Anticoagulation Flashcards
Your next patient is a 50 year old man who is a known case of AF and CKD. He was started on Warfarin 3 weeks ago and his INR results are 2.4.
Tasks:
Explain results and the follow up schedule to him
Explain specific points of warfarin use and side effects
Open-ended question
D: Hi, my name is ____. May I know your name? Hi ___, I’ll be taking care of you today. How can I help you?
D: Do you have any concerns before we go forward?
Indication
D: Warfarin is an anticoagulant which means it increases the time it takes for your blood to clot. We use this medication when there is an increased risk of forming clots in your blood. In your case, having atrial fibrillation and an irregular heart beat increases the chance of forming clots.
We usually measure how long it takes for your blood to clot with a test called INR. Your INR result is in the target range of 2 - 3.
Dosing
D: It is important to use this medication correctly, as if you don’t take enough, there is a chance you’ll have clots and if you take too much, it can lead to severe bleeding. It is important to take the exact dose the doctor has instructed you to take. You need to take it at the same time every day, you can print out a warfarin calendar so you don’t forget to take it. If you miss a dose, do not double the dose. Do not change the brand that you use.
The dose is adjusted based on your INR blood test results. We monitor how warfarin works with a test called INR. This test measures how long it takes for your blood to clot. We aim for a target range between 2-3.
Scheduling
D: When we start the medication, we may need to do a blood test every 1 to 2 days to adjust the dose, but once we reach our target goal or target range, we repeat the test every 4-6 weeks. I will refer you to the warfarin clinic, once you do the blood test, they will notify you and me with a text message.
Side effects
D: The most important side effect of this medication is an uncontrolled bleeding which can sometimes be hidden.
D: If you notice excessive/easy bruising, nosebleeds, bleeding in your stools, vomit blood, cough up blood, start having headache/dizziness, abdominal pain and back pain, please come back.
D: If you get any head injuries or significant falls, please also come to me for an examination just to make sure everything is fine.
D: You can buy and wear a medic alert bracelet, and also inform your family members and carers that you are taking this medication.
Interactions
D: Remember to always inform your GP and the pharmacist that you are taking warfarin. Even if you are taking over the counter medications or herbal medications. I will print out a medication list for you which you can keep in your wallet, and always show the pharmacist.
A few medications that you need to avoid:
Anti-inflammatory painkillers
St. John’s wort herbal supplements as this can increase the risk for bleeding.
Avoid excessive alcohol intake. Have a healthy, balanced diet. Avoid dramatic changes in your diet especially green leafy vegetable including broccoli, spinach and cranberry juice and grapefruit juice, as it can drop your INR.
Referral
D: I’ll arrange a medication review and education session with the pharmacist. I will also refer you to the warfarin clinic, they can do regular testing, inform you of the results, and can adjust the dose for you.
D: I will give you reading materials from the NPS medicines website
Review
D: I will follow-up your INR results. Please see your GP when you are sick, as vomiting and diarrhea can affect the function of your warfarin.
D: If you miss a dose, if it’s less than 4 hours from the scheduled regular time of medication, you can take the missed tablet; but if it’s more than 4 hours, skip the dose, never double the dose, and take the next dose at the usual time and inform your GP as it can affect your blood test results.
Your next patient is a 55 year old lady who is a known case of AF and was prescribed warfarin 6 months ago. Her INR result today is 1.4.
Tasks:
Take history to find the reason of the low INR
Explain findings to the patient and counsel her.
Open-ended question
D: Hi, my name is ____. May I know your name? Hi ___, I’ll be taking care of you today. How can I help you?
D: Do you have any specific concerns that you want me to address today?
Explore the Past Medical History: Atrial fibrillation
D: Since when were you diagnosed with atrial fibrillation?
D: Are you compliant with your treatment?
D: Have you ever had any bleeding episodes?
D: Are you having regular follow-ups with your GP and regular blood tests?
D: Has you GP explained why you need to take this medication?
D: Have you had any funny racing of your heart lately?
D: Have you had any chest pain?
