Study And Vivo Observation On Bulbar Conjunctival Microcirculation Of Severe Scalded Rabbits

Objective: to observe the alternation of bulbar conjunctiva! microcirculation (BCMC) in severe scalded rabbits, explore the pathophysiological mechanism so that get the knowledge of the alter regularity and characteristics.Method: 10 adult rabbits, each as a group, every group should experience two steps in the experiment. Sham scald step and severe scald step. The data from sham step as control, the data from severe step as achievement. The experimental rabbit was anesthetized, it's back hair was depilated 25%-45% total body surface area. When made sham scald, the rabbit was submerged in 39 degree C water for 30 seconds, then took the BCMC sequential photos through microscope; after that, the thermal injury was inflicted by dipping the same area into hot water at 85-90 degree C for 30 seconds. Such the deep second degree trauma and the third degree trauma was finished, also recorded the sequential varied BCMC photos. The record time were at the injury time and 2 4 6 8 12 18 24 36h after.Results: severe scald could make rabbit's BCMC alter markedly, include microvascular morphologic, microvascularhemorheologic and perivascular condition. Especially in vasocaliber, vasodilatation, blood velocity, microthrombus, erythrocyte aggregation and bleed,etc. Further more, e alternation of these items was progressive. From scald time to 24h after injury, each changing almost aggravated progressively, and then, the alternation recovered gradually. In this study, there were also other phenomena: when severe scalded, the alternation of vasocaliber in medial bulbar conjunctival was earlier than that of the lateral vasocaliber ; the vasocaliber had two phase: vasoconctriction phase, which earlier and shorter, and vasodilation phase, which later and longer; in addition, the bleed time was associated with the trauma area and depth.Conclusion: the disorder after severe scald was connected with the trauma area and depth. The injury severer, the earlier and longer of the disorder. Additionally, the lateral BCMC can reflect the central bloodstream, the medial BCMC mainly represents peripheral circulation. From BCMC, we can acquire lots of messages on most organs and tissues indirectly, such as brain, heart, kidney and so on. That is beneficial to the clinical diagnose and treatment.