不同潮气量通气对内毒素肺损伤大鼠Th1/Th2平衡的影响

目的 探讨内毒素肺损伤Thl/Th2平衡变化及不同潮气量通气对内毒素肺损伤大鼠Thl/Th2平衡的影响。方法 健康大鼠32只随机分成4组：生理盐水正常对照A组、内毒素肺损伤非机械通气B组、内毒素肺损伤＋小潮气量C组、内毒素肺损伤＋传统潮气量D组。监测平均动脉压(MAP)、心率(HR)，计算氧合指数（OI），检测PBMC中IFN-γ、IL-4浓度水平并计算IFN-γ/IL-4。取右肺中叶计算肺组织湿干比值(W/D)；观察右肺下叶肺组织病理变化；分析支气管肺泡灌洗液(BALF)中白细胞(WBC)与中性粒细胞(PMN)。结果 1. B、C、D组OI、W/D及病理学变化符合急性肺损伤表现；2. B组IFN-γ/IL-4比值明显高于A组；C组IFN-γ/IL-4比值明显低于B组；D组IFN-γ/IL-4比值明显高于B组；3. B组肺W/D及BALF中WBC、PMN计数明显高于A组；C组肺W/D及BALF中WBC、PMN计数明显低于B组；D组肺W/D及BALF中WBC、PMN计数明显高于B组。结论 1.注射LPS可成功复制大鼠急性肺损伤动物模型；2.内毒素致大鼠肺损伤早期，其PBMC中IFN-γ和IL-4浓度增加，IFN-γ/IL-4升高，Thl/Th2失衡；3.传统潮气量机械通气可加重内毒素肺损伤大鼠炎症反应，使肺损伤早期大鼠Th1/Th2失衡加剧；4.保护性通气策略的小潮气量机械通气可减轻内毒素肺损伤大鼠PMN在肺内“扣押”，改善Th1/Th2失衡状态。     

小潮气量机械通气对海水淹溺急性肺损伤兔治疗作用的实验研究

目的 观察小潮气量机械通气在海水淹溺急性肺损伤应用时的治疗作用和安全性.方法 分别应用潮气量为6 ml/kg和12 ml/kg的机械通气对海水淹溺急性肺损伤兔进行分组救治.在不同时间点检测血气分析、呼吸动力学、血液动力学,观察血清和肺泡灌洗液肿瘤坏死因子a、白介素6以及肺HRCT变化,并进行肺病理学检查,以评价治疗效果和安全性.结果 采用6 ml/kg小潮气量机械通气不仅能改善SWD-ALI时的氧合,而且能有效控制气道峰压和气道平均压,从而在一定程度上避免呼吸机相关肺损伤.结论 小潮气量保护性机械通气策略应用治疗海水淹溺急性肺损伤兔,能够明显改善氧合,避免继发肺损伤,是一种安全有效的治疗海水淹溺急性肺损伤的机械通气手段.     

内皮素-1在呼吸机所致肺损伤犬肺中的表达变化研究

目的 检测内皮素-1(ET-1)在呼吸机所致肺损伤(VILI)模型肺组织的表达分布及变化.方法 普通级犬随机分为正常对照组(N组,n=6)、急性肺损伤(ALI)组(n=14).用油酸静脉内注射制备ALI模型,制备成功后随机取2只作为ALI组,其他随机分为小潮气量机械通气组(LV组,n=6)、大潮气量机械通气组(即VIL...     

低潮气量维持通气治疗老年肺结核合并呼吸衰竭的临床分析

目的　探索使用低潮气量维持通气对老年肺结核合并呼吸衰竭患者的血气分析影响。方法 在有效的抗结核、抗炎治疗的基础上，在各种通气参数保持不变的情况下，以使用呼吸机前，调节患者的潮气量分别为10mL/kg、8mL/kg、6mL/kg后1h及维持6mL/kg12h之血气分析进行比较。结果 以潮气量为6mL/kg维持通气治疗，PaCO₂及PaO₂/FiO₂较在使用呼吸机前有明显改善(P＜0.05)。结论 对于老年肺结核合并呼吸衰竭患者，使用低潮气量进行机械通气即可有效纠正呼吸衰竭。     

