Comparison Of The Effects Of Different Dosages Of Dexamethasone Of Reexpansion Pulmonary Edema By Implanting And Removing A Plugged, Bullet-shaped, Angled Stent In Rabbits

Part 1 Model of reexpansion pulmonary edema by implanting and removing a plugged, bullet-shaped, angled Stent.Objective To discuss the technology of stent implantation in rabbit's trachea and make a base for animal experiment under DSA. To evaluate the feasibility of a lung recruitment animal model by implanting and removing a plugged, bullet-shaped angled stent with the aim to improve the repeatability and controllability of the model.Methods Randomly selected healthy Japanese white rabbits 15, Zhengzhou University School of Medicine by the Experimental Animal Center weighing 1.87～3.70kg,were divided into two groups. We implanted plugged, bullet-shaped, angled stent in 8 rabbit's chest by guiding of DSA in the light anesthesia condition and then removed the stent in 1w. The weight,temperature and MSCT were performed in every group preoperative and Specified time to determine whether obstructive atelectasis formed or reexpansion occurred.Result We put 8 stents successfully and 7 stents were correct located. The successful rate is 87.5%; All rabbits who survived formed atelectasis. The successful rate of atelectasis formation is 87.5%.7 out of 8stents were removed successfully. The rate is 87.5%. The rate of reexpansion pulmonary edema is 87.5%.Conclusion It is a good technology that implant a plugged, bullet-shaped angled stent then remove it by the guiding of DSA in light anesthesia condition to make a model of lung recruitment in rabbits. The method is simple and. easy. Either the successful rate of stent implantation and removal or the successful rate of atelectasi and lung recruitment is higher.Part 2 Comparison of the effects of different dosages of dexamethasone of reexpansion pulmonary edema by implanting and removing a plugged, bullet-shaped, angled Stent in rabbitsObjective To explore the desirable dosage of dexamethasone (DM) by comparison of the therapeutic effects of different dosages of dosages on reexpansion pulmonary edema by implanting and removing a plugged, bullet-shaped, angled Stent in rabbitsMethods Model of reexpansion pulmonary edema was established in twenty-eight healthy adult rabbits, and they randomly allocated to 4 groups by using a random number table. After successful animal model, animals of DO.5, D1 and D5 group were given DM with the dosage of 0.5,1 and 5 mg/kg, respectively, while of N group were given on treatment. Respiratory rate were recorded before DM administration, the immediately after administration,and 30min,lh,3h and 5h after giving DM, pathologic changes were observed, and wet-to-dry lung weight ratio were calcaluted at the termination of the experiment. The weight,temperature and MSCT were performed in every group preoperative and Specified time to determine whether obstructive atelectasis formed or reexpansion pulmonary edema occurred.Result After stents were removed successfully, tachypnea appeared in all the animals.Spasmodic attacks appered only in the D5 group. Compared with that of N group wet-to-dry ratio of lung tissue,pathologic scores and image of MSCT also remarkably (p<0.01) in all DM treatment groups.Conclusions Dexamethasone, especially in a low dosage, may improve the ameliorate pulmonary edema and lung injuries decrease the pulmonary capillary permeability and alleviate inflammatory reaction.