Novel carbon dioxide removal device driven by a renal-replacement system without hemofilter: an experimental approach and validation

Introduction

Management of acute respiratory diseases must avoid ventilator-induced lung injuries along with the rise of PaCO₂ and respiratory acidosis [1]. Efforts are made to find devices assisting protective ventilation and able to remove arterial CO₂ and correct acidosis [2]. An extracorporeal CO₂ removal device driven by the widely used Prismaflex^® platform called PrismaLung^® was tested in vivo.

Methods

Five hypercapnic ventilated pigs were equipped with the PrismaLung^® system designed to remove CO₂ from the bloodstream through a decarboxylation membrane mounted on a renal replacement device without any hemofilter. Experiments examined the potential for blood decarboxylation by gas-exchanger membrane with different sets of parameters (blood flow rate: 200, 300 and 400 ml/minute, sweep gas flow: 2, 5, 10 and 50 l/minute, FiO₂: 21 and 100%). Statistical analysis was performed with the Student t test.

Results

The extracorporeal device allowed efficient CO₂ removal rates at FiO₂ 1 (Figure 1) and 0.21 (Figure 2), ranging from 40 to 60 ml/ minute. Efficiency was increased with blood and sweep gas flows. Carbia and pH of animals were significantly modified after 10 minutes of treatment. No significant modification of blood oxygenation was obtained with pure oxygen, allowing the use of ambient air as the sweep gas through the membrane. No side effects or filter clotting occurred during experiments.

Figure 1

CO ₂ removal rates at FiO ₂ 1.

Figure 2

CO ₂ removal rates at FiO ₂ 0.21.

Conclusion

The device based on the Prismaflex^® platform efficiently removed CO₂ from blood and decreased PaCO₂ and acidosis of hypercapnic pigs. Benefits for patients with acute to chronic respiratory diseases need evaluation.