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Exchange Information Implementation Guide Professional Development Resource Room Project Team Main Resource Room Home Venous Thromboembolism Resource Room

Draft a VTE Protocol

Construct your VTE protocol

It is time to construct the VTE protocol. Available time and attention must be focused on drafting and field-testing this critical ingredient. To be more efficient and more effective, we recommend reviewing and adapting the sample VTE protocols. Some of these protocols will suit some environments better than others. Some have been refined through generations of feedback and revisions, while others have not. Teams are encouraged to use specific features of any of these and even to paste entire sections – whatever it takes to get closer to field-testing and refining a local version of the VTE protocol.

What exactly is the VTE protocol?

The VTE protocol consists of a standardized VTE risk assessment with a linked menu of appropriate prophylaxis options, plus a method to determine contraindications to pharmacologic VTE prophylaxis.

  1. standardized VTE risk assessment - this simply delivers decision support to the point of care; in other words, at the moment of medical decision-making, providers have what they need to stratify the patient to a specific VTE risk level
  2. linked menu of appropriate prophylaxis options - this just allows providers to choose the right VTE prophylaxis by “backing in” to the choice from the VTE risk level derived from the standardized VTE risk assessment
  3. contraindications to pharmacologic or heparin prophylaxis - just like the VTE risk assessment, this also simply delivers decision support to the point of care, so providers know when to choose alternative prophylaxis, i.e. if specific contraindications to anticoagulation or heparin products exist

The VTE protocol accomplishes several things at once. First, if well-integrated into all admission, transfer, or post-op orders, it prompts providers to do the right thing at the right time. Second, it gives providers the option of using, or not using, the decision support elements. Third, the VTE protocol is a definition of what the team will consider “appropriate prophylaxis” for the patients within the scope of the improvement effort. This definition will be critical when it comes time to measure baseline and new prevalence of appropriate VTE prophylaxis. It will be helpful also as an educational tool and its existence will help set expectations for care. While we recommend trying to create a VTE protocol for the majority of adult patients at the institution, both medical and surgical, ultimately the team must make its own decision about the scope of the VTE protocol. The steps to define “appropriate prophylaxis” are:

  1. Create or adapt any VTE risk assessment to meet local needs (see the sample VTE protocols)
  2. Choose recommended options for each level of VTE risk
  3. Decide upon acceptable options for each level of VTE risk. The term “acceptable” is intentionally looser than “recommended” and will become significant when measuring whether prophylaxis is appropriate, i.e. while IV heparin may not be recommended for VTE prophylaxis, it probably should be considered an acceptable alternative when it is being used for other indications.
  4. Identify absolute and relative contraindications to pharmacologic prophylaxis and settle on acceptable alternatives for these patients.

In this section, we offer specific advice in constructing a VTE protocol to meet local needs.  The power of the VTE protocol will be unleashed only when it is well-integrated into the clinical workflow. That integration will be the team’s next most important objective. How the team accomplishes this will depend on institutional culture and infrastructure, such as whether the hospital uses CPOE or paper order sets.

No single VTE risk assessment has been prospectively validated as superior to others. Many factors should be taken into account when adapting one. A list of published articles focusing on VTE risk assessment appears on the last page of this section. The ideal VTE risk assessment would have the following characteristics:

  1. Applicable across all patients in the scope.
    We recommend an approach where the team creates a single VTE protocol for all patient groups targeted by the improvement effort. For example, if the scope includes all medical and surgical patients, avoid customizing separate VTE protocols for general surgery, gyn/onc, orthopedic surgery, and medical patients. Instead try to construct a single VTE protocol that can be applied to all of them. The advantage of this approach comes from the power of standardization. A universal VTE protocol can be more readily approved and initiated; it is more likely to be recognized as definitive in its authority; it is easier to modify based on feedback; and adherence to a single VTE protocol can more readily serve as a surrogate measure for performance tracking. The predictable disadvantages are those that come from any effort that tries to apply a common solution to different groups. The challenge will be to strike a balance between limiting prophylaxis options too much (“satisfying nobody”) and allowing every option under the sun (“too busy”). There are several ways to overcome these disadvantages, but the simplest rule-of-thumb is always to allow providers the leeway of going “off protocol” when clinically appropriate.
  2. Easy to access and easy to use.
    Simpler is better. Eventually the team may be asking providers to refer to or recall elements of the VTE protocol several times during a patient’s admission.
  3. Each level of risk should be linked to evidence-based choices for prevention.
    Explore local factors that may play a role in selecting agents of choice for each level of VTE risk. Accounting for these local factors, the team should then move on to draft the VTE protocol. The team will be exploring not only which options are most appropriate for each level of risk, but which agents, given own local factors, should be the preferred agents for each level of risk. Relative efficacy, dosing schedules, formulary costs, and side effect profiles are all important considerations.
  4. Contraindications to prophylaxis should be listed and reasonable alternatives should be encouraged.
    When defining contraindications to pharmacologic prophylaxis, be wary of being too liberal in defining the contraindications: many patients with “relative contraindications” develop VTE and usually end up on full dose anticoagulation anyway. Be as specific as possible when using time parameters. For example, “recent gastrointestinal hemorrhage” is not as useful as “gastrointestinal hemorrhage within one month.”

