Scope of this protocol
This protocol describes the practice based monitoring of oral anti
coagulants. It details:
1. The way in
coagulant dosing is done safely
2. The way the results are recorded
3. The way the patients are informed of changes in their medication
4. What to do when the INR is out of range
5. What to do in emergency situations.
6. How equipment is maint
ained and calibrated
coagulants are very dangerous and this protocol must be followed in all circumstances. If there is any
doubt on the safety of a patient this must be brought to the attention of the Duty Doctor.
This protocol describes
the use of the Coagu
check XS near patient testing anti
coagulant monitoring machine is kept in the Nurses Treatment room.
Lancet device & single use lancets
Procedure for testing patients INR
These instructions must be followed in all detail. Ensure that you always have adequate time to carry out an
INR and never rush.
1. Switch on the machine and check it is signalling that it is warm enough (about 2 minutes to warm up)
2. Ensure the device
is clean and that the display is well powered by battery or external D.C. source
3. Before each clinic (or one off use) of the monitoring equipment the batch number of the sensor strips
must be compared with the number on display screen on the device. This
ensures the strips are perfectly
calibrated to the device.
4. Open a sensor strip from its wrapping and use within 4 minutes of opening it. Insert the sensor strip and
wait for it to display 'ready'. This takes about 1 minute and the display will give you
180 seconds to get a
droplet of patient’s blood. Ensure container is closed immediately after removing strip.
5. Using a patient lancet device prick one of the patient's fingers and place a rounded drop of blood on the
strip and wait for the devise to dis
play an INR
6. Record the INR result immediately in the patient’s records, remove the strip and make sure the machine
If the coguchek XS records an INR of less than 1.5 & greater than 4.5
a venous sample must be
drawn and sent to the laborato
ry for analysis
Computer chips and the INR testing machine
The machine checks a correct computer chip is inserted for each new box of sensor strips. When a box of
sensor strips has been finished immediately remove the 'box specific computer chip' from th
e machine and
discard it. Do not insert the new 'chip' (which comes with each new box of sensor strips) until the new box
of sensors is opened to use on the first patient
coagulant doses and recording the result
For Nurse taking
1. Ask the patient or their carer about their use of warfarin since the last time their blood was tested. Make
sure they are aware that the computer programme will assume they were 100% compliant with their
medication since the last test. If the
patient is aware that they have not taken their tablets as directed they
must make us aware of this. Record the INR result, in the patients yellow book, and on the Vision patient
record and inform the duty doctor.
2. If a patient does not attend for their
monitoring, enter a record of this in the patient’s notes, as well as on
the computer. If they are unwell, this is not a good excuse to miss monitoring (as INRs are more erratic
during times of illness). Every attempt should be made to contact the patient
& ask them to attend as soon
as possible. If a patent is unable to attend the surgery then arrangements should be made for the District
Nurse to take a blood sample for laboratory analysis
For the medical officer dosing the anti
rse will input the INR result into the computer using the INR guideline...
If the time for the next appointment falls during a holiday or time, which it is impossible for a patient to
attend, and then the next test can be brought forward.
The nurse will
record the new weekly regime and the time of next appointment on the Vision computer
system. The doctor/nurse is responsible for informing the patient about any new regimes.
Informing the patient of the result and their new regime (responsibility of the
There are two ways of informing a patient, or their carers of an INR result and new regime, depending on
whether they are in a care home or independently living in the community. In all cases instructions to alter
coagulant dose must be gi
ven in written form. Only in exceptional circumstances can the message
be given verbally, as there is significant risk of error when doses are not clearly documented.
For care homes the INR and instructions for the new regime are telephoned to the home wi
thin 24 hours of
the INR result being obtained.
The Practice Manager will continue to enter data onto the computer of those patients whose INRs are taken
by the District Nurses or are phoned from the Victoria Hospital Laboratories
For independent patient
s their anti
coagulant (yellow book) is completed by the doctors/nurse usually
before they leave the building. In some cases, where regime changes are small, or the INR result is stable
the patient can leave their yellow book and return the following day t
o collect their new dose regime.
