高呼气末正压通气结合小潮气量对急性肺损伤/急性呼吸窘迫综合征患者预后影响的荟萃分析

目的 系统评价高呼气末正压(PEEP)与低PEEP机械通气对急性肺损伤/急性呼吸窘迫综合征(ALI/ARDS)患者预后的影响.方法 通过检索美国<医学索引>、荷兰<医学文摘>、Cochrane临床试验数据库、中国生物医学文献数据库(CBM)和中国期刊网全文数据库(CNKI)等文献数据库,全面收集全世界范围内高PEEP与低PEEP治疗ALI/ARDS患者的随机对照试验(RCT),提取文献中的相关资料和评估方法学质量,而后采用Cochrane协作网RevMan 5.0软件对资料进行荟萃分析(Meta分析).结果 最终纳入6个RCT共2484例ALI/ARDS患者.A亚组的3个RCT中试验组采用了高PEEP(相对于对照组),对照组采用了低PEEP(相对于试验组),两组均采用了小潮气量(6 ml/kg)通气;B亚组的3个RCT中试验组采用了高PEEP加小潮气量,对照组采用了低PEEP加传统潮气量通气.合并结果显示,B亚组中高PEEP加小潮气量通气策略可以降低患者的28 d病死率[Peto比值比(OR)=0.40,95%可信区间(95%CI)0.22～0.72,P=0.003]和气压伤发生率(OR=0.20,95%CI 0.05～0.82,P=0.02);A亚组中,两组患者的28 d病死率(OR=0.86,95%CI 0.72～1.02,P=0.08)和气压伤发生率(OR=1.19,95%CI 0.89～1.58,P=0.25)差异无统计学意义.结论 高PEEP加小潮气量通气可以改善ALI/ARDS患者的28 d病死率和气压伤发生率,单独高PEEP的作用需要进一步评价.

Abstract：

Objective To compare the effects of high and low positive end-expiratory pressure (PEEP) levels on prognosis of patients with acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Methods The data in PubMed, EMbase, Cochrane Library, CBM and CNKI were retrieved. All randomized controlled trials (RCTs) of treatment of ALI/ARDS with PEEP with high or low level were included. Study selection and assessment, data collection and analyses were undertaken by two independent reviewers. Meta-analyses were done using Cochrane Collaboration's RevMan 5.0 software.Results Six RCTs, involving a total of 2 484 patients of ALI/ARDS were included in the review. According to ventilation strategy, all trials were divided into subgroup A (high PEEP+low tidal volume of 6 ml/kg vs.low PEEP+low tidal volume) and subgroup B (high PEEP+low tidal volume vs. low PEEP+traditional tidal volume). In subgroup B, there were three RCTs, and high PEEP was found to be associated with a lower 28-day mortality [odds ratio (OR)=0. 40, 95% confidence interval (95%CI) 0.22 -0.72, P=0.003]and a lower barotraumas (OR = 0.20,95%CI 0.05 - 0.82, P = 0.02) in patients with ALI/ARDS. In subgroup A, there were three RCTs, and it was found that the differences in 28-day mortality (OR=0.86,95%CI 0.72 - 1.02, P = 0.08) and barotraumas (OR = 1.19, 95%CI 0.89 - 1.58, P= 0.25) were not significant. Conclusion As compared with conventional ventilation, high PEEP and low tidal volume ventilation are associated with improved survival and a lower rate of barotrauma in patients with ALI/ARDS.It is necessary to further confirm the role of high PEEP only in the ventilation strategy in patients with ALI/ARDS.     

脓毒症大鼠肺基质金属蛋白酶-2/9表达与血必净干预

Objective To detect the expression of MMP-2/9 and TIMP-1/2 in the lung of Vibrio vulnificus sepsis rats and observe the intervention of Xuebijing injection. Method One hundred and ten SD rats of clean grade were randomly(random number) divided into normal control group (group A, n = 10),Vibrio vulnificus sepsis group (group B, n = 50. Sepsis was reproduced in rats with subcutaneous injection in left lower limb with Vibrio vulnificus) and Xuebijin intervention group ( group C, n = 50. Rats were intraperitoneal(ip) with the dose of Xuebijing 4mL/kg at the time of 30 min later after infection). The rats in group B and C were sacrificed at 1 h, 6 h, 12 h, 24 h, 48 h after infection, the expression of MMP-2/9 and TIMP-1/2 were examined by PCR, Immunohistochemistry or ELISA methods, the lung permeability were measured by Coomassie Brilliant Blue method. Experimental data used single factor analysis of variance, and between groups by LSD method for pairwise comparison,P ＜0.05 statistically significant difference. Results The lung permeability increased both in group B and C compared with group A,and in group B were relatively higher. The lung MMP-2/9, TIMP-1/2mRNA expression in groups B and C compared with in group A was markedly higher, and reached the peak at 6 h(0. 344 ± 0. 108 ),6 h ( 1. 230 ± 0.377 ), 12 h (0.523 ±0.098),12 h(0.280±0.070) (P＜0.05) in group B while at 12 h(0.256 ±0.074),6 h(0.968±0.225) ,12 h(0.746 ±0. 316) ,12 h(0.356 ±0.035) (P ＜0. 05) in group C; the MMP-2/9mRNA expression in group C decreased(P＜0. 05) compared with the group B while the TIMP-1/2mRNA expression increased(P＜0. 05). The lung MMP-2/9, TIMP-1/2 protein expression in groups B and C compared with the group A(0.345±0.109) also increased, and the peak was at 12 h (0. 692 ± 0. 191 ), 12 h (0. 061 ±0.017) ,24 h(1384.42 ±91) ,24 h(41.04 ±3.60)in group B while at 24 h(0. 217 ±0.065) ,12 h(0. 045± 0. 013 ) ,24 h ( 1617.22 ± 103 ) ,24 h (47.66 ± 3.58 )in group C, the MMP-2/9 protein expression in group C was lower than in group B(P＜0.05), the TIMP-1/2 protein expression in group C was similar to in group B early while marked increased(P＜0.05)later. Conclusions MMP/TIMP imbalance was one of the mechanisms of the lung injury in the rats with Vibrio vulnificus sepsis, Xuebijing could restore the balance of MMP/TIMP ratio.     

