Evaluation of sublingual and gut mucosal microcirculation in sepsis: A quantitative analysis*

Abstract

Objective: To determine the relationship between sublingual and intestinal mucosal microcirculatory perfusion. Design: Observational, experimental study. Setting: University-affiliated large animal laboratory. Subjects: Ten fasted, anesthetized, mechanically ventilated, male pigs randomized to a sham group (n = 3) or to a hyperdynamic septic shock group (n = 7) in which cholangitis was induced by direct infusion of Escherichia coli into the common bile duct. This model was developed because it is not accompanied by changes in intra-abdominal pressure. Measurements and Main Results: The sublingual and intestinal microcirculations were simultaneously assessed at 4-hr intervals for up to 12 hrs with a modified orthogonal polarization spectral device and functional microvessel density and erythrocyte velocity were measured quantitatively. In sham animals, both regions maintained a stable functional microvessel density and erythrocyte velocity throughout the study period. In contrast, in septic animals, already after 4 hrs of sepsis, functional microvessel density was markedly decreased (>50%) in the sublingual and gut regions; mean erythrocyte velocity decreased dramatically and similarly in both regions, from 1022 ± 80 to 265 ± 43 μm/sec in the sublingual region and from 1068 ± 45 to 243 ± 115 μm/sec in the gut (p < 0.001, at T12). There was a significant correlation between the sublingual and gut microcirculations in septic animals (r² = 0.92, p < 0.0001). Conclusions: The severity and the time course of microcirculatory changes were similar in the sublingual and in the gut region in this clinically relevant model of severe sepsis. These findings support the sublingual region as an appropriate region to monitor the microcirculation in sepsis.