What to do when things go wrong? (Responsibility of the doctor)
Patient is overdosed. Their INR is dangerously high
Following the British Society of Haematology Guidelines as shown in the BNF and if there is a
ny doubt as
to the problem the doctor should contact the consultant haematologist at the Victoria Hospital, Kirkcaldy
INR>8.0 with no bleeding
∙ Stop the Anti
coagulant immediately and discuss with doctor
∙ Check the INR on a daily basis until below 5.0
and then consider restarting anti
the duty doctor’s instructions
∙ Check for reasons for overdose
INR > 8.0 with bleeding or a significant risk of bleeds (falls, trauma, recent stroke, recent
∙ Stop the anti
oagulant immediately and discuss with the duty doctor
∙ Give 5mg of oral vitamin K if prescribed by GP
∙ Monitor INR daily until below 5.0
∙ Check for reasons for overdose
Major bleed of any source regardless of INR
∙ Discuss with duty doctor immediately
and admit to hospital
INR between 8 and 5
∙ Stop anti
check INR 2
3 days later (depending on weekends)
∙ Restart anti
coagulant once INR < 5
. Patient is under
∙ Check compliance with medication. This is the commonest r
eason for a low INR
∙ Check use of other medication, which may interfere with warfarin
. Patient DNAs appointment
Find out the reason why (there is usually a reasonable explanation)
∙ Contact the patients and arrange for monitoring the following week if
INRs are stable, and ASAP if
they are problematic. Only allow the patients to be overdue an INR test for 2 weeks maximum and
then stop all warfarin medication. Always err on the side of caution.
The INR dose is highly variable
∙ Check compliance and use
of other prescribed and non
∙ Must come in to discuss their management with the GP
What to do when patient is unwell or started on interacting medication?
It is the responsibility of the GPs to be aware of illnesses and drugs, which can i
nterfere with anti
coagulants. All drug interactions are 'flagged up' on the computer when prescribed and generally would
require a patient to have an INR checked a week or so after starting interacting medication.
current illnesses are more unpredi
ctable. Probably the most common illness, which may cause
problems, is heart failure. This can produce great changes in circulating volume and wide variations in
INRs. Generally beware a patient who is fluid over
loaded and then becomes stable; this is whe
Special note for alcohol
One of the commonest causes of an unstable INR in an independent patient is the erratic use of
alcohol. It is the doctor’s responsibility to take a clinical decision over the risks and benefits of a
patient who i
s using alcohol in this way. Many patients who are steady, but heavy drinkers find their
INR stable. Any reduction of their intake however can cause increases in the INR.
Management of other conditions
this should be discussed with the
duty doctor and patient informed. This should then be
documented in the notes and on the computer.
operative management of warfarin
Quality Control and Audits
The practice will carry out the following safety checks:
Responsibility of t
he Nurse using the monitoring machine
. The INR Machine is calibrated by its internal calibration system.
A monthly coagu
chek is preformed in conjunction with a venepuncture blood test for laboratory
analysis. Both results are entered onto the coagu
check list (found on the computer in the Nurses
folder). Report in major discrepancies to the duty doctor.
Responsibility of the doctors
The manufacturers carry out regular checks as part of a service agreement.
. The practice will produce an annual au
dit into the safety of the service
Initiating Warfarin on a new patient
Many patients will have started their anti
coagulants in the hospital, and be stabilised by the anti
clinic. If the practice agrees to take over the monitoring of a patients war
farin this should be done with
the written permission from the hospital anti
coag clinic, and a date agreed for transfer of
coagulants is not easy, and there are many things, which can go wrong. It is best if one
throughout the whole process manages the whole process. Before anti
coagulants are even
started the clinician must discuss the following points.
1. The risks of anti
2. How the monitoring of medication is undertaken
3. The responsibilities of
the patient to attend for monitoring, and what happens if they DNA for more
than two weeks
4. How we record the INRs and dosing regimes and pass this information onto patients
5. Alcohol, drugs and illness with anti
6. What to do if the patient
has abnormal bleeding
7 The GPs must input the therapeutic target onto the computer and in the patient’s notes, as well
as diagnosis and duration
Patients must receive information on how to remain well on anti
coagulants. This is in the form of
nd verbal information, which covers
Their responsibility to ensure they get regular checks
2. The use of alcohol
3. The use of OTC medication and prescription medication
4. How to identify when things are going wrong
New referrals from hospital
me to time the hospital will discharge patients stabilised on anti
coagulants and ask us to
take over their care. There is an agreement with the hospital that all verbal communications to and
from the clinic will be backed up with a written, faxed copy. It
is essential that at all times we are
aware of who has responsibility for which patients.
When a hospital INR is generated and the results come for our records, we will input the INR, and
the hospitals chosen regime into our VISION computer programme
Women in child
bearing age and pregnancy
If a patient becomes pregnant, or would like to become pregnant whilst using anti
should be referred to the hospital anti
coagulant services for their monitoring and care.
Patients not included
in this scheme
Patients whose INR is dangerously high or very difficult to stabilise
Children under 16
unless authorised by hospital & GP
Pregnant women (see above)
Patients who are unable to visit the surgery, as the coagu
chek XS machine is not suita
transportation. This includes Nursing homes and housebound patients
Patients who are not registered at the surgery.
Patients with complex pathologies whose management is beyond the competence of the nurse.
Patients with warfarin intolerance.