Preventing DVT Disasters

Joseph A. Caprini, MD, FACS, RVT, DFSVS, is succinct in explaining why you must make DVT prevention a priority. “The leading cause of death after surgery or hospitalization is pulmonary embolism,” says Dr. Caprini, a senior clinician educator at the Pritzker School of Medicine at the University of Chicago, emeritus physician at NorthShore University HealthSystem in Evanston, Ill., and the creator of the Caprini Risk Assessment Score for Thromboembolism and DVT (osmag.net/capriniscore). “That’s what DVT prevention is all about.”

Jeremy Podolnick, MD, an assistant professor of surgery at Mount Sinai Health System in New York City, puts the effects of DVT into a concerning perspective. “Complications from DVT kill more people every year than breast cancer, motor vehicle accidents and HIV combined,” he says. “Even though it doesn’t get as much attention as some of those issues, DVT complications can be quite significant.”

DVT occurs when blood clots form in a vein, typically in the leg. Clots that break free and travel to the lungs could cause a pulmonary embolism that has fatal consequences. What’s worse, DVT is a particularly pernicious condition because its classic symptoms (chest or lung pain, shortness of breath) often don’t occur until after the patient has been discharged. Plus, there’s a common misconception that patients who undergo outpatient procedures — particularly young, healthy individuals — are at low risk for DVT.

DVT can happen to anybody. Even the healthiest people can develop it.
— Jeremy Podolnick, MD

“Minor procedures such as arthroscopies, appendectomies and cholecystectomies may be low-risk procedures from the surgical standpoint, but if the patient has several risk factors for DVT, they could actually be more dangerous than a high-risk procedure,” says Dr. Caprini.

It’s up to your care team to determine how many risk factors a patient presents with, and provide the appropriate preemptive measures to prevent DVT from occurring.

The best way to prevent DVT is through a thorough patient assessment — checking for red flags such as inflammatory bowel disease, cancer, past history or family history of thrombosis and obstetrical complications, which indicates a patient might carry antiphospholipid antibodies that cause blood clots — to create a clearer picture of whether the individual may be at risk. “DVT can happen to anybody,” says Dr. Podolnick. “Even the healthiest people can develop it.”

For Dr. Podolnick, this assessment centers around a questionnaire that looks at different medical comorbidities and risk factors such as family history of DVT, cancer diagnosis or receiving cancer treatments, obesity, smoking status. It’s especially important to ask about family history of thrombosis, the discovery of which may mean the difference between life and death. “It’s one of the most significant risk factors in the development of blood clots,” says Dr. Caprini, “especially for patients undergoing operations that are considered minor procedures.”

Of course, there are many factors that can lead to increased risk of DVT. That’s what makes the Caprini risk assessment such a valuable tool. Dr. Caprini says using the tool is essentially the same as performing a thorough history and physical. 

The assessment combines the number of risk factors with the strength of those risk factors to come up with a risk score based on the synergistic combination of the two. “As that score increases, the possibility of blood of venous thromboembolism increases,” says Dr. Caprini.

Providers can use the patient’s risk score to determine what preventative steps to take. Here’s a breakdown of the scale’s scoring:
0 (very low risk)
1-2 (low risk)
3-4 (moderate risk)
5-8 (high risk)
9 (severe risk)

The Caprini score, which has been validated in more than 5 million patients, is the gold standard for predicting which patients are at risk for DVT. However, even Dr. Caprini admits the thoroughness of the assessment does sometimes present a challenge for busy outpatient surgery facilities. “The Achilles’ Heel of the scale is that it includes 40 elements,” says Dr. Caprini. “The most difficult part is taking the time to collect the data.”

Still, there are ways to make such an assessment more manageable. For instance, he says nurse practitioners or physician assistants can ask patients about their risk factors during pre-admission exams.

Regardless of how the risk assessment is conducted, it’s absolutely vital that it’s done because of what’s at stake. “Physicians simply can’t fall into the trap of thinking, ‘the likelihood of this patient developing DVT is really low, so it’s not worth screening for,’” says Dr. Podolnick.

Once you determine a patient’s risk for developing DVT, you can decide what type of prophylactic measure is needed to prevent it. As Dr. Podolnick points out, some very effective noninvasive methods can prevent DVT from forming in low-risk patients.

“There are several basic interventions that can help reduce the risk, whether it’s encouraging patients to get up and move around the facility, ambulate at home, or applying compression stockings or pneumatic compression devices to the patient’s lower legs,” he says.

For high-risk patients, anticoagulants are a must. Giving these patients low-molecular weight or unfractionated heparin for seven to 10 days after surgery (or for a month if they are extremely high risk) is a particularly effective intervention.

It’s also important to avoid overapplying preventative measures. “Not all patients need protection,” says Dr. Caprini. “Individuals with a risk score of five or less are at low risk for developing blood clots and can be spared anticoagulation.” With these patients, he says, you can use mechanical methods such as compression boots. That’s important, considering some surgical patients may be receiving anti-clotting medications they don’t truly need, and those anticoagulants could increase the risk of intraoperative bleeding.

Still, if you’re on the fence about whether or not to opt for anticoagulant prophylaxis in borderline cases because of this risk, Dr. Caprini offers some perspective. While bleeding during surgery is certainly a complication surgeons want to avoid, it pales in comparison to the dangers involved in not giving an anticoagulant to a patient who is at high risk for DVT, which could prove fatal. Generally, that’s not a complication you have to worry about with anticoagulants or, as Dr. Caprini puts it, “If you get your hip replaced and it bleeds, you can still play checkers with your grandson.”

As someone who has dedicated his career to educating providers and the public about the dangers of DVT, he knows of far too many cases where patients went in for minor procedures and wound up losing their lives.  “I’ve seen too many instances where providers didn’t perform an accurate risk assessment, didn’t give a prophylaxis as a result and the patient died,” he says.

When it comes preventing potentially fatal blood clots from forming, it’s up to your providers to use all the tools at their disposal. “DVT is an under-appreciated and under-recognized complication of surgery that can be easily preventable with appropriate screening and treatment,” says Dr. Podolnick. “It’s important for providers and facilities to be vigilant.” OSM