亚低温对急性肺损伤大鼠肺泡表面活性蛋白A含量的影响

目的 探讨亚低温对内毒素脂多糖(LPS)诱导急性肺损伤(ALI)大鼠肺泡表面活性蛋白A(SP-A)含量的影响.方法 按随机数字表法将40只雄性Wistar大鼠分组.采用气管内滴入LPS制备ALI动物模型;对照组气管内只滴人生理盐水.模型组和对照组分别于术后1 h和8 h处死8只大鼠;亚低温组于滴入LPS 1 h后将体温降低并维持在32.5～33.0℃,8 h后处死8只大鼠.各组分别于术前及术后1 h、8 h测定动脉血气,并计算氧合指数(PaO2/FiO2);采用酶联免疫吸附法检测支气管肺泡灌洗液(BALF)中SP-A含量;光镜下观察肺组织形态结构的变化.结果 气管内滴入LPS 1 h后,大鼠PaO2/FiO2均达到ALI的诊断标准.与对照1 h组比较,模型1 h组BALF中SP-A含量(μg/L)明显降低(53.27±1.95比74.81±6.55,P＜0.01);模型8 h组和亚低温8 h组SP-A含量(4.35±2.76和51.36±2.33)均较对照8 h组(70.81±5.01)明显降低,但亚低温8 h组SP-A含量较模型8 h组明显增高(均P＜0.01).光镜下观察,对照1 h和8 h组肺泡结构基本正常;模型8 h组肺组织炎症反应最重;模型1 h组和亚低温8 h组肺组织炎症反应较模型8 h组有所减轻.结论 亚低温能延缓内毒素诱导的ALI大鼠早期肺泡内SP-A含量下降的程度,在一定程度上可减轻肺损伤.

Abstract：

Objective To investigate the effect of hypothermia (HT) on the concentration of surfactant protein A (SP-A) during lipopolysaccharide (LPS) induced acute lung injury (ALI) in rats.Methods Forty male Wistar rats were randomly divided into three groups. The ALI model was reproduced by LPS intratracheal instillation; only saline was instilled intratracheally for control group. Rats in both model group and control group were sacrificed respectively at 1 hour and 8 hours (each n= 8). In HT group the body temperature was lowered to 32. 5 - 33.0 ℃ 1 hour after LPS instillation, and 8 rats were sacrificed st 8 hours. The arterial blood gas was determined in all the groups before and 1 hour and 8 hours after instillation of saline or LPS, and the oxygenation index (PaO2/FiO2) was calculated. The concentration of SP-A in bronchoalveolar lavage fluid (BALF) was determined by enzyme linked immunosorbent assay. The morphological changes in lung tissue of rats were observed under light microscope. Results At 1 hour after intratracheal instillation of LPS, the PaO2/FiO2 of each group reached the diagnostic criterion of ALI.Compared with control 1-hour group, the SP-A (μg/L) in BALF of model 1-hour group was decreased (53. 27±1.95 vs. 74. 81±6. 55, P＜0. 01); the SP-A in model 8-hour group and HT 8-hour group (4.35±2. 76 and 51.36±2. 33) was both obviously decreased compared with control 8-hour group (70. 81±-5. 01,both P＜0. 01). Compared with model 8-hour group, the SP-A of HT 8-hour group was obviously increased (P＜0. 01). Results of light microscopic examination, it was revealed that the alveolar structure of control 1-hour group and control 8-hour group was almost normal. Inflammatory response in lung tissues in model 8-hour group was found to be most serious; compared with model 8-hour group, inflammatory response in lung tissues in model 1-hour group and HT 8-hour group was reduced in certain degree. Conclusion A certain extent of HT may reduce lung injury of early endotoxin-induced ALI rats by delaying lowering of alveolar SP-A levels.     

脓毒症大鼠肺基质金属蛋白酶-2/9表达与血必净干预

目的 观察创伤弧菌脓毒症大鼠肺基质金属蛋白酶(MMP)-2/9和组织型金属蛋白酶抑制剂(TIMP)-1/2的动态表达及血必净干预.方法 温州医学院生命科学院实验室,清洁级SD大鼠110只,随机(随机数字法)分为正常对照组(A组,n=10)、创伤弧菌脓毒症组(B组,n=50,采用大鼠左下肢皮下注射创伤弧菌悬液制作创伤弧菌脓毒症大鼠模型)及血必净干预组(C组,n=50,感染后0.5 h腹腔注射血必净4 mL/kg).B、C组大鼠于染菌后1,6,12,24,48 h麻醉后活杀,留取右肺标本.观察大鼠行为学变化,采用考马斯亮蓝法测肺通透性,采用逆转录-聚合酶链式反应(RT-PCR)法测肺MMP-2/9,TIMP-1/2 mRNA的表达,免疫组化法和双抗体夹心酶联免疫吸附法(ELISA)测肺MMP-2/9和TIMP-1/2的表达.数据采用单因素方差分析,并用LSD-t法进行组间两两比较,以P＜0.05为差异有统计学意义.结果 B组和C组肺通透性显著高于A组,C组显著低于B组.B组和C组MMP-2/9,TIMP-1/2mRNA显著升高,B组分别于6 h(0.344±0.108),6 h(1.230±0.377),12 h(0.523±0.098),12 h(0.280±0.070)达高峰(P＜0.05),C组分别于12 h(0.256±0.074),6 h(0.968±0.225),12 h(0.746±0.316),12 h(0.356±0.035)达高峰(P＜0.05),C组MMP-2/9mRNA升高趋势显著低于B组(P＜0.05),TIMP-1/2mRNA显著高于B组(P＜0.05).B组和C组MMP-2/9,TIMP-1/2蛋白也升高,B组分别于12 h(0.692±0.191),12 h(0.061±0.017),24 h(1384.42±91),24 h(41.04±3.60)达高峰(P＜0.05);C组分别于24 h(0.217±0.065),12 h(0.045±0.013),24 h(1617.22±103),24 h(47.66±3.58)达高峰(P＜0.05);C组MMP-2/9蛋白升高趋势低于B组(P＜0.05),TIMP-1/2蛋白早期与B组差别不大,后期显著高于B组(P＜0.05).结论 MMP/TIMP比例失衡是创伤弧菌脓毒症大鼠肺损伤机制之一,血必净可促进MMP/TIMP比例恢复平衡,对创伤弧菌脓毒症大鼠肺损伤具有保护作用.

