title: Pumpless extracorporeal interventional lung assist in patients with acute respiratory distress syndrome: a prospective pilot study.
abstract: BACKGROUND
  Pumpless interventional lung assist (iLA) is used in patients with acute respiratory distress syndrome (ARDS) aimed at improving extracorporeal gas exchange with a membrane integrated in a passive arteriovenous shunt. In previous studies, feasibility and safety of the iLA system was demonstrated, but no survival benefit was observed. In the present pilot study we tested the hypothesis that timely initiation of iLA using clear algorithms and an improved cannulation technique will positively influence complication rates and management of lung protective ventilation.
  
  
  METHODS
  iLA was implemented in 51 patients from multiple aetiologies meeting ARDS-criteria (American-European Consensus) for more than 12 hours. Initiation of iLA followed an algorithm for screening, careful evaluation and insertion technique. Patients with cardiac insufficiency or severe peripheral vascular disease were not considered suitable for iLA. Arterial and venous cannulae were inserted using a new strategy (ultrasound evaluation of vessels by an experienced team, using cannulae of reduced diameter). The incidence of complications and the effects on tidal volumes and inspiratory plateau pressures were primary outcome parameters, while oxygenation improvement and carbon dioxide removal capabilities were secondary study parameters.
  
  
  RESULTS
  Initiation of iLA resulted in a marked removal in arterial carbon dioxide allowing a rapid reduction in tidal volume (<or= 6 ml/kg) and inspiratory plateau pressure. Adverse events occurred in 6 patients (11.9%). The hospital mortality rate was 49%.
  
  
  CONCLUSIONS
  The use of an indication algorithm for iLA in early ARDS, combined with a refined application technique was associated with efficient carbon dioxide removal and a reduced incidence of adverse events. iLA could serve as an extracorporeal assist to support mechanical ventilation by enabling low tidal volume and a reduced inspiratory plateau pressure.
authors.affiliation: Department of Anesthesiology, University of Regensburg Medical Center, Regensburg, Germany. markus.zimmermann@klinik.uni-regensburg.de
authors.forename: Markus
authors.initials: M
authors.lastname: Zimmermann
authors.forename: Thomas
authors.initials: T
authors.lastname: Bein
authors.forename: Matthias
authors.initials: M
authors.lastname: Arlt
authors.forename: Alois
authors.initials: A
authors.lastname: Philipp
authors.forename: Leopold
authors.initials: L
authors.lastname: Rupprecht
authors.forename: Thomas
authors.initials: T
authors.lastname: Mueller
authors.forename: Matthias
authors.initials: M
authors.lastname: Lubnow
authors.forename: Bernhard M
authors.initials: BM
authors.lastname: Graf
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Schlitt
mesh_terms: D000328:Adult; D001166:Arteriovenous Shunt, Surgical / Q000295:instrumentation / Q000379:methods; D015331:Cohort Studies; D005112:Extracorporeal Circulation / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012121:Respiration, Artificial / Q000295:instrumentation / Q000379:methods*; D012128:Respiratory Distress Syndrome / Q000503:physiopathology / Q000628:therapy*