OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Matthew Herring, MD in response to a recent study in the Journal of Orthopaedic Trauma.
Pulmonary embolism (PE) is a potentially life-threatening complication among many orthopaedic trauma patients. PE can be a silent killer, with only about 30% of fatal PEs being detected before death. Chemical prophylaxis with “blood thinners” such as injectable enoxaparin is effective in mitigating the risk of PE, but in the poly-traumatized patient, its application is often contraindicated. In an effort to develop a more effective approach to PE prevention in the trauma population, Starr et al. built a tool to estimate the risk of PE early and effectively, and then developed a multidisciplinary protocol for deep vein thrombosis (DVT) prophylaxis. They present their preliminary experience with the risk-assessment tool and the new protocol in the February 2019 issue of the Journal of Orthopaedic Trauma.
The smart-phone app (ParkLandOrtho) to risk-stratify trauma patients in the ED is based on 7 easily captured variables that the authors’ prior work identified as statistically significant predictors for developing a PE. Patients who are identified as “high risk” are aggressively started on enoxaparin, with the first dose ideally given prior to ED discharge. If contraindications for chemical prophylaxis are present, enoxaparin is withheld for up to 24 hours after admission. After 24 hours, if the patient is still unable to receive enoxaparin, a removable inferior vena cava (IVC) filter is placed.
The authors performed a retrospective review of PE incidence among 368 consecutive orthopaedic trauma patients admitted to their hospital after this new protocol was implemented and compared it to PE incidence among a historic cohort of 420 similar consecutive patients admitted during the year prior to the protocol. The two groups were similar in age and injury severity. In the control group, 51 patients were retrospectively classified as high risk, and 9 patients (2.1%) developed symptomatic PEs, one of which was fatal. In the group managed under the new protocol, 40 patients were identified as high risk, and only 1 patient (0.27%) developed a nonfatal PE. The difference in incidence of PE between the two groups was statistically significant (P = 0.02).
This paper highlights two significant achievements in my opinion. First, I was excited to see the success of a smart-phone app to facilitate rapid risk assessment. This was a significant key to the success of the multidisciplinary PE protocol, which depends on buy-in and compliance. Second, this thoughtful, decisive, and team-based protocol for DVT/PE prophylaxis in an orthopaedic trauma setting seems to be making a meaningful impact on patient outcomes.
The authors report that they are currently designing a multicenter trial to prospectively validate their protocol. I eagerly await this and hope that their next step includes a ParklandOrtho app release for Android devices, as it is only available now for iPhone and Samsung users.
Matthew Herring, MD is a fellow in orthopaedic trauma at the University of California, San Francisco and a member of the JBJS Social Media Advisory Board.
It seems that anytime a lower extremity undergoes operative treatment, the question is raised regarding the need for and type of thromboprophylaxis. However, controversy exists regarding the use of prophylaxis against venous thromboembolic disease (VTED) after foot and ankle surgery, largely because there are insufficient data from large-scale randomized trials to help guide foot and ankle surgeons in their decision-making processes. Currently, foot and ankle surgeons are forced to make decisions on the basis of incomplete information and contradictory guidelines. Moreover, there is inaccuracy in extrapolating findings from hip and knee arthroplasty studies to the foot and ankle population.
In the December 2015 issue of JBJS Reviews, Guss and DiGiovanni review VTED in the setting of foot and ankle surgery and recognize that certain patient populations may be at higher risk, including patients over the age of forty years with acute Achilles tendon ruptures, patients over the age of fifty years with ankle fractures, patients with diabetes mellitus, patients with connective-tissue inflammatory diseases, and patients with a history of VTED. They also consider associated factors such as the use of oral contraceptives, cigarette smoking, recent air travel, and a family history of VTED. They emphasize that there have been limited randomized controlled trials addressing the question of thromboprophylaxis after foot and ankle surgery and that current data suggest that the use of chemoprophylaxis against VTED in patients undergoing foot and ankle surgery may not necessarily lower the incidence of VTED events. Large-scale postoperative randomized trials are necessary to better guide foot and ankle surgeons in their decision-making processes regarding thromboprophylaxis after surgery. As a result, current foot and ankle surgeons continue to have to make decisions on the basis of incomplete information and contradictory guidelines.
In order to provide some clarity to these issues, specialty societies and associations, including the American College of Chest Physicians and the American Academy of Orthopaedic Surgeons, have issued recommendations regarding the appropriate use of prophylaxis against VTED in the postoperative period. However, these guidelines are largely based on literature of variable quality and applicability. For example, there is no agreement on the appropriate framework for risk-benefit analysis of these issues. Furthermore, unlike the American College of Chest Surgeons and the American Academy of Orthopaedic Surgeons, the American Orthopaedic Foot & Ankle Society has repeatedly expressed its inability to provide any guidance because of the lack of available information.
The literature examining the incidence of VTED after foot and ankle surgery is limited. Nevertheless, clinicians must make decisions against the backdrop of global quality initiatives that consider VTED to be a preventable event.
Thomas Einhorn, MD
Editor, JBJS Reviews
The venographic prevalence of deep vein thrombosis in people with distal lower-extremity injuries that require surgery or casting ranges from 10% to 40%. But a prospective cohort study in the May 21, 2014 JBJS found that only 0.6% of 1200 patients with lower-leg fractures and no medical or mechanical thromboprophylaxis had symptomatic, objectively confirmed venous thromboembolism (VTE) over a 12-week follow-up. Moreover, none of the seven thrombotic complications was fatal. This leads the authors to conclude that “the risk-benefit ratio and cost effectiveness of routine anticoagulant prophylaxis are unlikely to be favorable for these patients.” They go on to say that despite the large sample size in this study, the low prevalence of VTE made it impossible to pinpoint characteristics that could identify a subgroup of similar patients who might be at higher risk of clotting problems.