Abstract：

Objective To detect the expression of MMP-2/9 and TIMP-1/2 in the lung of Vibrio vulnificus sepsis rats and observe the intervention of Xuebijing injection. Method One hundred and ten SD rats of clean grade were randomly(random number) divided into normal control group (group A, n = 10),Vibrio vulnificus sepsis group (group B, n = 50. Sepsis was reproduced in rats with subcutaneous injection in left lower limb with Vibrio vulnificus) and Xuebijin intervention group ( group C, n = 50. Rats were intraperitoneal(ip) with the dose of Xuebijing 4mL/kg at the time of 30 min later after infection). The rats in group B and C were sacrificed at 1 h, 6 h, 12 h, 24 h, 48 h after infection, the expression of MMP-2/9 and TIMP-1/2 were examined by PCR, Immunohistochemistry or ELISA methods, the lung permeability were measured by Coomassie Brilliant Blue method. Experimental data used single factor analysis of variance, and between groups by LSD method for pairwise comparison,P ＜0.05 statistically significant difference. Results The lung permeability increased both in group B and C compared with group A,and in group B were relatively higher. The lung MMP-2/9, TIMP-1/2mRNA expression in groups B and C compared with in group A was markedly higher, and reached the peak at 6 h(0. 344 ± 0. 108 ),6 h ( 1. 230 ± 0.377 ), 12 h (0.523 ±0.098),12 h(0.280±0.070) (P＜0.05) in group B while at 12 h(0.256 ±0.074),6 h(0.968±0.225) ,12 h(0.746 ±0. 316) ,12 h(0.356 ±0.035) (P ＜0. 05) in group C; the MMP-2/9mRNA expression in group C decreased(P＜0. 05) compared with the group B while the TIMP-1/2mRNA expression increased(P＜0. 05). The lung MMP-2/9, TIMP-1/2 protein expression in groups B and C compared with the group A(0.345±0.109) also increased, and the peak was at 12 h (0. 692 ± 0. 191 ), 12 h (0. 061 ±0.017) ,24 h(1384.42 ±91) ,24 h(41.04 ±3.60)in group B while at 24 h(0. 217 ±0.065) ,12 h(0. 045± 0. 013 ) ,24 h ( 1617.22 ± 103 ) ,24 h (47.66 ± 3.58 )in group C, the MMP-2/9 protein expression in group C was lower than in group B(P＜0.05), the TIMP-1/2 protein expression in group C was similar to in group B early while marked increased(P＜0.05)later. Conclusions MMP/TIMP imbalance was one of the mechanisms of the lung injury in the rats with Vibrio vulnificus sepsis, Xuebijing could restore the balance of MMP/TIMP ratio.     

多次活性炭灌胃对大鼠血浆敌敌畏浓度的影响

Objective To assess the therapeutic effects of activated charcoal on the acute dichlorvos poisoning in rats. Method Thirty male clean grade Wistar rats were randomly (random number) divided into three groups: control group (group A, n = 10), single dose activated charcoal group (group B, n = 10) and multi-dose activated charcoal (group C, n=10). The rats of group A were suffered from 35 mg/kg dichlorvos exposure by oral without activated charcoal and senna. The rats of group B received 35 mg/kg dichlorvos exposure by oral with 175 mg/kg activated charcoal given immediately after dichlorvos exposure and 35 mg/kg senna given half an hour later. In the group C, 35 mg/kg dichlorvos was given to rats by oral with 175 mg/kg activated charcoal given immediately after dichlorvos exposure and 35 mg/kg senna given half an hour later and then every four hours. Blood samples were collected from the carotid artery at different intervals after exposure. DDVP concentration and total blood acetyl-cholinesterase activity were detected. Differences in serum DDVP concentration, Cmax, AUC (0→∞ ), MRT and acetylcholinesterase among three groups were calculated by using ANOVA. Results Serum DDVP levels in single dose group and in multi-dose group were significantly different from those in control group (P < 0.05). The DDVP levels in multi-dose group were significantly different from those in single dose group 4 hours after exposure (P < 0.05). The AUC and Cmax in activated charcoal treatment groups were significantly different from those in control group (P < 0.05). There were no significant differences in MRT among three groups. Fours hours after exposure to dichlorvos,the levels of serum acetylcholinesterase in rats of group B and group C were significantly different from that in rats of group A (P < 0.05), and there was no significant difference in acetylcholinesteras between group B and group C (P > 0.05). Another four hours later, no differences in acetylcholinesterase were found a-mong three groups (P > 0.05). Conclusions The peak concentrations of dichlorvos in blood are lower in group B and group C, and the blood acetylcholinesterase inhibition is quelled by activated charcoal. Therefore, the effects of multi - dose of activated charcoal is better than that of single dose of activated charcoal.     

多次活性炭灌胃对大鼠血浆敌敌畏浓度的影响

Objective To assess the therapeutic effects of activated charcoal on the acute dichlorvos poisoning in rats. Method Thirty male clean grade Wistar rats were randomly (random number) divided into three groups: control group (group A, n = 10), single dose activated charcoal group (group B, n = 10) and multi-dose activated charcoal (group C, n=10). The rats of group A were suffered from 35 mg/kg dichlorvos exposure by oral without activated charcoal and senna. The rats of group B received 35 mg/kg dichlorvos exposure by oral with 175 mg/kg activated charcoal given immediately after dichlorvos exposure and 35 mg/kg senna given half an hour later. In the group C, 35 mg/kg dichlorvos was given to rats by oral with 175 mg/kg activated charcoal given immediately after dichlorvos exposure and 35 mg/kg senna given half an hour later and then every four hours. Blood samples were collected from the carotid artery at different intervals after exposure. DDVP concentration and total blood acetyl-cholinesterase activity were detected. Differences in serum DDVP concentration, Cmax, AUC (0→∞ ), MRT and acetylcholinesterase among three groups were calculated by using ANOVA. Results Serum DDVP levels in single dose group and in multi-dose group were significantly different from those in control group (P < 0.05). The DDVP levels in multi-dose group were significantly different from those in single dose group 4 hours after exposure (P < 0.05). The AUC and Cmax in activated charcoal treatment groups were significantly different from those in control group (P < 0.05). There were no significant differences in MRT among three groups. Fours hours after exposure to dichlorvos,the levels of serum acetylcholinesterase in rats of group B and group C were significantly different from that in rats of group A (P < 0.05), and there was no significant difference in acetylcholinesteras between group B and group C (P > 0.05). Another four hours later, no differences in acetylcholinesterase were found a-mong three groups (P > 0.05). Conclusions The peak concentrations of dichlorvos in blood are lower in group B and group C, and the blood acetylcholinesterase inhibition is quelled by activated charcoal. Therefore, the effects of multi - dose of activated charcoal is better than that of single dose of activated charcoal.     

