A Novel Extracorporeal CO2 Removal System

Abstract

C OPD causes signifi cant morbidity and mortality, and is the fourth leading cause of death in the world. 1 Hypercapnic respiratory failure in COPD worsens the prognosis and increases the mortality. 2-5 Noninvasive positive pressure ventilation (NIPPV) is now established as the standard treatment of respira-tory failure in acute exacerbation of COPD 6 ; however, 26% to 54% of these patients still require invasive positive pressure ventilation (IPPV). 7,8 The prognosis for patients with COPD who require IPPV is poor with hospital survival ranging from 31% to 76%. 6,9,10 As an adjunct to IPPV, extracorporeal CO 2 removal (ECCO 2 R) techniques were fi rst applied to patients with hypoxic respiratory failure over three decades ago 11,12 but have not achieved widespread use. Curi-ously, the application of ECCO 2 R specifi cally for hypercapnic respiratory failure has not been well stud-ied. We describe here a pilot study of the application Background : Hypercapnic respiratory failure in patients with COPD frequently requires mechan-ical ventilatory support. Extracorporeal CO 2 removal (ECCO 2 R) techniques have not been sys-tematically evaluated in these patients. Methods : This is a pilot study of a novel ECCO 2 R device that utilizes a single venous catheter with high CO 2 removal rates at low blood fl ows. Twenty hypercapnic patients with COPD received ECCO 2 R. Group 1 (n 5 7) consisted of patients receiving noninvasive ventilation with a high like-lihood of requiring invasive ventilation, group 2 (n 5 2) consisted of patients who could not be weaned from noninvasive ventilation, and group 3 (n 5 11) consisted of patients on invasive ven-tilation who had failed attempts to wean. Results: The device was well tolerated, with complications and rates similar to those seen with cen-tral venous catheterization. Blood fl ow through the system was 430.5 Ϯ 73.7 mL/min, and ECCO 2 R was 82.5 Ϯ 15.6 mL/min and did not change signifi cantly with time. Invasive ventilation was avoided in all patients in group 1 and both patients in group 2 were weaned; Pa CO 2 decreased signifi cantly (P , .003) with application of the device from 78.9 Ϯ 16.8 mm Hg to 65.9 Ϯ 11.5 mm Hg. In group 3, three patients were weaned, while the level of invasive ventilatory support was reduced in three patients. One patient in group 3 died due to a retroperitoneal bleed following catheterization. Conclusions: This single-catheter, low-fl ow ECCO 2 R system provided clinically useful levels of CO 2 removal in these patients with COPD. The system appears to be a potentially valuable addi-tional modality for the treatment of hypercapnic respiratory failure. Trial registry: ClinicalTrials.gov; No.: NCT00987740 and 01021605; URL: www.clinicaltrials.gov CHEST 2013; 143(3):678–686