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Lab Dept:
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Coagulation
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Test Name:
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PTT (FAIRVIEW UNIVERSITY)
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General Information
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Lab Order Codes:
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PTTU
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Synonyms:
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APTT to Fairview University; Partial Thromboplastin Time to Fairview University; Activated PTT to Fairview University
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CPT Codes:
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85730 – Thromboplastin time, partial (PTT); plasma or whole blood
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Test Includes:
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PTT result reported in seconds.
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Logistics
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Test Indications:
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Useful for screening of the intrinsic and common pathways in the coagulation system (factors II, V, VIII, IX, X, XI and XII); screening for dysfibrinogenemia, disseminated intravascular coagulation (DIC), congenital hypofibrinogenemia, vitamin K deficiency, HMWK deficiency and prekallikrein deficiency
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Lab Testing Section:
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Coagulation - Sendouts
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Referred to:
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Fairview University Medical Center
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Phone Numbers:
Minneapolis:
Saint Paul:
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612-813-6280
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651-220-6550
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Test Availability:
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Daily, 24 hours
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Turnaround Time:
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8 hours routine; 4 hours STAT
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Special Instructions:
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Patient should not be receiving Coumadin® or heparin.
If so, this should be noted on the request form. Heparin or warfarin therapy can affect certain coagulation factors or assays, preclude their performance, or cause spurious results.
Indicate when specimen is drawn from a line or a heparin lock. Deliver immediately to the laboratory.
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Specimen
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Specimen Type:
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Whole blood
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Container:
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Light Blue top (Buffered Na Citrate 3.2%) tube
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Draw Volume:
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2.7 mL blood in a 3 mL tube (Minimum: 1.8 mL in a 2 mL tube)
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Processed Volume:
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Specimen will be processed by reference lab facility.
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Collection:
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A clean venipuncture is essential. Do Not use the first 2 mL of blood collected.
If the patient’s hematocrit is >55%, contact the laboratory to obtain a special tube.
Fill tube completely. Mix thoroughly by gentle inversion.
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Special Processing:
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Lab Staff: Do Not centrifuge. Send to reference lab in original Vacutainer®. Specimen must arrive within 24 hours. If more than 24 hours is required for transport, contact laboratory for processing instructions
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Patient Preparation:
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None
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Sample Rejection:
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Improper tube; clotted sample; overfilled tube; underfilled tube; mislabeled or unlabeled specimens
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Interpretive
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Reference Range:
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Age:
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Range (Seconds):
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0 – 1 month:
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27 - 52
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1 – 6 months:
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24 - 47
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>6 months:
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22 - 37
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Critical Values:
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>105 seconds
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Limitations:
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N/A
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Methodology:
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Activated partial thromboplastin time
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Contraindications:
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Patient on heparin therapy
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References:
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Fairview University Medical Center Web Page http://labguide.fairview.org/diagnostic.asp July 2012
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Harmening DH (1997) Clinical Hematology and Fundamentals of Hemostasis
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Updates:
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6/3/2004: Reference ranges previously ≥1 yr = 23.0 – 33.0 seconds, current ranges broken down by age under Reference Range:
Critical value changed from >70 seconds to >105 seconds.
Draw volume changed from 4.5 mL to 2.7 mL blood. Minimum Draw Volume changed from 2.7 mL to 1.8 mL blood.
5/25/2010: Tubing patient specimens is no longer prohibited.
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