We highly recommend asking a focus group of hospitalists, residents, or anybody who frequently writes admission orders to try out early drafts of the VTE protocol. It is never too early to start listening to the end-user. Whatever is learned from focus groups should feed back immediately into a new version. Using qualitative feedback to make daily revisions for a week can bring the team very close to perfecting the usability of the VTE protocol. More detail on how to get the most out of these early pilot efforts can be found in Section 3.3 (Data Collection).

Ultimately the team should be striving for perfect integration of the VTE protocol into admission and transfer order-writing, so the importance of a simple and easy-to-use model cannot be overstated. Even if the VTE protocol is supremely easy to use, it will be ineffective if patients bypass the protocol. In later sections, we outline a number of approaches to prevent this, and many other methods to enhance the reliability of the VTE protocol.

How UCSD Handled a Few Common Questions:
UCSD is a 300-bed referral center

Should IPC be a first line “appropriate” choice for patients at moderate risk of VTE?
At UCSD, we originally wanted to keep IPC as an option for patients at moderate risk for VTE (in spite of a lack of solid evidence in the literature for medical patients). Our audits revealed about 55% compliance with IPC, however, and we then adapted the approach of the ACCP Consensus conference, which relegates IPC to patients with contraindications for pharmacologic prophylaxis but also as a secondary method to enhance the effectiveness of pharmacologic prophylaxis.

Which patients need IPC in addition to pharmacologic prophylaxis?
At UCSD, we decided the very high risk MUST have it, while other patients COULD have it.

Which patients should have Heparin 5000 units q 12 hours as an option vs Heparin 5000 units q 8 hours?
We initially had 4 levels of VTE risk. We allowed Heparin 5000 units q 12 h as a choice for patients at moderate VTE risk (which described many of our medical ward patients), but advocated the higher frequency 5000 units q 8 h for high risk patients (which typified our sicker medical and critical care patients).

Eventually we collapsed our moderate and high-risk categories into a single category because:
   -poor compliance with IPC eliminated that as a viable first line method.
   -many of our patients on heparin 5000 units q 12 h were still developing VTE
   -it would greatly simplify our risk assessment tool and order sets if we eliminated it as an option for all patients unless they    were 50 kg or less.
Your team may very logically make alternative choices based on your local factors.

Should we offer UFH 7,500 q 12 h as an option?
At first glance this is an attractive choice, as it retains q 12 h dosing and pharmacodynamically should deliver the same protection as offered by the clinical trial proven UFH 5000 q 8 h regimens. Unfortunately, we found that our pharmacy or nurses had to draw up 7500 unit doses on special order, while the 5000 unit doses came pre-packaged from the distributor. Your situation may vary, but for us the 7500-unit dose carried too many labor, cost, and potential safety issues.

Should LMWH or UFH be our recommended choice for VTE prophylaxis in moderate to high-risk patients?

This is a difficult decision for many institutions, and your task is to make a team decision that is best for your patients and nurses, while still being fiscally responsible.

To make an informed decision, you need to take into account:

  1. Pharmacy cost
  2. Cost of administration (q 8 hours vs q day.)
  3. Patient satisfaction / Nursing satisfaction
  4. Lower incidence of HIT with LMWH
  5. Danger of using LMWH as default (will you forget to use UFH in patients with renal insufficiency, or do you have a reminder process that works in these situations?)
  6. Roughly equivalent performance (some would argue a slight edge exists for LMWH, especially in the critically ill patients)

At UCSD we found the following:


Pharmacy cost

Admin time / cost

Total cost

LMWH q day


10 min /  $5.33


UFH q 8 h


30 min / $16.00


Pharmacy costs above are based on actual pharmacy purchase costs at UCSD (not retail cost to customer). Admin time / cost are based on GRASP methodology estimates of nursing time to administer UFH q 8h vs LMWH q day: estimated as 10 minutes per injection, multiplied by the going average RN rate ($32/hour).  Note, that this does not mean the institution really reaps the savings of 20 minutes nursing time per day, but rather it represents an opportunity cost, i.e. the nurse is freed up for 20 minutes for other responsibilities. For more on GRASP methodology:

While there was only a $4.33 difference in cost per patient day between these two options, and the q day dosing of LMWH is attractive to patients and nurses, we decided to allow for either UFH 5000 q 8 h or Enoxaparin 40 mg / day as first options for patients at intermediate VTE risk.  We thought is was important to retain an UFH choice in patients with ESRD, and had no valid reason to exclude it as an option in the intermediate VTE risk population. Your team needs to make these decisions based on your own environment.

How Emory Handled a Few Common Questions:
Emory University Hospital is a 550-bed referral center and Emory Crawford Long Hospital is a 550-bed community teaching hospital

Should LMWH or UFH be our recommended choice for VTE prophylaxis in moderate to high-risk patients? 
At Emory, because the literature demonstrates superiority of LMWH over UFH in a relatively small sub-set of patient populations* we decided to design a simple VTE protocol that could be applied to the majority of patients for whom efficacy is comparable.  We also found this made it much easier to risk stratify and recommend prophylaxis options for these patients. Since only a small percentage of our inpatients could be considered low risk, almost all our inpatients without contraindications to pharmacologic prophylaxis should be receiving either UFH or LMWH.

