title: Extracorporeal carbon dioxide removal in patients with chronic obstructive pulmonary disease: a systematic review.
abstract: BACKGROUND
  Extracorporeal carbon dioxide removal (ECCO2R) has been proposed for hypercapnic respiratory failure in chronic obstructive pulmonary disease (COPD) exacerbations, to avoid intubation or reduce length of invasive ventilation. Balance of risks, efficacy, and benefits of ECCO2R in patients with COPD is unclear.
  
  
  METHODS
  We systematically searched MEDLINE and EMBASE to identify all publications reporting use of ECCO2R in COPD. We looked at physiological and clinical efficacy. A favorable outcome was defined as prevention of intubation or successful extubation. Major and minor complications were compiled.
  
  
  RESULTS
  We identified 3123 citations. Ten studies (87 patients), primarily case series, met inclusion criteria. ECCO2R prevented intubation in 65/70 (93%) patients and assisted in the successful extubation of 9/17 (53%) mechanically ventilated subjects. One case-control study matching to noninvasively ventilated controls reported lower intubation rates and hospital mortality with ECCO2R that trended toward significance. Physiological data comparing pre- to post-ECCO2R changes suggest improvements for pH (0.07-0.15 higher), PaCO2 (25 mmHg lower), and respiratory rate (7 breaths/min lower), but not PaO2/FiO2. Studies reported 11 major (eight bleeds requiring blood transfusion of 2 units, and three line-related complications, including one death related to retroperitoneal bleeding) and 30 minor complications (13 bleeds, five related to anticoagulation, and nine clotting-related device malfunctions resulting in two emergent intubations).
  
  
  CONCLUSIONS
  The technique is still experimental and no randomized trial is available. Recognizing selection bias associated with case series, there still appears to be potential for benefit of ECCO2R in patients with COPD exacerbations. However, it is associated with frequent and potentially severe complications. Higher-quality studies are required to better elucidate this risk-benefit balance.
authors.affiliation: Department of Anesthesiology, University of Toronto, Toronto, ON, Canada.|Keenan Research Centre and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Sklar
authors.affiliation: Keenan Research Centre and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada.|Département de Réanimation Médicale et Médecine Hyperbare, Université d'Angers, CHU d'Angers, Angers, France.
authors.forename: Francois
authors.initials: F
authors.lastname: Beloncle
authors.affiliation: Keenan Research Centre and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada.|Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada.
authors.forename: Christina M
authors.initials: CM
authors.lastname: Katsios
authors.affiliation: Keenan Research Centre and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada. brochardl@smh.ca.|Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada. brochardl@smh.ca.
authors.forename: Laurent
authors.initials: L
authors.lastname: Brochard
authors.affiliation: Keenan Research Centre and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada.|Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada.
authors.forename: Jan O
authors.initials: JO
authors.lastname: Friedrich
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002245:Carbon Dioxide / Q000097:blood*; D016022:Case-Control Studies; D005112:Extracorporeal Circulation / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D063087:Noninvasive Ventilation / Q000379:methods*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000628:therapy*; D012131:Respiratory Insufficiency / Q000209:etiology* / Q000628:therapy*; D018570:Risk Assessment
chemical_list: D002245:Carbon Dioxide
keywords: Acute respiratory failure; Hypercapnia; Noninvasive ventilation