脓毒症大鼠肺高迁移率族蛋白B1的表达及意义

目的 观察创伤弧菌脓毒症大鼠肺组织HMGB1表达和肺损伤的动态变化,并探讨HMGB1在创伤弧菌脓毒症肺损伤中作用.方法 温州医学院生命科学院实验室,清洁级SD大鼠60只,随机分为正常组(A组,n=10)和创伤弧菌脓毒症组(B组,n=50),采用大鼠左下肢皮下注射创伤弧菌悬液(浓度为6×108cfu/mL,剂量为0.1 mL/100 g)制作大鼠创伤弧菌脓毒症模型),B组于染菌后1、6、12、24、48 h后活杀(各时间点n=10),采用逆转录聚合酶链式反应(RT-PCR)和蛋白免疫印迹(Western blot)分别检测大鼠肺组织HMGB1基因与蛋白的表达,检测肺含水分数和光镜观察肺组织病理变化,数据采用单因素方差分析,并用LSD法进行组间两两比较,P＜0.05为差异有统计学意义.结果 B组染菌后12 h(1.161±0.358,P=0.013)、24 h(1.679±0.235,P=0.000)及48 h(1.258±0.274,P=0.004)大鼠肺组织HMGB1 mRNA表达量较A组(0.652±0.177)明显增高(P＜0.05),并于24 h达到高峰;与A组(0.594±0.190)比较,B组HMGB1蛋白表达量于感染后6 h(1.408±0.567,P=0.026)(P＜0.05)逐渐增加,24 h达到高峰(2.415±1.064,P=0.000);与A组(0.699±0.054)比较,B组大鼠肺含水分数于感染后6 h(0.759±0.030,P=0.001)、12 h(0.767±0.023,P=0.000)、24 h(0.771±0.043,P=0.000)和48 h(0.789±0.137,P=0.000)明显增大(P＜0.05),呈逐渐递增趋势;感染后12 h,大鼠肺内血管明显充血,间质水肿并伴炎性浸润,且逐渐加重,到48 h肺泡腔塌陷明显,肺泡间隔分界不清.结论 大鼠创伤弧菌脓毒症可导致肺脏损伤,HMGB1的表达增加可能是创伤弧菌脓毒症大鼠肺组织损伤的机制之一.

Abstract：

Objective To observe the dynamic changes of high mobility group protein B1 ( HMGB1 )expression in the lung of rats with Vibrio vulnificus sepsis so as to unravel the role of HMGB1 in lung injury.Methods Sixty rats of clean grade were randomly divided into normal control group ( A group, n = 10) and Vibrio vulnificus sepsis group (B group, n =50). Sepsis model was made in rats with subcutaneous injection of Vibrio vulnificus with concentration of 6 × 108 cfu/ml in dose of 0. 1 ml/100 g into left lower limb.The rats of group B were sacrificed 1 h, 6 h, 12 h, 24 h and 48 h after infection for taking lung tissues to detect the water content of lung and to observe the histopathological changes in lung under light microscope.The expression of HMGB1 mRNA and the level of HMGB1 protein in the lungs were detected by RT-PCR and Western blot, respectively. Data were analysed with ANOVA and LSD method for comparison between groups, and P ＜0.05 was considered statistically significant. Results Compared with the group A (0.652±0. 177), the expressions of HMGB1 mRNA in lung of rats of group B were significantly higher in 12 hours (1. 161 ±0.358, P=0.013), 24 hours (1.679 ±0.235, P =0.000) and 48 hours (1.258 ±0.274, P=0.004) and reached the peak in 24 h. Compared with group A (0.594 ±0. 190), the level of HMGB1 protein in rats of group B 6 h after infection ( 1. 408 ± 0. 567, P = 0. 026) was significantly increased (P＜0.05), and it reached peak in 24 h (2.415 ± 1.064, P =0.000) after infection. Compared with group A (0.699 ± 0.054), the lung water contents in rats of group B were significantly increased in 6 h (0.759±0.030, P=0.001), in 12 h (0.767 ±0.023, P =0.000), in 24 h (0.771 ±0.043, P=0.000) and in 48 h (0.789 ±0.137, P=0.000) after infection. Compared with group A, the pathological changes in the lung of rats in group B showed clearly marked pulmonary vascular congestion, interstitial edema and inflammatory cell infiltration, and those changes became more and more serious until alveolar sacs entirely collapsed and the boundaries of the alveolar septa could not be clearly identified in 48 h. Conclusions Vibrio vulnificus sepsis leads to the lung injury of infected rats, and the increase in the expression of HMGB1 mRNA in lung might be one of the mechanisms of lung injury in rats with Vibrio vulnificus sepsis.     

