title: In-parallel attachment of a low-resistance compliant thoracic artificial lung under rest and simulated exercise.
abstract: BACKGROUND
  Previous thoracic artificial lungs (TALs) had blood flow impedance greater than that of the natural lungs, which could cause abnormal pulmonary hemodynamics. New compliant TALs (cTALs), however, have an impedance lower than that of the natural lung.
  
  
  METHODS
  In this study, a cTAL of new design was attached between the pulmonary artery (PA) and the left atrium (LA) in 5 sheep (60.2 ± 1.9 kg). A distal PA band was placed to control the percentage of cardiac output (CO) routed to the cTAL. Rest and exercise conditions were simulated using a continuous dobutamine infusion of 0 and 5 μg/kg/min, respectively. At each dose, a hemodynamic data set was acquired at baseline (no flow to the cTAL), and 60%, 75%, and 90% of CO was shunted to the cTAL.
  
  
  RESULTS
  Device resistance did not vary with blood flow rate, averaging 0.51 ± 0.03 mm Hg/(L/min). Under all conditions, CO was not significantly different from baseline. Pulmonary system impedance increased above baseline only with 5 μg/kg/min of dobutamine and 90% of CO diverted to the cTAL.
  
  
  CONCLUSIONS
  Results indicated minimal changes in pulmonary hemodynamics during PA-LA cTAL attachment for high device flows under rest and exercise conditions.
authors.affiliation: Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Schewe
authors.forename: Christopher N
authors.initials: CN
authors.lastname: Scipione
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Koch
authors.forename: Keith E
authors.initials: KE
authors.lastname: Cook
mesh_terms: D000818:Animals; D001187:Artificial Organs; D008168:Lung; D008170:Lung Compliance; D008297:Male; D010805:Physical Conditioning, Animal / Q000502:physiology*; D019919:Prosthesis Implantation / Q000379:methods; D012039:Regional Blood Flow; D012146:Rest / Q000502:physiology*; D012756:Sheep; D014655:Vascular Resistance