#16 VTE Prophylaxis Demystified

Venous thromboembolism (VTE) prophylaxis is a core marker of healthcare excellence. Dr. Walter Cheng, hospitalist, explains that almost every hospitalized patient is at an increased risk for developing a deep vein thrombosis (DVT) or pulmonary embolism (PE) and that nurses play a crucial role in preventing, assessing for, and educating our patients about VTE. 

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Virchow’s Triad

  • Basis for understanding risk factors for DVT/PE
  • Blood Stasis, hypercoagulability, trauma
  • When inpatient, immobility is common because patients are not moving and getting out of bed cannot circulate venous blood well


What are SCDs?

Sequential compression devices are a venous thromboembolism prevention strategy that works to stimulate circulation in the lower extremities through inflation and deflation one at a time to simulate the pumping effect of walking.

What are TED hose?

TED hose stands for “thromboembolism deterrent” hose, and are used as compression stocking for the prevention of venous dilation and therefore prevention of clots, as noted below. They work by applying continuous pressure from the calf to the thigh, thereby compressing the veins and preventing venous stasis. 

Quick Anatomy Rundown

  • Arterial Blood Flow: heart pumps blood and provides pressure to drive blood forward
  • Venous blood flow is passive — blood moves back to the heart through muscle contractions of the legs and the arms. Immobility causes the veins to not return blood as effectively (think: airplanes, prolonged bed rest)


  • Genetic causes of hypercoagulability: inflammatory diseases, infections, cancer, rheumatologic diseases, organ failure

Common Orders/interventions for DVTs

  • Most Common: injectable heparin-based compounds (ex: SQ Heparin, Lovenox)
  • Compression stockings
  • SCDs (mimic walking by squeezing the calf to encourage blood flow)

“Mobilization is as important as medication. It’s harder to give but more effective than just injecting heparin all the time → mobilization also helps to lower r/o aspiration pneumonia, delirium, ulcers, etc.” -Dr. Cheng

Risk factors for VTE

  • Obesity
  • Postoperative status and bed rest
  • Heart disease
  • > 40 years of age
  • Limb trauma
  • Coagulation disorders
  • Pregnancy
  • Advanced neoplasm
  • Oral contraceptives

Some statistics of VTE from the CDC:

  • VTEs affects an estimated 900,000 people annually (exact incidence unknown) is responsible for approximately 60,000–100,000 deaths annually
  • 10–30% of people die within 1 month of a VTE diagnosis
  • Sudden death is the first symptom in approximately 25% of people who have a PE


  • PO anticoagulants are rarely prescribed for DVT prophylaxis
  • Heparin SQ is widely used because of the ability to stop injections to do procedure 12 hrs later, with Lovenox 24 hrs later
  • Oral anticoagulants usually have to be held 24-72 hrs before a procedure

What happens if a patient is unable to take their home regimen of anticoagulants while inpatient?

  • If it is their first DVT, the patient should be treated for at least three months, if not six
  • If a patient just had one, we know they still have an active clot situation and they must continue anticoagulants.
  • If a patient is taking an anticoagulant prophylactically for atrial fibrillation, you need to think about risk of a clot in the period of time they’re inpatient

“I think that maybe other doctors will hate me for saying this, but I think that nurses should always contact a physician If a patient cannot take their oral anticoagulant because the potential consequences of missing anticoagulation could be very severe. I personally don’t think that any doctor should ever fault the nurse for contacting them about this issue.”

Tips for explaining the need for SCDs, TED hose, and the Heparin/Lovenox

  • A million cases of DVT and PE occur every year in this country. There is a real risk that this could happen to you. And unfortunately, with DVT, PE, it can be something from a very inconvenient swollen leg to a devastating and life- threatening pulmonary embolism.
  • DVT prophylaxis with subcutaneous heparin or Lovenox, decreases that risk significantly (70-80%) and the SCDs also decrease that to some percent
  • If they develop a DVT or PE, they’ll be stuck on like, oral anticoagulants from months, lowering their quality of life, prolonging hospitalization

Assessment findings of DVT/PE

  • DVT: Asymmetry in the circumference of, of one limb versus the opposite
  • PE: suddenly shorter breath and can happen very suddenly, pleuritic chest pain
  • Despite the classic signs, sometimes it can be subtle and hard to find DVT/PE, so we need to use lab tests such as:
    • D-Dimer: looks at products of clotting (elevates in PE). If negative, likelihood of DVT is low
    • CT angiogram
    • Ventilation perfusion (VQ) scan

Prophylactic v. Therapeutic Anticoagulation Therapy

  • Prophylactic anticoagulation is the use of blood thinners usually in lower doses to try to prevent a blood clot from forming in the first place.
  • Therapeutic anticoagulation is the treatment of an existing or discovered blood clot that has occurred
  • With anticoagulation, we’re trying to prevent the formation of new clot and to stabilize a preexisting clot. The goal of anticoagulants is NOT to break down the clot. The body will break down the clot on its own over time.
  • Stable patient with a DVT or PE, we use anticoagulation, because it does a really good job of just arresting the clot where it is not making any worse, and then the body can just break it down by itself nice and slowly over time
  • Signs of instability: rapid heart rates, dizziness, hypotension, syncope
  • Remember: the heart and lungs are integrated organs and when one goes down, the other will go down with it


  • We don’t use tPA because those are very strong drugs that can kill people if not used correctly
  • Major risk is catastrophic bleeding
  • You have to really be kind of knocking on death’s door to qualify for systemic thrombolytics.

Heparin Routes:


  • The key reason you give IV heparin is to stabilize a clot as fast as possible.
  • Additionally, Heparin can be turned off very quickly. For example, if a patient developed a DVT and also need a procedure,  they can turn off the heparin drip, right before the needed procedure.
  • Intravenous heparin is the only drug that can be safely then people with renal failure


If someone has a very stable clot, they can go straight to oral anticoagulation because those newer drugs actually are quick

“What my big takeaway from from our talk today is the fact that that therapeutic dosing of anticoagulants stabilizes a thrombus enough that it’s not going to produce emboli.”

Annie Fulton, RN


Mennella, H. (2018). Core Measure: Intensive Care Unit Venous Thromboembolism Prophylaxis. Evidence Based Care Sheet. CINAHL Information Systems. Unable to share link b/c accessed from school database. Shared google doc with you!

Prajwal Dhakal, Ling Wang, Joseph Gardiner, Shiva Shrotriya, Mukta Sharma, Supratik Rayamajhi. (2019). Effectiveness of Sequential Compression Devices in Prevention of Venous Thromboembolism in Medically Ill Hospitalized Patients: A Retrospective Cohort Study. Turkish Journal of Hematology. 36:193-198 DOI: 10.4274/tjh.galenos.2019.2018.0413 Retrieved from https://jag.journalagent.com/tjh/pdfs/TJH_36_3_193_198.pdf

Ouellette, D. R., (2020). Are white anti-embolic stockings (Ted hose) effective in the treatment of DVT and pulmonary embolism (PE)? MedScape. Retrieved from https://www.medscape.com/answers/300901-8576/are-white-anti-embolic-stockings-ted-hose-effective-in-the-treatment-of-dvt-and-pulmonary-embolism-pe#:~:text=The%20ubiquitous%20white%20stockings%20known,even%20that%20inadequate%20gradient%20compression.