Policy/Principle: | Certification: | Testing Prerequisites: | Specimen: | Materials: | Reagents: | Procedure: | Performing a | Editing Test | Entering Cartridge | Entering Control | Limitations: | Results Derivation: | Expected Result(s) | Quality Control: | References: | Perfusionists:
Testing is performed in the Hepcon HMS Plus as a definitive function to monitor patient HDR, HPT, and HR-ACT during cardiac bypass surgery. The Hepcon HMS Plus can also perform the hemoSTATUS Platelet Function test (this test not released yet). Results of these tests trigger therapeutic interaction without reflex laboratory analysis.
The Hepcon HMS Plus is an integrated system consisting of a component for tracking clot detection and computing results, a component for sample delivery, and the single use test cartridges for actual performance of the tests. The cartridge instructs the system, through an optical code, as to the type of test or tests being performed, the calculation and format required for results, and the volume of sample needed for each channel.
The detection process uses the plunger assembly within the cartridge. The assembly is lifted and dropped through the sample/reagent mixture by a lifting mechanism in the HMS Plus actuator. As the sample clots, a fibrin web forms around the daisy, located on the bottom of the plunger assembly, and impedes the assembly rate of descent. A photo optical system, located in the actuator assembly of the instrument, detects this change in fall rate. The end point of the test is the time the clot formation is detected; from these clotting times, derived results are calculated for all tests.
Heparin Dose Response (HDR) is a modified HR-ACT that measures the in vitro anticoagulant response to a known concentration of heparin. The results can be used to screen for patient resistance to heparin, and to estimate a minimum heparin dose required to achieve a desired target clotting time.
The Heparin Assay (HPT) test uses the principle of heparin/protamine titration to quantitatively determine the concentration of heparin in the sample. Each channel of the cartridge contains a different amount of protamine with a constant amount of thromboplastin for activation of the test. The channel that most closely neutralizes the heparin in the sample will be the first to clot.
The Activated Clotting Time (HR-ACT) is a functional evaluation of the intrinsic coagulation system. The test is activated by kaolin suspended in calcium containing HEPES (hydroxyethyl-piperazine-ethanesulfonic acid) buffer. It evaluates heparin anticoagulation as well as numerous factors affecting intrinsic clotting.
HemoSTATUS PAF test is used to access platelet function. This test uses PAF (Platelet Activating Factor) to activate functional platelets. If a platelet is functional, exposure to PAF will cause the platelet membrane to “flip-flop” releasing the membrane constituents and exposing the various receptor sites. If a platelet is not functional or has already been activated, it will not be able to respond to the PAF (Not Yet Released).
1. Orientation, authorization and competency of staff and licensed practitioners performing POCT are provided by the director’s (named on the CLIA certificate) designee as indicated in the “Point of Care (POCT) Program” procedure.
2. Certified operators only will perform testing on the Hepcon HMS Plus.
3. Certification Requirements:
A. An operator must successfully complete the requirements of the Hepcon HMS Plus; Operate: POCT - Operator Certification Record. He/she must read and understand the principles written into the Hepcon HMS Plus; Operate: POCT procedure.
B. Recertification is required annually:
The certified operator will review the current policy/procedure, and complete the Hepcon HMS Plus: Operate: POCT self-instructional/competency documentation packet.C. The certification record of operators and instructors will be maintained in the Mercy Perfusion Office.
1. The only designated analyzer for the Whole Blood HDR/HRACT/HPT/hemoSTATUS PAF test/; POCT Program is the Hepcon HMS Plus.
Fresh whole blood: 3.0ml for HDR, HPT, HR-ACT, and hemoSTATUS PAF. If only an HR-ACT test is to be run 1.5 ml is required.
1. Paired Hepcon HMS Plus instruments
2. 3cc Monoject syringes (syringes accompany cartridges)
3. 19 gauge blunt needles (needles accompany cartridges)
Store stock cartridges from 2 - 8°C for the expiration dating period indicated on the box. Do not use if cartridge appears discolored, cracked or disfigured, or if the reagent appears to have evaporated or become contaminated. Stable until expiration date listed on box. Store HRACT cartridges in use at room temperature.
