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Objective:To compare the efficacy of individualized PEEP determined by lung electrical impedance tomography (EIT) and dynamic lung compliance (Cdyn) during lung-protective ventilation strategies in the patients undergoing general anesthesia.Methods:Sixty patients of both sexes, aged 18-64 yr, of American Society of Anesthesiologists physical status Ⅰor Ⅱ, with body mass index of 18.5-28.0 kg/m 2, undergoing elective surgery with general anesthesia and endotracheal intubation in the Second Affiliated Hospital of Soochow University, were selected.Lung-protective ventilation strategy was applied in supine position after general anesthesia.The peak value of PEEP did not exceed 10 cmH 2O, with an increment/decrement of 2 cmH 2O for titration.The corresponding Cdyn value and lung EIT data were collected during titration.The patients were divided into 2 groups ( n=30 each) using a random number table method: titration first increased and then decreased group (group A) and titration first decreased and then increased group (group B). The determination method of individualized PEEP: Cdyn method was the PEEP corresponding to the maximum Cdyn value; EIT method was obtained through PV500 PC software analysis.The level and success rate of individualized PEEP determined by the Cdyn and EIT methods were compared, and the ICC consistency analysis of the determined individualized PEEP was performed. Results:Compared with the Cdyn method, the success rate of individualized PEEP determined by EIT method was significantly increased, and the level of individualized PEEP was decreased in the two group ( P<0.05). In group A, the individualized PEEP titrated by the EIT and Cdyn methods showed good agreement (the ICC value of the increment-Cdyn and increment-EIT methods was 0.761, P<0.05; the ICC value of the decrement-Cdyn and decrement-EIT methods was 0.763, P<0.05). In group B, the individualized PEEP titrated by the EIT and Cdyn methods showed good agreement (the ICC value of the increment-Cdyn and increment-EIT methods was 0.809, P<0.05; the ICC value of the decrement-Cdyn and decrement-EIT methods was 0.797, P<0.05). Conclusion:The agreement between the individualized PEEP determined by lung EIT method and Cdyn method during lung-protective ventilation is good in the patients undergoing general anesthesia, and the success rate of EIT method is higher, and the level of individualized PEEP is lower.
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Objective To evaluate the effect of nicotinamide adenine dinucleotide phosphate(NADPH)on myocardial ischemia-reperfusion(I/R)injury in rats.Methods Fifty-six SPF adult male Sprague-Dawley rats,weighing 220-320 g,aged 1-2 months,were divided into 4 groups(n＝14 each)using a random number table method: sham operation group(Sham group),myocardial I/R group(I/R group),NADPH group(N group)and diltiazem group(D group).The model of myocardial I/R injury was established by ligation of the left anterior descending branch for 30 min followed by 2-h reperfusion in anesthetized rats.NADPH 16 mg/kg was intravenously infused over 5 min starting from 5 min of reperfusion in N group.Diltiazem 5 mg/kg was infused through the internal jugular vein starting from 10 min before is-chemia until the end of ischemia.At 2 h of reperfusion,blood samples were taken from the internal jugular vein for measurement of serum LDH and cTnI concentrations,and myocardial tissues were taken for deter-mination of infarct size and ROS level.Results Compared with Sham group,the serum LDH and cTnI concentrations,myocardial infarction size and ROS levels were significantly increased in I/R group(P＜0.05).Compared with I/R group,the serum LDH and cTnI concentrations,myocardial infarction size and ROS levels were significantly decreased in N and D groups(P＜0.05).Compared with N group,the LDH concentration was significantly decreased(P＜0.05),and no significant change was found in the cTnI con-centration,myocardial infarction size or ROS level in D group(P>0.05).Conclusion NADPH can re-duce myocardial I/R injury through antioxidant effect in rats.
