Teaching session - VTE
I have made a guideline on venous thromboembolism and its management in the NHS based on my experience.
This is only for educational purposes and if in doubt, kindly refer to your local guidelines and ask your seniors. Please remember that these guidelines vary from trust to trust which you will be introduced to during your induction and your first few days in your trust.
VTE PROPHYLAXIS
Is there are reversal agent for warfarin?
Yes-
Beriplex which is prothrombin complex. This acts immediately
Vitamin K - which takes some time to act.
Both medications are given after a discussion with your seniors and in most trusts, with the hematologist on call.
OTHER NOACS - NOVEL ORAL ANTICOAGULANTS
These include:
- Dabigatran
-Apixaban
-Rivaroxaban.
How do we monitor the efficacy of these?
Unfortunately we cannot.
How do we reverse the effects of these if the patient has had a bleed?
Currently, only dabigatran has a reversal agent. This is called Idarucizumab. This is a very expensive drug and therefore is given after a discussion with your seniors and in most trusts, with the hematologist on call.
A patient needs an anticoagulant- what should I prescribe. Warfarin or a NOAC?
This is the patients decision. Some trusts may also have guidelines on a particular NOAC to give in a particular condition therefore go through your trusts local guidelines and ask your seniors for advice.
There is no particular guidance on this. What should I do?
Usually every trust has an pharmacists or anticoagulant nurse who counsels the patients.
These have also been explained here:
https://www.bhf.org.uk/heart-matters-magazine/medical/drug-cabinet
What are the PROS and CONS of warfarin?
PROS:
1. Can be reversed easily.
2. We know how well it is working and adjust the dose accordingly.
CONS:
1. High risk of bleeding
2. Regular blood tests - known as INR.
3. Can interact with a lot of medications and food items some of which are mentioned here:
https://www.nhs.uk/conditions/warfarin/
How do we diagnose DVT?
The gold standard is ultrasound doppler of the legs which checks if the veins are patent or not.
What is the treatment?
Initially, patients may be started on LMWH at a dose higher than prophylactic LMWH.
I have a high clinical suspicion of DVT. The ultrasound is being awaited.
If you have a high clinical suspicion and there is no contraindication, treat it. Of course, inform your seniors and go through your trusts guidelines.
What is the DVT pathway?
Most trusts have a pathway flowchart on the intranet which you can download and print out. Tick the boxes and follow whatever it says.
PULMONARY EMOBOLISM
What are the clinical signs of this?
Chest pain, shortness of breath, desaturation on mobility, features of right heart strain on the ECG.
The history, blood tests are the same as DVT.
What is the gold standard investigation?
CTPA- dye is injected into the veins (make sure such patients have a wide bore cannula like a pink cannula) which then enhances the pulmonary vessels. If there is a filling defect, this means the patient has a PE.
The CTPA can also show features of right heart strain which means that the patient is at high risk of becoming unstable.
Are there any contraindications to CTPA?
A worsening renal function, allergy to dye, claustrophobia. In this case, discuss it with your seniors. Sometimes stopping nephrotoxic drugs and giving IV fluids over 24 hours can improve the renal function and the patients can then have a CTPA.
How should I treat this?
The initial treatment is the same as DVT - make sure that patient has had treatment dose LMWH. Do not wait for the CTPA. If you suspect a PE on clinical grounds, treat it unless there is any contraindication.
Is there any other investigation I could do?
An echocardiogram to ascertain what the baseline pulmonary artery systolic pressure is. Some consultants state that they do not need it if the CTPA confirms right heart strain but there is varying advice on this therefore always talk to your consultant.
How long will the patient stay on LMWH?
The management varies from trust to trust. In some trusts, they are bridged with warfarin (ie they receive both LWMH and warfarin) till the INR is above a certain level. In some trusts they are discharged on a NOAC if they remain well with a follow up in 3 to 6 months.
Is there a guideline on this?
Yes- it is available on the trusts intranet.
As mentioned above, this is just a short teaching session. Kindly follow your trusts guidelines and ask your seniors for advice.
