title: Hypercapnia in late-phase ALI/ARDS: providing spontaneous breathing using pumpless extracorporeal lung assist.
abstract: OBJECTIVE
  The fibroproliferative phase of late ALI/ARDS as described by Hudson and Hough (Clin Chest Med 27:671-677, 2006) is associated with pronounced reductions in pulmonary compliance and an accompanying hypercapnia complicating low tidal volume mechanical ventilation. We report the effects of extracorporeal CO(2) removal by means of a novel pumpless extracorporeal lung assist (p-ECLA) on tidal volumes, airway pressures, breathing patterns and sedation management in pneumonia patients during late-phase ARDS.
  
  
  METHODS
  Retrospective analysis.
  
  
  METHODS
  Fourteen-bed university hospital ICU.
  
  
  METHODS
  Ten consecutive late-phase ALI/ARDS patients with low pulmonary compliance, and severe hypercapnia.
  
  
  METHODS
  Gas exchange, tidal volumes, airway pressures, breathing patterns and sedation requirements before (baseline) and after (2-4 days) initiation of treatment with p-ECLA were analysed. Patients were ventilated in a pressure-controlled mode with PEEP adjusted to pre-defined oxygenation goals.
  
  
  RESULTS
  Median reduction in pCO(2) was 50% following institution of p-ECLA. Extracorporeal CO(2) removal enabled significant reduction in tidal volumes (to below 4 ml/kg predicted body weight) and inspiratory plateau pressures [30 (28.5/32.3) cmH(2)O, median 25, 75% percentiles]. Normalization of pCO(2) levels permitted significant reduction in the dosages of analgesics and sedatives. The proportion of assisted spontaneous breathing increased within 24 h of instituting p-ECLA.
  
  
  CONCLUSIONS
  Elimination of CO(2) by p-ECLA therapy allowed reduction of ventilator-induced shear stress through ventilation with tidal volumes below 4 ml/kg predicted body weight in pneumonia patients with severely impaired pulmonary compliance during late-phase ARDS. p-ECLA treatment supported control of breathing pattern while sedation requirements were reduced and facilitated the implementation of assisted spontaneous breathing.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Charité, Universitätsmedizin Berlin, Campus Virchow-Klinikum, Campus Mitte, Berlin, Germany. steffen.weber-carstens@charite.de
authors.forename: Steffen
authors.initials: S
authors.lastname: Weber-Carstens
authors.forename: Sven
authors.initials: S
authors.lastname: Bercker
authors.forename: Matthias
authors.initials: M
authors.lastname: Hommel
authors.forename: Maria
authors.initials: M
authors.lastname: Deja
authors.forename: Martin
authors.initials: M
authors.lastname: MacGuill
authors.forename: Christiane
authors.initials: C
authors.lastname: Dreykluft
authors.forename: Udo
authors.initials: U
authors.lastname: Kaisers
mesh_terms: D055371:Acute Lung Injury / Q000503:physiopathology*; D000328:Adult; D000368:Aged; D005112:Extracorporeal Circulation / Q000295:instrumentation*; D005260:Female; D005858:Germany; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012119:Respiration; D012128:Respiratory Distress Syndrome / Q000503:physiopathology*; D012189:Retrospective Studies; D012656:Self-Help Devices