warfarin is a vit k antagonist - irish practice nurses management.pdf · warfarin is a vit k...
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Warfarin is a Vit K Antagonist Vit K is essential for the synthesis of the blood clotting Factors II, VII, IX and X Oral medication 1mg,3mg and 5mg
PT is measurement of how fast your blood clots
INR is Ratio of your Prothrombin Time(PT) to the average PT for patients who are not on anticoagulation
British Committee for standards 1990
◦ Target is midpoint of the designated range
Target
INR Target 2.5 Atrial fibrillation
Non rheumatic
Rheumatic heart disease
Congenital heart disease
thyrotoxicosis
Deep venous thrombosis/ calf vein thrombosis
Pulmonary embolus
Symptomatic inherited thrombophilia Protein C and S deficiency
Cardioversion
Congenital heart disease
Mural thrombosis
Cardiomyopathy
Coronary Artery thrombosis
Arterial graft
Antiphospholipid syndrome
Recurrence of DVT while on Warfarin
Mechanical Prosthetic Heart Valve
◦ Competence
◦ Skill
◦ Scope of Practice
◦ Accountable
◦ Autonomous
◦ Standard Operational Procedure document (The working group PCU)
Register
Recall system
Procedure and Policy documentation
Audit
Team analysis
Recording of incidents
Referral Hospital consultant
GP
Assessment tools/scores Assessment tools
Out patient bleeding risk index (OBRI)
Condition, Hypertension, Age, Diebetes, s Prior event (CHADS)
“Incidence of warfarin associated bleeding may be reduced by attending to modifiable risk factors, frequent monitoring, and careful patient selection”. Filu,S.D. et al. 1993
Alcoholic
Dementia
Other illness
Risk of bleeding Stroke Hypothyroidism Liver function Illness requiring NSAI’S Hypertension
Pre existing disease
Age --- >80 Fihu.S.D. et al 1996
Diet
Alcohol consumption
Interacting drugs
Genetic types Cyp2C9 and Vkorc1
Body size/ height.
On heparin? Rapid target level required Loading dose depending on age, liver function, CCf? Gradual introduction of warfarin
Protein C&S A.fib
Computer dose analyses
“5mg loading dose prevented excess anticoagulation and avoids the development of a hypercoagulable state due to precipitous decreases in protein C. “Harrison L. et al 1997
600 patient safety incidents of harm or near harm associated with the use of anticoagulants in UK between 1990-2002
20% resulted in death
MDU logged 79 reports of deaths due to warfarin, 60 occurred in primary care ◦ Inadequate monitoring
◦ NSAID’s
Over anticoagulation ◦ 31% Poor concordance
◦ 17% influence of other medications
◦ 28% CCF
Week 1 Up to 4 INR blood test (this will include inpatient blood tests)
Testing Daily or alternate days required until in therapeutic range.
If in range for 2 consecutive days then checked every 3 – 5 days.
Thereafter When INR and dose remain stable for a week, then check INR weekly.
