Alterations of Conjunctival Microcirculation in Brain Dead Patients

Study hypothesize that ocular microcirculation is reflecting cerebral perfusion. The purpose of this study is to evaluate ocular microcirculation in brain dead patients using side dark field (SDF) videomicroscope and compare it with microcirculatory parameters of healthy volunteers.

Microcirculation videomicroscopy techniques are used to evaluate a global organ perfusion in various critical conditions using limited suitable sites available for visualisation. However, ocular microcirculation may become a window to specifically cerebral perfusion due to related blood supply, close anatomical proximity and easy accessibility for videomicroscopy. Cerebral perfusion mainly depends on cerebral flow and intracranial pressure and therefore we aim, for the first time, to demonstrate microcirculatory status of ocular conjunctiva in clinical conditions when cerebral flow is completely absent. In a single center open label observational study investigators analyzed conjunctival and sublingual microcirculation using SDF videomicroscopy in brain dead patients after reaching systemic hemodynamic targets to optimise perfusion of donor organs. All brain death diagnoses were confirmed by cerebral angiography. Microcirculatory images obtained and analyzed using standardized published recommendations by experts in this field. Microcirculation of sublingual and conjunctival areas were recorded in matching number of healthy volunteers using same techniques.