Optimization of infusional calcium gluconate for prevention of hypocalcemic reactions during therapeutic plasma exchange

We sought to optimize direct intravenous infusion of calcium gluconate (CaGlu) for maintaining plasma ionized calcium concentration ([Ca2+]) and preventing hypocalcemic reactions during 34 consecutive 1‐volume therapeutic plasma exchanges (TPEs) in eight patients. CaGlu, 2 g in 50 mL of 0.9% NaCl, was prepared by our hospital pharmacy and infused at either 1.0 or 1.6 g/h during alternate TPE. Plasma [Ca2+] was monitored at intervals of 20 to 30 minutes. At 1 g/h of CaGlu, plasma [Ca2+] fell by 8.35% after 40 to 50 minutes and then plateaued. At 1.6 g/h of CaGlu, plasma [Ca2+] fell by 6% after 20 to 30 minutes and then plateaued. The difference at 40 to 50 minutes was significant (P = .015). Hypocalcemic reactions were noted in three patients during 5 of 17 TPE at 1.0 g/h (all after 40 to 60 minutes) but 0 of 17 TPE at 1.6 g/h (P = .044). CaGlu at 1.6 g/h stabilized plasma [Ca2+] and appears to prevent hypocalcemic reactions during TPE.