Clinical Practice Committee Anticoagulation Bridging Algorithm

1. 
   4 days prior to procedure- discontinue warfarin
   
2. 
   2 days prior – start Full Dose Enoxaparin (1mg/KG BID)
   
3. 
   12 hours prior – discontinue Enoxaparin
   
4. 
   Day of procedure – check INR, should be <1.5
   
5. 
   Evening of the day of procedure – restart warfarin
   
6. 
   Approximately 12 hours post procedure – restart Full Dose Enoxaparin
   
7. 
   3-5 days post – begin regularly monitoring INR, stop Enoxaparin when INR > 2. NOTE: In pregnant patients continuous unfractionated heparin should be used unless anti-factor Xa activity is measured and the dose of Enoxaparin appropriately adjusted.
   

Unfractionated heparin has been the standard bridging anticoagulant for patients with mechanical heart valves. Early studies with Low Molecular Weight Heparin (LMWH) bridging revealed an increased thromboembolic risk in pregnant women with MHV’s. It is now known that LMWH doses require adjustment in pregnancy to account for altered metabolism of the drug (based on measurements of anti-Xa activity). However, because of inadequate comparative trials the American College of Cardiology/American Heart Association gives its highest recommendation (Ia) to the use of UFH as outlined below with a IIb recommendation for the LMWH regimen outlined above for VTE.

1. 
   4 days prior to procedure - discontinue warfarin
   
2. 
   2 days prior (or when INR<2.0) start continuous UFH maintaining aPTT 55-70
   
3. 
   6 hours prior discontinue heparin
   
4. 
   Day of procedure – check INR, should be <1.5
   
5. 
   Evening of the day of procedure – restart warfarin
   
6. 
   Approximately 12 hours post procedure – restart UFH, continuing until INR>2.0
   

This is a heterogeneous group with a relatively low, however broad range of thromboembolic risk during this brief period of inadequate anticoagulation. The vast majority of these patients do not achieve a significant clinical benefit from bridging and can thus be managed using the Low Thromboembolic Risk strategy. The Department of Cardiology at Dean does not bridge this group of patients unless they have had a recent embolic event (i.e. stroke).

1. 
   4 days prior - discontinue warfarin
   
2. 
   Day of procedure – check INR, should be <1.5
   
3. 
   Day of procedure – restart warfarin
   

C. Patient Interview and Assessment

Initial assessment

1. During the initial interview the AC Clinic Clinician will:

complete medical history

family history of bleeding and/or clotting disorders

current medications list (including supplements and OTC drugs)

social, lifestyle, and employment profile

health beliefs and attitudes

level of understanding

health literacy

personal health motivation

healthcare resources

b. explain anticoagulation therapy to the patient and/or caregiver

c. provide a medium for alerting others that the patient is anticoagulated (i.e., Medic Alert Bracelet)

d. discuss operational aspects of the AC Clinic. Provide first appointment information

e. obtain a reliable means of communication with the patient to be able to discuss INR

results and implement a care plan (phone numbers, cell numbers, MyChart, contact

numbers)

g. assess the patient’s ability or willingness to comply with therapy and clinic visits

h. assess any significant risk(s) for bleeding and falls

i. assess level of alcohol use or abuse

j. assess significant drug and dietary interactions

k. provide education to the patient and/or caregiver or relative regarding the importance of

regular monitoring of INRs, regular follow-up, drug-food and drug-drug

interactions, and signs/symptoms of bleeding (see Attachment: Patient Education

Record). The patient or caregiver will be given written information regarding warfarin

(see Attachment: Warfarin Patient Education Guide)

b. signs and symptoms of bleeding

c. recent alterations of diet, medications or alcohol intake

d. changes in lifestyle and/or health status

e. compliance with anticoagulation regimen

f. status of specific medical indication requiring anticoagulant therapy

g. status of other disease states or acute problems unrelated to anticoagulation
2. Evaluation of the patient will include an interview either face-to-face or per phone

and an assessment of the patient’s laboratory results relating to anticoagulation therapy

3. When assessing for recently added medications, the AC Clinic clinician will screen for drug

interactions with anticoagulation therapy. Based on the clinical significance of

the potential interaction, the AC Clinic clinician may contact the physician and suggest use

of alternative non-interacting medication if available

Agreement, the AC Clinic Clinician may adjust or make recommendations to adjust the

anticoagulation regimen to keep the patient’s INR (or other lab test) in the desired range utilizing

the guidelines below:

above with telemetry and close monitoring of patient(i.e., ER, ICU, etc.).

*Can expect a significant reduction in INR within 24 hours of vitamin K administration.

*Contact supervising physician or physician on call if any significant problems develop.

