Abstract
INTRODUCTION: Effective anticoagulation is essential for maintaining extracorporeal circuit patency during continuous renal replacement therapy (CRRT), yet commonly used anticoagulants have limitations. Herein, we present an innovative hybrid anticoagulation strategy for CRRT. CASE PRESENTATION: A 98-year-old female admitted with a left sacroiliac joint abscess developed decompensated heart failure and acute kidney injury, necessitating CRRT. Conventional-dose regional citrate anticoagulation (RCA) was projected to be intolerable in this ultra-elderly patient with progressive hepatic dysfunction, coagulopathy, and hyperlactatemia, whereas low-dose RCA failed to prevent filter clotting within hours. A modified anticoagulation protocol combining low-dose citrate with nafamostat infusion successfully sustained extracorporeal circuit patency without citrate-related metabolic complications or bleeding. Despite this success, the patient ultimately died of unrelated respiratory failure. CONCLUSION: The innovative hybrid anticoagulation strategy effectively prolonged CRRT circuit longevity in an ultra-elderly patient at high risk of citrate accumulation without procedure-associated complications. This approach represents a promising alternative for patients who have contraindications to conventional citrate anticoagulation.