One INR
therapeutic
Recall in 1 week
One more INR
therapeutic
Recall in 1 week
Two INRs
therapeutic
Recall in 2 weeks
Three INRs
therapeutic
Recall in 3 weeks
One INR high Recall in 7-14 days (stop treatment for 1-3 days)
(maximum 1 week in prosthetic valve
patients)
One INR low Recall in 7-14 days
One INR
therapeutic
Recall in 4 weeks (as a follow on from table 2)
Two INRs
therapeutic
Recall in 6 weeks (maximum for prosthetic
valve patients)
Three INRs
therapeutic
Recall in 8 weeks, apart from prosthetic valve
patients
Four INRs
therapeutic
Recall in 10 weeks, apart from prosthetic
valve patients
Five INRs
therapeutic
Recall in 12 weeks, apart from prosthetic
valve patients
Note: Patients seen after discharge from hospital with prosthetic valves may need more frequent INR monitoring in the first few weeks (based on data from Ryan et al. British Medical Journal 1989; 299: 1207-1209 *Taken from the BMA outline for National Enhances Service-anticoagulation monitoring
Develop a care plan ◦ Assessment
◦ History
◦ Family support
◦ Educational needs
Manage Treatment
Constant Evaluation
What warfarin is? Why they are taking it? Duration of treatment? Blood tests, The importance of monitoring and achieving target INR. The importance of compliance Warfarin should be taken at the same time each day. Adequate supply of warfarin tablets Book Record INR reading Agreed dose Next appointment
interacting medications, foods, drinks and herbal products. alcohol For visually impaired colour blind patients, or confused patients 1mg brown tablets only Management of bleeding educate re over/under coagulation Young women and fertility Compression stockings Dementia Pill box Family member
Lifestyle advice ◦ Regular exercise
◦ Regular diet
Travel ◦ Comfortable seat
◦ Bend+ straighten legs
◦ Press ball of feet down
◦ Occasional walks
◦ Compression stocking
◦ Fluids
◦ Avoid sleeping pills
Venosection Blue bottle
Full sample
Delivery same day
Contact patient with result and dose of warfarin
Point of care devices Finger prick
Instant results
Costs
Almost any drug will interact with Warfarin therapy
Most will potentiate effect
Drugs that reduce effect Anti-epeleptics
Barbiturates
Sucralfate
Rowachol
rifampicin
Amoxicillin has low risk of interaction.
Increase Alcohol (with liver
impairment) Cranberry juice Mango Smoking cessation Tonic Water Grapefruit
Decrease Alcohol Avocado Broccoli Beetroot Brussel Sprouts Cabbage Enteral feeds Green Tea Ice Cream Smoking
Turnip greens
Spinach
Lettuce
Liver
Anise
Arnica
Celery
Chamomile
Clover
Liquorice root
Ginger
Garlic
Onion
Ginseng
Goldenseal
St John’s Wort
Parsley
Turmeric
Willow Bark
Sweet Woodruff
Meadowsweet
Tonka Beans
Poplar
Passionflower Herb
Allopurinol
Amidorone
NSAID’s
Fluconazole
Oxandrolone
Metronidazole
Miconazole
Erythromycin
Co-proxamol
Barbiturates
Carbamazepine
Griseofulvin
Phenobarbital
Phenytoin
Phytomenadione
Rifampicin
Vitamin K
Cimetidine
Aspirin
Phenylbutazone
Anabolic steroids
INR3- 5 reduce dose of Warfarin or stop ◦ Check for evidence of bleeding ie. Urine
◦ If using Coaguchek repeat test
◦ Restart when INR reduces
◦ Is there a reason?
INR 6-8 (no evidence of bleeding) ◦ Stop warfarin
◦ Restart when INR <5
INR>8 No evidence or minor bleeding ◦ Stop Warfarin and resume when < 5
Vit K (oral) /Vit K IV
Resuscitate and IV Vit K 5-10mg and transfer to Hospital.
Factor Concentrate
Underlying hypercoagulable state so management will have to be carefully monitored.
Reduced risk of large haematomas if INR reduced quickly. Yasaka et al 2003
Is there a local anatomical reason for bleeding.
Prosthetic Valve patients who are fully reversed with vit k can result in prolonged resistance to Warfarin
Cost of machine
patient 540€
surgery 1,612.50€ /1,110.00€
Cost of strips
Patient
GMS-Hardship fund
Audit/calibration of machine
Tina Breen -Promed
Pregnancy
Clexane(LMWH)
Inohep (LMWH)
Surgery
Dental Extraction
Therapeutic range usually adequate
Tranexamic Acid mouthwash
Anti-thrombolytic Pradaxa (Dabigatran etexilate)
Xarelto (rivaroxaban)
Aspirin
Anti platelet agents
Plavix (clopidogrel)
British Journal of Haematology
“Guidelines on oral anticoagulation”
British Committee for standards in Haematology