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Test Code LAB2934 COAG MIX PANEL

Clinical System Name

Coagulation Panel with Reflex to 1:1 Mix

Description

Panel includes: PT, PTT, FIB, TT, and mixing studies when indicated.

 

Mixing studies may be indicated when a PT or APTT test result is prolonged, whether the prolonged result was due to factor deficiency or the presence of an inhibitor. If the abnormality was the result of factor deficiency, the 1:1 mix with Pooled Normal Plasma will shorten the clotting time of the assay ("correct it") to within the normal reference range for the assay. If the abnormality was due to the presence of an inhibitor, the clotting time obtained on the 1:1 mix may shorten or ‘correct' only partially or not at all. APTT mixes are incubated for 1 hour with Pooled Normal Plasma to help detect factor VIII inhibitors.

Fibrinogen and Thrombin Time are run as part of this panel to rule out other causes for prolonged PT or PTT, such as hypofibrinogenemia, or the presence of heparin.

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, FIB, TT, and mixing studies when indicated.

 

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: Main Campus

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. 

Processing Instructions: Offsite & Regional Clinics

Reject due to: clotted, insufficient quantity (underfill), or improper collection (overfill).

Spin: Y

Aliquot: Y

Storage location:  -70 C (preferred) or -20 C. 

 

Specimen should be centrifuged within one hour of collection. Double spin, transfer upper 3/4 layer of plasma to plastic tube affixed with large sample label. Freeze one aliquot of plasma at -70 C (preferred) or -20 C. Preferred plasma volume: 1.0 mL, minimum plasma volume: 0.6 mL. Do not pool. 

 

Non-Children's Hospital Offsite collection: Ship completely frozen on dry ice.

 

Children's Hospital Regional Clinic collection: 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

 

Performing Laboratory

Seattle Children's Laboratory

Department

Department:  Coagulation

Phone Number: 206 987-2617 (Client Services)

Synonyms

LAB2934

COAG MIX

1:1 Mix
50:50 Mix
Mixing Study

Coag Mix Panel

Availability

STAT Performed TAT
Y

Daily

3 h

 

Reference Range

 

APTT

 

Newborn – 3 months

 

25 – 40 seconds

 

3 months and older

 

25 - 35 seconds

 

PT

 

Newborn – 3 months

 

12.5 – 17.0 seconds

 

3 months and older

 

12.5 – 15.2 seconds

 

Fibrinogen

 

All ages

 

230 – 450 mg/dL

 

Thrombin Time

 

Newborn – 3 months

 

14 – 30 seconds

 

3 months and older

 

14 – 17 seconds

 

 

 

Methodology

Method:  Electromagnetic mechanical clot detection assay by STA-R MAX

Analytical Volume: 600 uL plasma

Limitations: Methods are affected by insufficient quantity (underfill), improper collection (overfill), improper processing, and improper storage. High hematocrit greater than or equal to 56% requires a citrate adjusted tube.

 

Mixing studies will only be run if the PT or APTT results exceed the normal reference range for the assay. The Coag Mix Panel may be added on to a previous coagulation specimen provided there is adequate sample remaining. If there is not enough sample remaining for the entire mix panel, a mixing study alone on the affected analyte will be attempted. Samples that do not contain enough remaining plasma to complete at least a mixing study must be recollected and the Coag Mix Panel performed on the new specimen.

CPT Codes

85610

85611

85730

85732

85670

85384

Critical Values

 

APTT

 

≥ 150 seconds (all ages)

 

PT

 

> 30 seconds (all ages)

 

Fibrinogen

 

< 60 mg/dL

 

Thrombin Time

 

None defined