1:1 Mix _ Prothrombin Time

General Information

Lab Name

Lab Code

PROX1P

Epic Name

1:1 MIX _ PROTHROMBIN TIME

Description

A protime mixing study is ordered to evaluate the prolongation of Prothrombin Time (PT) only. It is used to distinguish the cause of prolonged PT due to factor deficiency or inhibitor. A 1:1 mix of the patient's plasma and normal pooled plasma is performed and the PT is measured again. If the PT corrects, this suggests a factor deficiency. If the PT does not correct, this suggests presence of an inhibitor. A mixing study interpretation may direct further coagulation testing.

Synonyms

Mix-Prothrombin 1:1, Prothrombin -Mix 1:1

Components

Code	Name
PROMX1	1:1 Mix _ Prothrombin Time
PROPT	PT Patient
PRONOR	PT Normal Pool
PROMIX	PT 1:1 Mix
PROCOM	PT 1:1 Mix Comment
XMIX	1:1 Mix, 2nd tube

Interpretation

Method: Clot based
Reference Range: See individual components
Ref. Range Notes: For interpretation contact the Lab Med Resident on-call through the paging operator at 206-598-6190.

Ordering & Collection

Specimen Type: Blood
Collection: Two 3 mL plastic BLUE TOP (Citrate) Tubes
Handling Instructions: The Laboratory MUST process specimen, within 6 hrs of blood collection.
Quantity: Requested: entire sample

Processing

Receiving Instructions: UW-MT/HMC: Take specimen to the Coag bench for processing.

Outside Laboratory: Centrifuge for 10 minutes, remove plasma & re-spin plasma for another 10 minutes. Decant & Freeze plasma (minimum 2.0 mL) @ -20°C to -80°C. Send Frozen on dry ice.

Misc Sendout

Performance

Lab Department

Frequency

Daily

Available STAT?

Yes, Daily 7 am – 10 pm. For other times, contact the Lab Medicine Resident for approval.

Performing Location(s)

HMC	Coagulation 206-520-4600 325 9th Ave, Rm # GWH-47, Seattle, WA 98104-2420
UW-MT	Coagulation 206-520-4600 Clinical Lab, Room NW220, University of Washington Medical Center, 1959 NE Pacific street, Seattle, WA 98195

Billing & Coding

CPT Codes: 85610, 85611
LOINC: 18720-3
Interfaced Order Code: UOW4751