The influence of propofol on blood and cerebrospinal fluid lactic acid and glucose levels after traumatic brain injury in rabbits / 中华麻醉学杂志

ABSTRACT

Objective Blood lactic acid(LA) and glucose(Glu) level are important parameters of anaerobic glycolysis and can be used to assess the severity of brain injury and cerebral metabolism. The purpose of this study was to evaluate effect of propofol on traumatic brain injury by measuring blood and CSF level of LA and Glu in addition to microscopic and NSE immunohistochemical examination of brain tissue. Methods Ninety New Zealand rabbits weighing 2.6-3.0 kg were used . Traumatic brain injury model was established according to Wang's method. Part Ⅰ . Twenty rabbits were divided into two groups of ten animal each. Blood and CSF samples were taken before and 4h, 24h, 48h, 72h and 1 week after trauma for determination of LA and Glu levels. Propofol group received propofol 30mg' kg-1?h-1 infusion for 30 min in addition to ketamine 1mg/kg before each collection of samples. PartⅡ . Seventy rabbits were divided into seven groups with ten animals in each group. Brain tissues were taken before and 24h, 72h, and 1 week after trauma for microscopic and NES immunohistochemical examination. Propofol group received infusion of 30 propofol mg kg-1 h-1 for 30 mm every day. In control group animals received same amount of normal saline. Results Blood and CSF levels of LA increased significantly after trauma in both groups but were significantly higher in control group than those in propofol group at corresponding intervals. Blood and CSF Glu levels decreased significantly in control group after trauma but in propofol group blood Glu level decreased only at 4h and 24h after trauma and CSF Glu level at 24h after trauma. There was significant difference in blood and CSF levels of Glu after trauma between the two groups. In both groups microscopic examination of brain tissue showed hemorrhage, degeneration, decrease in glial cells and vacuolization of some neuron in brain tissue of injured and surrounding areas at 24h after trauma, infiltration of neutrophils at 72h after trauma and cerebral interstitial edema and glial cell proliferation at 1 week after trauma. Neurons showed no NSE expression. In propofol group the above mentioned changes were relatively slight. Conclusions Propofol can significantly reduce blood and CSF LA levels after trauma and protect the animal from traumatic brain injury. Further studies are needed on the dosage and method of administration of propofol.