When should heparin (unfractionated heparin) be discontinued before surgery?

From the Guidelines

Heparin should be discontinued 4-6 hours before surgery for intravenous unfractionated heparin, as recommended by the American College of Chest Physicians evidence-based clinical practice guidelines 1. When considering the discontinuation of heparin before surgery, several factors must be taken into account, including the type of heparin, the patient's renal function, and the bleeding and thrombotic risks associated with the surgery.

• For patients on therapeutic unfractionated heparin, stopping the infusion 4-6 hours preoperatively and checking an activated partial thromboplastin time (aPTT) to ensure it has normalized is a common approach, as seen in observational studies 1.
• The timing of discontinuation may vary based on the patient's renal function, as heparin is cleared by the kidneys, and patients with renal impairment may need earlier discontinuation, particularly for low molecular weight heparin (LMWH) 1.
• For patients with high thrombotic risk, such as those with recent venous thromboembolism or mechanical heart valves, bridging with shorter-acting unfractionated heparin when stopping LMWH may be considered, as noted in the guidelines 1.
• After surgery, heparin can typically be resumed 24-48 hours post-procedure, depending on the bleeding risk of the specific surgery performed and adequate hemostasis, as suggested by observational studies 1. The decision to discontinue heparin should balance bleeding risk against thrombotic risk, and the specific circumstances of each patient should be carefully evaluated to determine the optimal timing for discontinuation and resumption of heparin 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 optimal timing of heparin discontinuation may vary depending on the individual patient's situation, and the decision should be made on a case-by-case basis 4.
• In patients with renal failure, the management of heparin is complex and requires careful monitoring to avoid bleeding complications 5, 6.
• The use of low-molecular-weight heparin (LMWH) may be preferred in some cases, as it has a more predictable anticoagulant effect and a lower risk of bleeding compared to unfractionated heparin 3.

Considerations for Discontinuation of Heparin

• The risk of bleeding is a major concern when discontinuing heparin before surgery, and the patient's individual risk factors should be taken into account 2.
• The type of surgery being performed is also an important consideration, as some procedures may carry a higher risk of bleeding than others 3.
• The presence of any underlying medical conditions, such as renal failure or liver disease, may also affect the decision to discontinue heparin before surgery 5, 6.
• The use of other anticoagulants, such as warfarin or novel oral anticoagulants, may also be considered in some cases, depending on the patient's individual needs and risk factors 2.