ABSTRACT
Acute inpatient management of patients with end-stage renal failure (ESRF) requiring anticoagulation is problematic. Low molecular heparins (LMWHs) and direct oral anticoagulants (DOAC) are convenient, but largely dependent on renal function for clearance . Vitamin K antagonists (VKAs) are suitable for long-term anticoagulation, but often not appropriate in hospital, where rapid adjustments may be required. Unfractionated heparin (UFH) infusion is the conventional alternative, but this requires intensive monitoring, often not available outside high dependency/ intensive care units. A weight-adjusted, unmonitored subcutaneous UFH regimen avoids these problems and has been successfully trialled but is not widely used. 1,2 This is a single-centre retrospective analysis of 48 patients treated with subcutaneous UFH at a dose of 250 UI/Kg twice daily for treatment or prevention of venous thromboembolism (VTE), between September 2020 and August 2021. All patients receiving this regimen were identified via pharmacy database. The aims of this study are to evaluate indication for use and to assess safety (bleeding) and efficacy (breakthrough thrombosis) in our cohort. All patients had renal impairment with a median creatinine clearance at time of prescription of 15 ml/min (range 4-48 ml/min, interquartile range 10.25). A third was on established renal replacement therapy. Overall, two thirds required anticoagulation for either atrial fibrillation (AF) or VTE treatment. In such patients, UFH was used for bridging to an oral agent and it was preferred over LMWH in view of reduced/deteriorating renal function. The remaining patients required anticoagulation for VTE prevention or for presurgical management, in view of known pre-existing pro-thrombotic conditions. One patient was incorrectly given subcutaneous UFH to manage subtherapeutic INR in the presence of a metallic heart valve. Collectively, 18 patients deceased during or within 6 months from admission. Twelve per cent experienced non-major/major bleeding. 3 Three deaths were directly attributed to major gastro-intestinal bleeding (only one case was confirmed radiologically). Non-major events included bleeding from surgical wounds ( N = 2) and skin cancer lesion ( N = 1). Only one breakthrough thrombosis was reported. No death was attributed to thrombosis (table 1). In conclusion, weight-adjusted UFH is an effective anticoagulant regimen. It was originally studied in VTE but appears to be effective in AF as well. The risk of bleeding is relatively high, but comparable to similarly ill patients (e.g. COVID19) receiving monitored UFH infusions. 4.