多器官功能障碍综合征大鼠肺组织血栓调节蛋白和基质金属蛋白酶-9的表达

Objective To determine the expressions of thrombomodulin (TM) and matrix metalloproteinase-9(MMP-9) in the lung of rats with multiple organ dysfunction syndrome (MODS) and to investigate the mechanism of lung injury in MODS. Method Forty adult mule Sprague-Dawley (SD) rats were randomly divided into two groups,namely the normal control group and the MODS model group. The rats of model group were further divided into four subgroups as per different intervals (6 h, 12 h, 24 h and 48 h) ,and there were 8 rats in each groups. The animal models of MODS were estabhshed by two hits,the left eyeball of each model rat was removed to bleed to 2 mL/100g,and four hours later, lipopolysaccharide (LPS 5 mg/kg) was injected into intraperitoneal cavity of model rats. The same volume of saline was injected intraperitoneally into rats of control group instead of LPS. All rats were sacrificed at various intervals. The histological changes in lung tissue were observed by naked eye and light microscope. The expressions of TM and MMP-9 proteins were deteceted by using immunohistechemistry. One-way ANOVA was used for comparison among multiple group. Results (1)There were no histopathological changes in lung of rats of control group, and the lung injury was serious in MODS rots. (2) Compared with the rots of con-trol group, the expression of TM in lung tissue of MODS rats increased 6 hours after LPS, reached peak 12 hours later(P <0.01),and then decreased during 24～48 period.There was no significant difference in expression of TM between two groups 48 hours later. Compared with control group, the expressions of MMP-9 in lung tissue of MODS rats didn't significantly increase 6 ～ 48 hours after LPS (P < 0.01). Conclusions There are endothelium damage and extracellular matrix damage found in the lung tissue of rats at the early phase of MODS. TM and MMP-9 are good biomarkers of endothelium and extracellular matrix damage, and they can be used for diagnosing and es-timating the severity of injury lungs at the early phase of MODS.     

肺牵张反射对急性呼吸窘迫综合征的肺保护作用

目的 观察肺牵张反射对急性呼吸窘迫综合征(ARDS)兔肺损伤的影响.方法 盐酸吸入法复制兔ARDS模型,应用神经电活动辅助通气(NAVA)进行机械通气,潮气量(VT)维持6 mL/kg,膈肌电活动(EAdi)法选择呼气末正压(PEEP),随机(随机数字法)分为2组:(1)假手术(Sham)组(5只);(2)迷走神经离断(VAG)组(5只).观察在基础状态、ARDS成模、机械通气1,2,3 h时的气体交换及呼吸力学指标.测定肺通透性、病理以及炎症反应指标.结果 机械通气2,3 h,VAG组氧合指数(PaO2/FiO2)显著低于Sham组(P＜0.05).在机械通气1,2,3 h时,VAG组二氧化碳分压(PaCO2)与Sham组差异无统计学意义(P＞0.05),VAG组VT、气道峰压(Ppeak)及平均气道压(Pm)均显著高于Sham组(P＜0.05).机械通气3 h,与Sham组相比,VAG组死腔分数(VD/VT)、肺弹性阻力(Ers)明显升高,肺静态顺应性(Cst)明显降低(P＜0.05).与Sham组相比,VAG组肺组织湿/干质量(W/D)、肺损伤评分、肿瘤坏死因子-α(TNF-α)、白介素-8(IL-8)、髓过氧化物酶(MPO)及丙二醛(MDA)含最均显著升高(P＜0.05).结论 离断迷走神经加重ARDS肺损伤,维持完整肺牵张反射对ARDS具有肺保护作用.

Abstract：

Objective To evaluate the effect of the pulmonary stretch reflex on the lung injury in acute respiratory distress syndrome (ARDS). Method ARDS models of rabbits were induced by intratracheal infusion hydrochloric acid and ventilated with neurally adjusted ventilatory assist (NAVA) with a tidal volume ( VT) of 6 mL/kg and the electrical activity of diaphragm ( Eadi)-determined PEEP level. The rabbits were randomly ( random number) divided into two groups: ( 1 ) sham operation (Sham) group ( n = 5 ),(2) bilateral vagotom (VAG) group( n = 5 ). Gas exchange and pulmonary mechanics were determined at baseline, after lung injury and ventilation 1, 2, 3 h respectively. Indices about pulmonary permeability,pathological changes and inflammatory response were also measured. Results Compared with Sham group,the PaO2/FiO2in VAG group decreased significantly at ventilation 2 h, 3 h (P ＜0.05). There was no significant difference on PaCO2 between Sham and VAG group (P ＞ 0.05 ), and VAG group had the higher VT,peak pressure ( Ppeak), mean pressure (Pm) compared with Sham group at the time point of ventilation 1 h, 2 h, 3 h (P＜0.05). Compared with Sham group, the dead space fraction (VD/VT) and the respiratory system elastance (Ers) in VAG group increased (P ＜ 0.05 ) and the static pulmonary compliance (Cst)decreased markedly (P ＜ 0.05 ) after 3 h ventilation. The wet/dry weight (W/D), lung injury score, tumor necrosis factor-α ( TNF-α), interleukin-8 ( IL-8 ), myeloperoxidase ( M PO ) and malondialdehyde ( M DA )in VAG group elevated significantly when compared with Sham group ( P ＜ 0.05 ). Conclusions The lung injury in ARDS was aggravated after bilateral vagotomy, which demonstrated that the pulmonary stretch reflex may have the lung protective effect.     

血管外肺水指数在脓毒症相关性ALI/ARDS患者液体管理中的意义

Objective The management of fluid infusion is crucial in severe sepsis/septic shock patients.The correlation of extravascular lung water index(EVLWI) versus oxygenation index ( PaO2/FiO2 ) and EVLWI versus intrathoracic blood volume index(ITBVI) were analysed in this present study. Method Totally 24 patients,admitted to the Intensive Care Unit of Second Affiliated Hospital of Zhejiang University, College of Medicine and diagnosed as severe sepsis/septic shock with acute lung injury and/or acute respiratory distress syndrome,were enrolled. ITBVI and EVLWI were detected with PiCCO technique. Correlation of EVLWI and PaO2/FiO2, ITBVI and EVLWI were analysed,respectively. Simple correlation and simple linear regression were used for statistical analysis. Results Significant negative correlation was found of EVLWI and PaO2/FiO2 ( r = - 0. 45, P ＜ 0.01).EVLWT = 14 mL/kg was defined as the cutoff value for the subgroup analysis. No correlation was found between EVLWI and PaO2/FiO2 in the subgroup with EVLWI≤ 14 mL/kg ( r = 0. 12, P = 0.243), but in the subgroup with EVLWI ＞ 14 mL/kg, significant negative correlation was found ( r = - 0. 47, P ＜ 0. 01 ). When EVLWI was higher than 14 mL/kg,EVLW should be decreased to improve oxygenation and other aspects should be taken into account. No significant correlation was found between ITBVI and EVLWI. A ITBVI value 1000 mL/m2 was also defined as the cutoff value for the subgroup analysis. No significant correlation was found in the subgroup with ITBVI≤ 1000 mL/m2( r = 0.13, P = 0.17), while significant positive correlation was found in the subgroup with ITBVI ＞ 1000 mL/m2. This result suggested that in patients of severe sepsis/septic shock with ALI/ARDS, when the blood volume is high, ITBV should be decreased to improve the oxygenation,however,it is not useful in the situation of high pulmonary vascular permeability. Conclusions Extravascular lung water has a important role in the fluid management in patients of severe sepsis/septic shock with ALI/ARDS.     