1. HDR cartridges (#304-20 POR)
2. HPT cartridges (#304-01 POR, #304-03 POR, #304-04 POR, #304-05 POR)
3. HR-ACT cartridges (#304-30)
4. HemoSTATUS PAF cartridges (Not Yet Released)
5. CLOTtrac HR control pak coagulation controls (#550-13)
A. Each box of controls contains 15 vials of lyophilized control and 15 vials of de-ionized water. Two boxes, normal and abnormal levels, come with the pack. Store at 2-8°C until use.
B. The expiration date of the control and de-ionized water is indicated on the vial label and refers to storage at 2 - 8°C.
C. To rehydrate: Using a 3 ml plastic syringe, carefully add 1.8 ml of de-ionized water to each control vial. Allow the vial to set undisturbed for at least 2 minutes. Do not agitate the control until completely rehydrated. Allow at least 2 minutes for adequate rehydration. Once rehydrated, shake the control vigorously until the red blood cells are uniformly dispersed. Once reconstituted, the control is stable for 2 hours at room temperature.
6. Hepcon HMS Controls (Red/Yellow #306-01 POR; Tan/Silver #306-02 POR; Blue/Gold #306-03 POR)
A. Each box of controls contains 10 vials of lyophilized control and 10 vials of de-ionized water.
B. Lyophilized Hepcon HMS controls must be stored refrigerated at 2 - 8°C until use and are stable for the expiration dating on the bottle label. Once reconstituted, controls are stable for 2 hours at room temperature or refrigerated.
C. Bring controls to room temperature. Each vial contains enough sample to run one cartridge.
D. Add 2.5ml of deionized water, packaged with the controls, to each vial. Do NOT Shake.
E. Allow the control to rehydrate for at least 3 minutes.
F. Swirl gently to thoroughly mix the control.
Turn ON the HMS Plus at least 20 minutes prior to use. The instrument may be used when it reaches a temperature of 36.5 - 37.5°C.
1. Set Patient Parameters:
A. From the Main Menu screen, press Patient/Protocol Parameters.
B. Press Set Patient Parameters.
C. Select patient #1.
Note: The default protocol parameters used at MMC-Surgery are programmed for patient #1.D. Press the PID key. Using the numeric keypad, enter the patient ID, and press Enter.
E. Press the Sex key. Enter the Sex key again to toggle to the desired setting, and press Enter.
F. Press the Height key. Press the Height key again to change to the desired units (ft-in or cm).
G. Using the numeric keypad, enter the patient’s height. If the selected units are ft-in, the first value entered is the feet “ft” value and the second and third values entered will be the inches “in” values. Press Enter to accept the value.
H. Press the Weight key. Press the Weight key again to change to the desired units (kg or lbs).
I. Using the numeric keypad enter the patient’s weight. Press Enter to accept the value.
J. Press User ID. Using the numeric keypad, enter the User ID. Press Enter.
K. Press Exit to Patient/Protocol Parameters.
2. Set Protocol Parameters if parameters are to be changed from default:
A. Press Set Protocol Parameters.
B. Press the Protocol Hep Conc key. Enter the appropriate Protocol Hep Conc value, and press Enter.
C. Press the Pump Heparin key. Enter the appropriate Pump Heparin value, and press Enter.
D. Press the Pump Volume key. Enter the appropriate Pump Volume value, and press Enter.
E. Press the ACT Target Time key. Enter the appropriate ACT Target Time value, and press Enter.
F. Press Exit to Patient/Protocol Parameters.
3. Press Print to obtain a printout of Patient/Protocol Parameters.
4. Verify that the HMS Plus temperature is at 37 ± 0.5°C.
5. Run a Heparin Dose Response (HDR) Test to determine patient’s individual response to heparin. The HDR should be performed prior to vein and artery harvesting and before any heparin or aprotinin is administered.
Note: If a patient has been on heparin before surgery, it is necessary to run a HPT cartridge in addition to an HDR cartridge. The heparin concentration as projected by the HDR should be added to the heparin concentration already in the patient to determine the heparin concentration needed for bypass.
A. HDR cartridges should be run on unheparinized samples obtained prior to vein or artery harvesting, or any other invasive procedure.