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Objective@#To evaluate the effect of nicotinamide adenine dinucleotide phosphate (NADPH) on myocardial ischemia-reperfusion (I/R) injury in rats.@*Methods@#Fifty-six SPF adult male Sprague-Dawley rats, weighing 220-320 g, aged 1-2 months, were divided into 4 groups (n=14 each) using a random number table method: sham operation group (Sham group), myocardial I/R group (I/R group), NADPH group (N group) and diltiazem group (D group). The model of myocardial I/R injury was established by ligation of the left anterior descending branch for 30 min followed by 2-h reperfusion in anesthetized rats.NADPH 16 mg/kg was intravenously infused over 5 min starting from 5 min of reperfusion in N group.Diltiazem 5 mg/kg was infused through the internal jugular vein starting from 10 min before ischemia until the end of ischemia.At 2 h of reperfusion, blood samples were taken from the internal jugular vein for measurement of serum LDH and cTnI concentrations, and myocardial tissues were taken for determination of infarct size and ROS level.@*Results@#Compared with Sham group, the serum LDH and cTnI concentrations, myocardial infarction size and ROS levels were significantly increased in I/R group (P<0.05). Compared with I/R group, the serum LDH and cTnI concentrations, myocardial infarction size and ROS levels were significantly decreased in N and D groups (P<0.05). Compared with N group, the LDH concentration was significantly decreased (P<0.05), and no significant change was found in the cTnI concentration, myocardial infarction size or ROS level in D group (P>0.05).@*Conclusion@#NADPH can reduce myocardial I/R injury through antioxidant effect in rats.
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Objective To determine the optimal positive end-expiratory pressure (PEEP) for volume-controlled ventilation using pulmonary electrical impedance tomography in the patients undergoing surgery with general anesthesia.Methods Fifty patients of both sexes,aged 18-64 yr,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,with body mass index of 18.5-28.0 kg/m2,scheduled for surgery for ureteral calculi under general anesthesia,were enrolled in this study.The patients were tracheally intubated after anesthesia induction and mechanically ventilated in volume-controlled mode,with tidal volume 6 ml/kg,mean arterial pressure was recorded at 3 min of ventilation and served as the baseline value,and then PEEP was increased with an increment of 3 cmH2O every 3 min until PEEP reached 15 cmH2 O.The percentage of dorsal pulmonary ventilation and peak airway pressure were recorded at 3 min of ventilation with different PEEPs.When the decrease in mean arterial pressure was more than 20％ of the baseline value during ventilation,deoxyepinephrine 0.1 mg was injected intravenously,and the consumption of deoxyepinephrine was recorded within 3 min of ventilation with different PEEPs.Results Peak airway pressure was gradually increased with the increase of PEEP (P＜0.05),the percentage of dorsal pulmonary ventilation was gradually increased when PEEP was 6 cmH2O (P＜ 0.05),and the consumption of deoxyepinephrine was gradually increased when PEEP was 15 cmH2O (P＜0.05).Conclusion The optimal PEEP is 12 cmH2O during volume-controlled ventilation with tidal volume of 6 ml/kg in the patients undergoing surgery with general anesthesia.
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Objective To investigate the double-lumen endobronchial intubation-related anatomical factors of respiratory tract in adult patients through measurement of the parameters of glottis and left main bronchus using computed tomography(CT). Methods A total of 206 patients of both sexes, aged 20-80 yr, of American Society of Anesthesiologists physical status Ⅰ-Ⅲ, scheduled for elective surgery, were enrolled in this study.The cervical and thoracic CT images were evaluated.The anteroposterior glottic diame-ter(AP-GD), anteroposterior tracheal diameter(AP-TD), transverse tracheal diameter(Tr-TD), left and right main bronchus diameters(LBD and RBD)and length between glottis and carina(G-TL)were measured.Multiple linear regression analyses were performed to detect the correlations between obtained pa-rameters and between obtained parameters and height. Results AP-GD was(19±3)mm, AP-TD(20± 4)mm, Tr-TD(16.6±2.4)mm, LBD(12.3±2.0)mm, RBD(13.7±2.0)mm and G-TL(126± 11)mm.AP-GD, height, AP-TD and Tr-TD were moderately correlated with LBD(r was 0.522, 0.584, 0.648 and 0.606, respectively, P<0.05).AP-TD +Tr-TD+AP-GD+height served as the inde-pendent variable, the fitting curve was confirmed, and the results showed that AP-TD, Tr-TD and height were the affecting factors for LBD, and the degree of correlation with LBD was as follows from high to low:Tr-TD(b′=0.334), AP-TD(b′=0.323), height(b′=0.243). When AP-GD served as the independ-ent variable and curve fitting was performed, there was no significant difference(P>0.05). Conclusion Tr-TD and AP-GD should be considered besides double-lumen endobronchial intubation-related anatomical factors such as LBD and height in adult patients.
