Management of over-anticoagulation
Bleeding while on oral anticoagulants increases significantly with INR (International Normalised Ratio) results > 5.0 particularly in patients with risk factors for bleeding.
Risk factors for bleeding include:
- Age ( > 70) years
- Previous bleeding complications
- GI haemorrhage/ulcers
- Hx CVA
- Recent surgery
- Uncontrolled BP
- Recent initiation of anticoagulants
The majority of over-anticoagulated patients will return to their target therapeutic range within 3 days of discontinuing warfarin therapy.
Vitamin K
- Is the first drug of choice to be administered for the reversal of excessive anti-coagulation if the patient has evidence of bleeding.
- Vitamin K is dispensed in ampoules of 1ml/10mgs known as Konakion®, or 0.2mls/2mgs known as paediatric Konakion® . This can be administered sublingually using a 1ml syringe and a filter needle to draw up and administer the solution.
- Vitamin K is also available in 10mg tablets for oral administration.
- When partial correction is required to achieve a target therapeutic INR, IV Vitamin K can be administered in low doses of 1-2mgs sublingually.
- 5mgs of Vitamin K will completely reverse anticoagulation, which is only indicated if the patient is presenting with bleeding as a result of a high INR.
- Particular caution is advised for patients with Prosthetic heart valves, where the use of vitamin K may increase the risk of thrombosis due to overcorrection of the INR.
- Therefore, if indicated, small doses of vitamin K only (e.g. 1 – 2 mg) are recommended, if in doubt seek advice from the cardiology and haematology team.
- Prothrombin Complex Concentrate (PCC) is not routinely administered to reverse excessive anticoagulation in the absence of bleeding but should be administered in life threatening major haemorrhage.
- PCC is more effective than Fresh Frozen Plasma (FFP) for reversal of bleeding associated with excessive anticoagulation, therefore FFP is not indicated or recommended when PCC is available.
Please discuss cardiac valve patients with cardiology BEFORE reversing warfarin.
Procedure
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Major or life threatening bleeding
- Intracranial bleed
- Retroperitoneal bleed, Intraocular bleed
- Muscle bleed with compartment syndrome
- Pericardial bleed
- Active bleed with hypotension or 2g fall in Hb
- Consult haematology team.
- Stop Warfarin and admit
- Give 10 mg of Vitamin K (oral or i.v.)
- Give PCC - prothrombin complex concentrate(eg Octaplex®) 50 units/kg
or
SDP 12-15 mls/kg
| Patients INR | Dose PCC |
|---|---|
| INR 2 - 3.9 | 25 IU / Kg |
| INR 4 - 6 | 35 IU / Kg |
| INR > 6 | 50 IU / Kg |
- National Haemovigilance Office SD Plasma Info Leaflet (Jan 2004). Local copy
- ED Handbook information on Solvent Detergent Plasma
- Irish Blood Transfusion Service
- CUH Octaplex policy
References
BaglinTP et al on behalf of BCSH. Guidelines on oral anticoagulation (warfarin): third edition – 2005 update. British Journal of Haematology 2005: 132:277-285
BaglinTP et al on behalf of BCSH. Guidelines on oral anticoagulation (warfarin): third edition. British Journal of Haematology 1998; 101:374-387
Baker et al. Warfarin Reversal: Consensus guidelines on behalf of the Australiasian Society of Thrombosis and Haemostasis. Med J Australia 2004; 181: 492-497.
Ansel et al. The pharmacology and management of vitamin K antagonists. Chest 2004; 126: 204- 233S