B. Gently shake or tap the HDR cartridge and then place into the heat block and allow to prewarm for at least 3 minutes prior to drawing the sample.
C. Draw a full 3.0ml of sample into the syringe and attach the blunt end needle. Fill (prime) the needle with sample.
D. Insert the syringe and needle into the dispenser of the HMS Plus and press the Start/Stop key to initiate the test.
E. The HDR in Progress screen will be displayed.
F. At test completion, the HDR Results screen will be displayed. The Projected Heparin Concentration, the Heparin Bolus values, and the Baseline ACT will be displayed.
G. Additional test information can be accessed from this screen by pressing the More Test Information key. Channel clotting time, the HDR Slope and the screen for editing channel clotting times will be available. The individual channel clotting times and the paired channel clotting time averages are presented. Channels are paired based on the heparin reagent concentration in the cartridge.
H. Check the slope result. If the slope is less than 65, this indicates that the patient is quite resistant to heparin. This is an unlikely result and the patient sample should be redrawn and rerun. If the slope is again low, and if the specimen was collected and handled correctly, the patient may be resistant to heparin and an increased dose of heparin will be required. Check the patient history if the slope is greater than 150. The patient, most likely, has a condition indicating possible sensitivity to heparin.
I. HDR data calculations can be affected by incorrect sample volume or inappropriate detections. Channel clotting times can be edited and the results recalculated following removal of the edited channel’s clotting time from the calculation. Press the Edit HDR Channel key to access the Edit HDR Channel screen.
a. Select the channel to be edited by pressing the Go to Next Channel key until the desired channel is selected.
b. Press the Edit Channel key. An “X” appears to replace the channel’s clotting time; the average for the channel pair is now the remaining clotting time.
c. To restore to edited channel, simply select the edited channel and press the Undo Edit key.
6. Run an HPT and HR-ACT test. A two channel HR-ACT test can be run with a HPT assay or it can be run by itself. The HR-ACT must be run in channels 5 and 6
*The initial HPT and HR-ACT tests are run after the heparin has circulated for 3 to 5 minutes, and every 20 to 30 minutes while on bypass.
*Just prior to coming off bypass, a HPT and HR-ACT test is performed to determine the required protamine dose.
*After protamine has been slowly administered and allowed to circulate for 10 minutes, verify neutralization by running a red HPT cartridge and HR-ACT.
A. Select the appropriate HPT cartridge (by color) indicated by the HDR. The desired heparin concentration to maintain the patient HepConc should correspond to the 3rd or 4th channel of the HPT cartridge.
B. Gently shake or tap the cartridge and then place into the heat block. Allow the cartridge to prewarm for at least 3 minutes prior to drawing the sample. To ensure that a cartridge is always ready, the next cartridge to be run can be placed into the heat block upon completion of the current test. The two-channel HR-ACT cartridge is placed in the right side of the heat block (channels 5 and 6).
C. Draw approximately 3.0ml of sample into the syringe and attach the needle. Fill (prime) the needle with sample.
D. Insert the syringe and needle into the dispenser of the HMS Plus and press the Start/Stop key to initiate the test.
E. Once dispensing is complete, the HPT In Progress Screen will appear. As the HPT test proceeds, the “Elapsed Time” is displayed to indicate the test’s run time. If an HR-ACT is being run, the test continues until clot detects occur for this cartridge, or the ACT elapsed time has exceeded the limit allowed by the instrument. The ACT test typically has a longer test time than the HPT test.
F. When the HPT test is complete the HPT Results screen will be displayed. The Heparin Conc. result is the measured heparin concentration (quantity of heparin titrated). The Heparin Required result shows the additional heparin required for the patient, pump or total volume to achieve (or maintain) the desired heparin level [Protocol Hep Conc.] for the patient. HPT and HR-ACT results should be interpreted based on the current stage of the procedure.
