Comparison of sublingual microcirculatory parameters measured by sidestream darkfield videomicroscopy in anesthetized pigs and adult humans.

Conscious humans had a significantly lower TVD, PVD and MFI than anesthetized pigs. No significant difference in PPVs was observed between the species. Perfusion of the microcirculation is a critical determinant of tissue metabolic function and viability. Whilst it may not be surprising that some interspecies differences in the sublingual microcirculatory anatomy were identified between pig and human subjects, it is interesting to report the insignificant difference in PPVs. This direct microcirculatory measure represents a relative change which should hold translatable value across species. We therefore conclude the pig is a suitable model for microcirculatory research and may be a suitable species to investigate changes in microcirculatory perfusion following perturbations in cardiovascular homeostasis, for example during traumatic haemorrhagic shock and resuscitation.