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Epic Code LAB325 APTT

Important Note

Specimens collected from patients receiving heparin therapy must be centrifuged within 1 hour and the plasma removed and frozen, if not test should be run immediately.

Specimen tube must be full.

There is currently a nationwide shortage of this tube. Please take steps to ensure specimen integrity to reduce recollection. Specimen Tube Shortage (link)

Test Name Alias

Activated Partial Thromboplastin Time | PTT | 8450

Interface Order Alias

10055

Clinical Information

The activated partial thromboplastin time is a measurement of the activity of the factors involved in the intrinsic and common pathways of coagulation. The APTT is also used to monitor unfractionated heparin therapy.  Prolonged APTT may occur in the following:  Inherited factor deficiencies, anticoagulant therapy, vitamin K deficiency, liver disease, circulating anticoagulants, lupus inhibitors, factor inhibitors, or consumption of fibrinogen or other coagulation factors in DIC.

Icons & Photos

Collection Instructions

Specimen Collection: Blood

 

Container(s): 3.2% Na Citrate Tube (blue top)

Preferred Volume to Collect: 2.7 mL (full tube)

Minimum Volume to Collect: 1.8 mL (full tube)

Capillary collect ok: No

Microtainer acceptable: No

 

Collection Instructions:

  • Detailed instructions (link): Anticoagulant Correction for High Hematocrit

  • Detailed instructions (link): Blue Citrate Tube

  • Specimen should be processed within 4 hours – See Processing Instructions below.
    • Specimens collected from patients receiving heparin therapy must be processed within 1 hour – See Processing Instructions below.

Processing Instructions (Laboratory, Outpatient or Off-site collection)

Processed Specimen: Platelet Poor Plasma

 

Centrifuge/Spin: Yes

Aliquot: Yes

 

Processing Instructions:

  • Detailed instructions (link): Preparing Platelet Poor Plasma
  • Separate plasma into 1 – 2 aliquots, minimum of 0.5 mL each.
  • Freeze aliquots in plastic transport tubes immediately.

Transport Temperature:

  • Ambient (up to 4 hours in whole blood state, 1 hour for patients on heparin therapy)
  • Frozen (plasma only >4 hours)

Rejection Criteria

  • Hemolysis
  • Specimen has been thawed

Specimen Stability

Ambient: up to 4 hours in whole blood state if the patient is not on heparin

Refrigerate: Not Acceptable

Frozen: Aliquot and freeze platelet poor plasma within 1 hour of collection if the patient is on heparin. Also freeze if >4 hours post collection plasma.

Laboratory Retention: 24 hours

Test Frequency

Available 24 hours, usual TAT 1 day.

Reference Range

  • 21 - 27 seconds (Spectrum Health Regional Lab, Grand Rapids - BCS XP analyzer)
  • 21 - 31 seconds (Spectrum Health Regional Lab, Grand Rapids - CS 5100 analyzer)
  • 21 - 31 seconds (Spectrum Health Regional Hopsital Labs including Blodgett, Big Rapids, Gerber, Kelsey, Ludington, Pennock, Reed City, United and Zeeland)

 

High and Reduced intensity anticoagulation therapeutic range:  42 - 57 seconds. See individual nomograms for therapeutic ranges for other indications.

Laboratory Critical Values Table

Performing Department

COAGULATION

Performing Department Laboratory Location

Spectrum Health Regional Laboratory, Grand Rapids, MI

Regional Hospital Labs:
Spectrum Health Big Rapids Laboratory, Big Rapids, MI
Spectrum Health Blodgett Laboratory, Grand Rapids, MI
Spectrum Health Gerber Laboratory, Fremont, MI
Spectrum Health Kelsey Laboratory, Lakeview, MI
Spectrum Health Ludington Laboratory, Ludington, MI
Spectrum Health Pennock Laboratory, Hastings, MI
Spectrum Health Reed City Laboratory, Reed City, MI
Spectrum Health United Laboratory, Greenville, MI
Spectrum Health Zeeland Laboratory, Zeeland, MI

Methodology

Clot-based assay

CPT

85730

CDM Code

80101963

Epic Test ID

1230100362

LOINC

APTT: 14979-9

Beaker LOINC

APTT NO CLOT DETECTED: N/A
APTT: 14979-9

Mayo Access Code

SHO8450

Reviewed Date

10/11/2021

Beaker Names

Beaker Procedure Name: APTT
Beaker Display Name: Activated Partial Thromboplastin Time (APTT)
BEAKER TEST NAME: APTT
BEAKER TEST REPORT NAME: APTT

Beaker Synonyms

No synonym on file

Beaker Collection and Specimen Handling

BEAKER COLLECTION: +(1)S10/PO/F

Beaker Location, Container and Temperature

BW COAGULATION: BLUE TOP TUBE (Preferred)
BL COAGULATION: BLUE TOP TUBE (Preferred)
BR COAGULATION: BLUE TOP TUBE (Preferred)
GM COAGULATION: BLUE TOP TUBE (Preferred)
KL COAGULATION: BLUE TOP TUBE (Preferred)
LH COAGULATION: BLUE TOP TUBE (Preferred)
PH COAGULATION: BLUE TOP TUBE (Preferred)
RC COAGULATION: BLUE TOP TUBE (Preferred)
UN COAGULATION: BLUE TOP TUBE (Preferred)
ZH COAGULATION: BLUE TOP TUBE (Preferred)