小窝蛋白-1在大潮气量机械通气大鼠肺组织中的表达

目的 通过观察不同时间段机械通气大鼠肺组织中小窝蛋白-1(caveolin-1,cav-1)的表达水平,探讨cav-1在呼吸机所致肺损伤(VILI)发病中的作用.方法 雄性SD大鼠32只,随机分为对照组、通气0.5h组(H-VT0.5h组)、通气1h组(H-VT1h组)和通气2h组(H-VT2h组).采用免疫组织化学染色法测定各组大鼠肺组织cav-1的表达水平,测定其肺湿/干重(W/D)比值和支气管肺泡灌洗液(BALF)中总蛋白含量,并在光镜下观察各组大鼠肺组织的病理学改变.结果 ①肺组织cav-1表达结果显示,H-VT0.5h组和对照组均明显高于H-VT2h组和H-VT1h组(P值均＜0.001),H-VT0.5h组明显高于对照组(P＜0.001),H-VT1h组明显高于H-VT2h组(P＜0.01).②肺组织W/D比值和BALF总蛋白含量测定结果显示,H-VT2h组和H-VT1h组均明显高于对照组和H-VT0.5h组(P值均＜0.001),H-VT2h组明显高于H-VT1h组(P＜0.001),H-VT0.5h组与对照组比较差异无统计学意义(P＞0.05).③肺组织病理学结果显示,随着机械通气时间延长,大鼠肺组织损伤程度呈逐渐加重趋势.结论 肺组织cav-1在机械通气不同时间段表达水平明显不同,表现为先增高后降低.提示肺组织cav-1高表达对VILI起一定保护作用;大潮气量机械通气可通过抑制肺组织cav-1表达,诱发和加重肺组织损伤.     

早期经皮扩张气管切开对长期机械通气患者预后的影响

目的探讨早期气管切开对长期机械通气患者预后的影响。方法回顾分析衡水市哈励逊临床医学院重症医学科2009年6月至2012年11月经皮扩张气管切开的患者178例,按气管切开时间分为早期气管切开组（机械通气≤10d）及晚期气管切开组（机械通气〉10d）,比较两组患者呼吸机相关性肺炎（VAP）的发生率、机械通气时间、住ICU时间和28d病死率。结果早期气管切开组VAP的发生率低于晚期气管切开组,机械通气时间及住ICU时间均明显缩短,28d病死率差异无统计学意义。结论对于需要长时间机械通气患者,早期气管切开可以降低VAP的发生率,缩短患者机械通气时间及住ICU时间,但对患者28d病死率无影响。     

机械通气对大鼠肺组织SP—A表达的影响及氨溴索的干预作用研究

目的通过观察氨溴索对机械通气致大鼠急性肺损伤时肺表面活性蛋白A（SP—A）表达的影响,探讨SP-A在呼吸机所致肺损伤（VILI）发生过程中的作用,以及氨溴索对VILI的防治作用。方法健康Wistar大鼠24只,随机分为对照组、机械通气组（MV组）和氨溴索干预组（AMB组）。观察各组大鼠肺组织病理学变化,检测支气管肺泡灌洗液（BALF）中性粒细胞记数,采用考马斯亮蓝法测定BALF蛋白含量,采用反转录聚合酶链反应（RT—PCR）和免疫组织化学染色法测定肺组织SP—A mRNA及其蛋白的表达。结果MV组大鼠BALF中性粒细胞计数、BALF蛋白含量较对照组和AMB组明显升高（P〈0．01）,而肺组织SP-A mRNA及其蛋白表达水平较对照组和AMB组明显降低（P〈0．01）;对照组上述指标与AMB组比较差异无统计学意义（P〉0．05）。结论SP—A在VILI的发生、发展过程中具有重要作用,氨溴索可通过促进SP—A表达,减轻肺组织损伤,对VILI有一定保护作用。     

Lung inflammation in preterm infants with respiratory distress syndrome: effects of ventilation with different tidal volumes

