May 1, 2020
Algorithm for Practical Diagnosis and Treatment of Suspected VTE During COVID-19 Pandemic Proposed
May 1, 2020—The Society for Vascular Surgery announced the publication of an evidence-based algorithm espousing empiric treatment for venous thromboembolism (VTE) without confirmatory imaging during the COVID-19 pandemic. The algorithm was created by a committee of vascular surgeons, medical physicians, and technologists from the University of Michigan in Ann Arbor, Michigan.
The preproof manuscript by Andrea T. Obi, MD, et al is available online in Journal of Vascular Surgery: Venous and Lymphatic Disorders.
“The COVID-19 pandemic has caused a massive challenge to the diagnosis and treatment of positive patients at risk for VTE,” commented senior author Peter K. Henke, MD, in the SVS press release. “For a variety of reasons during the crisis, the surge of patients has resulted in delays in diagnosis and therapy for these critically ill patients.”
Dr. Henke continued, “Facing mounting requests for vascular ultrasounds and CT imaging, we formed an ad hoc committee of venous thrombosis experts to review our existing protocols, including that used during the H1N1 crisis, alongside current guidelines from the American College of Chest Physicians and the National Institution for Health and Care Excellence.”
“In this treatment paradigm, we emphasize preventing VTE-related morbidity and mortality at the expense of bleeding complications over a short term while imaging is delayed, and also utilizing therapy that has shown benefits for other severe viral states (H1N1),” added Dr. Henke. “With such an approach, the commitment to providing follow-up—the deep vein thrombosis (DVT) scan that would normally be obtained in 24 hours and now will be delayed 2 to 4 weeks—must be absolute, meticulous and unwavering.”
As outlined in the SVS announcement, the guideline’s critical guiding principles include:
- All patients with or suspected of COVID-19 should be treated with thromboprophylaxis.
- Elevated D-dimer is expected with severe infection and should not be a determinant in the decision to obtain imaging; however, a negative test in combination with a low clinical score safely excludes VTE.
- Current guidelines recommend empiric treatment for those suspected of pulmonary embolism (PE) and DVT if CT is delayed more than 4 hours and venous duplex more than 24 hours, respectively; during the pandemic, however, the benefit of empiric therapy outweighs risk even if imaging is delayed more than 1 month.
- Duplex ultrasound is indicated when the following exist simultaneously: high bleeding risk; results will change management, and clinical suspicion for PE is high and CT unavailable or clinical suspicion for DVT is high (modified Wells and Wells scoring).
- Most patients with confirmed or suspected VTE, not at high bleeding risk should receive therapeutic doses of anticoagulation.
- In patients with Adult Respiratory Distress Syndrome, low-dose heparin infusion may reduce the risk of major bleeding while protecting from thrombotic events.
- Patients treated with low-dose anticoagulation protocols should be transitioned to full-dose anticoagulation when they are no longer in intensive care status.
- Referral for CT or duplex may be performed upon recovery as an inpatient; however, this may be delayed to an outpatient setting in a resource-scarce environment.
- Unilateral upper extremity limb swelling should be imaged according to the fourth guideline above.