From the Guidelines
Heparin should be discontinued 4-6 hours before surgery for intravenous unfractionated heparin and 24 hours before surgery for low molecular weight heparin (LMWH). When considering the discontinuation of heparin before surgery, it's crucial to balance the risk of bleeding against the risk of thrombotic events.
- The American College of Chest Physicians provides guidelines for the perioperative management of antithrombotic therapy, including heparin, in their 9th edition of evidence-based clinical practice guidelines 1.
- For patients on therapeutic doses of unfractionated heparin, stopping the medication 4-6 hours prior to the procedure is recommended, with a check of the activated partial thromboplastin time (aPTT) to ensure normalization 1.
- In contrast, for low molecular weight heparin (LMWH), administering the last preoperative dose 24 hours before surgery is advised, especially for therapeutic doses, to minimize the risk of postoperative bleeding 1.
- The decision on when to discontinue heparin is influenced by the type of heparin used, the patient's thrombotic risk, and the surgical procedure's associated bleeding risk.
- After surgery, heparin can typically be resumed 24 hours post-procedure for surgeries with low to moderate bleeding risk, but the timing may vary depending on the specific surgical procedure and the patient's individual risk factors 1.
- It's also important to consider the half-life of heparin products, with unfractionated heparin having a shorter half-life compared to LMWH, which guides the timing of discontinuation and resumption of therapy.
From the Research
Discontinuation of Heparin Before Surgery
- The decision to discontinue heparin before surgery depends on various factors, including the type of surgery, the patient's risk of bleeding, and the presence of any underlying medical conditions 2.
- There is no specific guideline on when to discontinue heparin before surgery, but it is generally recommended to stop heparin 2-4 hours before surgery to minimize the risk of bleeding 3.
- However, the management of heparins is complex and requires frequent laboratory measurements for monitoring, and the role of the haemostasis laboratory is essential to adjust the dose of unfractionated heparin 2.
- In patients with renal failure, the use of fondaparinux, a synthetic pentasaccharide, may be considered as an alternative to heparin, but its use requires careful monitoring of anti-factor Xa activity levels 4.
- The use of argatroban, a direct thrombin inhibitor, has been shown to be effective in patients with heparin-induced thrombocytopenia, and its use may be considered in patients who require anticoagulation therapy before surgery 5.
Considerations for Discontinuation of Heparin
- The risk of bleeding is a major concern when discontinuing heparin before surgery, and patients should be closely monitored for signs of bleeding or thrombosis 3.
- The use of heparin and other anticoagulants requires careful consideration of the patient's medical history, including any history of bleeding or thrombotic events 2.
- The management of anticoagulation therapy in patients with renal failure or heparin-induced thrombocytopenia requires careful consideration of the available treatment options and close monitoring of the patient's condition 4, 6, 5.