title: Hemodynamic and gas transfer properties of a compliant thoracic artificial lung.
abstract: A compliant thoracic artificial lung (TAL) has been developed for acute respiratory failure or as a bridge to transplantation. The development goal was to increase TAL compliance, lower TAL impedance, and improve right ventricular function during use. Prototypes were tested in vitro and in vivo in eight pigs between 67 and 79 kg to determine hemodynamic and gas transfer properties. The in vitro compliance was 16.2 +/- 4.4 ml/mm Hg at pressures < 7.8 mm Hg and 4.3 +/- 1.1 ml/mm Hg above 7.8 mm Hg. In vivo, this compliance significantly reduced blood flow pulsatility from 1.7 at the inlet to 0.36 at the outlet. Device resistance was 1.9 and 1.8 mm Hg/(L/min) at a flow rate of 4 L/min in vitro and in vivo, respectively. Approximately 75% of the resistance was at the inlet and outlet. In vivo TAL O2 and CO2 transfer rates were 188 and 186 ml/min, respectively, at 4 L/min of blood and gas flow, and average outlet O2 saturations exceeded 98% for average flow rates up to and including the maximum tested, 5.3 L/min. The new design has a markedly improved compliance and excellent gas transfer but also possesses inlet and outlet resistances that must be reduced in future designs.
authors.affiliation: University of Michigan Department of Surgery and Biomedical Engineering, Ann Arbor, MI 48109-0522, USA.
authors.forename: Keith E
authors.initials: KE
authors.lastname: Cook
authors.forename: Carrie E
authors.initials: CE
authors.lastname: Perlman
authors.forename: Ralf
authors.initials: R
authors.lastname: Seipelt
authors.forename: Carl L
authors.initials: CL
authors.lastname: Backer
authors.forename: Constantine
authors.initials: C
authors.lastname: Mavroudis
authors.forename: Lyle F
authors.initials: LF
authors.lastname: Mockrost
mesh_terms: D000818:Animals; D001187:Artificial Organs; D001698:Biomedical Engineering; D002245:Carbon Dioxide / Q000097:blood*; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D005260:Female; D006439:Hemodynamics; D020007:Implants, Experimental; D066298:In Vitro Techniques; D008168:Lung / Q000502:physiology*; D008170:Lung Compliance; D016040:Lung Transplantation; D008954:Models, Biological; D010100:Oxygen / Q000097:blood*; D011652:Pulmonary Circulation; D011659:Pulmonary Gas Exchange; D012131:Respiratory Insufficiency / Q000601:surgery; D015656:Respiratory Mechanics; D013552:Swine; D013909:Thorax
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen