Anticoagulant Recommendations

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It is vital that all anticoagulated patients have the correct duration of treatment and target intensity identified and recorded.  When completing the Immediate Discharge Letter (IDL) for patients commencing anticoagulant therapy, an additional tab will be created. Once all sections of the IDL are authorised and it is completed for discharge the anticoagulant information will automatically be emailed to the haematology department. All letters will contain the anticoagulant information.

All patients should receive verbal and written information (Anticoagulant Treatment Booklet – see BNF for sources) on commencement of anticoagulant therapy.

 Chapter 2 Highland Formulary

Major Bleeding

Life-threatening bleeding (eg intracranial or major gastro-intestinal bleed)

  1. Stop warfarin.
  2. Intravenous phytomenadione (vitamin K1) by slow intravenous injection 10mg, repeated if necessary 12 hours later.
  3. Prothrombin complex concentrate (Beriplex®). The dose will depend on the current INR and the targeted INR. In the following table approximate doses (mL/kg body weight of the reconstituted product) required for normalisation of INR (≤1·2 within 1 hour) at different initial INR levels are given.
Initial INR 2.0 to 3.9 4.0 to 6.0 >6.0
Approximate intravenous dose* (units Factor IX/kg weight) 25 35 50

*The maximum single dose should not exceed 5000 units Factor IX, given at a maximum rate of 200 units/min, ie 8 mL/min of the 25 units/mL reconstituted solution.

The correction of the INR persists for approximately 6 to 8 hours. However, the effects of phytomenadione (vitamin K1) if administered simultaneously, are usually achieved within 4 to 6 hours. Thus, repeated treatment with Beriplex® is not usually required when phytomenadione (vitamin K1) has been administered.

  1. If Beriplex® is unavailable, fresh frozen plasma (15mL/kg body weight – approximately 1 litre for adult). Beriplex® and fresh frozen plasma are accessible from the Blood Transfusion Service after discussing with on-call Haematologist.

Minor Bleeding

Less severe bleeding (eg haematuria, epistaxis)

  • INR >8·0, minor bleeding - stop warfarin; give phytomenadione (vitamin K 1) 1 to 5mg by slow intravenous injection; repeat dose of phytomenadione (vitamin K 1) if INR still too high after 24 hours; restart warfarin at 15 to 20% less than previous maintenance dose when INR <5·0, and bleeding has stopped.
  • INR 2.0 to 8·0, minor bleeding - stop warfarin; give phytomenadione (vitamin K 1) 1 to 3mg by slow intravenous injection; restart warfarin at 10 to 15% less than previous maintenance dose when INR <5·0 (if target INR range is between 3·0 and 4·0), or when INR <4·0 (if target INR range is between 2·0 and 3·0) and bleeding has stopped.
  • Unexpected bleeding at therapeutic levels - always investigate possibility of underlying cause, eg unsuspected renal or gastro-intestinal tract pathology, and haemorrhagic stroke. Also drug interactions, patient unwell, diet change etc.

Discuss with Haematology if more advice required.

High INR but no Bleeding

  • INR >8·0, no bleeding - stop warfarin; give phytomenadione (vitamin K 1) 1 to 3mg by mouth using the intravenous preparation orally [off-label]; repeat dose of phytomenadione (vitamin K 1), if INR still too high after 24 hours; restart warfarin at a 15 to 20% less than previous maintenance dose when INR <5·0.
  • INR 5·0 to 8·0, no bleeding - withhold 1 or 2 doses of warfarin and restart warfarin at 10 to 15% less than previous maintenance dose, when INR <5·0 (if target INR range is between 3·0 and 4·0), or when INR <4·0 (if target INR range is between 2·0 and 3·0).
  • Unexpected high INR - always investigate possibility of underlying cause, eg unsuspected renal or gastro-intestinal tract pathology and haemorrhagic stroke. Also drug interactions, patient unwell, diet change etc.

Discuss with Haematology if more advice required.

Other Factors

Consider other factors contributing to prolonged coagulation tests e.g.

DIC
Congenital coagulation factor deficiency
Liver disease
Lupus inhibitor
Inadequate replacement

SEEK HAEMATOLOGICAL ADVICE

Anticoagulant Monitoring Service Referral Form

Anticoagulant monitoring service referral form

Abbreviation

Abbreviation Meaning
INR International normalised rate
PT Prothrombin Time
APTT Activated partial thromboplastin time
DIC Disseminated intravascular coagulation 

Last reviewed: 31 March 2015

Next review: 31 March 2017

Author(s): Consultant Haematologist

Version: 5

Approved By: TAM subgroup of ADTC

Reviewer Name(s): Dr Jo Craig

Document Id: TAM214