title: Mesenteric and renal oxygen transport during hemorrhage and reperfusion: evaluation of optimal goals for resuscitation.
abstract: BACKGROUND
  Changes in flow to the gut and the kidney during hemorrhage and resuscitation contribute to organ dysfunction and outcome. We evaluated regional and splanchnic oxygen (O2) flow distribution and calculated oxygen supply distribution during hemorrhage and reperfusion and compared them with global measures.
  
  
  METHODS
  Seven anesthetized pigs were instrumented to evaluate global hemodynamics, visceral blood flow, and oxygen transport. Tonometric pH probes were positioned in the stomach and jejunum. Animals were bled to 45 mm Hg for 1 hour. Crystalloids and blood were infused during the following 2 hours to normalize blood pressure, heart rate, urine output, and hemo- globin.
  
  
  RESULTS
  During hemorrhage, mesenteric flow and O2 consumption were significantly decreased, whereas systemic consumption remained normal. Renal flow was reduced, but renal O2 consumption remained normal. After resuscitation, despite normal hemodynamics, neither systemic, mesenteric, nor renal O2 delivery returned to baseline. Lactate remained significantly increased. Arterial pH, base excess, and gastric and jejunal pH were all decreased.
  
  
  CONCLUSIONS
  During hemorrhage, the gut is more prone than other regions to O2 consumption supply dependency. After resuscitation, standard clinical parameters do not detect residual O2 debt. Lactate, arterial pH, base excess, and intramucosal gut pH are all markers of residual tissue hypoperfusion.
authors.affiliation: Istituto di Chirurgia d'Urgenza, Universita' degli Studi di Milano, Ospedale Maggiore IRCCS, Milano, Italy.
authors.forename: O
authors.initials: O
authors.lastname: Chiara
authors.forename: P
authors.initials: P
authors.lastname: Pelosi
authors.forename: M
authors.initials: M
authors.lastname: Segala
authors.forename: M G
authors.initials: MG
authors.lastname: Turconi
authors.forename: L
authors.initials: L
authors.lastname: Brazzi
authors.forename: N
authors.initials: N
authors.lastname: Bottino
authors.forename: P
authors.initials: P
authors.lastname: Taccone
authors.forename: M
authors.initials: M
authors.lastname: Zambelli
authors.forename: G
authors.initials: G
authors.lastname: Tiberio
authors.forename: S
authors.initials: S
authors.lastname: Boswell
authors.forename: T M
authors.initials: TM
authors.lastname: Scalea
mesh_terms: D000136:Acid-Base Equilibrium / Q000502:physiology; D000818:Animals; D005260:Female; D005440:Fluid Therapy; D005745:Gastric Acidity Determination; D006439:Hemodynamics / Q000502:physiology; D019344:Lactic Acid / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology*; D012079:Renal Circulation / Q000502:physiology*; D015427:Reperfusion Injury / Q000503:physiopathology*; D012151:Resuscitation; D012771:Shock, Hemorrhagic / Q000503:physiopathology*; D013152:Splanchnic Circulation / Q000502:physiology*; D013552:Swine
chemical_list: D019344:Lactic Acid