Warfarin Interactions
D: Have you recently had any changes in the brand of the warfarin that you are taking?
D: Any changes in your usual diet?
D: Are you taking more green leafy vegetables like broccoli and spinach recently?
D: Any new medications that you are taking?
D: Any new herbal supplements that you are taking?
(If you have extra time ) Geriatric Screening
D: How’s your memory been lately?
D: How’s your mood been lately?
D: How’s your home situation?
D: Do you have enough support at home?
D: Who cooks your food? Do you cook for yourself or someone cooks for you?
D: Any recent falls at home?
Counselling
D: We monitor the function of this medication by checking a blood test called INR, which measures how long it takes for your blood to clot. In order to prevent a clot, we need the INR to be between 2-3. Your INR today is 1.4 which means that the medication cannot prevent a clot.
Reasons for not taking medication:
Compliance issues: educate about the important of taking the medication, complications
Memory problems: Webster pack, medication review
Financial problems: Support from Centrelink, generic brand
Support problems: aged-care assessment, social workers
Busy with sick mother: educate about the important of taking the medication, complications, arrange for a social worker to help with taking care of sick family member
Your next patient is a 67 year old man who has come to your general practice concerned of his medications. He is a known care of AF, HTN, and DM and his CHADSVAC score is 2. He is currently taking warfarin and he wants to stop it as he is not happy with doing multiple blood tests as it’s time consuming.
Tasks:
Counsel the patient about anticoagulant use and suggest other options he can use.
In the F2F exam, you had a MIMS book with Apixaban tagged
Open-ended question
D: Hi, my name is ____. May I know your name? Hi ___, I’ll be taking care of you today. How can I help you?
D: Do you have any specific concerns that you want me to address today?
Address Concern
D: Thank you for coming in today to discuss your concern. I also agree that regular blood tests can be time consuming. But is it okay if I explain more about the medication and our other options?
D: Do you have any other specific concerns that you want me to address today?
Indication
D: We use anticoagulants, also known as blood thinners whenever the patient has a high risk of forming clots in their blood. In your case, you have atrial fibrillation and an irregular heartbeat, which increases the risk of clots. We have calculated a score called the CHADS score which predicts the risk of clotting. And in your case, your score is 2, which means that you have a high risk of clotting. In your case, not taking a blood thinner will increase the risk of a clot which can lead to a stroke.
Warfarin
D: Warfarin needs dose adjustments based on the blood tests that we do monthly. It has some interactions with food and medications that you need to be careful of. We are concerned about a severe bleeding with this medication if you take an excessive dose or if it has interactions with other food or medication that you are taking.
NOAC Counselling
D: There is an newer group of blood thinners called the non-vitamin K/direct oral anticoagulants. There are 3 medications in this group that are currently approved to use in Australia: apixaban, rivaroxaban, and dabigatran.
Key point/Agenda 1: These medications do not need regular monitoring as they have a predictable effect and don’t need dose adjustment. I do understand that you were concerned about the regular blood tests, with these medications, we don’t need to do that.
Key point 2: However, we cannot use these medications if you have chronic kidney disease which is why we need to check your kidney function with a blood test called eGFR.
Con 1: These medications have a shorter half-life which means they stay active in your blood for a shorter amount of time. This signifies the importance of taking the medications on-time and not missing a dose.
Con 2: We have an antidote for Dabigatran that can reverse its effect in case you have an overdose but the antidotes for Apixaban and Rivaroxaban are still being studied and are not available in Australia.
D: I’ll give you a reading material about these medications from the NPS medication website.
D: I will talk with your cardiologist to make sure he is happy with this change and to confirm that you do not have a problems in the valves or gateways of your heart.
D: If we do decide to switch, we will stop warfarin. I know you would not like to have a lot of blood tests but we will have to do a blood test daily to measure INR this time. Once INR <2.5, we can start NOACs.
D: Being on this medication is similar to being on warfarin so make sure to look out for bleeding, headaches, dizziness, abdominal or back pain, please come back to us.
