Total extracorporeal arteriovenous carbon dioxide removal in acute respiratory failure: A phase I clinical study

Steven A. Conrad, Joseph B. Zwischenberger, Laurie R. Grier, Scott K. Alpard, Akhil Bidani

Research output: Contribution to journalArticlepeer-review

84 Scopus citations


Objective: To evaluate the safety and efficacy of pumpless extracorporeal arteriovenous carbon dioxide removal (AVCO2R) in subjects with acute respiratory failure and hypercapnia. Design: A phase I within-group time series trial in which subjects underwent up to 72 h of support with AVCO2R in intensive care units of two university hospitals. Patients: Eight patients with acute hypercapnic respiratory failure or hypoxemic respiratory failure managed with permissive hypercapnia. Interventions: Extracorporeal CO2 removal was achieved through percutaneous cannulation of the femoral artery and vein, and a simple extracorporeal circuit using a commercially available membrane gas exchange device for carbon dioxide exchange. Measurements and results: Measurements of hemodynamics, blood gases, ventilatory settings, and laboratory values were made before initiation of AVCO2R, and at subsequent intervals for 72 h. PaCO2 decreased significantly from 90.8 ± 7.5 mmHg to 52.3 ± 4.3 and 51.8 ± 3.1 mmHg at 1 and 2 h, respectively. This decrease occurred despite a decrease in minute ventilation from a baseline of 6.92 ± 1.64 l/min to 4.22 ± .46 and 3.00 ± .53 l/min at 1 and 2 h. There was a normalization of pH, with an increase from 7.19 ± .06 to 7.35 ± .07 and 7.37 ± .05 at 1 and 2 h. These improvements persisted during the full period of support with AVCO2R. Four subjects underwent apnea trials in which AVCO2R provided total carbon dioxide removal during apneic oxygenation, resulting in steady-state PaCO2 values from 57 to 85 mmHg. Hemodynamics were not significantly altered with the institution of AVCO2R. There were no major complications attributed to the procedure. Conclusion: Pumpless extracorporeal AVCO2R is capable of providing complete extracorporeal removal of carbon dioxide during acute respiratory failure, while maintaining mild to moderate hypercapnia. Applied in conjunction with mechanical ventilation and permissive hypercapnia, AVCO2R resulted in normalization of arterial PCO2 and pH and permitted significant reductions in the level of mechanical ventilation.

Original languageEnglish
Pages (from-to)1340-1351
Number of pages12
JournalIntensive Care Medicine
Issue number8
StatePublished - 2001

Bibliographical note

Funding Information:
Supported in part by an equipment grant from Avecor Cardiovascular, Inc., and the Constance Shafer Endowment for Respiratory Failure


  • Acute respiratory failure
  • Carbon dioxide
  • Extracorporeal circulation
  • Extracorporeal membrane oxygenation
  • Hypercapnia
  • Respiratory insufficiency

ASJC Scopus subject areas

  • Critical Care and Intensive Care Medicine


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