Home
HelpTest Code LAB3784 Direct Oral Anticoagulant (DOAC) Screen
Clinical System Name
Direct Oral Anticoagulant (DOAC) Screen
Description
The Direct Oral Anticoagulants (DOAC) screen is intended to rapidly identify patients who may be taking direct oral anticoagulants. This information may be useful in making decisions about performing surgery or treating with fibrinolytic agents. Direct Xa Inhibitor Screen will detect direct Xa inhibitors, while the thrombin time will detect direct thrombin inhibitors (DTI).
This screen does not indicate amount of specific DOAC present.
Panel Includes (3 separately reported results):
- Direct Xa Inhibitor Screen (units/mL)
- Thrombin Time (TT) (seconds)
- Anticoagulant Screen Interpretation
| Direct Xa Inhibitor Screen (Anti-Xa units/mL) |
Thrombin Time (TT sec) |
Anticoagulant Screen Interpretation | Notes |
|---|---|---|---|
| ≥0.10 | >25 | Heparin presence likely; cannot rule out presence of direct oral anticoagulant. Recommend specimen re-draw and repeat testing. | |
| <0.10 | >25 | Direct Thrombin inhibitor (DTI) (e.g. dabigatran) likely present. Order specific drug level if indicated | |
| <0.10 | ≤25 | No detectable factor Xa inhibitor or direct thrombin inhibitor present | |
| 0.10 - 0.30 | ≤25 | Low level factor Xa inhibitor likely present (e.g apixaban, rivaroxaban, edoxaban, enoxaparin, and/or fondaparinux). Order specific drug level if indicated. | Direct Xa inhibitor screen and direct Xa drug level may not be valid after administration of andexanet alfa. |
| >0.30 | ≤25 | Factor Xa inhibitor likely present (e.g. apixaban, rivaroxaban, edoxaban, enoxaparin, and/or fondaparinux). Order specific drug level if indicated. | Direct Xa inhibitor screen and direct Xa drug level may not be valid after administration of andexanet alfa. |
A significantly elevated Direct Xa result may indicate presence of direct Xa inhibitor (apixaban, rivaroxaban, edoxaban, enoxaparin, and/or fondaparinux), heparin or abnormal fibrin. Order specific drug level if indicated. Presence of direct Xa inhibitor or heparin is excluded with a direct Xa inhibitor level of <0.1 units/mL.
A significantly elevated Thrombin Time (TT) result may indicate presence of direct thrombin inhibitor (Dabigatran, bivalirudin, and/or argatroban), heparin or abnormal fibrin. Order specific drug level if indicated. Presence of direct thrombin inhibitor or heparin unlikely with a normal TT.
Sample Requirements
Specimen: Whole Blood
Container(s): Lt Blue/Citrate
Required Vol: (1) 1.8 mL or (1) 2.7 mL
Minimum Vol: N
Note: This is enough for a PT, PTT, TT, and Fibrinogen to be run on the same sample.
Preferred method of collection is venipuncture with vacuum fill. Test results are affected by incorrect blood volume. Use of a Vascular Access Device for the collection of coag testing is not recommended. Please review the Coagulation Lab Collection Job Aid for detailed instructions.
Processing Instructions
Deliver whole blood to Coag bench. Coag Technologist will process.
Reject due to: clotted, insufficient quantity (underfill), or improper collection (overfill).
Spin: Y
Aliquot: Y
Storage location: Core 14 Freezer ( -70 C).
Specimen should be centrifuged within one hour of collection. Transfer upper 3/4 layer of plasma to plastic tube affixed with large Epic aliquot label. Do not pool. Assay immediately.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Citrated platelet-poor plasma | Room temp | ≤4 h |
| Refrigerated | N | |
| Frozen -20 C or -70 C | ≤3 m |
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Coagulation
Phone Number: 206 987-2617 (Client Services)
Synonyms
LAB3784
DOAC
DOAC Screen
Direct Xa Inhibitor Screen
Anti-Xa Inhibitor Screen
EPIC Order Code 1230121854
Availability
| STAT | Performed | TAT |
|---|---|---|
| Y |
Daily |
1 h |
Methodology
Method: Chromogenic Substrate by STA-R MAX
Analytical Volume: 1 mL plasma
This is enough for a PT, PTT, DOAC Screen, and Fibrinogen on the same sample.
Limitations: This assay requires antithrombin III (ATIII) in patient's plasma. Low level of ATIII may underestimate the heparin level.
Results affected by moderate lipemia, moderate hemolysis, and moderate icterus.
High hematocrit greater than or equal to 56% requires a citrate adjusted tube.
CPT Codes
85520
85670
Therapeutic Range
N/A
Order specific drug level if indicated.
DOAC activity is reported in Anti-Xa IU/mL (Anti-Xa International Units/mL).
Critical Value
N/A
Critical or elevated results do not necessarily correlate with anticoagulant concentration. Order specific drug level if indicated.