大鼠机械通气所致肺损伤时p38丝裂原活化蛋白激酶通路的激活

目的探讨大鼠机械通气所致呼吸机相关性肺损伤(VILI)时p38丝裂原活化蛋白激酶(MAPK)的激活以及致炎因子的表达。方法30只健康SD大鼠随机均分成A、B、C3组,A组:潮气量(VT)8ml/kg,呼吸频率(RR)80次/min;B组:VT20ml/kg,RR80次/min;C组:VT40ml/kg,RR80次/min。各组机械通气时间均为2h。实验结束处死大鼠,收集支气管肺泡灌洗液(BALF)和肺组织标本,光镜下观察肺组织病理学改变。采用蛋白质免疫印迹法(Western blotting)检测各组肺组织中p38、磷酸化p38(p-p38)水平,逆转录-聚合酶链反应(RT-PCR)检测细胞间黏附分子-1(ICAM-1)表达水平,考马斯亮蓝染色法检测肺组织中总蛋白浓度和髓过氧化物酶(MPO)活性,双抗体夹心酶联免疫吸附法检测BALF中肿瘤坏死因子-α(TNF-α)、巨噬细胞炎症蛋白-2(MIP-2)和白细胞计数(WBC)。结果肺组织病理观察显示,A、B、C3组的改变依次加重;与A组相比,B、C两组p-p38和ICAM-1的表达以及总蛋白、WBC、MIP-2、TNF-α及MPO的水平均显著增高(P均<0.01);与B组相比,C组p-p38和ICAM-1的表达以及总蛋白、WBC、MIP-2、TNF-α及MPO的水平均显著增高(P<0.05或P<0.01)。结论大VT机械通气能显著激活p38通路以及致炎因子的表达,这可能是大鼠机械通气所致肺损伤的重要致病机制之一。     

合成短肽S247对呼吸机所致肺损伤p38MAPK通路激活的影响

目的研究合成短肽S247对大鼠呼吸机所致肺损伤(VILI)p38MAPK通路激活的影响。方法30只健康雄性SD大鼠随机均分成A、B、C三组：A组潮气量(V_T)为8mL/kg,B组V_T为40 ml/kg,C组V_T为40mL/kg。试验前一周每天一次腹腔注射合成短肽S247溶液(100 mg/kg),直至试验前0．5h。各组通气时间均为2h,呼吸频率均为80次/min。试验结束处死大鼠,收集肺灌洗液和组织标本,光镜观察肺病理改变,Western Blot方法检测各组肺组织中p38、磷酸化p38(p-p38)的水平。同时分别检测各组肺灌洗液中总蛋白、白细胞计数、MPO以及MIP-2的水平。结果和A组相比,B组肺病理改变明显,总蛋白、白细胞计数、MPO、MIP-2、p-p38等指标均显著高于A组(P＜0．01)。和B组相比,C组病理改变明显减轻,p-p38和其他各项指标指标均显著低于B组(P＜0．01或P＜0．05)。结论合成短肽S247能显著抑制VILI时p38通路的激活,减轻肺损伤,对VILI具有一定保护作用。     

肺复张后不同潮气量对急性肺损伤大鼠肺血管内皮舒张功能的影响

目的 观察肺复张与肺复张后不同潮气量对ALI大鼠肺内皮舒张功能的影响.方法 内毒素(LPS)静脉注射复制大鼠ALI模型.25只清洁级SD大鼠随机(随机数字法)分成5组,每组5只:对照组、ALI组、小潮气量(VT)组(LV组,VT 6 mL/kg)、SI+小VT组(SI+LV组,VT 6 mL/kg)、SI+常规VT组(SI+MV组,VT12mL/kg),SI(30 cmH2O)维持30 s,进行肺复张.应用不同潮气量联合肺复张监测呼吸功能和血流动力学,实验5 h后放血处死动物.观察肺组织病理形态改变和湿/干重比(W/D);放射免疫法检测肺组织中ET-1;免疫组织化学法半定量分析肺动脉内皮细胞内皮型一氧化氮合酶(eNOS)蛋白表达水平;血管张力实验检测离体肺动脉环对乙酰胆碱(Ach)和硝普钠(SNP)介导的舒张功能的影响;ELISA检测肿瘤坏死因子-α(TNF-α)炎症反应指标.结果 与CON组比较,LPS增加各组内肺水肿,加重肺损伤,增加TNF-α含量,增加ET-1含量,减少肺动脉内皮细胞eNOS蛋白表达,减弱Ach介导的内皮依赖的舒张功能,最终影响内皮功能.SI+LV组ET-1含量为(109.18±15.62)pg/mL,SI+MV组和LV组肺组织ET-1含量分别为(158.78±30.40)pg/mL和(152.35±8.21)pr/mL,较SI+LV组升高(P＜0.05);SI+LV组肺组织eNOS蛋白表达的iOD值为(12663.83±1348.93),SI+MV组和LV组肺组织eNOS蛋白表达的iOD值分别为(9208.12±2773.68)和(9339.53±3366.40),较SI+LV组无统计学差异,但有降低趋势(P＞0.05);与SI+LV组比较,ALI组和SI+MV组在不同浓度Ach作用下内皮依赖的舒张功能降低(P＜0.05),LV组虽然与SI+LV组比较差异无统计学意义,但Ach介导舒张功能有下降的趋势;SI+LV组肺组织TNF-α含量(2374.53±410.60)ng/L,较SI+MV组(3468.86±659.25)ng/L和LV组(3370.75±314.17)ng/L降低(P＜0.05).结论 肺复张联合大潮气量和小潮气量机械通气能够改善ALI大鼠肺血管内皮舒张功能,肺复张联合小潮气量可进一步减轻ALI大鼠肺血管内皮舒张功能的损伤.     

