This test is intended only for patients receiving low molecular weight heparin (e.g., enoxaparin, dalteparin, tinzaparin). Other anti-Xa medications, such as unfractionated heparin and direct anti-Xa inhibitors (e.g., apixaban, rivaroxaban, edoxaban) may interfere with this test. Please check lab manual for appropriate tests specific to the anticoagulant the patient is receiving.
Available Stat
Yes
Performing Lab
Parnassus Hematology
Mission Bay Hematology
Performed
Daily
Methodology
Chromogenic
Reported
STAT: 1 hour
Routine: 24 hours
Additional Information
The utility of measuring LMW heparin levels is limited to a few clinical settings. Common indications for monitoring patients receiving LMW heparin include renal insufficiency, clinical obesity, weight < 50 kg or pregnancy.
The STA- Liquid anti-Xa method is aone-step reaction where factor Xa is added to the plasma-subsrate mixture. Two reactions take place simultaneously,
-Hydrolysis of the substrate by factor Xa
-Inhibition of factor Xa by the heparin-antithrombin complex*.
After the necessary period of time for the competitive reaction to reach equilibrium, the quantity of pNA that is released is inversely proportional to the concentration of heparin present in the test medium.
*The heparin-antithrombin complex is made up from the heparin medication and the patient’s endogenous antithrombin.
Note that a similar methodology used for detecting other anti-Xa medications; however, the calibration curve is distinct for each drug. Therefore, while a positive result from this test (anti-Xa Low Molecular Weight Heparin level) indicates the presence of anti-Xa activity, the exact level of any drug other than low molecular weight heparin cannot be assessed.
The appropriate therapeutic range will vary with the specific medication, the disease, and the treatment intensity desired. An overview of recommendations is available on the UCSF Carelinks webpage for reference purposes only. Recommendations for therapy and monitoring are also available through the Hematology consultation services: for adults, pager 443-4276, for pediatrics pager 443-6966.
Synonyms
LMW
LMWH
Sample Type
Plasma
Collect
Blue top filled to full extent of vacuum (3.2% sodium citrate)
Amount to Collect
See Preferred Volume
Preferred Volume
1.0 mL plasma
Minimum Volume
0.5 mL plasma
Remarks
Deliver specimen to lab immediately for processing
Stability (from collection to initiation)
2 hours
Storage/Transport Temperature
Deliver whole blood at room temperature
Plasma acceptable on dry ice and stored -20 to -80C
Unacceptable Conditions
Hemolysis, Icterus, Lipemia
Under-filled or Over-filled tubes
Clotted
Test Code
LMHEP
Performing Lab
Parnassus Hematology
Mission Bay Hematology
Specimen Preparation
Deliver sample immediately to Hematology Lab
Preferred Volume
1.0 mL plasma
Minimum Volume
0.5 mL plasma
Unacceptable Conditions
Hemolysis, Icterus, Lipemia
Under-filled or Over-filled tubes
Clotted
Stability (from collection to initiation)
2 hours
Storage/Transport Temperature
Deliver whole blood at room temperature
Plasma acceptable on dry ice and stored -20 to -80C
These are general guidelines only. Detailed recommendations for heparin therapy and monitoring are available through the the Hematology consultation services: for adults, pager 443-4276, for pediatrics, pager 443-6966.
Critical Values
> 2.0 U/mL
Additional Information
The utility of measuring LMW heparin levels is limited to a few clinical settings. Common indications for monitoring patients receiving LMW heparin include renal insufficiency, clinical obesity, weight < 50 kg or pregnancy.
The STA- Liquid anti-Xa method is aone-step reaction where factor Xa is added to the plasma-subsrate mixture. Two reactions take place simultaneously,
-Hydrolysis of the substrate by factor Xa
-Inhibition of factor Xa by the heparin-antithrombin complex*.
After the necessary period of time for the competitive reaction to reach equilibrium, the quantity of pNA that is released is inversely proportional to the concentration of heparin present in the test medium.
*The heparin-antithrombin complex is made up from the heparin medication and the patient’s endogenous antithrombin.
Note that a similar methodology used for detecting other anti-Xa medications; however, the calibration curve is distinct for each drug. Therefore, while a positive result from this test (anti-Xa Low Molecular Weight Heparin level) indicates the presence of anti-Xa activity, the exact level of any drug other than low molecular weight heparin cannot be assessed.
The appropriate therapeutic range will vary with the specific medication, the disease, and the treatment intensity desired. An overview of recommendations is available on the UCSF Carelinks webpage for reference purposes only. Recommendations for therapy and monitoring are also available through the Hematology consultation services: for adults, pager 443-4276, for pediatrics pager 443-6966.
CPT Codes
85520
LOINC Codes
3271-4
Available Stat
Yes
Ordering Recommendations
This test is intended only for patients receiving low molecular weight heparin (e.g., enoxaparin, dalteparin, tinzaparin). Other anti-Xa medications, such as unfractionated heparin and direct anti-Xa inhibitors (e.g., apixaban, rivaroxaban, edoxaban) may interfere with this test. Please check lab manual for appropriate tests specific to the anticoagulant the patient is receiving.
