Sweeping new clinical guidelines issued by the American College of Chest Physicians provide updated recommendations on how to prevent and manage thrombosis in surgical patients and special risk groups, including pregnant women, children, obese patients, and patients with prosthetic heart valves or a history of cardiovascular disease or stroke.
Separate sections address patients with inherited thrombophilias and treatment of deep vein thrombosis and pulmonary embolism.
Unveiled in the June issue of Chest, the guidelines represent the first major revision in the recommendations since 2004. Compiled by more than 90 experts, the 700 recommendations run more than 1,000 pages, although a concise, 38-page executive summary is available (Chest 2008;133:71S-109 [doi:10.1378/chest.08–0693]). In accordance with many new clinical guidelines, grades are assigned to each recommendation or suggestion, based on the quality of the available evidence and the strength of the recommendation.
Among the most noteworthy recommendations is a renewed call for venous thromboembolism (VTE) prophylaxis of most hospitalized patients.
“For every general hospital, we recommend that a formal, active strategy that addresses the prevention of VTE be developed … in the form of a written, institution-wide thrombo-prophylaxis policy,” the guidelines state.
Computer decision support systems, preprinted orders, and periodic audits and feedback mechanisms are advocated by the committee, while “passive methods” such as educational meetings and handouts are deemed inadequate as standalone strategies to increase adherence to thromboprophylaxis.
“Despite very good evidence, prophylaxis is still underutilized in people who would benefit,” Dr. Jack Hirsh said in an interview.
Hospitals need to have firm policies and enforce them, he added. “Instead of surgeons or physicians kicking a box, saying they should be used, the box should only have to be kicked when they are not used,” said Dr. Hirsh, professor emeritus of medicine at McMaster University and founding director of the Henderson Research Center, both in Hamilton, Ont.
In the new guidelines, the recommendation for VTE prophylaxis has been expanded beyond major general, gynecologic, and orthopedic surgeries to include bariatric and coronary artery bypass surgery.
No prophylaxis is recommended for low-risk patients undergoing laparoscopic surgery or knee arthroscopy, or those taking long airplane flights.
As expected, the new guidelines reaffirm the position of the American College of Chest Physicians that aspirin alone is not sufficient therapy to prevent venous thromboembolism in any patient population, because more effective alternatives are available, including heparin, low-molecular-weight heparin, and a synthetic, selective factor Xa inhibitor, fondaparinux, which was approved by the FDA in 2001.
Many of the guidelines now mentioning fondaparinux as an alternative anticoagulant rate the evidence for its use as 1A, meaning that the supportive data are strong.
Dr. Geno J. Merli, chief medical officer of Thomas Jefferson University Hospital, Philadelphia, welcomed the renewed emphasis on prophylaxis therapy that does not depend solely on aspirin.
“Aspirin is still being widely used for prophylaxis,” he said, noting that some consensus-based guidelines for orthopedic surgery still advocate the use of aspirin as a solo preventive agent.
The length of recommended postsurgical prophylaxis has been extended in the guidelines to 28 days (and in some surgeries, 35 days) for most general, gynecologic, and orthopedic procedures, he noted. Previously, prophylaxis was generally advised for 2 weeks following surgery.
A new chapter greatly expands evidence-based guidance concerning the perioperative management of patients on antithrombotic therapy who require emergency or elective surgery. Detailed sections provide advice for specific conditions and surgical circumstances, ranging from minor dermatologic surgery to hip fracture.
“This [publication] is not meant to be read from cover to cover,” Dr. Hirsh said. “It is an encyclopedic reference to be used by physicians if the patient has had a stroke, is at risk of stroke, has had a heart attack, is at risk of heart attack, has atrial fibrillation, has an inherited thrombophilia, or is pregnant and on antithrombotic therapy.”
Among the most pivotal changes in the recommendations are guidelines on patients with atrial fibrillation, management of pregnant women and children, and treatment of DVT.
▸ Atrial fibrillation. Antithrombotic therapy in patients with atrial fibrillation is awarded the strongest evidence grade (1A), reflecting widespread agreement of findings from randomized, controlled trials.
Target international normalized ratio ranges, drug choices, and dosages are detailed in the new guidelines in the hopes that primary care physicians will use the document to guide therapy, Dr. Hirsh said.
“There is marked underutilization of warfarin [in atrial fibrillation patients], not by cardiologists, but by family physicians. The logistics of monitoring are difficult,” he said.
As a result, the guidelines include one entire section that addresses the nuts and bolts of monitoring. Evidence is cited that affirms the rationale for using computer assistance to adjust dosages based on monitoring data.