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HelpTest Code LAB3784 Direct Oral Anticoagulant (DOAC) Screen
Clinical System Name
Direct Oral Anticoagulant (DOAC) Screen
Synonyms
LAB3784
DOAC
DOAC Screen
Direct Xa Inhibitor Screen
Anti-Xa Inhibitor Screen
EPIC Order Code 1230121854
Sample Requirements
Specimen: Whole Blood
Container(s): Lt. Blue/Citrate
Required Vol: one 1.8 mL tube or one 2.7 mL tube (do NOT over or under fill)
Minimum Vol: N
Note: This is enough for a PT, PTT, DOAC Screen, and Fibrinogen 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.
If a venipuncture is not possible and drawing from a line is necessary:
a. Draw from a heparin-free line.
b. If patient has a line infused or flushed with heparin, such as an arterial line or central venous line, waste the following volume:
A 6-mL waste volume for PIVs, PICCs, temporary venous lines (femoral, jugular) and Baby Broviacs.
A 12-mL waste volume for all other permanent lines (Hickman, Portacath, HD, tunneled lines).
Blood must be transferred to the Lt. Blue/Citrate tube by use of a blood transfer device to ensure proper fill.
Processing Instructions
Reject due to: Clotted, Hemolyzed, Insufficient quantity (under fill) or Overfill, and Improper collection.
Spin: N
Aliquot: N
Storage location: Core 14 Freezer ( -70 C).
Note: Deliver blood to Core Coag bench. Coag Technologist will process. Specimen should be centrifuged within 1 hour of collection. Spin whole blood, remove plasma. Transfer upper 3/4 layer of plasma to plastic tube affixed with large computer label.
Off-site collection: Preferred method of collection is venipuncture with vacuum fill. Test results are affected by incorrect blood volume, note fill line on tube. Use of a Vascular Access Device for the collection of coag testing is not recommended.
If a venipuncture is not possible and drawing from a line is necessary:
a. Draw from a heparin-free line.
b. If patient has a line infused or flushed with heparin, such as an arterial line or central venous line, waste the following volume:
A 6-mL waste volume for PIVs, PICCs, temporary venous lines (femoral, jugular) and Baby Broviacs.
A 12-mL waste volume for all other permanent lines (Hickman, Port-a-cath, HD, tunneled lines).
Blood must be transferred to the Lt. Blue/Citrate tube by use of a blood transfer device to ensure proper fill.
Specimen should be centrifuged within 1 hour of collection. Double spin, transfer upper 3/4 layer of plasma to plastic tube affixed with large computer label. Freeze until solid one aliquot of 1.0 mL plasma in plastic tube at -70C (preferred) or -20C.
Non-Children's Hospital Off-site collection: Ship completely frozen on dry ice.
Children's Regional Clinics: Ship completely frozen in frozen Nalgene Labtop cooler with ice pack inside an insulated soft cooler.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Citrated platelet-poor plasma | Room temp | ≤4 h |
| Refrigerated | N | |
| Frozen -20 C or -70 C | ≤3 m |
Availability
| STAT | Performed | TAT |
|---|---|---|
| Y |
Daily |
1 h |
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Coagulation
Phone Number: 206 987-2617 (Client Services)
CPT Codes
85520
85670
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.
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 (2 separately reported results):
- Direct Xa Inhibitor Screen (units/mL)
- Thrombin Time (TT) (seconds)
| Direct Xa Inhibitor Screen (Anti-Xa units/mL) | Thrombin Time (TT sec) | Interpretation |
|---|---|---|
| elevated | significantly elevated | Heparin in the sample, cannot rule out presence of DOAC, repeat assay |
| elevated | normal | Anti-Xa inhibitor present: (apixaban, rivaroxaban, edoxaban, enoxaparin, and/or fondaparinux) |
| normal | significantly elevated |
Direct Thrombin inhibitor (DTI) present: |
| normal (<0.1 units/mL) | normal | No detectable direct Xa inhibitor or direct thrombin inhibitor present |
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.
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.