Ventilation with an inappropriate tidal volume (Vt) triggers lung inflammation, an important predisposing factor of bronchopulmonary dysplasia. It still remains uncertain what the appropriate starting target Vt should be during the acute phase of respiratory distress syndrome (RDS). Our aim was to evaluate lung inflammation in preterm infants undergoing synchronized intermittent positive-pressure ventilation (SIPPV) with two different tidal volumes Vt during the acute phase of RDS. Thirty preterm infants (gestational age, 25-32 weeks) with acute RDS were randomly assigned to be ventilated with Vt = 5 ml/kg (n = 15) or Vt = 3 ml/kg (n = 15). Proinflammatory cytokines (interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor (TNF)-alpha) were determined in the tracheal aspirate on days 1, 3, and 7 of life. IL-8 and TNF-alpha levels collected on day 7 were significantly higher (P < 0.05), and mechanical ventilation lasted longer in the group with Vt = 3 ml/kg (16.8 +/- 4 vs. 9.2 +/- 4 days; P = 0.05). In conclusion, our data show significantly higher lung inflammation in preterm infants ventilated with Vt = 3 ml/kg, suggesting a role for Vt = 5 ml/kg in reducing both inflammatory response during the acute phase of RDS and the length of ventilation. Whether the use of this starting Vt prevents bronchopulmonary dysplasia requires further study.     

肺表面活性物质异常在呼吸机所致肺损伤发生中作用的实验研究

目的 探讨肺表面活性物质(PS)异常在呼吸机所致肺损伤(VILI)发生中的作用.方法 40只成年SD大鼠随机分成5组,每组8只,对照组于手术完毕后处死,其余4组给予机械通气(MV)(1)P7组,设置吸气峰压(cmH2O)/频率(次/min)/吸呼比/呼气末正压(PEEP)(cm H2O)为7/40/11/0;(2)P45组,45/20/11/0;(3)PS组,经气道滴入PS100mg/kg,45/20/11/0;(4)PEEP组,45/20/11/10,20min后处死.观察动脉血氧(Pa02)、最大胸肺顺应性(Cmax)、支气管肺泡灌洗液(BALF)的总蛋白(TP)、总磷脂(TPL)、大小聚集体(LA、SA)和最小表面张力(STmin).结果 与P7组比较,P45组Pa02和Cmax均明显降低(P均＜0.01),BALF的TP、SA/LA和STmin显著增加,TPL/TP降低(P均＜0.01).PS组和PEEP组各指标均显著优于P45组(P＜0.05或P＜0.01).P7组和对照组间各指标均相近.结论 VILI时有明显的PS异常;外源性PS和PEEP均可恢复和维持PS结构和功能,减轻VILI,表明PS异常与VILI的发生密切相关.     

Lung volume measurements immediately after extubation by prediction of “extubation failure” in premature infants

To test the hypothesis that premature infants in whom extubation fails in the first 10 days of life have low volume lungs, functional residual capacity (FRC) was measured in the first hour after extubation. Once extubated, infants received the appropriate level of inspired oxygen necessary to maintain acceptable arterial oxygen saturation. After humidification, oxygen was bled into a headbox, and FRC was assessed using a helium gas dilution technique and a specially designed infant circuit. The results were related to extubation failure, which was diagnosed when the infant required nasal continuous positive airway pressure or re-intubation and ventilation within 48 hours. The latter two forms of respiratory support were instituted by the clinical team, whenever the infant developed recurrent or severe apnea or respiratory acidosis. Infants were eligible for entry into the study when born prematurely and extubated within the first 10 days of life. Twenty infants initially ventilated for respiratory distress syndrome at a median gestational age of 29 weeks (range, 26–36 weeks) were studied at a median postnatal age of 3 days (range, 1–7 days). All were receiving theophylline. Extubation failed in seven infants, who did not differ significantly from the rest of the cohort regarding gestational age, birthweight, postnatal age, or inspired oxygen concentration (F₁O₂) at extubation, but their maximum F₁O₂ during ventilation was higher than in those infants who did not require reintubation (P < 0.05). In the infants who failed extubation, the median FRC was 19 ml/kg (range, 12–27 ml/kg), which was lower than that of the infants in whom extubation was successfully accomplished (median, 28 ml/kg; range, 19–37 ml/kg; P < 0.01). An FRC of less than 26 ml/kg had a sensitivity of 71% and specificity of 77% in predicting extubation failure. These results support the hypothesis that a very low lung volume relates to extubation failure in the first 10 days of life. Pediatr Pulmonol. 1996; 21: 250–254. © 1996 Wiley-Liss, Inc.     