This is only for educational purposes and if in doubt, kindly refer to your local guidelines and ask your seniors. Please remember that these guidelines vary from trust to trust which you will be introduced to during your induction and your first few days in your trust.
VTE PROPHYLAXIS
What is VTE?
This stands of venous thromboembolism which includes deep vein thrombosis and pulmonary embolism.
What is the fuss about VTE prophylaxis?
Studies have shown that patients admitted to hospitals are at high risk of developing clots in their lungs and lungs especially if they are immobile.
https://www.england.nhs.uk/statistics/statistical-work-areas/vte/
So what is the management?
The usual management is giving low molecular weight heparin or enoxaprin/unfractionated heparin once a day. The dose is based on the patients weight and the creatinine clearance.
This is known as VTE prophylaxis.
These are given subcutaneously into the abdomen.
What are the contraindications to low molecular weight/unfractionated heparin/enoxaparin?
Here are some contraindications:
1. Acute ischemic stroke - These VTE prophylactic medications can increase of bleeding into that area of infarct. The risk is especially high in the first 2 to 4 weeks (the cut off duration varies from trust to trust - check your local guidance)
2. Acute hemorrhagic stroke or any acute bleed (ie upper GI bleed, etc)
3. Undergoing a radiologically invasive procedure like a lumbar puncture, pleural aspiration.
4. Low platelet count- the cut off varies from trust to trust. Some use 70 or 75 as the cut off .
5. Concomitant use of anticoagulants like warfarin, rivaroxaban, apixaban, dabigatran
6. Acute drop in Hb.
7. If the patient is on ACS protocol (ie aspirin plus ticagrelor/clopidogrel plus fondaparinux).
Kindly also check your trusts guidelines on this.
Why is prescribing VTE prophylaxis a big deal?
NHS trusts have to meet targets for VTE prophylaxis. The patients notes and drug charts are analyzed by the coding department which then tabulates how many patients received it and the reason behind why they did not. The trust then gets paid by the Department of Health is it meets the target.
How do I prescribe VTE prophylaxis?
When the patient does not have any contraindication mentioned above, you should prescribe appropriate VTE prophylaxis.
Is there an assessment form for this?
Usually there is a VTE assessment form in the clerking booklet.
Is there any indication of holding VTE prophylaxis on admission?
If you are worried about the contraindications mentioned above or if the patient has been admitted with confusion and is awaiting a CT head ( prescribe it if it is normal and the patient does not have any features of stroke).
Do we need to monitor clotting or any other blood indices to check for the efficacy of LMWH?
No you do not.
WARFARIN
What are the reasons for a patient to be on warfarin?
You can read about the indications and target INRs for patients on warfarin here:
https://www.gpnotebook.co.uk/simplepage.cfm?ID=1617625155
This stands of venous thromboembolism which includes deep vein thrombosis and pulmonary embolism.
What is the fuss about VTE prophylaxis?
Studies have shown that patients admitted to hospitals are at high risk of developing clots in their lungs and lungs especially if they are immobile.
https://www.england.nhs.uk/statistics/statistical-work-areas/vte/
So what is the management?
The usual management is giving low molecular weight heparin or enoxaprin/unfractionated heparin once a day. The dose is based on the patients weight and the creatinine clearance.
This is known as VTE prophylaxis.
These are given subcutaneously into the abdomen.
What are the contraindications to low molecular weight/unfractionated heparin/enoxaparin?
Here are some contraindications:
1. Acute ischemic stroke - These VTE prophylactic medications can increase of bleeding into that area of infarct. The risk is especially high in the first 2 to 4 weeks (the cut off duration varies from trust to trust - check your local guidance)
2. Acute hemorrhagic stroke or any acute bleed (ie upper GI bleed, etc)
3. Undergoing a radiologically invasive procedure like a lumbar puncture, pleural aspiration.
4. Low platelet count- the cut off varies from trust to trust. Some use 70 or 75 as the cut off .
5. Concomitant use of anticoagulants like warfarin, rivaroxaban, apixaban, dabigatran
6. Acute drop in Hb.
7. If the patient is on ACS protocol (ie aspirin plus ticagrelor/clopidogrel plus fondaparinux).
Kindly also check your trusts guidelines on this.