Test Code
LMHEP
Performing Lab
Parnassus Hematology
Mission Bay Hematology
Performed
Daily
Methodology
Chromogenic
Remarks
Deliver specimen to lab immediately for processing
Collect
Blue top filled to full extent of vacuum (3.2% sodium citrate)
Amount to Collect
See Preferred Volume
Sample Type
Plasma
Preferred Volume
1.0 mL plasma
Minimum Volume
0.5 mL plasma
Unacceptable Conditions
Hemolysis, Icterus, Lipemia
Under-filled or Over-filled tubes
Clotted
These are general guidelines only. Detailed recommendations for heparin therapy and monitoring are available through the the Hematology consultation services: for adults, pager 443-4276, for pediatrics, pager 443-6966.
Critical Values
> 2.0 U/mL
Synonyms
LMW
LMWH
Storage/Transport Temperature
Deliver whole blood at room temperature
Plasma acceptable on dry ice and stored -20 to -80C
Stability (from collection to initiation)
2 hours
Reported
STAT: 1 hour
Routine: 24 hours
Additional Information
The utility of measuring LMW heparin levels is limited to a few clinical settings. Common indications for monitoring patients receiving LMW heparin include renal insufficiency, clinical obesity, weight < 50 kg or pregnancy.
The STA- Liquid anti-Xa method is aone-step reaction where factor Xa is added to the plasma-subsrate mixture. Two reactions take place simultaneously,
-Hydrolysis of the substrate by factor Xa
-Inhibition of factor Xa by the heparin-antithrombin complex*.
After the necessary period of time for the competitive reaction to reach equilibrium, the quantity of pNA that is released is inversely proportional to the concentration of heparin present in the test medium.
*The heparin-antithrombin complex is made up from the heparin medication and the patient’s endogenous antithrombin.
Note that a similar methodology used for detecting other anti-Xa medications; however, the calibration curve is distinct for each drug. Therefore, while a positive result from this test (anti-Xa Low Molecular Weight Heparin level) indicates the presence of anti-Xa activity, the exact level of any drug other than low molecular weight heparin cannot be assessed.
The appropriate therapeutic range will vary with the specific medication, the disease, and the treatment intensity desired. An overview of recommendations is available on the UCSF Carelinks webpage for reference purposes only. Recommendations for therapy and monitoring are also available through the Hematology consultation services: for adults, pager 443-4276, for pediatrics pager 443-6966.
CPT Codes
85520
LOINC Codes
3271-4
Ordering
Ordering Recommendations
This test is intended only for patients receiving low molecular weight heparin (e.g., enoxaparin, dalteparin, tinzaparin). Other anti-Xa medications, such as unfractionated heparin and direct anti-Xa inhibitors (e.g., apixaban, rivaroxaban, edoxaban) may interfere with this test. Please check lab manual for appropriate tests specific to the anticoagulant the patient is receiving.
Available Stat
Yes
Performing Lab
Parnassus Hematology
Mission Bay Hematology
Performed
Daily
Methodology
Chromogenic
Reported
STAT: 1 hour
Routine: 24 hours
Additional Information
The utility of measuring LMW heparin levels is limited to a few clinical settings. Common indications for monitoring patients receiving LMW heparin include renal insufficiency, clinical obesity, weight < 50 kg or pregnancy.
The STA- Liquid anti-Xa method is aone-step reaction where factor Xa is added to the plasma-subsrate mixture. Two reactions take place simultaneously,
-Hydrolysis of the substrate by factor Xa
-Inhibition of factor Xa by the heparin-antithrombin complex*.
After the necessary period of time for the competitive reaction to reach equilibrium, the quantity of pNA that is released is inversely proportional to the concentration of heparin present in the test medium.
*The heparin-antithrombin complex is made up from the heparin medication and the patient’s endogenous antithrombin.
Note that a similar methodology used for detecting other anti-Xa medications; however, the calibration curve is distinct for each drug. Therefore, while a positive result from this test (anti-Xa Low Molecular Weight Heparin level) indicates the presence of anti-Xa activity, the exact level of any drug other than low molecular weight heparin cannot be assessed.
The appropriate therapeutic range will vary with the specific medication, the disease, and the treatment intensity desired. An overview of recommendations is available on the UCSF Carelinks webpage for reference purposes only. Recommendations for therapy and monitoring are also available through the Hematology consultation services: for adults, pager 443-4276, for pediatrics pager 443-6966.