Volume guarantee: stability of tidal volume and incidence of hypocarbia

Excessive tidal volume (V(T)) can lead to lung injury, hypocarbia, and neurologic damage. Volume guarantee (VG) uses exhaled V(T) as the control variable to reduce the risk of volutrauma and more closely control PaCO(2). Our objective was to test the hypothesis that VG combined with assist/control (A/C) will maintain PaCO(2) and V(T) within target range more consistently than assist/control alone during the first 72 hr of life in ventilated preterm infants. Eligible infants were randomly assigned to A/C + VG or A/C alone. Data were recorded directly from the pressure and volume module of the Draeger Babylog 8000+ ventilator. Arterial blood gases were obtained every 2-6 hr, as clinically indicated. In A/C, inspiratory pressure was adjusted to achieve a V(T) of 4-6 ml/kg. In VG, the target V(T) was 5 ml/kg. Subsequent adjustments were made by the clinical team in response to arterial blood gas measurements (ABG). Proportion of breaths and PaCO(2) values outside the target range were compared by chi(2), and continuous variables by t-test. There were no differences in demographic or baseline ventilator variables between the 18 infants in the two groups. For 1,805/11,950 breaths (15.1%), V(T) was > target with A/C + VG, vs. 2,503/9,853 (25.4%) with A/C (P < 0.001). V(T) was < target for 21.7% of breaths with A/C + VG, vs. 35.7% with A/C (P < 0.001). Twenty percent of PaCO(2) values were < target, with A/C + VG vs. 36.3% with A/C, P < 0.05. The proportion of PaCO(2) values > target was similar in the two groups. Oxygenation and mean pH were not different. No complications related to mechanical ventilation were observed. In conclusion, VG significantly reduced hypocarbia and excessively large V(T). This suggests the potential to reduce pulmonary and neurologic complications of mechanical ventilation. Larger studies are needed to establish safety and demonstrate such benefits.     

小潮气量通气对ALI/ARDS高风险患者疗效及预后的影响分析

目的研究机械通气治疗的急性肺损伤/急性呼吸窘迫综合症(ALI/ARDS)高风险患者,应用小潮气量通气对患者疗效和预后的影响。方法采用随机数字表法将本院重症监护病房(ICU)收治的56例ALI/ARDS高风险患者分为研究组和对照组各28例,研究组采用小潮气量(VT6~8ml/kg)通气治疗,对照组采用常规潮气量(VT10~12ml/kg)通气治疗,比较两组患者治疗后不同时间的血气指标、血清炎症变化及预后差异。结果通气48h、通气96h后两组患者的Pa O2、Pa CO2、氧饱和度、p H值、氧合指数、中心静脉压均较通气即刻显著好转(P0.05)。通气48h、通气96h后两组患者的血清IL-6、TNF-ɑ、CRP水平均较通气即刻显著的降低(P0.05),研究组在通气48h、通气96h后血清IL-6、TNF-ɑ、CRP水平均显著的低于对照组(P0.05)。研究组的ALI/ARDS发病率(14.29%)、ICU治疗时间(9.5±2.6)d、机械通气治疗时间(7.4±1.3)d、住院时间(13.7±3.2)d、死亡率(10.71%),均显著的低于对照组患者(P0.05)。结论 ALI/ARDS高风险患者应用小潮气量机械通气治疗,较常规潮气量通气治疗具有更好的临床效果,预后效果更好。     

气道压力释放通气对中重度急性呼吸窘迫综合征临床疗效观察

目的探讨气道压力释放通气(APRV)对中重度急性呼吸窘迫综合征(ARDS)的临床疗效。方法选择海南省第二人民医院2013年6月至2016年6月接诊的60例中重度ARDS患者,通过随机数表法分为两组,气道压力释放通气组(APRV组)和小潮气量肺保护通气组,即使用容量同步间歇指令通气+呼气末正压(SIMV组),各30例。比较两组患者通气效果。结果通气后1、2、3 d,两组患者在气道峰压(Ppeak)、气道平均压(Pmean)、氧合指数(Pa O2/Fi O2)、血管外肺水指数(ELWI)、心率(HR)、平均动脉压(MAP)、中心静脉压(CVP)、急性生理学与慢性健康状况评分系统Ⅱ(APACHEⅡ)评分、Murray急性肺损伤评分均较通气前得到改善(P0.05);APRV组在通气后1、2 d时,Ppeak、Pmean、ELWI水平均比SIMV组低(P0.05),APRV组在通气后1、2、3 d时,Pa O2/Fi O2水平均比SIMV组高(P0.05),APRV组在通气后1、2、3 d时,HR、CVP水平均低于SIMV组,MAP水平均高于SIMV组(P0.05),APRV组通气后1、2、3 d时,Murray急性肺损伤评分均低于SIMV组(P0.05);APRV组无镇静剂使用时间、脱离呼吸机时间长于SIMV组,住ICU时间短于SIMV组(P0.05),两组在无脏器衰竭时间上无显著差异(P0.05);两组患者1个月内死亡率无显著差异(P0.05)。结论在中重度ARDS患者中使用APRV通气模式,可提高有效的呼吸支持,值得应用推广。     

