Purpose: In membrane-based therapeutic plasma exchange (TPE), regional citrate anticoagulation (RCA) is associated with difficulties because of citrate accumulation and consequent, potentially significant, metabolic complications, especially when using fresh frozen plasma (FFP) as replacement fluid. We modified the technical setup of a commercially available continuous veno-venous hemodialysis RCA module (multiFiltrate Ci-Ca®) to establish an RCA-protocol for TPE.
Methods: Description of the modified technical setup and retrospective analysis of the feasibility of the RCA-protocol for TPE in all patients treated between 2009 and 2010.
Results: 411 consecutive TPE with RCA were performed in 42 patients, all using FFP as replacement fluid. Median procedure characteristics were: blood flow 160 ml/min, filtrate flow 36 ml/min, duration 93 min, processed total plasma volume 3600 mL. Trisodium citrate was infused at a rate of 0.43 mmol/min to achieve post-filter ionized calcium levels of <0.4 mmol/l. Calcium substitution rate was 0.19 mmol/min to maintain physiologic iCa levels. RCA was well tolerated with no significant differences in pH, iCa, bicarbonate or potassium after repeated sessions. Clotting events complicated 7.3% of the procedures. Adverse events occurred in 3.4% of TPE procedures; none was severe or fatal. No significant differences were observed comparing the rate of adverse events to those observed in TPE using standard anticoagulation at our center (4.8%).
Conclusions: We describe for the first time a modified protocol for RCA in TPE using an integrated citrate module. Based on our experience, this RCA protocol is a feasible alternative for anticoagulation in TPE with FFP, especially in patients with a high risk of bleeding.