Synonyms
LMW
LMWH
Collection
Sample Type
Plasma
Collect
Blue top filled to full extent of vacuum (3.2% sodium citrate)
Amount to Collect
See Preferred Volume
Preferred Volume
1.0 mL plasma
Minimum Volume
0.5 mL plasma
Remarks
Deliver specimen to lab immediately for processing
Stability (from collection to initiation)
2 hours
Storage/Transport Temperature
Deliver whole blood at room temperature
Plasma acceptable on dry ice and stored -20 to -80C
Unacceptable Conditions
Hemolysis, Icterus, Lipemia
Under-filled or Over-filled tubes
Clotted
Processing
Test Code
LMHEP
Performing Lab
Parnassus Hematology
Mission Bay Hematology
Specimen Preparation
Deliver sample immediately to Hematology Lab
Preferred Volume
1.0 mL plasma
Minimum Volume
0.5 mL plasma
Unacceptable Conditions
Hemolysis, Icterus, Lipemia
Under-filled or Over-filled tubes
Clotted
Stability (from collection to initiation)
2 hours
Storage/Transport Temperature
Deliver whole blood at room temperature
Plasma acceptable on dry ice and stored -20 to -80C
These are general guidelines only. Detailed recommendations for heparin therapy and monitoring are available through the the Hematology consultation services: for adults, pager 443-4276, for pediatrics, pager 443-6966.
Critical Values
> 2.0 U/mL
Additional Information
The utility of measuring LMW heparin levels is limited to a few clinical settings. Common indications for monitoring patients receiving LMW heparin include renal insufficiency, clinical obesity, weight < 50 kg or pregnancy.
The STA- Liquid anti-Xa method is aone-step reaction where factor Xa is added to the plasma-subsrate mixture. Two reactions take place simultaneously,
-Hydrolysis of the substrate by factor Xa
-Inhibition of factor Xa by the heparin-antithrombin complex*.
After the necessary period of time for the competitive reaction to reach equilibrium, the quantity of pNA that is released is inversely proportional to the concentration of heparin present in the test medium.
*The heparin-antithrombin complex is made up from the heparin medication and the patient’s endogenous antithrombin.
Note that a similar methodology used for detecting other anti-Xa medications; however, the calibration curve is distinct for each drug. Therefore, while a positive result from this test (anti-Xa Low Molecular Weight Heparin level) indicates the presence of anti-Xa activity, the exact level of any drug other than low molecular weight heparin cannot be assessed.
The appropriate therapeutic range will vary with the specific medication, the disease, and the treatment intensity desired. An overview of recommendations is available on the UCSF Carelinks webpage for reference purposes only. Recommendations for therapy and monitoring are also available through the Hematology consultation services: for adults, pager 443-4276, for pediatrics pager 443-6966.
Administrative
CPT Codes
85520
LOINC Codes
3271-4
Complete View
Available Stat
Yes
Ordering Recommendations
This test is intended only for patients receiving low molecular weight heparin (e.g., enoxaparin, dalteparin, tinzaparin). Other anti-Xa medications, such as unfractionated heparin and direct anti-Xa inhibitors (e.g., apixaban, rivaroxaban, edoxaban) may interfere with this test. Please check lab manual for appropriate tests specific to the anticoagulant the patient is receiving.
Test Code
LMHEP
Performing Lab
Parnassus Hematology
Mission Bay Hematology
Performed
Daily
Methodology
Chromogenic
Remarks
Deliver specimen to lab immediately for processing
Collect
Blue top filled to full extent of vacuum (3.2% sodium citrate)
Amount to Collect
See Preferred Volume
Sample Type
Plasma
Preferred Volume
1.0 mL plasma
Minimum Volume
0.5 mL plasma
Unacceptable Conditions
Hemolysis, Icterus, Lipemia
Under-filled or Over-filled tubes
Clotted
These are general guidelines only. Detailed recommendations for heparin therapy and monitoring are available through the the Hematology consultation services: for adults, pager 443-4276, for pediatrics, pager 443-6966.
Critical Values
> 2.0 U/mL
Synonyms
LMW
LMWH
Storage/Transport Temperature
Deliver whole blood at room temperature
Plasma acceptable on dry ice and stored -20 to -80C
Stability (from collection to initiation)
2 hours
Reported
STAT: 1 hour
Routine: 24 hours
Additional Information
The utility of measuring LMW heparin levels is limited to a few clinical settings. Common indications for monitoring patients receiving LMW heparin include renal insufficiency, clinical obesity, weight < 50 kg or pregnancy.
The STA- Liquid anti-Xa method is aone-step reaction where factor Xa is added to the plasma-subsrate mixture. Two reactions take place simultaneously,
-Hydrolysis of the substrate by factor Xa
-Inhibition of factor Xa by the heparin-antithrombin complex*.
After the necessary period of time for the competitive reaction to reach equilibrium, the quantity of pNA that is released is inversely proportional to the concentration of heparin present in the test medium.
*The heparin-antithrombin complex is made up from the heparin medication and the patient’s endogenous antithrombin.
Note that a similar methodology used for detecting other anti-Xa medications; however, the calibration curve is distinct for each drug. Therefore, while a positive result from this test (anti-Xa Low Molecular Weight Heparin level) indicates the presence of anti-Xa activity, the exact level of any drug other than low molecular weight heparin cannot be assessed.
The appropriate therapeutic range will vary with the specific medication, the disease, and the treatment intensity desired. An overview of recommendations is available on the UCSF Carelinks webpage for reference purposes only. Recommendations for therapy and monitoring are also available through the Hematology consultation services: for adults, pager 443-4276, for pediatrics pager 443-6966.
