Morphologic analysis of the cerebral microcirculation after thermal injury and the response to fluid resuscitation

Using the pial window model, we have previously demonstrated that there is a disruption of the blood brain barrier with distal thermal injury [1-3]. Our laboratory has shown that treatment with Lactated Ringer's Solution did not improve labeled albumin leakage. However, treatment with hypertonic hyperosmotic saline (HHS) solution post thermal injury seemed to essentially eliminate the albumin leakage in cerebral vessels. Using adult Sprague-Dawley rats and epifluorescent microscopy, the cerebral vessel size and diameter were measured, as well as the number of leukocytes rolling or adherent to the endothelium. The results show that there was significant progressive arterial dilatation over six hours in the thermally injured animals treated with HHS. There was also a significant increase in leukocyte number if the animals were thermally injured and had no resuscitation fluid or if the animals were thermally injured and underwent resuscitation fluid with Lactated Ringer's compared to either the control group or the group that was treated with HHS after thermal injury.