Why is prescribing VTE prophylaxis a big deal?
NHS trusts have to meet targets for VTE prophylaxis. The patients notes and drug charts are analyzed by the coding department which then tabulates how many patients received it and the reason behind why they did not. The trust then gets paid by the Department of Health is it meets the target.
How do I prescribe VTE prophylaxis?
When the patient does not have any contraindication mentioned above, you should prescribe appropriate VTE prophylaxis.
Is there an assessment form for this?
Usually there is a VTE assessment form in the clerking booklet.
Is there any indication of holding VTE prophylaxis on admission?
If you are worried about the contraindications mentioned above or if the patient has been admitted with confusion and is awaiting a CT head ( prescribe it if it is normal and the patient does not have any features of stroke).
Do we need to monitor clotting or any other blood indices to check for the efficacy of LMWH?
No you do not.
WARFARIN
What are the reasons for a patient to be on warfarin?
You can read about the indications and target INRs for patients on warfarin here:
https://www.gpnotebook.co.uk/simplepage.cfm?ID=1617625155
What is INR?
It is used to calculate the blood thinning capacity and to ensure that it is within therapeutic range.
When should INR be calculated?
On admission, if a patient is started on a new medication as an inpatient or when the INR is climbing up or is sub-therapeutic and the warfarin dose has changed.
A patients INR is very high. What should I do?
https://gpnotebook.co.uk/simplepage.cfm?ID=1443233855
It is used to calculate the blood thinning capacity and to ensure that it is within therapeutic range.
When should INR be calculated?
On admission, if a patient is started on a new medication as an inpatient or when the INR is climbing up or is sub-therapeutic and the warfarin dose has changed.
A patients INR is very high. What should I do?
https://gpnotebook.co.uk/simplepage.cfm?ID=1443233855
There are local guidelines for management of high INR - make sure you follow them.
If a patient is on high dose warfarin it is best to discuss this with your pharmacists/anticoagulant nurses if there are no features of bleeding if you could possibly reduce the dose rather than stopping it completely.
If a patient is on high dose warfarin it is best to discuss this with your pharmacists/anticoagulant nurses if there are no features of bleeding if you could possibly reduce the dose rather than stopping it completely.
Is there are reversal agent for warfarin?
Yes-
Beriplex which is prothrombin complex. This acts immediately
Vitamin K - which takes some time to act.
Both medications are given after a discussion with your seniors and in most trusts, with the hematologist on call.
OTHER NOACS - NOVEL ORAL ANTICOAGULANTS
These include:
- Dabigatran
-Apixaban
-Rivaroxaban.
How do we monitor the efficacy of these?
Unfortunately we cannot.
How do we reverse the effects of these if the patient has had a bleed?
Currently, only dabigatran has a reversal agent. This is called Idarucizumab. This is a very expensive drug and therefore is given after a discussion with your seniors and in most trusts, with the hematologist on call.
WARFARIN OR NOAC?
A patient needs an anticoagulant- what should I prescribe. Warfarin or a NOAC?
This is the patients decision. Some trusts may also have guidelines on a particular NOAC to give in a particular condition therefore go through your trusts local guidelines and ask your seniors for advice.
There is no particular guidance on this. What should I do?
Usually every trust has an pharmacists or anticoagulant nurse who counsels the patients.
These have also been explained here:
https://www.bhf.org.uk/heart-matters-magazine/medical/drug-cabinet
Basically they explain the PROS and CONS of each medication.
What are the PROS and CONS of warfarin?
PROS:
1. Can be reversed easily.
2. We know how well it is working and adjust the dose accordingly.
CONS:
1. High risk of bleeding
2. Regular blood tests - known as INR.
3. Can interact with a lot of medications and food items some of which are mentioned here:
https://www.nhs.uk/conditions/warfarin/
What are the PROS and CONS of NOACS?
