Introduction: Microcirculation is one of the ultimate determinants of the outcome of circulatory shock. It differs extensively among organs especially during the low flow states. Sublingual is easy to access and has been considered an ideal location to evaluate microcirculation. However, whether it fully reflects visceral microcirculation remains unclear. In the present study, we investigated the relationship between sublingual and mesenteric microcirculation. Methods: Fifteen male Sprague-Dawley rats weighing 500 ± 50 g were randomized into two groups: 1) CPR group (n=10): ventricular fibrillation (VF) was untreated for 8 mins followed by 8 mins of CPR; 2) Sham control group (n=5): a sham operation was performed without the induction of VF and CPR. Sublingual and mesenteric microcirculatory blood flow was visualized simultaneously by a sidestream dark-field imaging device at baseline and 1, 2, 4, 6 and 8 hrs post-resuscitation (PR). Perfused microvessel density (PVD) was measured semiquantitatively. Results: During PR, both sublingual PVD (baseline: 5.57 ± 0.81 n/mm, PR 8 hrs: 2.32 ± 0.64 n/mm) and mesenteric PVD (baseline: 19.82 ± 1.71 n/mm, PR 8 hrs: 10.07 ± 1.78 n/mm) decreased significantly when compared with the sham control group (both p<0.05, at PR 8 hrs). There was a close correlation between the sublingual and mesenteric microcirculations (r=0.658, p<0.01). Conclusions: The changes of sublingual microcirculation during PR reflect changes of mesenteric microcirculation.
1Weil Institute of Critical Care Medicine, Rancho Mirage, CA, 2Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China, 3Keck School of Medicine of the University of Southern California, Los Angeles, CA