In:
Journal of Applied Physiology, American Physiological Society, Vol. 122, No. 6 ( 2017-06-01), p. 1406-1417
Kurzfassung:
Derangements of microvascular blood flow distribution might contribute to disturbing O 2 extraction by peripheral tissues. We evaluated the dynamic relationships between the mesenteric O 2 extraction 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 and P = 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] ( R 2 = 0.88, P 〈 0.001) and these, in turn, by mesenteric lactate changes ( R 2 = 0.86, P 〈 0.001). There were no significant differences in cardiac output and systemic O 2 delivery throughout the experiment. In conclusion, dynamic changes in microvascular blood flow heterogeneity at jejunal mucosa are closely related to the mesenteric O 2 extraction ratio, suggesting a crucial role for microvascular blood flow distribution on O 2 uptake during development and resuscitation from septic shock. NEW & NOTEWORTHY Our observations suggest that dynamic changes in the heterogeneity of microvascular blood flow at the gut mucosa are closely related to mesenteric O 2 extraction, thus supporting the role of decreasing functional capillary density and increased intercapillary distances on alterations of O 2 uptake 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 O 2 consumption.
Materialart:
Online-Ressource
ISSN:
8750-7587
,
1522-1601
DOI:
10.1152/japplphysiol.00886.2016
Sprache:
Englisch
Verlag:
American Physiological Society
Publikationsdatum:
2017
ZDB Id:
1404365-8
SSG:
12
SSG:
31
