Effects of dobutamine on intestinal microvascular blood flow heterogeneity and O2extraction during septic shock.
Derangements of microvascular blood flow distribution might contribute to disturbing O2extraction by peripheral tissues. We evaluated the dynamic relationships between the mesenteric O2extraction ratio ([Formula: see text]) and the heterogeneity of microvascular blood flow at the gut and sublingual mucosa during the development and resuscitation of septic shock in a swine model of fecal peritonitis. Jejunal-villi and sublingual microcirculation were evaluated using a portable intravital-microscopy technique. Simultaneously, we obtained arterial, mixed-venous, and mesenteric blood gases, and jejunal-tonometric measurements. During resuscitation, pigs were randomly allocated to a fixed dose of dobutamine (5 µg·kg-1·min-1) or placebo while three sham models with identical monitoring served as controls. At the time of shock, we observed a significant decreased proportion of perfused intestinal-villi (villi-PPV) and sublingual percentage of perfused small vessels (SL-PPV), paralleling an increase in [Formula: see text] in both dobutamine and placebo groups. After starting resuscitation, villi-PPV and SL-PPV significantly increased in the dobutamine group with subsequent improvement of functional capillary density, whereas [Formula: see text] exhibited a corresponding significant decrease (repeated-measures ANOVA,P= 0.02 andP= 0.04 for time × group interactions and intergroup differences for villi-PPV and [Formula: see text], respectively). Variations in villi-PPV were paralleled by variations in [Formula: see text] (R2= 0.88,P< 0.001) and these, in turn, by mesenteric lactate changes (R2= 0.86,P< 0.001). There were no significant differences in cardiac output and systemic O2delivery throughout the experiment. In conclusion, dynamic changes in microvascular blood flow heterogeneity at jejunal mucosa are closely related to the mesenteric O2extraction ratio, suggesting a crucial role for microvascular blood flow distribution on O2uptake during development and resuscitation from septic shock.NEW & NOTEWORTHYOur observations suggest that dynamic changes in the heterogeneity of microvascular blood flow at the gut mucosa are closely related to mesenteric O2extraction, thus supporting the role of decreasing functional capillary density and increased intercapillary distances on alterations of O2uptake during development and resuscitation from septic shock. Addition of a low-fixed dose of dobutamine might reverse such flow heterogeneity, improving microcirculatory flow distribution and tissue O2consumption.
Department of Intensive Care Medicine, Fundación Valle del Lili, Universidad ICESI, Cali, Colombia; gusospin@gmail.com.|Universidad del Valle, Escuela de Ciencias Básicas, Cali, Colombia.
Gustavo A
http://orcid.org/0000-0001-9370-3298
GA
Ospina-Tascón
Department of Intensive Care Medicine, Fundación Valle del Lili, Universidad ICESI, Cali, Colombia.
Alberto F
AF
García Marin
Department of Intensive Care Medicine, Fundación Valle del Lili, Universidad ICESI, Cali, Colombia.
Gabriel J
http://orcid.org/0000-0001-6432-0327
GJ
Echeverri
Department of Intensive Care Medicine, Fundación Valle del Lili, Universidad ICESI, Cali, Colombia.
William F
WF
Bermudez
Department of Intensive Care Medicine, Fundación Valle del Lili, Universidad ICESI, Cali, Colombia.
Humberto
H
Madriñán-Navia
Department of Intensive Care Medicine, Fundación Valle del Lili, Universidad ICESI, Cali, Colombia.
Juan David
JD
Valencia
Department of Intensive Care Medicine, Fundación Valle del Lili, Universidad ICESI, Cali, Colombia.
Edgardo
E
Quiñones
Department of Intensive Care Medicine, Fundación Valle del Lili, Universidad ICESI, Cali, Colombia.
Fernando
F
Rodríguez
Department of Intensive Care Medicine, Fundación Valle del Lili, Universidad ICESI, Cali, Colombia.
Angela
A
Marulanda
Department of Intensive Care Medicine, Fundación Valle del Lili, Universidad ICESI, Cali, Colombia.|Universidad del Valle, Escuela de Ciencias Básicas, Cali, Colombia.
César A
CA
Arango-Dávila
Departamento de Medicina Intensiva, Pontificia Universidad Católica de Chile, Santiago, Chile; and.
Alejandro
A
Bruhn
Departamento de Medicina Intensiva, Pontificia Universidad Católica de Chile, Santiago, Chile; and.
Glenn
G
Hernández
Intensive Care Department, CHIREC Hospitals, Université Libre de Bruxelles, Brussels, Belgium.
Daniel
D
De Backer
D000818:Animals; D001784:Blood Gas Analysis / Q000379:methods; D002302:Cardiac Output / Q000187:drug effects; D004280:Dobutamine / Q000494:pharmacology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000098:blood supply* / Q000187:drug effects*; D008833:Microcirculation / Q000187:drug effects*; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D012039:Regional Blood Flow / Q000187:drug effects*; D012151:Resuscitation / Q000379:methods; D012772:Shock, Septic / Q000188:drug therapy* / Q000378:metabolism; D013552:Swine
D004280:Dobutamine; D010100:Oxygen
gut mucosal perfusion; microcirculation; microcirculatory blood flow; oxygen consumption; oxygen extraction ratio; villi perfusion