Effect of sevoflurane on brain injury in a pig model of hemorrhagic shock in hypothermia environ-ment / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of sevoflurane on brain injury in a pig model of hem?orrhagic shock in hypothermia environment. Methods Twenty?four Bama miniature pigs, weighing 21-25 kg, aged 3-5 months, were equally randomized into 3 groups using a random number table sham opera?tion group (group Sham);hemorrhagic shock (group HS); sevoflurane group (group Sev). The animals were anesthetized, tracheostomized and mechanically ventilated. Bilateral femoral arteries were cannulated for continuous mean arterial pressure, and heart rate monitoring, blood?letting and blood sampling. A cath?eter was inserted into the right internal jugular vein for body temperature monitoring. After the animals were awake, they were placed in an environment at-15℃. Hemorrhagic shock was induced by withdrawing 40%of blood volume from the right femoral artery within 15 min ( 30 ml∕kg) in HS and Sev groups. The animals inhaled 2% sevoflurane for 30 min after establishment of the model in group Sev. Before hemorrhagic shock, and at 30, 60, 90, 120, 180 and 240 h after hemorrhagic shock ( T0?6 ) , blood samples were collected from the femoral artery for determination of plasma tumor necrosis factor?alpha ( TNF?α) , interleukin?6(IL?6), nuclear factor kappa B (NF?κB), S100β protein and neuron?specific enolase (NSE) concentra?tions. After blood sampling at T6 , the animals were sacrificed, and brains were removed for microscopic examination of pathological changes, and for determination of Toll?like receptor 4 ( TLR4) expression by Western blot. Results Compared with group Sham, the plasma NSE, S100β protein, TNF?α, IL?6 and NF?κB concentrations were significantly increased at T2?6 , and TLR4 expression was up?regulated at T6 in HS and Sev groups ( P<0?05) . Compared with group HS, the plasma NSE, and S100βprotein concentra?tions were significantly decreased at T4?6 , the plasma TNF?α, IL?6 and NF?κB concentrations were de?creased at T2?6, and TLR4 expression was down?regulated at T6 (P<0?05), and the pathological changes were significantly attenuated in group Sev. Conclusion Sevoflurane can mitigate brain injury in a pig mod?el of hemorrhagic shock in hypothermia environment, and the mechanism may be related to inhibited TLR4∕NF?κB signaling pathway and attenuated inflammatory responses.