title: Pharmacologic attenuation of the hyperdynamic response to supraceliac aortic clamping.
abstract: BACKGROUND
  Aortic occlusion is accompanied by a hyperdynamic cardiovascular response secondary to increased systemic vascular resistance and increased cardiac output. This study was designed primarily to determine the safety and cardiovascular response to hydrogen sulfide (H2S; HS) administration with supraceliac aortic cross-clamp and, secondarily, on short-duration resuscitation.
  
  
  METHODS
  A validated porcine model (five sham swine compared with five controls) demonstrated a significant hyperdynamic cardiovascular response to 35% blood volume hemorrhage, 50-minute suprarenal aortic cross-clamping, and 6-hour resuscitation. Eight additional experimental swine were administered HS at 4 mg/min during aortic cross-clamping.
  
  
  RESULTS
  During the cross-clamp period, hemodynamic curves of mean arterial pressure and heart rate demonstrated a blunting effect with HS administration, with a significant decrease being seen with mean arterial pressure at the end of the cross-clamp period (120 vs 149 mm Hg; P = .04). Resuscitation requirements were significantly reduced at 6 hours because the HS cohort received 8 L less crystalloid (P = .001) and 10.4 mg less epinephrine (P < .001). There was not a significant change in cardiac output, systemic vascular resistance, pulmonary vascular resistance, or pathologic liver analysis.
  
  
  CONCLUSIONS
  The administration of HS during the 50 minutes of supraceliac aortic cross-clamp significantly reduced stress of the left heart. On clamp release, HS significantly reduced the need for volume and pressors. HS has positive benefits during cross-clamp and subsequent resuscitation, demonstrating that targeted pharmacologic therapy is possible to minimize adverse physiologic changes with aortic occlusion.
authors.affiliation: Department of Surgery, Madigan Army Medical Center, Tacoma, Wash. Electronic address: mwcausey@msn.com.
authors.forename: Marlin Wayne
authors.initials: MW
authors.lastname: Causey
authors.affiliation: Department of Surgery, Madigan Army Medical Center, Tacoma, Wash.
authors.forename: Seth
authors.initials: S
authors.lastname: Miller
authors.affiliation: Department of Surgery, Madigan Army Medical Center, Tacoma, Wash.
authors.forename: Niten
authors.initials: N
authors.lastname: Singh
authors.affiliation: Department of Surgery, Madigan Army Medical Center, Tacoma, Wash.
authors.forename: Matthew
authors.initials: M
authors.lastname: Martin
mesh_terms: D000818:Animals; D001011:Aorta / Q000503:physiopathology / Q000601:surgery*; D062186:Arterial Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D016887:Cardiopulmonary Resuscitation / Q000379:methods; D002316:Cardiotonic Agents / Q000008:administration & dosage; D002317:Cardiovascular Agents / Q000494:pharmacology*; D003250:Constriction; D000077324:Crystalloid Solutions; D004195:Disease Models, Animal; D004837:Epinephrine / Q000008:administration & dosage; D005440:Fluid Therapy; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006470:Hemorrhage / Q000150:complications / Q000503:physiopathology; D006862:Hydrogen Sulfide / Q000494:pharmacology*; D007552:Isotonic Solutions / Q000008:administration & dosage; D015428:Myocardial Reperfusion Injury / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D013552:Swine; D013997:Time Factors
chemical_list: D002316:Cardiotonic Agents; D002317:Cardiovascular Agents; D000077324:Crystalloid Solutions; D007552:Isotonic Solutions; D004837:Epinephrine; D006862:Hydrogen Sulfide