Renal replacement anticoagulant management: Protocol and analysis plan for an observational comparative effectiveness study of linked data sources

Acute kidney injury is common in critical illness. In patients with severe acute kidney injury, renal replacement therapy is needed to prevent harm from metabolic and electrolyte disturbances and fluid overload. In the UK, continuous renal replacement therapy (CRRT) is the preferred modality, which requires anticoagulation. Over the last decade, conventional systemic heparin anticoagulation has started being replaced by regional citrate anticoagulation for CRRT, which is now used in approximately 50% of ICUs. This shift towards regional citrate anticoagulation for CRRT is occurring with little evidence of safety or longer term effectiveness. Renal replacement anticoagulant management (RRAM) is an observational comparative effectiveness study, utilising existing data sources to address the clinical and cost-effectiveness of the change to regional citrate anticoagulation for CRRT in UK ICUs. The study will use data from approximately 85,000 patients who were treated in adult, general ICUs participating in the case mix programme national clinical audit between 1 April 2009 and 31 March 2017. A survey of health service providers' anticoagulation practices will be combined with treatment and hospital outcome data from the case mix programme and linked with long-term outcomes from the Civil Registrations (deaths), Hospital Episodes Statistics for England, Patient Episodes Data for Wales, and the UK Renal Registry datasets. The primary clinical effectiveness outcome is all-cause mortality at 90-days. The study will incorporate an economic evaluation with micro-costing of both regional citrate anticoagulation and systemic heparin anticoagulation.

Automated summary

Acute kidney injury is common in critical illness, and renal replacement therapy is needed for severe cases. In the UK, conventional systemic heparin anticoagulation for continuous renal replacement therapy is being replaced by regional citrate anticoagulation, but the safety and long-term effectiveness of this shift is not well-established. The Renal Replacement Anticoagulant Management (RRAM) study aims to use existing data sources to evaluate the clinical and cost-effectiveness of regional citrate anticoagulation compared to systemic heparin anticoagulation in UK ICUs.