PROS:
1. Equally effective as warfarin.
2. No need for frequent blood tests.
CONS:
1. High risk of bleeding.
2. Some NOACS like apixaban or rivaroxaban cannot be taken when the renal function worsens.
3. Some NOACS like apixaban or rivaroxaban cannot be reversed.
The patients are given information leaflets and then make a decision.
DEEP VEIN THROMBOSIS
History is very important - Long haul flights, pregnancy, malignancy, long periods of immobility, family history, previous history are all risk factors
What are the clinical signs of this?
Calf tenderness, asymmetrical swelling.
What initial tests can we do?
Send routine bloods which includes FBC, CRP, U and E's, LFTs, clotting and a D dimer.
What is a D Dimer?
This a index used to check the fibrin degradation products in your blood. Do bear in mind that this can be falsely positive in a few conditions which are mentioned here:
https://www.gpnotebook.co.uk/simplepage.cfm?ID=x20050523071756411760
PROS:
1. Equally effective as warfarin.
2. No need for frequent blood tests.
CONS:
1. High risk of bleeding.
2. Some NOACS like apixaban or rivaroxaban cannot be taken when the renal function worsens.
3. Some NOACS like apixaban or rivaroxaban cannot be reversed.
The patients are given information leaflets and then make a decision.
DEEP VEIN THROMBOSIS
History is very important - Long haul flights, pregnancy, malignancy, long periods of immobility, family history, previous history are all risk factors
What are the clinical signs of this?
Calf tenderness, asymmetrical swelling.
What initial tests can we do?
Send routine bloods which includes FBC, CRP, U and E's, LFTs, clotting and a D dimer.
What is a D Dimer?
This a index used to check the fibrin degradation products in your blood. Do bear in mind that this can be falsely positive in a few conditions which are mentioned here:
https://www.gpnotebook.co.uk/simplepage.cfm?ID=x20050523071756411760
How do we diagnose DVT?
The gold standard is ultrasound doppler of the legs which checks if the veins are patent or not.
What is the treatment?
Initially, patients may be started on LMWH at a dose higher than prophylactic LMWH.
I have a high clinical suspicion of DVT. The ultrasound is being awaited.
If you have a high clinical suspicion and there is no contraindication, treat it. Of course, inform your seniors and go through your trusts guidelines.
What is the DVT pathway?
Most trusts have a pathway flowchart on the intranet which you can download and print out. Tick the boxes and follow whatever it says.
PULMONARY EMOBOLISM
What are the clinical signs of this?
Chest pain, shortness of breath, desaturation on mobility, features of right heart strain on the ECG.
The history, blood tests are the same as DVT.
What is the gold standard investigation?
CTPA- dye is injected into the veins (make sure such patients have a wide bore cannula like a pink cannula) which then enhances the pulmonary vessels. If there is a filling defect, this means the patient has a PE.
The CTPA can also show features of right heart strain which means that the patient is at high risk of becoming unstable.
Are there any contraindications to CTPA?
A worsening renal function, allergy to dye, claustrophobia. In this case, discuss it with your seniors. Sometimes stopping nephrotoxic drugs and giving IV fluids over 24 hours can improve the renal function and the patients can then have a CTPA.
How should I treat this?
The initial treatment is the same as DVT - make sure that patient has had treatment dose LMWH. Do not wait for the CTPA. If you suspect a PE on clinical grounds, treat it unless there is any contraindication.
Is there any other investigation I could do?
An echocardiogram to ascertain what the baseline pulmonary artery systolic pressure is. Some consultants state that they do not need it if the CTPA confirms right heart strain but there is varying advice on this therefore always talk to your consultant.
How long will the patient stay on LMWH?
The management varies from trust to trust. In some trusts, they are bridged with warfarin (ie they receive both LWMH and warfarin) till the INR is above a certain level. In some trusts they are discharged on a NOAC if they remain well with a follow up in 3 to 6 months.
Is there a guideline on this?
Yes- it is available on the trusts intranet.
As mentioned above, this is just a short teaching session. Kindly follow your trusts guidelines and ask your seniors for advice.
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