"Effect of dexmedetomidine sedation on acute lung injury induced by trauma and endotoxemia ""two-hit"" in rats" / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of dexmedetomidine sedation on acute lung injury induced by trauma and endotoxemia two-hit in rats.Methods Twenty-four adult male Sprague-Dawley rats,aged 6-8 weeks,weighing 150-200 g,were randomized into 3 groups (n =8 each) using a random number tablecontrol group (group C),two-hit group (group T) and dexmedetomidine group (group D).Bilateral middle femoral shaft fractures were produced using hemostatic forceps.In group D,dexmedetomidine 2.5 tμg· kg-1· h-1 was infused via the caudal vein immediately after fractures,while the equal volume of normal saline was infused for 8 h in C and T groups.Lipopolysaccharide 2.5 mg/kg was injected via the caudal vein at 4 h after fractures in T and D groups.All the animals were monitored for 24 h with a continuous glucose monitoring system.Blood glucose concentrations were recorded within 24 h after fractures,and mean amplitude of glucose excursions (MAGE) was calculated.The arterial blood samples were collected at 24 h after fractures for blood gas analysis.The lungs were then harvested for determination of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) contents in lung tissues and for microscopic examination of pathological changes which were scored.Results Compared with group C,MAGE,PaCO2,TNF-α and IL-6 contents and pathological scores were significantly increased,and pH value and PaO2 were decreased in T and D groups.Compared with group T,MAGE,TNF-α and IL-6 contents and pathological scores were significantly decreased,and pH value and PaO2 were increased,and no significant change was found in PaCO2 in D group.Conclusion Dexmedetomidine sedation can mitigate acute lung injury induced by trauma and endotoxemia two-hit,and the mechanism is related to reduced stress and inflammatory responses in rats.