title: Low-dose versus high-dose heparinization during arteriovenous carbon dioxide removal.
abstract: The purpose of this study was to compare low-dose (LD) and high-dose (HD) systemic heparinization in a prospective randomized study of arteriovenous carbon dioxide removal (AVCO2R) during acute respiratory distress syndrome, using a commercially available heparin-coated oxygenator. Adult sheep (n = 13) received an LD50 smoke inhalation and 40% TBSA third degree cutaneous flame burn injury. At 40-48 h post-injury, animals underwent cannulation of the carotid artery and jugular vein and were then randomized to HD heparin (activated clotting time, ACT > 300s, n = 6) and LD heparin (ACT < 200s, n =7) and placed on AVCO2R for approximately 72 h using an oxygenator with the Trillium Bio-Passive Surface. Mean ACTs were significantly different, as expected (HD: 446 +/- 26s, LD: 213 +/- 12s, p < 0.05). AVCO2R shunt flow averaged approximately 13% of cardiac output with mean CO2 removal similar in HD and LD, p = NS. The hematocrit, platelet count, and fibrin degradation products for the two groups were not different. No differences in thrombosis or bleeding were noted. In conclusion, LD systemic heparin (ACT < 200s) with a heparin-coated oxygenator does not increase thrombogenicity during AVCO2R for smoke/burn-induced severe lung injury in sheep.
authors.affiliation: Department of Surgery, The University of Texas Medical Branch, Galveston 77555-0528, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Murphy
authors.forename: C M
authors.initials: CM
authors.lastname: Savage
authors.forename: S K
authors.initials: SK
authors.lastname: Alpard
authors.forename: D J
authors.initials: DJ
authors.lastname: Deyo
authors.forename: J B
authors.initials: JB
authors.lastname: Jayroe
authors.forename: J B
authors.initials: JB
authors.lastname: Zwischenberger
mesh_terms: D000208:Acute Disease; D000818:Animals; D001166:Arteriovenous Shunt, Surgical / Q000379:methods / Q000592:standards; D001783:Blood Flow Velocity / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood*; D020099:Coated Materials, Biocompatible; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D015199:Extracorporeal Membrane Oxygenation / Q000009:adverse effects / Q000379:methods* / Q000592:standards; D005260:Female; D005340:Fibrinogen / Q000187:drug effects / Q000378:metabolism; D006493:Heparin / Q000008:administration & dosage / Q000494:pharmacology*; D010107:Oxygenators, Membrane / Q000592:standards; D010976:Platelet Count; D012131:Respiratory Insufficiency / Q000150:complications / Q000628:therapy; D012756:Sheep; D016896:Treatment Outcome; D014914:Whole Blood Coagulation Time
chemical_list: D020099:Coated Materials, Biocompatible; D002245:Carbon Dioxide; D005340:Fibrinogen; D006493:Heparin