Effects of vasopressin on microcirculatory blood flow in the gastrointestinal tract in anesthetized pigs in septic shock.
BACKGROUND
Vasopressin increases arterial pressure in septic shock even when alpha-adrenergic agonists fail. The authors studied the effects of vasopressin on microcirculatory blood flow in the entire gastrointestinal tract in anesthetized pigs during early septic shock.


METHODS
Thirty-two pigs were intravenously anesthetized, mechanically ventilated, and randomly assigned to one of four groups (n=8 in each; full factorial design). Group S (sepsis) and group SV (sepsis-vasopressin) were made septic by fecal peritonitis. Group C and group V were nonseptic control groups. After 300 min, group V and group SV received intravenous infusion of 0.06 U.kg.h vasopressin. In all groups, cardiac index and superior mesenteric artery flow were measured. Microcirculatory blood flow was recorded with laser Doppler flowmetry in both mucosa and muscularis of the stomach, jejunum, and colon.


RESULTS
While vasopressin significantly increased arterial pressure in group SV (P<0.05), superior mesenteric artery flow decreased by 51+/-16% (P<0.05). Systemic and mesenteric oxygen delivery and consumption decreased and oxygen extraction increased in the SV group. Effects on the microcirculation were very heterogeneous; flow decreased in the stomach mucosa (by 23+/-10%; P<0.05), in the stomach muscularis (by 48+/-16%; P<0.05), and in the jejunal mucosa (by 27+/-9%; P<0.05), whereas no significant changes were seen in the colon.


CONCLUSIONS
Vasopressin decreased regional flow in the superior mesenteric artery and microcirculatory blood flow in the upper gastrointestinal tract. This reduction in flow and a concomitant increase in the jejunal mucosa-to-arterial carbon dioxide gap suggest compromised mucosal blood flow in the upper gastrointestinal tract in septic pigs receiving low-dose vasopressin.
Hiltebrand
Luzius B
LB
Department of Anesthesia, University of Bern, Inselspital, Bern, Switzerland, and Department of Anesthesia and Intensive Care Medicine, Landspitali University Hospital, Reykjavik, Iceland.
Krejci
Vladimir
V
Jakob
Stephan M
SM
Takala
Jukka
J
Sigurdsson
Gisli H
GH
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D041981:Gastrointestinal Tract / Q000098:blood supply* / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D008833:Microcirculation / Q000187:drug effects; D012772:Shock, Septic; D013152:Splanchnic Circulation / Q000187:drug effects*; D013552:Swine; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014667:Vasopressins / Q000494:pharmacology*
D014662:Vasoconstrictor Agents; D014667:Vasopressins