An 84-year-old with a displaced hip fracture who takes warfarin
Mr Chan, 84, lives alone in a walk-up flat in Sham Shui Po. He was found on the floor by his daughter after an unwitnessed fall and brought to the emergency department four hours ago. He has a displaced left subcapital femoral neck fracture and is in pain but haemodynamically stable (BP 138/76 mmHg, HR 88/min, afebrile). Background: permanent atrial fibrillation, a lacunar stroke three years ago with full recovery, hypertension, and eGFR 41 mL/min/1.73 m². Medications: warfarin (today's INR 2.9; stable target 2.0–3.0), amlodipine, metoprolol. He is alert and oriented and weighs 52 kg. The orthopaedic team wants to operate within 36 hours and an anaesthetist is available, but there is no haematology cover overnight. His daughter, who holds his durable power of attorney, asks why the team cannot simply "reverse the blood thinner" so that surgery is safer.
1. The daughter asks why you will not simply give vitamin K and fresh frozen plasma to reverse the warfarin before surgery. Explain your reasoning and state what, if anything, you would give.
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The decision balances bleeding against thrombosis, not just the INR number. At an INR of 2.9, an anaesthetist using general anaesthesia can proceed; the excess bleeding risk from a therapeutic INR is modest, whereas delaying hip fracture surgery beyond 48 hours increases mortality, delirium, pressure injury and length of stay. Full reversal in a man with AF and a previous stroke risks a further stroke, and vitamin K also makes him warfarin-resistant for several days, complicating re-anticoagulation.
So: no PCC and no FFP for a routine spinal or general anaesthetic. If a neuraxial block is planned, the INR must be ≤1.5, and then 1–2 mg IV vitamin K is reasonable, accepting a 6–12 hour wait. Reserve 4-factor PCC (25–50 units/kg) plus 1–2 mg IV vitamin K for INR >4.5, active bleeding, or surgery that cannot wait. FFP is a poor choice: it needs thawing, carries a volume load in an 84-year-old with eGFR 41, and corrects the INR less reliably than PCC.
2. Describe your anticoagulation plan from the perioperative period through the first postoperative week, and justify why you would or would not bridge.
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Stop warfarin now and check the INR daily; the INR should be ≤1.5 before any neuraxial procedure. I would not bridge with therapeutic low-molecular-weight heparin. His CHA₂DS₂-VASc score is high (age ≥75 = 2, prior stroke = 2, hypertension = 1, total 5), but a high stroke score is not by itself an indication to bridge in AF; bridging in this setting increases major bleeding without reducing stroke, and hip fracture surgery is itself a high-bleeding operation.
Postoperatively: mechanical prophylaxis from admission and prophylactic-dose LMWH (for example enoxaparin 20 mg daily, reduced for eGFR 41) once the surgeon confirms haemostasis, usually at 24 hours. Restart warfarin when he is eating and haemostasis is secure, typically day 1–3, and overlap with LMWH until the INR has been ≥2.0 on two consecutive days. If he develops a wound haematoma or falls again, reassess rather than automatically transfusing. Document a clear target INR of 2.0–3.0 and arrange early INR monitoring, since his renal function and age make him labile.
3. The team later discover he has a mechanical mitral valve rather than AF alone. How does that change your answer?
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A mechanical mitral valve is the classic high-thrombotic-risk situation in which bridging is indicated, and the position changes substantially. The annual thromboembolic risk off anticoagulation is high, and valve thrombosis can be fatal, so interruption must be covered.
Practical plan: stop warfarin, start therapeutic LMWH or unfractionated heparin when the INR falls below 2.0, and omit the last dose 24 hours before surgery (LMWH) or 4–6 hours before (UFH infusion, which is easier to titrate in renal impairment). For truly urgent surgery, give 4-factor PCC rather than FFP and avoid vitamin K unless bleeding is uncontrolled, because vitamin K prolongs the warfarin-free interval. Restart heparin within 24 hours of haemostasis and warfarin as soon as oral intake allows, overlapping until the INR is therapeutic. Because this is a valve, involve cardiology and the anaesthetist the same day rather than managing overnight without senior input.