for at least eight hours on a fully charged battery.
B. Battery Charging (As Needed)
1. The amount of charge remaining is displayed, either as a numerical percentage
or as a bar indicator whenever the battery is used to operate the system.
2. “CHARGE BATTERY” is displayed and the battery power display blinks when the
battery power drops to 30 % of the full charge.
3. The system can still be used until the battery power drops to 10 %.
4. “BATTERY TOO WEAK TO RUN TESTS” is displayed when the battery power
drops to 10 % of full charge.
5. “SHUTDOWN IN __ SECONDS” is displayed beginning 30 seconds before the
system is automatically shut down.
6. Plug the AC/DC Power Module into an electrical service outlet.
7
The system can still be used while charging.
NOTE: The AC/DC Power Module can remain connected indefinitely. To unplug
the instrument from the power plug, firmly grasp the plug and pull.
C. Cleaning (As Needed)
1. Inspect and clean the test well.
2. Remove residual dried blood or other foreign matter using a 1:10 dilution of
household bleach (sodium hypochlorite) with moistened cotton swabs.
3. Apply solution to clean and disinfect areas contaminated with residual blood.
4. DO NOT use solvents or strong cleaning solutions. They may deform the
instrument’s plastic components
D. Paper Loading (As Needed)
Printer paper must be loaded if the internal printer is to be used. When red lines on the
sides of the paper appear, replace the roll with a new roll to avoid a paper jam.
1. Open the paper door and remove the spent roll.
2. Unroll the end of the new roll and cut off the corners to form a pointed end.
3. Holding the roll of paper so the pointed end is pointing away from you and up,
thread the pointed end into the paper slot until it appears at the top of the printer.
4. Grasp the pointed end and pull it upwards.
5. Place the new roll into the printer and close the door.
E. Fan Filter Check (Monthly)
To maintain optimum system performance, the underside of the filter housing must be
clear to allow unobstructed air-flow in and out of the instrument. The filter should be
checked for accumulated dust or debris on a monthly basis.
To access the fan filter:
1. Turn the system off.
2. Lay the instrument on its front to expose the filter on the case bottom.
3. Remove the retainer plate by snapping out from the housing.
4. Remove the filter and wash with water and mild detergent. Dry the filter with a
paper towel.
5. Replace the filter and snap the retainer plate into place over the filter.
6. Return the instrument to an upright position for operation.
7. Check that airflow under the instrument is unrestricted.
OPERATOR CERTIFICATION
In the first year, each operator will have initial orientation training and again at six
months. Training will then occur annually.
REFERENCES
Bull BS, Korpman RA, Huse WM, Briggs BD; Heparin Therapy During Extracorporeal
circulation: I. Problems Inherent in Existing Protocols. J Thorac Cardiovasc Surg 1975;
69:674-684.
CLSI Document GP17 - Clinical Laboratory Safety for Information on Laboratory Safety
and Special Requirements.
CLSI Document H21 – Collection, Transport and Processing of Blood Specimens for
Testing Plasma-based Coagulation Assays and Molecular Hemostasis Assays
CLSI Document M29– Protection of Laboratory Workers from Occupationally Acquired
Infections
Doty DB, Knott HW, Hoyt JL, Koepke JA: Heparin dose for accurate anticoagulation in
cardiac surgery. J Cardiovasc Surg 20: 597-604, 1979.
Esposito RA, Culliford AT, Colvin SB, Thomas SJ, Lackner II, Spencer FE: The role of
the Activated Clotting Time in heparin administration and neutralization for
cardiopulmonary bypass. J ThoracCardiovasc Surg 85: 174-185, 1983.
Gambino R: Monitoring heparin therapy. Lab Report for Physicians 4: 17-20, 1982.
Hattersley PG: Activated Coagulation Time of Whole Blood. JAMA 1966:136-436.
Hattersley PG: Heparin anticoagulation. In: Koepke JA (editor): Laboratory Hematology.
Churchill Livingstone, 789-818, 1984.
ITC Package Inserts for the following tests:
Hemochron Activated Clotting Time (ACT) 11/11/2005
Hemochron Heparin Response Test (HRT) 11/03/2011
Hemochron High Dose Thrombin Time Test (HiTT) 12/28/2010
Hemochron OneStep Activated Partial Thromboplastin Time (APTT) 06/2001
Hemochron Protamine Dose Assay (PDAO) 10/14/2005
Hemochron Protamine Response Test (PRT) 07/2005
Hemochron Prothrombin Time Test (PT) 03/2007
Hemochron Thrombin Time (TT)/ Heparin Neutralized Thrombin Time (HNTT)
02/2002
Hemochron Whole Blood Blood Quality Control Package Insert 02/23/2011
Hemochron Response Operator’s Manual 2004
Hemochron Response RxDx Analysis Module 2004
Kerensky R, Azar G, Bertolet B, et al. Venous activated clotting time after intra-arterial
heparin: Effect of site of administration and timing of sampling. Cath and Cardiovasc.
Diag. 1996; 37: 151-153.
Lee RI, White PD: A clinical study of the coagulation time of blood. Am J Med Sci
145:495-503, 1913.
Metz S, Keat AS: Low Activated Coagulation Time during cardiopulmonary bypass does
not increase post-operative bleeding. Ann Thorac Surg 49: 440-444, 1990.
Ogilby JD, Kopelman HA, Klein LW, Agarwal JB: Adequate heparinization during PTCA:
Assessment using Activated Clotting Times. Cath and Cardiovasc Diag. 18:206-209,
1989.
Sanders PW, Curtis JJ: Management of anticoagulation for hemodialysis. In: Nissenson
AR, Fine RN (editors): Dialysis Therapy. The C.V. Mosby Company, St. Louis, MO.
1986; pp. 39-41.
Scott JA, Berenstein A, Blumenthal D: Use of the activate coagulation time as a
measure of anticoagulation during interventional procedures, Radiology 158:849-850,
1986.
Wang J-S, Lin C-Y, Hung W-T, Thisted RA, Karp RB: In vitro effects of aprotinin on
activated clotting time measured with different activators. J. Thorac Cardiovasc Surg
104, 4: 1135-1140, 1992.
Wilson J, Dougherty K, Ellis K, Ferguson J. Activated clotting times in acute coronary
syndromes and percutaneous transluminal coronary angioplasty. Cath and Cardiovasc.
Diag. 1995; 34: 1-5.
Young JA, Kisior T, Doty D: Adequate anticoagulation during cardiopulmonary bypass
determined by Activated Clotting Time and the appearance of fibrin monomer. Ann
Thorac Surg 26: 232-240, 1978.
Zucker ML, Walker C, Jobes D, LaDuca F: Comparison of Celite and kaolin based
heparin and protamine dosing assays during cardiac surgery: The in vitro effect of
aprotinin. J Extra-Corporeal Tech 1995; 27 (4): 201-207.12
ITC, HEMOCHRON, HEMOCHRON SIGNATURE ELITE, and directCHECK® are
registered trademarks of ITC in the United States and other jurisdictions.
Celite® is a registered trademark of Celite Corporation.