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

Abstract

Background: Ultra-protective lung ventilation in acute respiratory distress syndrome or early weaning and/or avoidance of mechanical ventilation in decompensated chronic obstructive pulmonary disease may be facilitated by the use of extracorporeal CO2 removal (ECCO2R). We tested the CO2 removal performance of a new ECCO2R (CO2RESET) device in an experimental animal model. Methods: Three healthy pigs were mechanically ventilated and connected to the CO2RESET device (surface area = 1.8 m2, EUROSETS S.r.l., Medolla, Italy). Respiratory settings were adjusted to induce respiratory acidosis with the adjunct of an external source of pure CO2 (target pre membrane lung venous PCO2 (PpreCO2): 80–120 mmHg). The amount of CO2 removed (VCO2, mL/min) by the membrane lung was assessed directly by the ECCO2R device. Results: Before the initiation of ECCO2R, the median PpreCO2 was 102.50 (95.30–118.20) mmHg. Using fixed incremental steps of the sweep gas flow and maintaining a fixed blood flow of 600 mL/min, VCO2 progressively increased from 0 mL/min (gas flow of 0 mL/min) to 170.00 (160.00–200.00) mL/min at a gas flow of 10 L/min. In particular, a high increase of VCO2 was observed increasing the gas flow from 0 to 2 L/min, then, VCO2 tended to progressively achieve a steady-state for higher gas flows. No animal or pump complications were observed. Conclusions: Medium-flow ECCO2R devices with a blood flow of 600 mL/min and a high surface membrane lung (1.8 m2) provided a high VCO2 using moderate sweep gas flows (i.e., >2 L/min) in an experimental swine models with healthy lungs.

Evaluation of CO2 removal rate of ECCO2R for a renal replacement therapy platform in an experimental setting

“…An experimental study of the CO 2 RESET device (surface area: 1.8 m 2 ; EUROSETS S.R.L., Medolla, Italy) by Nardo et al. revealed that VCO 2 tended to progressively achieve a steady‐state for gas flow rates higher than 2 L/min, while VCO 2 showed an obvious increase with gas flow rate when the rate was below 2 L/min 10 . However, when ECCO 2 R was performed using the ProLung System (surface area 1.8 m 2 ; Estor, Pero, Milan, Italy), VCO 2 was not affected at gas flow rates above 4 L/min 9 .…”

“…On the other hand, in low‐flow venovenous ECLS with large‐size membrane lungs (m 2 ), VCO 2 shows the “ceiling effect”. VCO 2 was not affected by gas flow above 4 L/min in one study, but tended to progressively achieve a steady state for gas flow rates higher than 2 L/min in another; however, these two studies used totally different ECBF platforms 9,10 . Studies showing the variable effects of different combinations of factors are scarce.…”

“…VCO 2 was not affected by gas flow above 4 L/min in one study, but tended to progressively achieve a steady state for gas flow rates higher than 2 L/min in another; however, these two studies used totally different ECBF platforms. 9,10 Studies showing the variable effects of different combinations of factors are scarce. Moreover, the ECCO 2 R devices available currently have a wide range of blood flow rates (i.e., 200 to 1800 mL/min), distinct sweep gas flow rates, and membrane lung sizes (m 2 ).…”

“…VCO 2 depends on several factors, including the surface area and specific features of the artificial lungs, the PCO 2 of venous blood entering the artificial lungs, extracorporeal blood flow (ECBF), and sweep gas flow 8–12 . In experimental animals, VCO 2 has been shown to increase linearly with membrane lung surface, ECBF, and inflow PCO 2 8,9 .…”

Alkaline Liquid Ventilation of the Membrane Lung for Extracorporeal Carbon Dioxide Removal (ECCO2R): In Vitro Study

“…However, the use of high sweep gas flows, while maximizing the transmembrane gradient, does not increase CO 2 clearance significantly. Indeed, during ECCO 2 R, most of the extracorporeal CO 2 removal capacity is achieved for sweep gas flows below 2 L × min −1 since, at higher flows, the system rapidly loses efficiency [ 13 , 14 , 15 , 16 ].…”