*Do NOT give Vitamin K to patients on warfarin with artificial mechanical valves per CV Surgery Department
2. Patients whose INRs have been stable, who now present with an INR outside of the

desired range will be questioned in an attempt to identify the responsible factors, which,

if controlled, would eliminate the need for dosage adjustment. If no reasonable factor is

identified, the warfarin dose will be adjusted based upon past dosing history, kinetic

parameters and dosage adjustment guidelines Return visits will be scheduled according to the

established guidelines.

assess for compliance with the regimen, drug interactions, dietary alterations, excessive

alcohol use, fever and overall health status. The AC Clinic clinician will increase the dose or

recommend a dosage increase based on established guidelines and clinical judgement.

guidelines above. Carefully monitor therapy to regain control if no signs of bleeding. If the

measured INR is >9.0, the AC Clinic clinican will hold the warfarin and update the primary or

on-call physician regarding the patient’s condition and plan a course of action.

3. The AC Clinic will inform the patient of the INR result and of any changes in care plan.

When possible, patients will be given a written dosing schedule for their anticoagulation

therapy which takes into account dosage adjustments, tablet strength, INR result, next

appointment date and telephone number to call with questions or problems (see warfarin dose

card below).

Name_____________________________________ Date__________________

Warfarin Schedule (number of tablets to take daily):

Wednesday ___________ Sunday ___________

4. The AC Clinic clinician will fax a prescription to the patient’s pharmacy on behalf of primary

physician for the specific anticoagulation medication in accordance with the Collaborative Care

Agreement.

E. Patient Education

anticoagulation therapy. Each patient or caregiver will be instructed during an AC Clinic office

0. 
   Indication for warfarin therapy.
   

0. 
   How warfarin works.
   

0. 
   Dosage strength, tablet color, brand name.
   

0. 
   Planned duration of therapy.
   

0. 
   The need for compliance with regimen:
   

0. 
   Take only as prescribed.
   

0. 
   Patient to refer to dosing card or warfarin calendar.
   

0. 
   Take warfarin at the same time daily (5:00 PM if possible).
   

0. 
   Missed doses: take the same day if missed earlier that day; if it is the next day take the usual
   

0. 
   To keep a sufficient supply of warfarin available for trips, vacations, etc.
   

0. 
   What the INR test is, desired range, need for regular INR blood draws.
   

0. 
   Who to call if patient misses a clinic visit or scheduled blood draw.
   

0. 
   Diet and Vitamin K intake needs to be consistent. Avoid both binge eating and crash diets.
   

0. 
   Alcohol consumption limited to 1-2 drinks per day. Avoid excessive intake.
   

0. 
   That other medications including OTCs can influence the action of warfarin.
   

0. 
   To tell the AC Clinic clinician if changing, starting, or stopping doses of other medications.
   

0. 
   To avoid taking aspirin-containing or NSAID-containing products unless prescribed by the
   

0. 
   Avoid smoking and chewing tobacco (at a minimum be consistent).
   

0. 
   The need to report ANY signs of bleeding to the pharmacist, nurse or doctor.
   

0. 
   What to do if any of the following occur:
   

0. 
   Skin rash.
   

0. 
   Fever or developing illness.
   

0. 
   Pain, swelling, excessive bruising, discomfort.
   

0. 
   Prolonged bleeding from cuts, nosebleeds, excessive bleeding from gums while brushing teeth, increased menstrual flow.
   

0. 
   Discoloration of the urine (pink, cherry red) and stool (black tarry, amber, red).
   

0. 
   To avoid physical activities such as sports or hobbies that may cause injury.
   

0. 
   To be careful when using sharp objects during work or at home.
   

0. 
   To keep physical activity consistent.
   

0. 
   To use soft bristle toothbrush.
   

0. 
   To use an electric razor for shaving if possible.
   

0. 
   To use care when getting in/out of bathtub shower.
   

0. 
   To use care when walking outside during the winter if slippery.
   

0. 
   The need to inform other doctors, dentists or other health care providers that patient is taking warfarin.
   

0. 
   NOT to take warfarin during pregnancy. Need to discuss with doctor.
   

0. 
   Warfarin Medication Guide
   

0. 
   Information about wearing a Medical Alert Bracelet or carrying a Coumadin user card.
   

F. Documentation

1. The AC Clinic clinican will record all objective and subjective findings in the Anticoagulation

Section of the computerized medical record (Epic). All pertinent patient anticoagulation data and patient-clinician interactions will be documented in the Anticoagulation Section of Epic, each encounter completed and signed by the AC Clinic clinician. All data must appear the the patient’s Anticogaulation Flowsheet in Epic.

1. Billing to Medicare and other insurance carriers for AC Clinic patients is done in the Epic encounter under Level of Service on the Visit Navigator.

i. An “incident to” or “Office Visit, Est, Level 1” charge (CPT 99211) can be billed by the AC Clinic clinician under Level of Service using the supervising physician for the AC Clinic or the on-call Internal Medicine physician for the day provided that:

ii. If the patient has an appointment with a provider who is the NOT the supervising physician, or another physician/advanced practitioner in the same department, or Internal Medicine on-call physician for the day, then then AC Clinic clinician can bill a Level 1 (CPT 99211) charge.

Ansell JE, Butarro ML, Thomas OV, Knowlton CH and the Anticoagulation Task Force. Consensus Guidelines for Coordinated Outpatient Oral Anticoagulation Therapy Management. Ann Pharmacother 1997;31:604-15.

(update)