Volume 10,Issue 9
Clinical Implementation of Regional Citrate Anticoagulation in Combined CRRT and ECCO₂R Therapy: A Case Report
Background: Hypercapnia is a common precipitating factor for multiple organ failure in critically ill patients. The combination of continuous renal replacement therapy (CRRT) and extracorporeal carbon dioxide removal (ECCO₂R) represents a targeted pulmonary-renal support strategy; however, anticoagulation management during prolonged treatment remains a clinical challenge. Traditional unfractionated heparin carries risks of bleeding or circuit clotting, while evidence for regional citrate anticoagulation (RCA) in CRRT-ECCO2R combination therapy remains limited, with practical data in high-flow settings particularly lacking. This case report describes a novel anticoagulation regimen combining low molecular weight heparin (LMWH) and 4% citrate, providing a practical alternative for anticoagulation management in this complex therapy. Case presentation: A 59-year-old male patient with over a decade of occupational dust exposure (cement plant, gold mine, coal mine) and a history of pulmonary tuberculosis presented with cough, sputum production, and dyspnoea. On admission, oxygen saturation was 30–40%, arterial partial pressure of carbon dioxide (PaCO₂) was 142.33 mmHg, and serum potassium was 6.13 mmol/L. Diagnoses included acute exacerbation of chronic obstructive pulmonary disease (AECOPD), sepsis, septic shock, Legionella pneumonia, pulmonary encephalopathy, type II respiratory failure, and acute respiratory distress syndrome (ARDS). Despite initial management with antimicrobial therapy, fluid resuscitation, and mechanical ventilation, persistent hypercapnia (PaCO₂ > 100 mmHg) and hyperkalaemia persisted. Combined CRRT-ECCO₂R therapy was initiated from 23 May to 5 June 2025 (total 197 cumulative hours), with blood flow rate 300 mL/min, oxygen flow rate 8–10 L/min. Anticoagulation comprised LMWH (2000 U loading dose + 200 U/h continuous infusion), 4% trisodium citrate (200–210 mL/min), and 10% calcium gluconate (2–5 mL/h). After treatment, the patient showed significant reduction in PaCO₂, restored pH, improved oxygenation, no clinically significant bleeding events, and stable haemoglobin levels. However, due to financial constraints, the patient was transferred to a local healthcare facility for further care. Conclusion: In CRRT-ECCO₂R combined therapy, the LMWH + 4% citrate anticoagulation regimen effectively maintained circuit patency (mean lifespan 65.67 hours) at a high flow rate of 300 mL/min, achieved efficient carbon dioxide clearance (mean clearance rate 44.5 mL/min), rapidly corrected acid-base imbalance, and demonstrated good safety. This approach overcomes limitations of conventional anticoagulation, offering a novel therapeutic option for critically ill hypercapnic patients at bleeding risk, with promising clinical utility and cost-effectiveness.
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