Regional Citrate Anticoagulation for RRT During V-V ECMO (CRRT ECMO)

Regional Citrate Anticoagulation for Continuous Renal Replacement Therapy During Veno-venous ECMO: a Crossover Randomized Controlled Study

Anticoagulation is an essential component of all extracorporeal therapies. Currently locoregional citrate anticoagulation is the recommended technique for continuous renal replacement therapy (CRRT). However, low clearance of citrate restricts its use to blood flow up to 150 mL/min, preventing its use in ECMO. Renal replacement therapy (RRT) is commonly provided to ECMO patients with AKI. In presence of systemic heparinization for ECMO, additional anticoagulation for the CRRT circuit (i.e. RCA) is usually not employed. Nevertheless, thrombosis occurs more frequently in the CRRT circuit than the oxygenator because of the slower blood flow. The aim of this prospective, cross-over study is to assess, in patients undergoing CRRT during veno-venous ECMO (vv-ECMO), the efficacy and safety of adding regional citrate anticoagulation (RCA) for CRRT circuit anticoagulation.

Patients are randomized to receive this sequence of anticoagulation regimens: UFH+RCA / UFH / UFH+RCA / UFH / UFH+RCA / UFH

Patients are randomized to receive this sequence of anticoagulation regimens: UFH / UFH+RCA / UFH / UFH+RCA / UFH / UFH+RCA

Rate of clotting in the intervention group (RCA+UFH) vs controls (UFH). I.e. : did the circuit clot in its 72h life?

According to the manufacturer recommendation elective RRT circuit replacement will be performed after 72 hours of circuit life.

"Circuit life" of RRT circuits in the intervention group (RCA+UFH) vs controls (UFH), comparison between groups will be performed as time to event(clotting) by log-rank test and described by the kaplan meier approach. Circuit replacement for other reasons (e.g. transfer to radiology to undergo a CT scan) will be right censored

According to the manufacturer recommendation elective RRT circuit replacement will be performed after 72 hours of circuit life.

Comparison of lab values of blood sampled during intervention (RCA+UFH) vs control (UFH). Values will be compared as absolute value and as a difference compared to each circuit baseline

Total to ionized calcium ratio (marker of citrate accumulation), rate of hypersodiemia and alkalosis will be compared between intervention (RCA+UFH) and control (UFH)

TEG analysis of blood samples with UFH vs UFH+RCA effect will be compared. Specifically, TEG R-time will be compared in blood sampled from circuit anti-coagulated with RCA+UFH vs UFH only

Inclusion Criteria: Patients admitted in ICU V-V ECMO support for acute respiratory failure CRRT therapy for acute kidney injury Exclusion Criteria: Pregnancy Pre-existing coagulation disorders Contraindication to heparin or citrate anticoagulation Moribund patients

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