EGFR在大鼠呼吸机肺损伤中的作用研究

目的研究呼吸机所致肺损伤中表皮生长因子受体(EGFR)的激活作用。方法 24只清洁级雄性SD大鼠按照是否AG1478处理和是否机械通气将其分为DMSO自主呼吸组(n=6)、DMSO机械通气组(n=6)、AG1478 10mg/kg处理自主呼吸组(n=3)、AG1478 50mg/kg处理自主呼吸组(n=3)、AG1478 10mg/kg处理机械通气组(n=3)和AG1478 50mg/kg处理机械通气组(n=3)。20%乌拉坦腹腔注射麻醉大鼠;自主呼吸的大鼠不作处理,机械通气的大鼠接小动物呼吸机行机械通气,机械通气参数设置为潮气量(Vt)20ml/kg,呼吸频率40次/min,吸呼比(I∶E)为1∶2,呼气末正压通气(PEEP)为0,吸入气体为室内空气。皮下切开行股静脉穿刺置管,监测动脉血压、心率等。4h后处死,分别收集肺组织、肺灌洗液标本。结果 AG1478 50mg/kg处理机械通气组与DMSO机械通气组相比蛋白渗漏更低,而且比AG1478 10mg/kg机械通气更低,差异均有统计学意义(P<0.05);细胞数量分析显示,AG147850mg/kg处理机械通气组与DMSO机械通气组相比中性粒细胞更低,而且比AG1478 10mg/kg处理自主呼吸组更低,差异均有统计学意义(P<0.01);AG1478 50mg/kg处理的大鼠巨噬细胞数量显著升高,均高于其他处理手段的大鼠。同样行机械通气的大鼠,AG1478组的肺血管渗漏水平与DMSO组相比更低。结论呼吸机相关肺损伤中,EGFR路径调节呼吸机诱导的肺损伤和与之相关的炎性反应,EGFR具有活化信号的作用,可调节呼吸机诱导的肺血管渗漏。     

机械通气对急性肺损伤大鼠细胞凋亡的影响

目的 研究不同潮气量及不同呼气末正压(PEEP)水平对急性肺损伤(AU)大鼠支气管和肺组织细胞凋亡的影响,并初步探讨细胞凋亡在呼吸机相关性肺损伤(VILI)中的作用机制.方法 选用40只SD大鼠,制作ALI模型,随机(随机数字法)分为:(1)小潮气量组(LV组),潮气量8 mL/kg,不加PEEP;(2)大潮气量组,潮气量30 mL./kg,不加PEEP;(3)小潮气量+ 2PEEP组(LV2P组),潮气量8 mL/kg,同时给PEEP 2 cmH2O(1 crnH2O =0.098 kPa);(4)小潮气量+5PEEP组(LV5P组),潮气量8 mL/kg,同时给PEEP 5 cmH2O;(5)小潮气量+8PEEP组(LV8P组),潮气量8 mL/kg,同时给PEEP 8 cmH2O.通气2h后处死动物,留取肺标本.用脱氧核糖核苷酸末端转移酶介导的末端标记法(TUNEL)分析肺组织中的细胞凋亡情况,用免疫组化法检测肺组织中caspase-3蛋白的表达及分布.结果 大潮气量组支气管和肺组织细胞凋亡的明显增加(P＜0.01),caspase-3蛋白酶表达最强.采用PEEP后,支气管和肺组织细胞凋亡减少,capase-3蛋白酶表达弱阳性,以LV5P组最为显著(P＜0.01).结论 小潮气量对肺组织有保护作用,采用PEEP后保护作用更加明显,细胞凋亡在VILI的发生中有重要作用.     

机械通气动态通气参数对急性呼吸窘迫综合征犬肺损伤的影响

目的观察机械通气动态通气参数对急性呼吸窘迫综合征(ARDS)犬肺损伤的影响,评价机械通气参数对肺损伤的保护作用。方法36条健康杂种犬,按照随机数字表法分为正常对照组(N组)、模型组(M组)及机械通气A～D组。采用气管内盐酸吸入法建立ARDS模型,按下述方案机械通气。A组:小潮气量(6ml/kg)、低吸气流速(6ml·kg-1·s-1)、高通气频率(30次/min);B组:大潮气量(20ml/kg)、高吸气流速(20ml·kg-1·s-1)、高通气频率(30次/min);C组:大潮气量(20ml/kg)、高吸气流速(17ml·kg-1·s-1)、低通气频率(15次/min);D组:大潮气量(20ml/kg)、低吸气流速(10ml·kg-1·s-1)、低通气频率(15次/min)。分组机械通气后0、1、2和4h各时间点分别记录呼吸力学各值。4h后处死动物,取肺脏测肺湿/干重(W/D)比值;光镜下观察病理组织学变化,并进行弥漫性肺泡损伤(DAD)评分及高倍镜下中性粒细胞计数;流式细胞仪检测肺组织核转录因子κB(NFκB)p65活性。结果B组肺W/D比值为9.95±0.99,高于A组6.78±0.56、D组7.11±0.47(P均<0.01),但与C组9.22±1.19差别不大(P>0.05)。肺组织病理DAD评分:B组为(12.80±1.47)分,明显高于A组(7.67±1.20)分和D组(8.83±1.17)分(P均<0.01),但与C组(11.50±1.87)分比较差异无显著性(P>0.05)。B组NFκBp65表达为(33.56±2.85)%,较A、D两组〔(10.35±0.60)%、(10.79±1.02)%〕表达增强(P均<0.01),与C组(30.87±1.16)%间比较差异无显著性(P>0.05)。结论大潮气量、高吸气流速、高通气频率机械通气可导致严重的呼吸机相关性肺损伤(VILI),降低通气频率可适当减轻这类损伤;在大潮气量基础上,降低通气频率及吸气流速,对损伤的肺组织可起到一定的保护作用。     