Why will you have overdose with Dabigatran?
Triple whammy: if you use it with ACEI and NSAIDs, the levels of Dabigatran can increase
Your next patient is a 50 year old lady who has recently been diagnosed with bowel cancer (high risk of bleeding). She has been scheduled for a right hemicolectomy in 3 weeks. She is a known case of hypertension, AF and has diabetes. She is currently on metformin, atorvastatin, warfarin, atenolol.
Investigations have been done:
INR 2.5, HbA1c 6.5%, BP normal
Tasks:
Take history regarding medications
Discuss your medication management plan
Give her practical advice before surgery
Tasks:
Take history regarding medications
Discuss your medication management plan
Give her practical advice before surgery
Open-ended question
D: Hi, my name is ____. I’ll be taking care of your today. How may I help you?
D: Do you have any specific concerns that you want me to address today?
Address concern
D: I understand, that is a valid concern. Is it okay if I ask you a few questions so we can make the best management plan together?
Medication
D: How long have you been taking these medications?
D: Have you been compliant with the medications?
D: Have you experienced any side effects with the medications?
D: Do you do your regular follow-up with your GP and specialist?
HASBLED: Bleeding Risk
Hypertension
D: When were you diagnosed with a high blood pressure?
Abnormal Liver/Kidney
D: Have you ever had abnormal kidney or liver function test?
D: Any previous diagnosis of kidney and liver disease?
Stroke
D: Any previous history of stroke or mini stroke?
Bleeding
D: Any previous episodes of bleeding?
Labile INR
D: Has your warfarin INR test been stable in the past?
Alcohol & Drugs
D: Do you drink alcohol? How much?
D: Any other drugs or medications or supplements that you use?
Clotting Risk
D: Any history of stroke?
D: Any history of heart valve replacement?
R: Yes, I have a mechanical aortic valve
D: Any previous history of clotting in your legs or your lungs?
CHADS Score: Clotting Risk
Congestive Heart failure
D: Have you ever been diagnosed with heart failure?
Hypertension
Age
Diabetes
D: Any previous history of diabetes or high blood sugar level?
Stroke
Vascular
D: Any previous heart attack or arterial disease in the leg?
Counselling
Thank you for answering the questions. I appreciate that this can be distressing. But I would like to reassure you that we will be taking care of you as a team and I will involve the surgeon, your GP and your cardiologist in the decision making and we will be taking good care of you.
The decision is based on comparing the bleeding risk to the clotting risk. The bleeding risk depends on the type of procedure and also some factors in the patient. In your case, you are doing a bowel surgery that has a high risk of bleeding. I assessed a score called HASBLED and since you have a high blood pressure, this further increases the risk for bleeding.
The clotting risk was calculated using a score called CHADS score. Your high blood pressure and high blood sugar level increases the risk for clotting. You also have a mechanical heart valve that increases the chance of clotting.
As the risk of bleeding is high, we will stop warfarin before your surgery. But we are also worried about the risk of clotting which is why we will start you on another blood thinner which is called enoxaparin.
Our plan is:
We will stop the warfarin 5 days before the surgery
24 hours later, we will start doing daily INR checks
Once INR is less than 2, we start the enoxaparin injections to prevent clots
We will continue enoxaparin and stop it 24 hours before surgery
We will do one last INR check before the surgery to make sure the INR is less than 1.5
All your other medications, we will stop them on the day of surgery. On the surgery day, we will monitor your sugar levels, and if needed, we will give you insulin.
I will talk to your cardiologist as you have a mechanical heart valve, we may need to prescribe you antibiotics before the surgery just to prevent an infection in your heart called infective endocarditis.
After surgery, the surgeon will decide when we can restart your warfarin. If there is a high risk of bleeding, we may give you enoxaparin to prevent clots in your leg until we start warfarin again.
Practical Advice Before Surgery
For this surgery, we need to prepare your bowels. I will give you an instruction sheet about taking laxatives before surgery. The day before surgery, you should start a clear fluid diet and start taking laxatives. Drink plenty of fluids to avoid dehydration.
