Coagulation Profile

OVERVIEW

  • Prothrombin Time
  • Activated Partial Thromboplastin Time
  • Thrombin Time
  • Fibrinogen
  • Fibrin Degradation Products (FDP’s)
  • APTT 50% NP
  • Retiplase Time
  • Euglobin Lysis Time
  • Urea solubility Test

PROTHROMBIN TIME

  • thromboplastin added
  • tests the extrinsic pathway
  • ratio compared to control (INR)
  • tests factors: I, II, V, VII, X

-> warfarin
-> vitamin K deficiency
-> liver disease
-> DIC
-> artefact: incorrect sampling or increased haematocrit (> 55%)

ACTIVATED PARTIAL THROMBOPLASTIN TIME

  • kaolin added
  • tests intrinsic pathway
  • tests factors: I, II, V, VIII, IX, XI, XII

-> heparin
-> DIC
-> haemophilia
-> liver disease

THROMBIN TIME

  • thrombin added to undiluted plasma
  • tests the conversion of fibrinogen -> fibrin
  • prolonged in:

-> heparin
-> DIC
-> hypofibrinogenaemia
-> fibrin degradation products

FIBRINOGEN

  • normal: 1.5-4.0
  • high in: acute phase response
  • low in:

-> sepsis
-> DIC

FIBRIN DEGRADATION PRODUCTS (FDPs)

  • marker of fibrin and fibrinogen breakdown

APTT 50% NP

  • mixing of patients sample with pooled normal plasma – 50:50 mix
  • failure to correct after mixing:

-> lupus anticoagulant present (should go on to autoantibodies and anti-cardiolipin antibodies)

ECHIS TIME

  • snake venom from Echis multisquamatus added to sample
  • differentiates liver dysfunction from vitamin deficiency
  • this activates prothrombin without requiring vitamin K
  • is normal in vitamin K deficiency or warfarin use
  • if prolonged:

-> factor deficiency (liver disease)

RETIPLASE TIME

  • used to detect deficiency or abnormalities in fibrinogen
  • snake venom that has similar action to thrombin but is resistant to inhibition by antithrombin III
  • interpret with TCT
  • if retiplase time normal and TCT prolonged:

-> heparin
-> hirudin
-> direct thrombin inhibitors

EUGLOBIN LYSIS TIME

  • shortened time:

-> presence of systemic fibrinolytic pathway activators

UREA SOLUBILITY TEST

  • factor 13 stabilises fibrin
  • if deficient 5M urea will dissolve it

CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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