p38信号通路参与呼吸机所致肺损伤大鼠高迁移率族蛋白B1的表达

目的 研究p38信号通路在呼吸机所致肺损伤(ventilator-induced lung injury,VILI)大鼠肺组织表达高迁移率族蛋白BI(high mobility group box 1 protein,HMGB1)中的作用.方法健康sD大鼠24只随机分为3组:对照组(A组)不行机械通气,保留自主呼吸;常规通气组(B组)潮气量(Vt)为8mL/kg;大潮气量通气组(C组)Vt为40 mL/kg.机械通气4 h后处死动物,测定支气管肺泡灌洗液中总蛋白水平、白细胞计数以及肺湿干重比值(W/D)和中性粒细胞髓过氧化物酶(MPO)活性.采用Western blot方法检测肺组织HMGB1蛋白和p38激酶活性变化,采用RT-PCR方法检测HMGB1 mRNA的表达.应用单因素方差分析进行不同组别间的比较.结果 通气4 h后,与A组相比,C组总蛋白水平(1.77±0.68)g/L、白细胞计数(106.55±28.17)×10~7 L~(-1)、肺W/D比值(7.16±1.02)、MPO活性(3.94±1.21)U/g、HMGB1蛋白(0.64±0.17)和mRNA(1.17±0.45)表达以及p38激酶活性(0.51±0.12)均明显增加(P<0.05),而B组上述各项指标的变化均无统计学意义(P>0.05).结论大潮气量机械通气可引起大鼠急性肺损伤,p38参与了机械牵张诱导肺组织HMGB1的表达.     

Effect of post recruitment maneuver ventilation by different tidal volume on lung vascular endothelial diastole function in rats with acute lung injury

BACKGROUND: This study aimed to observe the effect of recruitment maneuver (RM) and post-RM ventilation at different tidal volume on lung vascular diastole endothelial function in rats with acute lung injury (ALI).METHODS: A ALI rat model was produced by intravenous infusion of lipopolysaccharide (6 mg/kg). Twenty-five rats were randomly divided into five groups: control group (n=5), ALI group (n=5), low tidal volume group (LV group, VT 6 mL/kg, n=5), sustained inflation (SI) with low tidal volume group (SI+LV group, VT 6 mL/kg, n=5), and SI with moderate tidal volume group (SI+MV group, VT 12 mL/kg, n=5). RM was performed with SI, airway pressure 30 cmH₂O for 30 seconds, and positive end-expiratory pressure (PEEP) was set to 5 cmH₂O. Lung tissue was taken after 5 hours of mechanical ventilation. Mean arterial blood pressure (MAP) was monitored during the experiment. Endothelin-1 (ET-1), endothelial nitricoxide synthase (eNOS), Ach-induced endothelium-dependent relaxation response of isolated pulmonary artery rings were determined at 5 hours.RESULTS: LPS increased ET-1 level, decreased the expression of eNOS in lung tissue, impaired the Ach-induced endothelium-dependent relaxation response in the pulmonary artery, without obvious effect on systemic hemodynamics. SI+LV significantly reduced LPS-induced elevation of ET-1 level, increased the expression of eNOS, significantly improved endothelial dysfunction, and improved the dysfunction of endothelium-dependent relaxation in the pulmonary artery.CONCLUSIONS: RM with a high or low tidal volume ventilation could improve the lung vascular endothelial function of rats with acute lung injury, and RM with low tidal volume ventilation could lower significantly the injury of lung vascular endothelial diastole function in rats with acute lung injury.     

Animal model of unilateral ventilator-induced lung injury

Objective To design, implement, and test a selective lung ventilator for setting a rat model of unilateral ventilator-induced lung injury (VILI).Design and setting Interventional animal study in a university laboratory for animal research.Subjects Anesthetized and paralyzed male Wistar rats.Interventions A selective ventilator designed to apply varying tidal volume, PEEP, and breathing gas to each lung of the rat was implemented and evaluated. Five control animals were ventilated at 7 ml/kg (3.5 ml/kg each lung). Unilateral VILI was induced in six animals subjected to selective ventilation (3.5 ml/kg in one lung and 15 ml/kg in the other lung). After 3 h of ventilation the animals were killed and the lungs excised.Measurements and results Lung edema was assessed by means of the ratio between wet and dry lung weights. No significant differences were found in lungs of control animals (5.16±0.22 and 4.96±0.25), but the W/D ratio in the over ventilated lung (8.98±3.80) was significantly greater than that in the normally ventilated lung (4.76±0.15), indicating selective induction of lung edema by over stretch.Conclusions This selective ventilator can be implemented into a rat model of unilateral VILI to gain further insight into the mechanisms of pulmonary injury induced by different ventilatory strategiesThis work was supported in part by grants from Ministerio de Ciencia y Tecnologia (SAF 2002-03616 and SAF 2003-01334) and Ministerio de Sanidad y Consumo (Red GIRA-G03/063 and Red RESPIRA-C03/11).     

不同潮气量机械通气对肺损伤的影响及其针对性护理

目的 研究不同潮气量机械通气对肺损伤的影响,探讨机械通气时的针对性护理措施.方法 将24只健康SD大鼠随机分为对照组（n=8）、小潮气量通气组（n=8,VT=8 ml/kg）和大潮气量通气组（n=8,VT=40ml/kg）.通气时间均为4 h.检测肺组织总蛋白、肺湿干重比（W/D）、白细胞计数和中性粒细胞髓过氧化物酶（MPO）含量以及肿瘤坏死因子α（TNF-α）蛋白和mRNA的含量.结果与对照组比较,大潮气量通气组肺组织总蛋白、W/D、白细胞计数和MPO含量以及TNF-α蛋白和mRNA含量均显著增加（P〈0.05）,而小潮气量通气组上述指标的变化无统计学意义（P〉0.05）.结论 大潮气量机械通气可导致呼吸机所致肺损伤,临床上应加强对机械通气患者的护理防护.