Dealing with overdosing and situations with haemorrhagic risks and accidents for patients treated with anti-vitamin K.
Anti-vitamin K is an anticoagulant used by about 1% of the French people and is also the first factor provoking medication-related accidents. Indeed, 17,000 of the annual hospital admittances are due to haemorrhagic complications of the antivitamin K. Given these observations, the French National Authority for Health
published in April 2008 a series of recommendations to prevent risks related to these drugs.
Dealing with asymptomatic overdosing
In case of asymptomatic overdosing (INR exceeding the therapeutical limit), it is recommended to consider, when the context allows so, for an ambulance. It is then very important that the patient and his close relatives be informed about short term haemorrhagic risks. Furthermore, hospital admittance can become compulsory in case of haemorrhagic risk (i.e. haemorrhagic antecedents). Finally, INR must be re-checked the following day and the cause of the overdose must be identified in such a manner to readjust the posology.
Haemorrhage and trauma
A severe or almost severe haemorrhage requires hospital admittance. There are several criteria determining the seriousness of a haemorrhage:
- abundance of the bleeding, mainly noticed on the Hemodynamic impact.
- localisation that can lead to a vital or functional prognostic.
- absence of control by usual means.
- need for a blood transfusion or hemostatic action at a hospital.
If the haemorrhage is not serious, it is still recommended to take an ambulance. Reasons for haemorrhage must be looked for and any potential overdosing. In case of overdosing, the same measures as asymptomatic overdosing must be followed. In case of non cranial trauma, we should adopt the same behaviour according to the nature of the trauma and the potential seriousness of the haemorrhage. However, in case of cranial trauma, the patient must be systematicalling admitted in the hospital and kept under observation for no less than 24 hours. Cerebral scan is performed immediately in case of neurological symptoms and 4 to 6 hours later in other cases.
Finally, antivitamin K should be taken again within a period of time that would be calculated on the basis of haemorrhagic recurrence and the initial indication of the anti-vitamin K.
Performing invasive acts in community medecine
A small number of acts, responsible of less intense bleeding and easily controlled, can be performed in community without interrupting the anti-vitamin K.
Pre and post hospitalization treatment
Depending on the thrombotic function of the anti-vitamin K indication and the haemorrhagic risks of the surgery or the invasive acts, anti-vitamin K treatment would be carried on or interrupted, in this latter case, with or without heparin shift.