G. If an HR-ACT is also run, the average clotting time “Average ACT” results will also be displayed. If the HR-ACT run time exceeds 999 seconds before both channels detect, the test will be stopped and the screen’s Status Message area will indicate “ACT Test Time greater than 999 seconds”. The printout will indicate the channel(s) exceeding the allowed test time. If the difference in clotting times between the channel pair is greater that ±12%, an audible alert sounds and the screen’s Status Message area will indicate this condition. Additional heparin should be administered, if the HR-ACT result is not extended beyond the [ACT Target Time], and the HPT and HR-ACT repeated.
H. When a clot is detected in channel 1 of an HPT cartridge, which does not have a zero value in channel 1, the alert message “Hep Conc. may be less than indicated value” appears to indicate that the heparin concentration may be less than the channel 1 cartridge value. When a clot is detected in the last channel of the HPT cartridge (channel 4), the alert message “Hep Conc may be greater than indicated value” appears to indicate that the heparin concentration may be higher than the measured value. In these cases, run another test with a different cartridge, higher or lower as needed, to confirm the test result.
I. Additional test information is available by pressing the More Test Information key.
J. To view the Protamine Dose calculations for neutralizing the heparin concentration, press the Protamine Dose key to access the Protamine Dose screen. The pump volume protamine represents additional protamine required if the pump volume is to be given to the patient. It is not intended to indicate that protamine should be added to the pump, since this would result in clotting.
K. If desired, the protamine dose results can be recalculated with a different pump volume. To change the pump volume, press Change Pump Volume key to access the Change Pump Volume screen. The pump volume value will be flashing to indicate it is active and can be changed. A new pump volume value can be entered using the numeric keys and press Enter. If the pump volume is changed, the pump volume parameter entered during protocol parameter entry will also be changed for the current patient.
VIII. Performing a hemoSTATUS PAF Test (Not Yet Released):
1. Gently shake or tap the cartridge and then place into the heat block and allow to prewarm for at least 3 minutes prior to drawing the sample.
2. Draw 3.0ml of sample into the syringe and attach the needle. Fill (Prime) the needle with sample.
3. Insert the syringe and needle into the dispenser of the HMS Plus and press the Start/Stop key to initiate the test.
4. Once dispensing is complete, the Platelet Function Test in Progress screen will appear. This screen shows the concentration of Platelet Activating Factor for each of the six channels.
5. As the test proceeds, the “Elapsed Time” is displayed to indicate the test run time. When a clot occurs the channel will be highlighted and the channel’s clotting time appears (in seconds). The endpoint of the test is detection of clot formation in each cartridge channel or greater than 1500 seconds of elapsed test time. At test completion the Platelet Function Test Results screen is displayed.
6. The “Base” channel clotting times can be edited and the results recalculated based on the removal of the edited channel’s clotting time from the calculation. Press the Edit Channel key to display the Edit Platelet Function Channel. Only one clotting time from the “Base” channel pair can be edited. If only one channel in the “Base” channel pair detects, it cannot be edited.
In some tests, an average of paired channel clot times is used to calculate the test results. If there is a valid reason for excluding one of the paired values from the calculation, the Edit function may be used to remove the invalid value. The remaining value is then used in the calculation instead of the pair average. Paired data, which can be edited, are found in the HDR, HR-ACT, and platelet function (hemoSTATUS) tests. Heparin Assay test results cannot be edited. If there is no reason identified for inappropriate clot detection in a cartridge channel, the test should be repeated instead of editing a channel.
1. An invalid clotting time can be deleted from the calculations by using the Edit Channel key on the applicable test’s Results or Test Information screen.
2. For edited channels, the edit symbol (X) will appear in place of the channel’s clotting time and the results will be recalculated.
3. To recover edited values, press Undo Edit. The symbol (X) will disappear and the data will be recalculated again to include the edited value.
4. Only one clot detection in each pair of HDR and HR-ACT clotting times can be edited. Only channels one and two can be edited in the platelet function (hemoSTATUS PAF) test.
X. Entering Cartridge Lot Numbers and Expiration Dates:
1. From the Main Menu, press Cartridge Lot/Exp Date Key.
2. Use the Up/Down keys to highlight the desired cartridge.
3. Press the Edit key.
4. To add a new lot number, press Add Cartridge lot.
Press Add lot. Type in the lot number of the new cartridge and press Enter.
Press Add Exp Date. Type in the expiration date and press Enter.
