Synopsis
Choose and review surgical thromboprophylaxis by balancing venous thrombosis against bleeding, then prescribe the appropriate method, timing and duration with clear discharge arrangements.
- Assess venous thromboembolism and bleeding risk together, then reassess when the clinical situation changes.
- For abdominal surgery, add pharmacological prophylaxis when VTE risk outweighs bleeding risk, for at least seven days.
- Consider twenty-eight postoperative days of pharmacological prophylaxis after major abdominal cancer surgery.
Key red flags
Active haemorrhage, a concerning postoperative haemoglobin trend or the prospect of urgent reoperation may make immediate anticoagulant prophylaxis unsafe. Escalate to the responsible surgical team, document the reason for withholding and set a reassessment point; consider an appropriate mechanical method while risk is reviewed.
Spinal or epidural procedures introduce a separate timing constraint because bleeding into the spinal canal can cause severe neurological harm. Confirm insertion and removal plans with anaesthesia before prescribing or administering anticoagulants. An ordinary ward dose time must not override the neuraxial plan.
New unilateral leg swelling, unexplained hypoxaemia, pleuritic pain or collapse may represent VTE even when prescribed doses were given. Assess the patient urgently according to the presentation and seek diagnostic and treatment decisions. Prophylactic dosing neither excludes nor treats an established event.
Reasoning priorities
Identify the factors that change the likely benefit and harm of prophylaxis.
Use the approved risk tool alongside the operation, mobility, history and current haemostasis. A tool standardises prompts but does not know that the surgeon expects reoperation tonight unless that information is supplied.
Worked reasoning
A 67-year-old weighing 78 kg undergoes major elective abdominal cancer resection. Creatinine clearance is 78 mL/min, there is no HIT history or active bleeding, no neuraxial catheter is planned, and reduced mobility is expected. The proposed discharge prescription contains only three further days of prophylaxis.
- Confirm that VTE risk outweighs bleeding risk in the current postoperative state. Cancer, major abdominal surgery and reduced mobility support prevention, but review haemostasis and the possibility of another procedure before treating the risk score as sufficient.
- Check which locally approved prophylactic medicine and mechanical method apply. If enoxaparin is selected for this high-risk adult with the stated renal function and body size, the product-specific example is 40 mg subcutaneously once daily, with perioperative timing agreed against haemostasis and the operative plan.
- Consider the NG89 recommendation to extend pharmacological prophylaxis to twenty-eight days after major abdominal cancer surgery. Count the postoperative days already covered and calculate the remaining supply; discharge is a location change, not necessarily the end of thrombotic risk.
- Agree the duration and prescription with the responsible clinician, document the end date and check practical administration. Teach injection technique, provide the correct product and sharps arrangements, and establish who can help if the patient cannot inject independently.
- Verify that the patient can explain the daily plan, the stopping date and when to seek help for bleeding or possible thrombosis. Recheck renal function and medication changes if clinical circumstances alter before or after discharge.