In vitro characterization of PrismaLung+: a novel ECCO2R device

Abstract

Background Invasive mechanical ventilation is lifesaving in the setting of severe acute respiratory failure but can cause ventilation-induced lung injury. Advances in extracorporeal CO2 removal (ECCO2R) 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 CO2 removal capacity of the novel PrismaLung+ ECCO2R device compared with two existing gas exchangers. Methods The in vitro CO2 removal capacity of the PrismaLung+ (surface area 0.8 m2, Baxter) was compared with the PrismaLung (surface area 0.35 m2, Baxter) and A.L.ONE (surface area 1.35 m2, Eurosets) devices, using a closed-loop bovine blood–perfused extracorporeal circuit. The efficacy of each device was measured at varying pCO2 inlet (pinCO2) levels (45, 60, and 80 mmHg) and blood flow rates (QB) of 200–450 mL/min; the PrismaLung+ and A.L.ONE devices were also tested at a QB of 600 mL/min. The amount of CO2 removed by each device was assessed by measurement of the CO2 infused to maintain circuit equilibrium (CO2 infusion method) and compared with measured CO2 concentrations in the inlet and outlet of the CO2 removal device (blood gas analysis method). Results The PrismaLung+ device performed similarly to the A.L.ONE device, with both devices demonstrating CO2 removal rates ~ 50% greater than the PrismaLung device. CO2 removal rates were 73 ± 4.0, 44 ± 2.5, and 72 ± 1.9 mL/min, for PrismaLung+, PrismaLung, and A.L.ONE, respectively, at QB 300 mL/min and pinCO2 45 mmHg. A Bland–Altman plot demonstrated that the CO2 infusion method was comparable to the blood gas analysis method for calculating CO2 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 CO2 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.

Very low blood flow carbon dioxide removal system is not effective in a chronic obstructive pulmonary disease exacerbation setting

“…The only study published with this new membrane is performed in vitro. 24 However, to obtain blood flow rates of 600 mL/min, a catheter of at least 15 Fr will be necessary, with the risks inherent in this type of cannulation. Thus, clinical testing of PrismaLung + is warranted to further characterize its performance.…”

Evaluation of a New Extracorporeal CO2 Removal Device in an Experimental Setting

“…The use of low/medium-flow ECCO 2 R devices with this setting may have some advantages compared to high-flow ECCO 2 R devices. First, low/medium-flow ECCO 2 R are generally driven by roller pumps and have been developed specifically to remove CO 2 [ 15 ]. High-flow devices are generally centrifugal pumps designed for higher blood flows and used for extracorporeal membrane oxygenation (ECMO).…”

“…Thus, adding CO 2 with an external source for a limited amount of time is not the most accurate strategy to increase CO 2 storages [ 18 ]. However, we adopted this approach, previously used by other authors [ 15 , 16 ] to rapidly increase P pre CO 2 , avoiding the reduction of tidal volume (<4 mL/kg) and respiratory rate to unsafe levels that could have required an adjustment of the ventilator settings.…”

“…Second, only one fixed blood flow (600 mL/min) was used in our experiments, although the CO 2 elimination is known to increase with the increase of blood flow; the operating range of CO 2 RESET is wider with a maximum of 800 mL/min. However, our purpose was to maintain a blood flow that was comparable with the ones described in other studies [ 15 , 17 ]. Of note, we preferred not to use lower blood flows (i.e., 400 mL/min) [ 10 ], to avoid the use of higher ACT (300 sec) for anticoagulation [ 1 ].…”

“…Respiratory acidosis was induced with a 50% reduction of both the baseline tidal volume (from 8 to 4 mL/kg) and the respiratory frequency, to achieve an end tidal CO 2 (etCO 2 ) between 50 and 60 mmHg ( Figure 2 ). To ensure a pre-membrane lung CO 2 (P pre CO 2 ) between 80–120 mmHg, an external supplementation of 1 L/min CO 2 was provided to the inspiratory side of the ventilator circuit [ 15 , 16 ]. FiO 2 was adjusted to maintain a SpO 2 > 96%.…”