QuestionSBA
QuestionChoice
This would be indicated in any serious or life-threatening bleeding requiring immediate reversal, regardless of the INR
32022
e
Stop warfarin, administer prothrombin complex concentrate (PCC)
QuestionChoice
This woman has a background of dementia and has been admitted with delirium, suggesting possible issues with medication compliance or overdosing. As the INR is between 5-8 with no active sources of bleeding, it is safe to withhold warfarin and recheck the INR the next day
32018
a
Withhold one or two doses of warfarin, assess medication compliance and recheck INR
QuestionChoice
This would be indicated if the patient has active bleeding
32021
d
Stop warfarin, administer IV phytomenadione
QuestionChoice
This would be indicated if the INR is >8 without bleeding
32020
c
Stop warfarin, administer oral vitamin K
QuestionChoice
The patient has a supratherapeutic INR and further administration of warfarin even at a reduced dose would likely drive the INR higher and put her at increased risk of bleeding
32019
b
Continue warfarin at a reduced dose
Concept
Chapter
# Summary

The International Normalised Ratio (INR) is a measure of blood coagulation, typically monitored in patients on anticoagulant therapy. High INR can result from an overdose of anticoagulant medication, drug interactions, dietary changes, and medical conditions such as liver failure or infection. The assessment of high INR includes a thorough patient history, complete blood count, and clotting screen. Management strategies are determined by the presence of active bleeding and the INR level, with a general focus on withholding anticoagulants and administering vitamin K. Re-evaluation of patient compliance and understanding of dosage regimens is also crucial.

# Definition

International normalised ratio (INR) is a measure of blood coagulation and is commonly monitored in patients on warfarin at high risk of thromboembolic events (e.g. those with prosthetic heart valves, atrial fibrillation, or those being treated for a thromboembolic event (e.g. DVT or PE).

# Causes 

- Overdose of anticoagulant medication
- Drug interaction (e.g. antibiotics, antifungals, Aspirin, Amiodarone)
- Herbal products
- Increase in alcohol consumption
- Decrease in consumption of foods containing vitamin K
- Liver failure
- Infection

# Assessment

- History
  - Dosing history of anticoagulant
  - Concurrent illness
  - Change in medications
  - Change in diet/lifestyle (including alcohol and tobacco use)
  - History of any falls/injuries
  - History of blood loss
    - Haemoptysis
    - Haematemesis
    - Melaena
    - Bleeding from the gums
- Examination
  	- Evidence of bleeding
    - Overt blood loss
    - Bruising
- Bloods
  - Full blood count to check for concurrent anaemia, signs of infection
  - Clotting screen to check for other clotting abnormalities


# Management of high INR

Management depends on the presence of active bleeding and INR level.

If concerned regarding head injury and intracranial haemorrhage, consider CT head.

- Major bleeding
  - Stop anticoagulants
  - Administer IV vitamin K
  - Administer prothrombin complex (preferred to FFP)
- Minor bleeding
  - Stop anticoagulants
  - Administer IV vitamin K
  - Repeat INR after 24 hours, may need further vitamin K
- No bleeding with INR > 8
  - Stop anticoagulants
  - Administer IV or oral vitamin K
  - Repeat INR after 24 hours
- No bleeding with INR > 5
  - Withhold 1-2 doses of anticoagulant
  - Review maintenance dose of anticoagulant

It is important to also assess compliance and ensure the patient understands their dosing regime.

# NICE Guidelines

- [NICE Treatment Summary: Oral anticoagulants](https://bnf.nice.org.uk/treatment-summary/oral-anticoagulants.html)
- [NICE British National Formulary (BNF): Warfarin Sodium](https://bnf.nice.org.uk/drug/warfarin-sodium.html)

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If the INR is between 5-8 and there are no active sources of bleeding, it is generally safe to withhold warfarin and recheck the INR the following day.
An 80 year old woman is admitted to the ward with a one week history of confusion, dysuria and urinary incontinence. She lives alone with a carer coming in once weekly, who brought her into hospital upon realising she was "slightly muddled". She has a past medical history of ischaemic heart disease, atrial fibrillation and dementia and she currently takes warfarin. Her international normalised ratio (INR) is 6.5 on admission.

A CT head no evidence of acute intracranial abnormality.

Which of the following is the most appropriate management?
a