title: Effect of low-dose vasopressin infusion on vital organ blood flow in the conscious normal and septic sheep.
abstract: The effect of low-dose vasopressin (AVP) on vital regional circulations may be clinically relevant but has not been fully described. We sought to determine the effect of low-dose AVP on systemic haemodynamics, coronary, mesenteric and renal circulations in the conscious normal and septic mammal. We studied seven Merino sheep using a prospective randomized cross-over double-blind placebo-controlled animal design. We inserted flow probes around aorta, coronary, mesenteric and renal arteries and, three weeks later, we infused low-dose AVP (0.02 IU/min) or placebo in the normal and septic state induced by intravenous E. coli. In normal sheep, AVP (0.02 IU/min) induced a 17% decrease in mesenteric blood flow (393.0+/-134.9 vs 472.1+/-163.8 ml/min, P<0.05) and a 14% decrease in mesenteric conductance (P<0.05). In septic sheep, AVP decreased heart rate and cardiac output by 28% and 22%, respectively (P<0.05). It also decreased mesenteric blood flow and mesenteric conductance by 23% (flow: 468.5+/-159.7 vs 611.3+/-136.3 ml/min, P<0.05; conductance: 6.3+/-2.7 vs 8.2+/-2.7 ml/min/mmHg; P<0.05). Renal blood flow was unchanged but urine output and creatinine clearance increased (P<0.05). We conclude that low-dose AVP infusion has similar effects in the normal and septic mammalian circulation: bradycardia, decreased cardiac output, decreased mesenteric blood flow and conductance and increased urine output and creatinine clearance. This information is important to clinicians considering its administration in humans.
authors.affiliation: Department of Intensive Care, Austin Health, Heidelberg, Victoria, Australia.
authors.forename: D
authors.initials: D
authors.lastname: Di Giantomasso
authors.forename: H
authors.initials: H
authors.lastname: Morimatsu
authors.forename: R
authors.initials: R
authors.lastname: Bellomo
authors.forename: C N
authors.initials: CN
authors.lastname: May
mesh_terms: D000818:Animals; D002406:Catheterization, Peripheral; D003404:Creatinine / Q000097:blood; D004927:Escherichia coli Infections / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects; D007262:Infusions, Intravenous; D010052:Ovariectomy; D012039:Regional Blood Flow / Q000187:drug effects; D012079:Renal Circulation / Q000187:drug effects; D018805:Sepsis / Q000503:physiopathology*; D012756:Sheep; D013152:Splanchnic Circulation / Q000187:drug effects; D014563:Urodynamics / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000494:pharmacology*; D014667:Vasopressins / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D014662:Vasoconstrictor Agents; D014667:Vasopressins; D003404:Creatinine