Author: Chase Doyle
Although prevention of venous thromboembolism (VTE) after major orthopedic surgery is considered a patient safety measure in most mandated quality initiatives, providers disagree on specific approaches for mechanical or pharmacologic prophylaxis. According to Linda A. Russell, MD, the director of perioperative medicine at the Hospital for Special Surgery, in New York City, the crux of the debate centers on bleeding versus clotting, as efforts to reduce postoperative pulmonary embolism and deep vein thrombosis (DVT) can increase the risk for bleeding.
“In general, orthopedic surgeons worry more about bleeding, which may prevent patients from achieving full range of motion with a new joint or increase risk of infection,” said Dr. Russell, who noted that bleeding after spine surgery also can lead to severe neurologic consequences. “Hospitalists, on the other hand, are focused more on clotting. Patients can die from a pulmonary embolism or they can develop pulmonary hypertension, and deep vein thrombosis can lead to chronic venous insufficiency.”
Medical malpractice liability for pulmonary embolism is another concern, Dr. Russell added, as are nationally reported rates of VTE, which can damage institutional reputation and limit reimbursement from the Centers for Medicare & Medicaid Services.
At the American College of Perioperative Medicine’s 2018 Interdisciplinary Conference on Orthopedic Value-Based Care, Dr. Russell highlighted prophylactic guidelines from the American Academy of Orthopaedic Surgeons (AAOS) and the American College of Chest Physicians (CHEST) to illustrate the lack of consensus around this issue.
“Although the AAOS recommended mechanical compressive devices, early mobilization and neuraxial anesthesia, they were unable to recommend for or against specific prophylactics in these patients,” Dr. Russell said. “Not very helpful.”
In patients undergoing total hip or knee arthroplasty, CHEST guidelines published in 2012 recommended the use of one of the following for a minimum of 10 to 14 days rather than no antithrombotic prophylaxis: low-molecular-weight heparin, fondaparinux, apixaban (Eliquis, Bristol-Myers Squibb), dabigatran (Pradaxa, Boehringer Ingelheim), rivaroxaban (Xarelto, Janssen), low-dose unfractionated heparin, adjusted-dose vitamin K antagonist, aspirin (all grade 1B) or an intermittent pneumatic compression device.
Decreasing Rates of VTE
In order to decrease rates of VTE at the Hospital for Special Surgery, Dr. Russell and her colleagues invited the Greater New York Hospital Association for an observational visit. After performing a VTE prophylaxis tracer, consultants recommended the following:
- Improve consistency in performing VTE risk assessments.
- Improve awareness of the rationale for VTE risk assessment and treatment among the medical and nursing staff.
- Standardize DVT prophylaxis for patients, based on the type of surgery that the patient is undergoing.
- Standardize the interval of reassessment for VTE risk.
“In addition, although some of our patients are discharged right away, others experience complications and are hospitalized for a week or more,” she said. “We needed to do a better job of continually reassessing what DVT prophylaxis regimen they were on.”
For each service—whether arthroplasty, spine, foot and ankle, hand, limb lengthening or trauma—a VTE committee now reviews the newer anticoagulants and tries to make the safest selection. If a different regimen is to be used, the regimen and rationale for the use of the regimen should be clearly documented in the medical record. According to Dr. Russell, the spine service in particular has seen a dramatic reduction in rates of VTE with this approach.
Optimal Prophylaxis: The Case for Aspirin
Ronald A. Navarro, MD, the regional chief of orthopedic surgery at Kaiser Permanente of Southern California, underscored the need for prophylaxis that is clinically proven, low risk, practical and cost-effective. Without prophylaxis, he reported, DVT has been shown to occur in up to 84% of total knee arthroplasties and up to 57% of total hip arthroplasties (Chest 2001;119[1 suppl]:132S-175S), but the best option among preventive pharmacologic regimens is not well established.
A study from Kaiser Permanente of more than 30,000 patients receiving unilateral total knee arthroplasties between 2006 and 2013, however, may provide the answer (J Arthroplasty2017;32:3524-3528). In this retrospective analysis, patients received either aspirin (324-325 mg daily), enoxaparin (40-60 mg daily), fondaparinux (2.5 mg daily) or warfarin (all doses), and were followed up to 90 days postoperatively on several outcomes: DVT, pulmonary embolism, major bleeding, wound complications, infection and death. According to the investigators, there was no evidence that fondaparinux, enoxaparin or warfarin was superior to aspirin in the prevention of pulmonary embolism, DVT or VTE.
“This is a seminal study, and it showed that none of these regimens was better than aspirin with respect to safety and effectiveness,” Dr. Navarro said.
For uncomplicated prophylaxis in major orthopedic procedures, the general regimen at Kaiser Permanente is aspirin (81 mg, orally, twice daily). For high-risk patients, warfarin is administered daily, and blood is monitored to ensure an international normalized ratio between 1.5 and 2.5. High-risk patients include the following: prior VTE, known hypercoagulable state in the past, smokers, use of estrogen, cancer patients, morbidly obese, bilateral cases, major revision cases and trauma cases.
“I’ve seen hospitalists change their minds over the last three to five years about aspirin,” Dr. Navarro said. “It’s very safe, super cheap, and it has all the benefits compared with more costly agents.”