Lung cancer: Preoperative pulmonary evaluation of the lung resection candidate

Lung resection provides the best chance of cure for individuals with early stage non-small cell lung cancer. Naturally, lung resection will lead to a decrease in lung function. The population that develops lung cancer often has concomitant lung disease and a reduced ability to tolerate further losses in lung function. The goal of the preoperative pulmonary assessment of individuals with resectable lung cancer is to identify those individuals whose short- and long-term morbidity and mortality would be unacceptably high if surgical resection were to occur. Pulmonary function measures such as the forced expiratory volume in 1 second and the diffusing capacity for carbon monoxide are useful predictors of postoperative outcome. In situations in which lung function is not normal, the prediction of postoperative lung function from preoperative results and the assessment of exercise capacity can be performed to further clarify risks. Published guidelines help to direct the order of testing, permitting us to offer resection to as many patients as possible.     

Evaluation of the multiple linear regression method to monitor respiratory mechanics in ventilated neonates and young children.

A potentially useful method to monitor respiratory mechanics in artificially ventilated patients consists of analyzing the relationship between tracheal pressure (P), lung volume (V), and gas flow (V) by multiple linear regression (MLR) using a suitable model. Contrary to other methods, it does not require any particular flow waveform and, therefore, may be used with any ventilator. This approach was evaluated in three neonates and seven young children admitted into an intensive care unit for respiratory disorders of various etiologies. P and V were measured and digitized at a sampling rate of 40 Hz for periods of 20-48 s. After correction of P for the non-linear resistance of the endotracheal tube, the data were first analyzed with the usual linear monoalveolar model: P = PO + E.V + R.V where E and R are total respiratory elastance and resistance, and PO is the static recoil pressure at end-expiration. A good fit of the model to the data was seen in five of ten children. PO, E, and R were reproducible within cycles, and consistent with the patient's age and condition; the data obtained with two ventilatory modes were highly correlated. In the five instances in which the simple model did not fit the data well, they were reanalyzed with more sophisticated models allowing for mechanical non-homogeneity or for non-linearity of R or E. While several models substantially improved the fit, physiologically meaningful results were only obtained when R was allowed to change with lung volume. We conclude that the MLR method is adequate to monitor respiratory mechanics, even when the usual model is inadequate.     

体外循环肺缺血再灌注损伤的实验研究

研究兔体外循环中肺的缺血再灌注损伤并探讨其可能机制。采用兔体外循环模型 ,测定肺组织的丙二醛 (MDA) ,髓过氧化物酶 (MPO) ,一氧化氮 (NO)含量、肺血管通透性 (EB值 )及肺组织湿干比 (W /D值 )。CPB组肺组织MDA含量 (139 4± 17.0 )mmol/ g明显高于对照组 (2 7.6± 1.8)mmol/ g ,P <0 .0 1;MPO含量 (9.4± 0 .6 )u/ g明显高于对照组 (1.9± 0 .7)u/ g ,P <0 .0 1;NO含量 (8.4± 3.8) μmol/ g明显低于对照组(2 0 .9± 1.7) μmol/ g ,P <0 .0 1;W /D值 (8.5± 2 .1)明显高于对照组 (4 .5± 0 .9)P <0 .0 1;EB值 (3.2 33±0 .0 7)明显高于对照组 (1.394± 0 .0 6 ) ,P <0 .0 1。动物实验提示CPB中肺的缺血再灌注是肺损伤的重要原因 ,内源性NO减少是肺损伤的重要环节     

Sex Differences in the Effects of Obesity on Lung Volume

Background

Obesity is linked to variation of lung volume; however, it is still unclear whether a sex difference exists. The study aimed to find out the effect of obesity on lung volume and sex difference among the Chinese population.