Your next patient is a 60 year old lady who is scheduled for a laparoscopic hernia surgery. She is a known case of DM and AF and is on Dapagliflozin, rivaroxaban (apixaban/dabigatran), atorvastatin, and atenolol.
Tasks:
Take history for 3 minutes
Explain medication management and address your patient’s concerns
*The role player will be complaining about a lot of things
Tasks:
Take history for 3 minutes
Explain medication management and address your patient’s concerns
Open-ended question
D: Hi, my name is ___. I’ll be taking care of you today. How may I help you?
Address concern
D: I appreciate you sharing your concerns with me. But I’d like to reassure you that I will be doing my best to help you and address all of your concerns and we will make the best management plan for you. Is it okay if I ask you a few questions?
Medication History
D: How long have you been on these medications?
D: Are you compliant with your medications?
D: Have you ever had side effects with these medications?
D: Are you having regular follow-ups with your GP and regular blood tests?
HASBLED: Bleeding Risk
Hypertension
D: Have you been diagnosed with a high blood pressure?
Abnormal Liver/Kidney
D: Have you ever had abnormal kidney or liver function test?
D: Any previous diagnosis of kidney and liver disease?
Stroke
D: Any previous history of stroke or mini stroke?
Bleeding
D: Any previous episodes of bleeding?
Labile INR
D: Has your warfarin INR test been stable in the past?
Alcohol & Drugs
D: Do you drink alcohol? How much?
D: Any other drugs or medications or supplements that you use?
Clotting Risk: CHADS
D: Any history of stroke?
D: Any history of heart valve replacement?
R: Yes, I have a mechanical aortic valve
D: Any previous history of clotting in your legs or your lungs?
Counselling
We will be making a decision as a team and I will involve your surgeon, your regular GP, our cardiologist and I will do my best to find and talk to your own cardiologist. In case he’s not available, I will ask one of our experienced cardiologist to come and see you to help us make a decision.
How does this plan sound?
The decision is based on comparing the bleeding risk and the clotting risk. We have assessed your bleeding risk: 1) the procedure that you’re doing (lap hernia) has low risk for bleeding (in older cases, bowel surgery for diverticulitis: high risk for bleeding); 2) we also calculated your bleeding risk using the HASBLED score, and (put in whatever patient factors you find) also increases your bleeding risk.
We also calculated your clotting risk using the CHADS score, and in your case, your history of diabetes is the only thing that affects your clotting risk, so you have a low risk for clotting.
The special feature about your blood thinner (NOAC) that you are taking is it has a quick offset of action which means the effect wears off after a few hours of stopping the medication.
I will need to check your kidney function with a test called eGFR to decide when we can stop it.
It is safe to stop it close to surgery as it stops working extremely fast.
We are most likely going to stop apixaban/rivaroxaban 24 - 48 hours before surgery, or for dabigatran 24-72 hours before surgery.
After the surgery, the surgeon will decide when to restart your medication. If there is a low risk of bleeding, we will start it 24 hours after surgery. But if there is a high risk for bleeding, we will restart it 2-3 days after surgery.
We also need to stop your other medication, dapagliflozin. We need to stop this medication 3 days before surgery. We will monitor your sugar levels and give you insulin if needed. While you’re taking the medication, please remember that you need to drink enough fluids.
For the other medications, we’ll stop them on the day of surgery.
*I’m worried about elective surgery
In an elective surgery, we have time to prepare and plan better. This is why we do blood tests and make decisions about medications. This decreases the risk of an elective surgery compared to an urgent surgery.
*I don’t like a colostomy bag
We usually use colostomy bag when we do urgent surgeries on the bowel and if an elective surgery goes well, we usually don’t need to use a colostomy bag.
Reassurance:
If you had any other further questions and concerns, I’m always here to help you. I will make sure that you are aware about the decisions we make. I can also arrange with a family meeting to discuss other concerns that you may have.
Reminder: *NO BRIDGING THERAPY FOR NOACs
