Performance characteristics of the PowerFlow apheresis port: Early experience.

We prospectively evaluated the Bard PowerFlow Implantable Apheresis IV Port in four patients undergoing outpatient therapeutic plasma exchange over 18 to 97 days. Three had bilateral internal jugular access ports, and one had a single left internal jugular access port for the inlet line with return via antecubital vein. Two patients receiving 5% albumin as replacement fluid achieved peak inlet flow of 99 ± 5 mL/min and 101 ± 6 mL/min, and peak plasma flow of 53 ± 6 and 47 ± 6 mL/min, respectively. Two patients receiving plasma as replacement fluid achieved peak inlet flow of 46 ± 7 and 85 ± 4 mL/min and peak plasma flow of 27 ± 3 and 35 ± 4 mL/min, respectively. Apheresis nurses accessed the ports on the first attempt in all procedures. Pressure alarms occurred in 6 of 47 procedures and were easily resolved by lowering the inlet rate by 10% in 5 of them. The PowerFlow shows promise as an implantable venous access device for apheresis.

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.

Prophylactic infusion of calcium gluconate to prevent a symptomatic fall in plasma ionized calcium during therapeutic plasma exchange: A comparison of two methods.

We compared two methods of calcium gluconate infusion to maintain plasma ionized calcium ([Ca2+ ]) during therapeutic plasma exchange (TPE) performed using the Spectra Optia Apheresis System. Method A, our legacy method, consisted of adding 5 mL of 10% calcium gluconate to each 500 mL bottle of 5% albumin replacement fluid. Method B used an accessory IV infusion of calcium gluconate (2 g in 50 mL of 0.9% NaCl starting at 25 mL/h). Plasma [Ca2+ ] was measured at 20-minute intervals, and symptoms of hypocalcemia were recorded during TPE. Baseline [Ca2+ ] was the same (P = 0.616), as was total acid citrate dextrose Formula A used (P = 0.865), with either method. TPE with method A used 2.62 ± 0.52 g of calcium gluconate vs 1.13 ± 0.27 g with method B (P < 0.001). [Ca2+] remained stable with method A (P = 0.251), but fell on average by 5% with method B (P < 0.05). Hypocalcemic symptoms were reported in 0 of 23 TPE with method A and 2 of 24 TPE with method B. We conclude that both methods A and B prevent a symptomatic fall in plasma [Ca2+ ] during TPE. Method B requires significantly less calcium gluconate than does method A.