title: Vasopressin improves systemic hemodynamics without compromising mesenteric perfusion in the resuscitation of asphyxiated newborn piglets: a dose-response study.
abstract: OBJECTIVE
  Hypoxia and reoxygenation (H-R) contributes to multi-organ failure in neonates, including cardiac and systemic complications. Use of vasopressin, an endogenous vasoconstrictive hormone commonly used to treat refractory hypotension in adults, in neonates with shock remains limited and not yet fully studied. We hypothesize that vasopressin will improve mean arterial pressure (MAP), without compromising cardiac, mesenteric, or carotid hemodynamics using a swine model of neonatal asphyxia.
  
  
  METHODS
  Anesthetized piglets (1-4 days old, 1.4-2.5 kg, n = 33) were instrumented for continuous monitoring of cardiac index (CI), MAP, and regional arterial [common carotid (CA), superior mesenteric (SMA)] flow. The animals underwent hypoxia at 10-15% oxygen (2 h) followed by reoxygenation at 100% (0.5 h) and 21% (3.5 h) oxygen. Vasopressin infusion was initiated after 2 h reoxygenation at 0.005, 0.01, or 0.02 units/kg/h i.v. for 2 h (n = 7/group). H-R control (saline infusion) and sham-operated (non-asphyxiated) groups were also included. Intermittent blood gases and plasma lactate were determined as well as tissue lactate levels. Statistical significance was determined using ANOVA.
  
  
  RESULTS
  All H-R piglets had hypotension (36-49% decrease in MAP) and decreased regional blood flows (CA -28 to -34%, SMA -12 to +32% of baseline) at 2 h reoxygenation. Vasopressin infusion dose-dependently increased MAP (14% at 0.02 units/kg/h, P < 0.05) without significant detrimental effects in CI, regional blood flows, and intestinal or cerebral tissue lactate levels.
  
  
  CONCLUSIONS
  Vasopressin treatment causes a dose-dependent baro-specific effect, while preserving cardiac function and cerebral and mesenteric hemodynamics in newborn piglets following H-R.
authors: Faculty of Medicine and Dentistry, University of Alberta, 2C3.44 Walter MacKenzie Center, 8440-112St, Edmonton, AB T6G 2B7, Canada.
authors: Douglas C
authors: DC
authors: Cheung
authors: Richdeep S
authors: RS
authors: Gill
authors: Jiang-Qin
authors: JQ
authors: Liu
authors: Namdar
authors: N
authors: Manouchehri
authors: Consolato
authors: C
authors: Sergi
authors: David
authors: D
authors: Bigam
authors: Po-Yin
authors: PY
authors: Cheung
authors: Bryan J
authors: BJ
authors: Dicken
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001237:Asphyxia / Q000188:drug therapy*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006439:Hemodynamics / Q000187:drug effects*; D008643:Mesentery / Q000187:drug effects* / Q000503:physiopathology; D010100:Oxygen / Q000008:administration & dosage* / Q000627:therapeutic use; D010477:Perfusion / Q000379:methods; D011897:Random Allocation; D012151:Resuscitation / Q000379:methods; D014667:Vasopressins / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D014667:Vasopressins; D010100:Oxygen