RESUMEN
Objective To evaluate the effect of therapeutic hypercapnia preconditioning on lung ischemia-reperfusion (I/R) injury in rats.Methods Forty healthy adult Sprague-Dawley rats of either sex,aged 2 months,weighing 250-300 g,were divided into 5 groups (n=8 each) using a random number table:sham operation group (group S),grouP I/R and preconditioning with therapeutic hypercapnia of different level groups (group THP1-3).Lung I/R injury was induced by clamping the left hilum of lung for 45 min followed by 120 min of reperfusion.In THP1-3 groups,the respiratory parameters were adjusted at 5 min of stability after isolating the left hilum of lung to make PETCO2 reach 55-65,65-75 and 75-85 mmHg respetively and maintained at this level for 5 min,normal ventilation was then used to make PETCO2 restore the normal level,continuously repeating for 3 circles,and then the left hilum of lung was blocked for 45 min followed by 120 min of reperfusion.The bronchoalveolar lavage fluid (BALF) was collected at the end of reperfusion for determination of the total protein (TP) concentration using Coomassie brilliant blue staining.Lung tissues were obtained at the end of reperfusion for examination of pathological changes after haematoxylin and eosin staining (under a light microscope) and for determination of wet/dry weight ratio (W/D ratio),malondialdehyde (MDA) content,superoxide dismutase (SOD) activity,interleukin-8 (IL-8) and IL-10 contents (by enzyme-linked immunosorbent assay),tumor necrosis factor-alpha (TNF-α) expression (by immunohistochemistry) and expression of TNF-α mRNA (by real-time polymerase chain reaction).Results Compared with group S,the TP concentration in BALF,W/D ratio and contents of MDA,IL-8 and IL-10 in lung tissues were significantly increased,the SOD activity was decreased,the expression of TNF-α mRNA was up-regulated (P＜0.05),strong positive expression of TNF-α was found,and the pathological changes of lung tissues were aggravated in group I/R.Compared with group I/R,the TP concentration in BALF,W/D ratio and contents of MDA and IL-8 in lung tissues were significantly decreased,the SOD activity was increased,the expression of TNF-α mRNA was down-regulated (P＜0.05),no significant change was found in IL-10 content (P＞0.05),the staining range and intensity of TNF-α were decreased,and the pathological changes of lung tissues were significantly attenuated in THP1-3 groups.Conclusion Therapeutic hypercapnia preconditioning can reduce lung I/R injury in rats,and the mechanism is related to inhibiting inflammatory responses and oxidative stress responses.
RESUMEN
Objective This study was to investigate the effect of using laryngeal mask airway (LMA)as a transition method after double lumen endotracheal anesthesia on the stress response dur-ing the extubation period.Methods Ninety patient underwent general anesthesia with double lumen endotracheal intubation were randomly divided into 3 groups:group A,B and C (n=30).Patients in group A were extubated directly after surgery.The double lumen endotracheal tube were changed to single lumen endotracheal tube under deep anesthesia in group B patients,while the double lumen en-dotracheal tube were changed to LMA in group C.MAP,HR and rate pressure product (RPP)at the end of surgery (T0 ),1 minute before extubating the endotracheal tube (laryngeal mask)(T1 ),1 mi-nutes (T2 ),5 minutes after extubating (T3 )were recorded.The reaction of extubation,such as buc-king or restlessness,was also observed.Results Compared with T0 ,the MAP,HR,and RPP were significantly increased in groups A and B at T1-T3 (P <0.05 ).Compared with group A,the MAP, HR,RPP were significantly decreased in groups B and C at T1-T3 (P <0.05 ).The number of buc-king and restlessness in group C were lower than that in group A and group B (P < 0.05 ). Conclusion The use of laryngeal mask during the transition period in double lumen endotracheal anes-thesia to can reduce hemodynamic fluctuations and stress reaction during the extubation.