In vitro characterization of PrismaLung+: a novel ECCO(2)R device

BACKGROUND: Invasive mechanical ventilation is lifesaving in the setting of severe acute respiratory failure but can cause ventilation-induced lung injury. Advances in extracorporeal CO(2) removal (ECCO(2)R) technologies may facilitate more protective lung ventilation in acute respiratory distress syndrome, and enable earlier weaning and/or avoid invasive mechanical ventilation entirely in chronic obstructive pulmonary disease exacerbations. We evaluated the in vitro CO(2) removal capacity of the novel PrismaLung+ ECCO(2)R device compared with two existing gas exchangers. METHODS: The in vitro CO(2) removal capacity of the PrismaLung+ (surface area 0.8 m(2), Baxter) was compared with the PrismaLung (surface area 0.35 m(2), Baxter) and A.L.ONE (surface area 1.35 m(2), Eurosets) devices, using a closed-loop bovine blood–perfused extracorporeal circuit. The efficacy of each device was measured at varying pCO(2) inlet (p(in)CO(2)) levels (45, 60, and 80 mmHg) and blood flow rates (Q(B)) of 200–450 mL/min; the PrismaLung+ and A.L.ONE devices were also tested at a Q(B) of 600 mL/min. The amount of CO(2) removed by each device was assessed by measurement of the CO(2) infused to maintain circuit equilibrium (CO(2) infusion method) and compared with measured CO(2) concentrations in the inlet and outlet of the CO(2) removal device (blood gas analysis method). RESULTS: The PrismaLung+ device performed similarly to the A.L.ONE device, with both devices demonstrating CO(2) removal rates ~ 50% greater than the PrismaLung device. CO(2) removal rates were 73 ± 4.0, 44 ± 2.5, and 72 ± 1.9 mL/min, for PrismaLung+, PrismaLung, and A.L.ONE, respectively, at Q(B) 300 mL/min and p(in)CO(2) 45 mmHg. A Bland–Altman plot demonstrated that the CO(2) infusion method was comparable to the blood gas analysis method for calculating CO(2) removal. The resistance to blood flow across the test device, as measured by pressure drop, varied as a function of blood flow rate, and was greatest for PrismaLung and lowest for the A.L.ONE device. CONCLUSIONS: The newly developed PrismaLung+ performed more effectively than PrismaLung, with performance of CO(2) removal comparable to A.L.ONE at the flow rates tested, despite the smaller membrane surface area of PrismaLung+ versus A.L.ONE. Clinical testing of PrismaLung+ is warranted to further characterize its performance.