Medline ® Abstracts for References 8,12,69,70
of 'Perioperative management of patients receiving anticoagulants'
Perioperative management of antithrombotic therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.
Douketis JD, Spyropoulos AC, Spencer FA, Mayr M, Jaffer AK, Eckman MH, Dunn AS, Kunz R, American College of Chest Physicians
Chest. 2012;141(2 Suppl):e326S.
BACKGROUND: This guideline addresses the management of patients who are receiving anticoagulant or antiplatelet therapy and require an elective surgery or procedure.
METHODS: The methods herein follow those discussed in the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines. Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines article of this supplement.
RESULTS: In patients requiring vitamin K antagonist (VKA) interruption before surgery, we recommend stopping VKAs 5 days before surgery instead of a shorter time before surgery (Grade 1B). In patients with a mechanical heart valve, atrial fibrillation, or VTE at high risk for thromboembolism, we suggest bridging anticoagulation instead of no bridging during VKA interruption (Grade 2C); in patients at low risk, we suggest no bridging instead of bridging (Grade 2C). In patients who require a dental procedure, we suggest continuing VKAs with an oral prohemostatic agent or stopping VKAs 2 to 3 days before the procedure instead of alternative strategies (Grade 2C). In moderate- to high-risk patients who are receiving acetylsalicylic acid (ASA) and require noncardiac surgery, we suggest continuing ASA around the time of surgery instead of stopping ASA 7 to 10 days before surgery (Grade 2C). In patients with a coronary stent who require surgery, we recommend deferring surgery>6 weeks after bare-metal stent placement and>6 months after drug-eluting stent placement instead of undertaking surgery within these time periods (Grade 1C); in patients requiring surgery within 6 weeks of bare-metal stent placement or within 6 months of drug-eluting stent placement, we suggest continuing antiplatelet therapy perioperatively instead of stopping therapy 7 to 10 days before surgery (Grade 2C).
CONCLUSIONS: Perioperative antithrombotic management is based on risk assessment for thromboembolism and bleeding, and recommended approaches aim to simplify patient management and minimize adverse clinical outcomes.
Department of Medicine, McMaster University, Hamilton, ON, Canada.
Recurrence of venous thromboembolism.
Coon WW, Willis PW 3rd
Brief communication: Preoperative anticoagulant activity after bridging low-molecular-weight heparin for temporary interruption of warfarin.
O'Donnell MJ, Kearon C, Johnson J, Robinson M, Zondag M, Turpie I, Turpie AG
Ann Intern Med. 2007;146(3):184.
BACKGROUND: Preoperative low-molecular-weight heparin (LMWH) is often used when warfarin therapy is interrupted for surgery.
OBJECTIVE: To determine the preoperative anticoagulant activity of LMWH following a standardized "bridging" regimen.
DESIGN: Prospective cohort study.
SETTING: Single university hospital.
PATIENTS: Consecutive patients who had warfarin therapy interrupted before an invasive procedure.
INTERVENTION: Enoxaparin, 1 mg/kg of body weight, twice daily. The last dose was administered the evening before surgery.
MEASUREMENTS: Blood anti-factor Xa heparin levels measured shortly before surgery.
RESULTS: Preoperative anti-Xa heparin levels were obtained in 80 patients at an average of 14 hours after the last dose of enoxaparin was administered. The average anti-Xa heparin level was 0.6 U/mL. The anti-Xa heparin level, measured shortly before surgery, was 0.5 U/mL or greater in 54 (68%) patients and 1.0 U/mL or greater in 13 (16%) patients. A shorter interval since the last dose (P<0.001) and a higher body mass index (P = 0.001) were associated with higher preoperative anti-Xa heparin levels.
LIMITATIONS: The small sample size limits accurate estimates of the frequency of the clinical outcomes. A single regimen of LMWH was evaluated.
CONCLUSIONS: Anti-Xa heparin levels often remain high at the time of surgery if a last dose of a twice-daily regimen of LMWH is given the evening before surgery.
McMaster University and Hamilton Health Sciences Foundation, Hamilton, Ontario, Canada. firstname.lastname@example.org
Bridging anticoagulation with low-molecular-weight heparin after interruption of warfarin therapy is associated with a residual anticoagulant effect prior to surgery.
Douketis JD, Woods K, Foster GA, Crowther MA
Thromb Haemost. 2005;94(3):528.
Bridging anticoagulation with low-molecular-weight heparin (LMWH) is common in patients who require temporary interruption of warfarin before surgery or a procedure, but whether such patients have a residual anticoagulant effect just before a procedure is not known. Consecutive patients who received bridging anticoagulation with LMWH had anti-Xa levels measured just before a procedure. The proportion of patients with a residual anticoagulant effect, defined as an anti-Xa level>or = 0.10 IU/ml, was determined. Multivariable regression analysis identified predictors of a residual anticoagulant effect, expressed as an odds ratio (OR) and corresponding 95% confidence interval (CI). A pre-procedure residual anticoagulant effect was detected in 12 of 73 (16%) patients overall, in 11 of 37 (30%) patients who received therapeutic-dose LMWH, and in 1 of 36 patients (3%) who received low-dose LMWH. Receiving therapeutic-dose LMWH (OR = 118.8; 95% CI: 5.8, 999.9), and increasing age (OR = 4.0; 95% CI: 1.3, 12.5) were predictors of a residual pre-procedure anticoagulant effect. In patients who require bridging anticoagulation with LMWH, a residual anticoagulant effect from LMWH is detected in 1 of 6 patients, and receiving therapeutic-dose LMWH is the strongest predictor of such an effect.
Department of Medicine and St. Joseph's Heathcare, McMaster University, Hamilton, Canada. email@example.com