5. To remove a lot number, press the Remove key.
Use the up and down key to select the lot to remove.
Press Remove Selected Lot key.
6. Two lot numbers can be in the cartridge lot list. “*” indicates the active lot number. Press Toggle Active key to select active lot number.
7. Press Exit to Cart Selection key to return to the Cart Selection screen.
8. Press Exit to Main Menu key to return to the Main Menu.
XI. Entering Control Lot Numbers and Expiration Dates:
1. Select Quality Control from the Main Menu.
2. Press QC Setup key.
3. Press Control Lot/Exp. key
4. Use the Up/Down keys to highlight the desired control.
5. Press Edit Control key.
6. To add a new lot number Press Add Lot/Exp Date key.
A. Press Add lot. Type in the lot number of the new cartridge and press Enter.
B. Press Add Exp Date. Type in the expiration date and press Enter.
7. Press Exit to Control Selection.
8. Press Set Range
A. Press Low Range. Type in the low range and press Enter.
B. Press High Range. Type in the high range and press Enter.
9. Two lot numbers of each can be in the control lot list. “*” indicates the active lot number. Press Toggle Active key to select active lot number.
10. To Remove a lot number, press Remove key.
A. Use the up and down key to select the lot to remove.
B. Press Remove Selected Lot key.
The blood volume calculation is an approximation based on general (normal) patient populations. Computed blood volume may differ from actual blood volume in several disease states including, but not limited to, patients with poor mitral valves, heart transplant patients, patients with kidney disease, and patients with amputated limbs.
1. Test results, in their appropriate units, are displayed and printed directly on the Hepcon HMS Plus immediately following analysis. The tape must remain contiguous per case. The perfusionist will transcribe the patient’s name and case number to the printout and then sign it. Tapes must be stored present to past and must be readily accessible to the UCL Office of the technical Director.
2. These results are transcribed by the operator into the perfusionist’s case flow sheet. A copy of the flow sheet is inserted into the patient’s chart.
3. If any test results cannot be calculated because of insufficient patient data, dashes are displayed on the results screen.
XIV. Expected Result(s) and/or Critical Values:
The Perfusionist Team, Cardiothoracic Surgeon and/or Cardiologist establish the expected results pertinent to the clinical situation.
1. Routine Controls:
A. Heptrac Electronic Quality Control must be run once every 8 hours in which the system is used. The Heptrac Electronic Control is an interactive, mechanical, software controlled verification cartridge that includes both quantitative and qualitative results. It interacts with the HMS Plus by mechanically emulating a test cartridge. The Heptrac checks the following aspects of the HMS Plus that relate to proper test cartridge functioning; flag sensor function, reagent delivery, flag release force, flag height, and four-level tests (emulated clotting time ranges).
a. Place the Heptrac in the Hepcon HMS Plus instrument’s heat block.
b. Press the Start/Stop key to initiate the test. Heptrac Electronic QC will be displayed.
c. After completing the test (approximately 10 minutes), the HMS Plus sounds an audible tone and the results will be printed.
d. If any failures occur, the HMS Plus printout will print the failure(s) and the statement “QC Test Aborted”. If failures occur, repeat the test. If the repeat test still fails, contact the UCL Instrument Specialist Office (556-6823).
B. The HPT liquid controls must be run with each new lot number.
Note: To run a Quality Control test, both a valid cartridge lot and a valid control lot must be active. HPT and HR-ACT quality control tests must be run separately.a. From the Main Screen select the Quality Control Menu.
b. Enter the User ID.
c. Insert the appropriate HPT cartridge into the Hepcon HMS Plus instrument’s heat block.
d. Press the Start/Stop key to initiate the test.
e. The HMS Plus reads the cartridge code, identifies the appropriate control to use, and displays this information on the Quality Control Test screen.
f. Prepare the appropriate control for the cartridge type being used. Fill the syringe and prime the needle.
g. Insert the syringe and needle into the dispenser of the HMS Plus and press the Start/Stop key to initiate the test.
h. Once dispensing is complete, the Quality Control HPT in Progress screen will appear. At test completion, the Quality Control HPT Results screen appears. The screen will display if the control “Passed” or “Failed”.
i. If the control “Failed”, repeat using a new control vial and new cartridge. If control fails again, notify the UCL office of the Technical Director (556-2010 ext 124 or 156).
j. Record the control results on the Hepcon HPT Control Log.
