warfarin is a vit k antagonist - irish practice nurses management.pdf · warfarin is a vit k...

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