Thread by @nihardesai7

As a #medicine resident you'll come across 👇🏻 scenario often.

Your #surgery colleagues want you to opine on the type and duration of ANTICOAGULATION and also want to know why it occured in the first place🤷‍♂️

Let's dig deeper 👇🏻

1/24

#MedTwitter #DVT

Yeah, this is obviously a Deep Vein Thrombosis (DVT) !

It's fairly common, develops in about 1/1000 people 😮

Remember, DVT+PE = VTE

PE= pulm embolism
VTE= venous thromboembolism

⭐1/3 DVT develop PE⭐

The PE is what can lead to mortality!
Preventing PE is IMPORTANT 🙏🏻

2/24

DVT is not less of a monster !

Many w/ DVT will develop post thrombotic syndrome 😮 That's a lot of morbidity, leg pain, swelling, ulceration and all 😭

But
🔸Why does VTE occur ?
🔸Who's at risk of developing it ?
🔸Can we prevent it ?
🔸How does one treat it ?

3/24

Before we proceed any further, does anyone recognise 👇🏻 gentleman??

4/24

Yes, he's Dr Rudolf Carl Virchow, a 🇩🇪 physician/pathologist.

He coined the terms "thrombosis" & "embolism" amongst others!

The first to propose that clots in the lower limbs "embolize" to the lungs, back in 1856.

THE Virchow after whom Virchow nodes are named!

5/24

Ok, so a clot forms when there's:
1️⃣Bad blood (hypercoag)
2️⃣Bad vessel (vessel wall injury)
3️⃣Lazy blood (stasis)

So, these are the risk factors for VTE:
1. Surgery
2. Immobilization
3. Cancer
4. Pregnancy/post partum
5. Obesity
6. ⤴️Age
7. Bad blood (thrombophilia)

6/24

Most of these causes affect >1 of the Virchow triad factors !

As an example, cancer causes stasis + bad blood (cancer procoagulant) + bad vessel 😭

Ok, enough with the history and bad blood etc 🤣

7/24

#MedTwitter

What does a busy resident need to know 🤷‍♂️
🔸How to diagnose?
🔸How to treat?

There is something known as the Wells score !! It predicts the PRE-TEST PROBABILITY of DVT but I rarely use it.

So what do I use ?
🔸D-dimer
🔸Compression ultrasound (CUS)

8/24

#MedTwitter

The D-dimer is a fibrin degradation product. It is ⤴️ when the body tries to lyse a clot !!

DVT isn't the only cause of an ⤴️D-dimer. It's also ⤴️ in:
🔸Pregnancy
🔸Malignancy
🔸Liver disease

So we can't use D-dimer to diagnose DVT in these conditions !!

#MedTwitter

9/24

The D-dimer is NOT SPECIFIC for DVT but it is QUITE SENSITIVE !

What I mean to say is that it can RULE OUT a DVT ✅

Normal D-dimer=⤵️probability of DVT

⬇️

If the D-dimer is ➕ get a compression ultrasound (CUS)

10/24

#MedTwitter

There are other imaging modalities to diagnose DVT, like CT/MR venography !

But CUS is easy, cheap and accurate.

If a vein doesn't compress when the probe presses on it = thrombus ✅

#MedTwitter

11/24

CUS is good for picking up proximal DVT, not so much for distal DVT.

PROXIMAL = above the knee
PROXIMAL = ilio-femoral-popliteal veins

What you need to recognise clinically are the limb threatening signs 😮

Why?
Because, in addition to anticoag you will need to lyse the clot!

What are these LIMB THREATENING SIGNS?
🔸Absent pulse
🔸Cyanosis
🔸Gangrene

This is what we call PHELGMASIA CERULEA DOLENS (PCD) 👇

PCD is the ONLY indication of thrombolysis/ thrombectomy.

And catheter directed is always better than systemic thrombolysis 👍🏻

13/24

Let's summarise what we've learnt till now !
🔸DVT is bad/morbid
🔸Risk ⤴️ w/ ⤴️age
🔸Hospitalisation/SX is a risk factor
🔸Virchow triad messed up
🔸D-dimer negative = DVT unlikely
🔸CUS is good to pick it up
🔸PCD needs thrombolysis !!

#MedTwitter

14/24 phew 🤣

How do we treat run of the mill DVT ??

ANTICOAGULATION obviously 🤷‍♂️

But,
🔸Which one ?
🔸For how long ?

For DVT, I can now safely say 👇🏻
⭐NOAC > VKA/Heparin⭐

NOAC include:
🔸ApiXaban
🔸RivaroXaban
🔸EdoXaban
🔸Dabigatran

Xa = Factor Xa inhibitors

#MedTwitter

15/24

Dosing NOACs:
-ApiXAban:10mg BD x 7d➡️5mg BD
-RivaroXaban:15mg BD x 21d➡️20 OD
-EdoXaban: 60mg OD
-Dabigatran: 150mg BD

Can these be used in patients w/ cancer asso. thrombosis ?

YES ✅✅ (avoid in GI malignancies)

No money for NOAC, no problem. Use VKA, monitor INR !!

16/24

Next important question 👇🏻

That depends on whether the DVT was provoked or unprovoked ??

Provoked = Risk factor identified

Let's recap the risk factors:
Pregnancy
Surgery
OCP
Long distance travel
Immobilization
Cancer
Obesity

Provoked = 3 months of anticoagulation
Unprovoked = Tricky business 🤷‍♂️

See 👇🏻

To answer this we must remember that we need to balance the risk vs benefit of anticoagulation!

Risk=bleeding risk
Benefit=preventing recurrent clots

So who has ⤴️risk of recurrent clots?
-previous h/o VTE
-♂️
-Obese
-thrombophilia✅

May consider longer duration rx here!
19/24

LONGER DURATION 🤷‍♂️

What does that even mean ??

ANYTHING >3 MONTHS. Sometimes lifelong, sometimes till there is resolution of the underlying "provoking" factor !!

20/24

#MedTwitter

Next question 👇🏻

I've heard so much about these IVC filters, what's all that about ??

I almost never recommend it!

The only indication is:
Acute, proximal leg vein DVT and an ABSOLUTE CONTRAINDICATION to ANTICOAGULATION !

If necessary, place it for the shortest possible time!

Summary slide for those lazy to read the whole thread 🤷‍♂️

-DVT is common
-⤴️Risk during hospital stay/SX/🤰
-Normal D-dimer can rule it out
-CUS is a good test, sensitive✅
-DOAC > VKA/heparin
-LWMH = DOAC for cancer asso VTE
-NOAC not safe in pregnancy !

22/24

#MedTwitter

The most important point 👇🏻

⭐⭐NOT EVERY DVT NEEDS A FULL THROMBOPHILIA WORKUP ⭐⭐

No factor V Leiden, Protein C/S/AT/APLA et al 🛑

There are a lot of other "provoking" factors like obesity, immobility, smoking, surgery, drugs like OCP. Plz take a detailed history

23/24

If you have read the whole thread, THANK YOU 💪🏼👍🏻

If you have read just the summary slides, I still THANK YOU 🤣

Share, retweet if you found this useful !

24/24 🙏🏻

#MedTwitter