C. The HR-ACT liquid controls must be run with each new lot number.
Note: For HR-ACT quality control tests, the instrument will only perform the necessary 300 second incubation when the test is started from the Quality Control Menu screen.a. From the Main Screen select the Quality Control Menu.
b. Enter the User ID.
c. Insert the HR-ACT cartridge into the Hepcon HMS Plus instrument’s heat block.
d. Press the Start/Stop key to initiate the test.
e. For an HR-ACT cartridge, a normal/abnormal selection screen will appear. Press either the ACT Normal or the ACT abnormal key to select the control being run.
f. Prepare the appropriate control for the cartridge type being used. Fill the syringe and prime the needle.
g. Insert the syringe and needle into the dispenser of the HMS Plus and press the Start/Stop key to initiate the test.
h. Once dispensing is complete, the Quality Control HR-ACT Incubation screen will appear. An incubation time of 300 seconds is required when running an HR-ACT quality control test; this is automatically performed by the instrument when an HR-ACT test is run in the quality control mode.
i. When the incubation is complete, the Quality Control HR-ACT in Progress screen appears.
j. At test completion, the Quality Control HR-ACT Results screen appears. The screen will display if the control “Passed” or “Failed”.
k. If the control “Failed”, repeat using a new control vial and new cartridge. If control fails again, notify the UCL office of the Technical Director (556-2010 ext 124 or 156).
l. Record control results on the Hepcon HR-ACT Control Log.
2. Equivalent QC: The internal QC for this test monitors part of the analytic process; it is second level EQC. Therefore the HR-ACT Controls and the HPT Controls are routinely run once per week.
3. Criteria for accepting or rejecting a run is stated in the “General Quality Control” protocol in the Quality Assurance manual.
4. Analytical Range:
A. HDR: 15 - 999 seconds
B. HR-ACT: 0 - 600 seconds
C. HPT:
a. Red: 0.0 - 0.9 mg/kg heparin
b. Tan: 1.5 - 3.0 mg/kg heparin
c. Silver: 2.0 - 3.5 mg/kg heparin
d. Blue: 2.5 - 4.0 mg/kg heparin
5. Calibration: N.A.
6. Calibration Frequency: N.A.
7. Calibration Verification: The ACT is a test involving an instrument in which calibration is not practical. Therefore the calibration verification requirement does not apply to this test.
8. Control Ranges: Acceptable control ranges are obtained from the manufacturer’s package insert.
1. Medtronic Hepcon HMS Plus Operating Manual. Medtronic, Inc. Minneapolis, MN. 2002.
2. Medtronic “Important Product Notification” regarding change from bovine to porcine heparin for Heparin assay cartridges and controls, and for HDR cartridges. 8-26-04
3. Urgent Medical Device Notification. Medtronic Hemostasis Management System (HMS Plus) with Medtronic Heparin Assay Controls. Medtronic. Mounds View. MN. 3-8-2010
4. Product Notice: HMS Plus Version 4.0.15. Software Upgrade. Medtronic. Minneapolis, MN. 9-19-11.
i. February 2003 L. McGovern
ii. September 2004 S. Raymond/L. McGovern (Revised: XV., language/protocol updated for CMS status)
iii. December 2004 L. McGovern (Revised VI. product numbers for HDR & Heparin cartridges & controls due to change from bovine to porcine heparin)
iv. August 2008 L. McGovern (Revised: XV.1.A.)
v. October 2009 L. McGovern, S. Raymond (Revised: II.1. added)
vi. March 2010 L. McGovern (Revised: XV.1.B.a.,k.; XVI.3.added)
vii. October 2011 L. McGovern (Revised: XV.1.B.no need to chg heparin type for ctrls; XVI.4.added)
Pathologist:
Technical Director:
Perfusionist:
Perfusionist:
1. Rick Beecher #5
2. Brian McNeer #2
Interim Review: September 2011 R. Beecher, B. McNeer (no changes)
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