title: An artificial lung reduces pulmonary impedance and improves right ventricular efficiency in pulmonary hypertension.
abstract: OBJECTIVE
  Artificial lungs may have a role in supporting patients with end-stage lung disease as a bridge or alternative to lung transplantation. This investigation was performed to determine the effect of an artificial lung, perfused by the right ventricle in parallel with the pulmonary circulation, on indices of right ventricular load in a model of pulmonary hypertension.
  
  
  METHODS
  Seven adult male sheep were connected to a low-resistance membrane oxygenator through conduits anastomosed end to side to the pulmonary artery and left atrium. Banding of the distal pulmonary artery generated acute pulmonary hypertension. Data were obtained with and without flow through the device conduits. Outcome measures of right ventricular load included hemodynamic parameters, as well as analysis of impedance, power consumption, wave reflections, cardiac efficiency, and the tension-time index.
  
  
  RESULTS
  The model of pulmonary hypertension increased all indices of right ventricular load and decreased ventricular efficiency. Allowing flow through the artificial lung significantly reduced mean pulmonary artery pressure, zero harmonic impedance, right ventricular power consumption, amplitude of reflected waves, and the tension-time index. Cardiac efficiency was significantly increased.
  
  
  CONCLUSIONS
  An artificial lung perfused by the right ventricle and applied in parallel with the pulmonary circulation reduces ventricular load and improves cardiac efficiency in the setting of pulmonary hypertension. These data suggest that an artificial lung in this configuration may benefit patients with end-stage lung disease and pulmonary hypertension with right ventricular strain.
authors.affiliation: Department of Surgery, University of Michigan, and Michigan Critical Care Consultants, Ann Arbor, Mich, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Haft
authors.forename: P
authors.initials: P
authors.lastname: Montoya
authors.forename: O
authors.initials: O
authors.lastname: Alnajjar
authors.forename: S R
authors.initials: SR
authors.lastname: Posner
authors.forename: J L
authors.initials: JL
authors.lastname: Bull
authors.forename: M D
authors.initials: MD
authors.lastname: Iannettoni
authors.forename: R H
authors.initials: RH
authors.lastname: Bartlett
authors.forename: R B
authors.initials: RB
authors.lastname: Hirschl
mesh_terms: D000403:Airway Resistance / Q000502:physiology; D000818:Animals; D001187:Artificial Organs; D006976:Hypertension, Pulmonary / Q000503:physiopathology* / Q000628:therapy; D008168:Lung; D008297:Male; D011652:Pulmonary Circulation / Q000502:physiology; D012756:Sheep; D016278:Ventricular Function, Right / Q000502:physiology