LAUSR

Introduction We performed a safety and feasibility study to evaluate a simplified regional citrate anticoagulation (RCA) technique for intermittent hemodialysis (iHD) with calciumand magnesium-free citrate-containing dialysate and calcium/magnesium re-injection in the venous line of the extracorporeal circuit (ECC). Generators for iHD automatically perform an on-line measurement of ionic dialysance (ID). This measurement can be useful to optimize the rate of calcium and magnesium infusion during hemodialysis using a calciumand magnesium-free dialysate [see Electronic Supplementary Material (ESM) Methods] [1]. The primary endpoint of the present prospective study was to determine the incidence rate of ECC clotting during hemodialysis sessions. The secondary endpoint was to validate the kinetic model for calcium infusion. This RCA approach, which obviates the need for a citrate infusion and plasma ionized calcium monitoring, has not been previously investigated. We analyzed 29 dialysis sessions with RCA in 17 patients with contraindications for anticoagulation (see ESM Table 1). Efficacy Twenty-five sessions were finished at the expected time (240 min) without clotting. We stopped four dialysis sessions for the following reasons: one patient pulled out the arterial line, one patient had a deficient arteriovenous fistula, and two patients each had an initial RCA session of 3 h. At +30 min, all measurements of ionized calcium concentration from the dialyzer outlet (iCaout) were below 0.4 mmol/L (mean 0.21 ± 0.07 mmol/L). At +240 min, iCaout had increased significantly (0.35 ± 0.19 mmol/L, p = 0.0019), but remained below 0.4 mmol/L in 89.6% of sessions (ESM Fig. 1). After rinsing of the dialyzer we found only minor clots with a low global thrombosis index (ESM Table 2).