title: In vivo testing of a right heart mini-pump during a 24 hour period: is it safe?
abstract: A coaxial atrial cannula connected to a mini-centrifugal pump was developed to bypass the right heart during extreme exposures in off-pump coronary artery bypass surgery. This study was designed to test the effect of this pump, running during 24 hours, on blood elements to evaluate its use as a prolonged right heart support. In a calf model (body weight 68+/-5 kg), the pump was inserted and set to its maximal motor speed of 7000 rpm. Blood samples were drawn every 6 hours for blood gas analyses, as well as for hematology and chemistry. The right heart mini-pump performed perfectly at its maximal speed over the 24 hour period. Blood gas parameters and blood lactate levels reflected adequate tissue perfusion (baseline: 2.2+/-0.5 mmol/L vs. 24 h: 2+/-0.3 mmol/L; p = 0.64). Red blood cell count was stable (baseline: 9.8+/-1.4 x 10(12)/L vs. 24 h: 9.6+/-1.1 x 10(12)/L; p = 0.83). Free plasma hemoglobin remained below 100 mg/L throughout the experiment. Platelet count was stable during the first 6 hours and exhibited a tendency to drop thereafter (baseline: 749+/-104 x 10(9)/L vs. 24 h: 486+/-20 x 10(9)/L; p = 0.01). This right heart mini-pump appears to provide sufficient blood flow during a 24 hour period with minimal impact on red cell and moderate platelet damage after 6 hours. These results suggest a potential application of this system for postcardiotomy right heart support.
authors.affiliation: Department of Cardiovascular Surgery, Centre Hospitalier Universitaire de Sherbrooke, Quebec, Canada.
authors.forename: Xavier M
authors.initials: XM
authors.lastname: Mueller
authors.forename: Monique
authors.initials: M
authors.lastname: Augstburger
authors.forename: Yves
authors.initials: Y
authors.lastname: Boone
authors.forename: Hendrik T
authors.initials: HT
authors.lastname: Tevaearai
authors.forename: Ludwig K
authors.initials: LK
authors.lastname: von Segesser
mesh_terms: D000818:Animals; D001794:Blood Pressure; D002417:Cattle; D001026:Coronary Artery Bypass / Q000295:instrumentation*; D004867:Equipment Design; D004906:Erythrocyte Count; D006339:Heart Rate; D006353:Heart-Assist Devices; D006400:Hematocrit; D006454:Hemoglobins; D019344:Lactic Acid / Q000097:blood; D010100:Oxygen / Q000097:blood; D010976:Platelet Count
chemical_list: D006454:Hemoglobins; D019344:Lactic Acid; D010100:Oxygen