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Objective To investigate the effects of sevoflurane postconditioning on myocardial ischemiareperfusion (I/R)-induced oncosis of cardiomyocytes and the role of mitochondrial permeability transition pore (MPTP) in it.Methods Sixty male Sprague-Dawley rats,aged 3 months,weighing 280-360 g,were randomly divided into 5 groups (n =12 each):sham operation group (group S),group I/R,sevoflurane postconditioning group (group SP),sevoflurane postconditioning + atractyloside group (group SP + ATR) and atractyloside group (group ATR).Myocardial ischemia was induced by 30 min occlusion of left anterior descending branch (LAD) of coronary artery followed by 2 h reperfusion.2.5 ％ sevoflurane was inhaled for 5 min starting from 27 min of ischemia until 2 min after beginning of reperfusion in SP and SP + ATR groups,while 33 ％ oxygen was inhaled in the other groups.In SP + ATR and ATR groups,atractyloside 5 mg/kg was injected via the internal jugular vein at 15 min before ischemia.HR and systolic pressure were monitored and recorded and rate-pressure product (RPP) was calculated.At the end of reperfusion,the rats were sacrificed and the hearts removed for determination of myocardial infarct size.The myocardial ultrastrncture was observed by electron microscopy.The expression of Porimin (Pro-oncosis receptor inducing membrane injury) was measured by Western blot.Myocardial nicotinamide adenine dinucleotide (NAD+) content was determined by spectrophotometry.Results Compared with group S,the myocardial infarct size was significantly enlarged,the expression of Porimin was up-regulated,and NAD+ content and RPP were decreased in the other four groups (P ＜ 0.05).Compared with groups I/R and SP + ATR,the infarct size was significantly decreased,the expression of Porimin was down-regulated,and NAD+ content was increased in group SP (P ＜ 0.05),and no significant change was found in the indices mentioned above in group ATR (P ＞0.05).Conclusion Sevoflurane postconditioning can mitigate myocardial I/R injury by inhibiting MPTP opening and reducing oncosis of cardiomyocytes.
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Objective To evaluate the role of the mitochondrial ATP-sensitive potassium (mito-KATP)channel in sevoflurane preconditioning-induced delayed cardioprotection against ischemia-reperfusion (I/R) injury in isolated rat hearts.Methods Seventy-two adult male Sprague-Dawley rats were randomly divided into 6 groups (n =12 each):control group (group CON),I/R group,sevoflurane control group (group SEVO),sevoflurane preconditioning group (group SWO P),5-hydroxydeconoate (5-HD) + sevoflurane preconditioning group (group 5-HD+ SWOP) and 5-HD control group (group 5-HD).The rats were exposed to 33％ pure oxygen for 1 h in groups CON and I/R.The rats were exposed to 2.5％ sevoflurane for 1 h in groups SEVO and SWOP.5-HD (a mito-KATP channel inhibitor) 10 mg/kg was injected intraperitoneally 30 min before sevoflurane preconditioning in group 5-HD + SWOP.5-HD 10 mg/kg was injected intraperitoneally in group 5-HD.The hearts were immediately removed and perfused in a Langendorff apparatus.The hearts were made globally ischemic for 30 min followed by 120 min reperfusion in groups I/R,SWOP,5-HD + SWOP and 5-HD.The expression of phosphorylated protein kinase C-epsilon (p-PKC-ε) and caspase-8 was measured by Western blot immediately before ischemia (T0) and at 120 min of reperfusion (T1).The myocardial infarct volume was measured by TTC staining.Results Compared with group CON,the myocardial infarct volume was significantly increased at T1 in groups I/R,SWOP,5-HD +SWOP and 5-HD,p-PKC-ε expression was up-regulated at T0 in groups SEVO and SWOP and at T1 in groups I/R,SWOP,5-HD + SWOP and 5-HD,and caspase-8 expression was down-regulated at T1 in group SEVO (P ＜0.05).Compared with group I/R,the myocardial infarct volume was significantly decreased at T1 in groups SWOP and 5-HD + SWOP,p-PKC-ε expression was up-regulated at T0 in groups SEVO and SWOP,and caspase-8 expression was down-regulated at T1 in group SWOP (P ＜ 0.05).Compared with group SWOP,the myocardial infarct volume was significantly increased,p-PKC-ε expression was down-regulated at T0,and caspase-8 expression was up-regulated at T1 in group 5-HD + SWOP (P ＜ 0.05).Conclusion The mito-KATP channel is involved in sevoflurane preconditioning-induced delayed cardioprotection against I/R injury in isolated rat hearts through upregulation of p-PKC-ε expression before ischemia and inhibition of cell apoptosis during reperfusion.