Abstract
Purpose.
To evaluate our hospital protocol of low-dose vitamin K titration for preoperative warfarin reversal for early hip fracture surgery.
Methods.
Records of 16 men and 33 women aged 63 to 93 (mean, 81) years who were taking warfarin for atrial fibrillation (n=40), venous thromboembolism (n=9), cerebrovascular accident (n=3), and prosthetic heart valve (n=3) and underwent surgery for hip fractures were reviewed. The 3 patients with a prosthetic heart valve were deemed high risk for thromboembolism and the remainder low-risk. The international normalised ratio (INR) of patients was checked on admission and 6 hours after administration of vitamin K; an INR of <1.7 was considered safe for surgery.
Results.
No patient developed venous thromboembolism within one year. The 30-day and one-year mortality was 8.2% and 32.6%, respectively. For the 46 low-risk patients, the mean INR on admission was 2.6 (range, 1.1–4.6) and decreased to <1.7 after a mean of 2.2 (range, 0–4) administrations of 2 mg of vitamin K. Their INR was <1.7 within 18 hours (mean, 14 hours). 78% of patients underwent surgery within 36 hours. In the 22% of patients who did not undergo surgery within 36 hours, the delay was due to insufficient operative time or the patient being medically unfit for surgery. The 3 high-risk patients underwent bridging therapy of low-molecular-weight heparin and received no vitamin K; their mean INR on admission was 3.2 (range, 3.1–3.3) and the mean time to surgery was 5.3 (range, 3–8) days. Two low-risk patients and one high-risk patient died within 5 days of surgery.
Conclusion.
The low-dose intravenous vitamin K protocol is safe and effective in reversing warfarin within 18 hours. Hip fracture surgery within 36 to 48 hours of admission improves morbidity and mortality.