We decided it wouldn’t be hard to customize VTE protocols for patients groups in whom LMWH is a better choice.  Similarly, the provider groups for patients where pharmacologic prophylaxis is contraindicated appreciated that we could also customize their VTE protocols to hardwire mechanical prophylaxis and steer clear of check boxes for pharmacologic prophylaxis.

   *spinal cord injury, acute ischemic stroke, multiple major trauma, major orthopedic surgery, and bowel surgery for cancer      patients

Which patients need mechanical in addition to pharmacologic prophylaxis?
At Emory, because of the very large risk group “intermediate-to-high” we decided that mechanical prophylaxis should not be part of our recommendations for routine prophylaxis. But we did include mechanical prophylaxis as an option to add for patients with more risk factors and for patients with relative or absolute contraindications to pharmacologic prophylaxis.

In our orthopedic VTE protocol we did present the combination of mechanical and pharmacologic prophylaxis as the recommended option.

Which patients should have Heparin 5000 units q 12 hours as an option versus Heparin 5000 units q 8 hours?
At Emory we found that a portion of our inappropriate prophylaxis derived from the choice of BID Heparin in patients younger than 75, a group in whom BID Heparin is not convincingly better than placebo. So while we wanted to reduce the frequency of BID Heparin in those patients, we did decide to preserve it as an option for patients older than 75. To discourage inappropriate use of BID Heparin we indented it from the margin a bit and added the qualifier “inadequate except for patients older than 75.”

Suggested Reading

Published Papers Looking at VTE Risk Factors or VTE Risk Assessment

Samama MM, Dahl OE, Mismetti P, Quinlan DJ, Rosencher N, Cornelis M, de Vries H, van Beusekom I, Kahan JP. (2006) An electronic tool for venous thromboembolism prevention in medical and surgical patients. Haematologica. 2006 Jan;91(1):64-70.

Labarère, José, Bosson, Jean-Luc, Bergmann, Jean-François & Thilly, Nathalie (2004)
Agreement of Four Competing Guidelines on Prevention of Venous Thromboembolism and Comparison with Observed Physician Practices.
Journal of General Internal Medicine 19 (8), 849-855.

Labarere, J., Bosson, J.-L., Brion, J.-P., Fabre, M., Imbert, B., Carpentier, P. & Pernod, G. (2004)
Validation of a clinical guideline on prevention of venous thromboembolism in medical inpatients: a before-and-after study with systematic ultrasound examination.
Journal of Internal Medicine 256 (4), 338-348.

Caprini, J., Arcelus, J., & Reyna, J. (2001)
Effective Risk Stratification of Surgical and Nonsurgical Patients for Venous Thromboembolic Disease.
Seminars in Hematology 38 (2) Suppl 5, 12-19.

Motykie, G., Zebala, L., Caprini, J., Lee, C., Arcelus, J., Reyna, J., Cohen, E., Courtney, T., & Sullivan, L. (2000)
A Guide to Venous Thromboembolism Risk Factor Assessment.
Journal of Thrombosis and Thrombolysis 9, 253-262.

Anderson, F., Spencer, F. (2003)
Risk Factors for Venous Thromboembolism.
Circulation 107, I-9-I-16.

Gensini, G., Prisco, D., Falcini, M., Comeglio, M., & Colella, A. (1997)
Identification of Candidates for Prevention of Venous Thromboembolism.
Seminars in Thromboembolism and Hemostasis 23 (1), 55-67.

Haas, S. (2002)
Venous Thromboembolic Risk and Its Prevention in Hospitalized Medical Patients.
Seminars in Thromboembolism and Hemostasis 28 (6), 577-583.

National Experts’ Consensus Panels for Clinical Excellence in Thrombosis Management, Goldhaber, S (Chair). (2003)
Prophylaxis of Venous Thromboembolism in The Hospitalized Medical Patient.
Hospital Medicine Reports 1-20.




Venous Thromboembolism Resource Room Project Team
This resource room is sponsored in part by a non-educational sponsorship from sanofi-aventis US, LLC

The Venous Thromboembolism (VTE) Resource Room is an online resource for visitors to the Society of Hospital Medicine’s website. All content and links have been reviewed by the VTE Resource Room Project Team, however the Society of Hospital Medicine does not exercise any editorial control over content associated with the external links that have been made available via this website.

The contributions of Dr. Maynard and his UCSD collaborators in the development of the SHM VTE Prevention Resource Room and the VTE Prevention Implementation Guide were supported by grant number 1U18HS015826-01 from the Agency for Healthcare Research and Quality (AHRQ). The contents of this product are solely the responsibility of Dr. Maynard and the SHM VTE Resource Room team, and do not necessarily represent the official view of or imply endorsement by AHRQ or the U.S. Department of Health and Human Services.

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