全氟化碳对体外循环肺损伤保护的实验研究

目的探讨以全氟化碳(perfluorocarbon,PFC)为媒介的部分液体通气(partial liquid ventilation,PLV)结合持续肺动脉灌注(continuous pulmonary perfusion,CPP)对体外循环(cardiopulmonary bypass,CPB)后幼猪急性肺损伤(acute lung injury,ALI)的肺组织炎性变化及气体交换的影响。方法将18只幼猪(体重为10.2±1.6kg)随机分为3组,对照组即单纯CPB组:只行单纯CPB;CPP CPB组(CPP组):在主动脉阻断期间,以20～25ml/kg.min的血液流量持续灌注肺动脉;PLV CPP CPB组(PLV组):在CPP组基础上停CPB后即刻向肺内灌入12ml/kg的PFC。分别在CPB前、停CPB即刻及停CPB后1h、2h、3h观察动脉血气指标的变化;实验结束后,取不同部位肺组织标本于光学显微镜下观察组织病理的变化。结果与对照组比较,PLV组在1h、2h、3h时点动脉血氧分压(PaO2)明显升高,动脉-肺泡氧分压梯度(AaDO2)明显降低(P<0.05),3h时动脉血二氧化碳分压(PaCO2)下降显著(P<0.05);CPP组的通气、换气功能也有明显改善;PLV组保护作用则较为明显。停CPB后,3组血液中的肿瘤坏死因子-α(TNF-α)、白细胞介素-8(IL-8)和白细胞介素-6(IL-6)均有所增加;与对照组比较,PLV组3h后TNF-α显著降低(P<0.05)。组织学检查:光学显微镜下见对照组肺组织(HE染色)细胞间黏附因子-1(ICAM-1)表达呈强阳性,PLV组及CPP组均呈弱阳性。结论以PFC为媒介的PLV结合持续肺动脉灌注介入CPB诱导的急性肺损伤,可明显地降低肺组织炎症反应和改善其肺气体交换。     

间断肺通气对体外循环肺损伤的保护作用

目的研究间断肺通气对体外循环(CPB)肺损伤的保护作用,并探讨其机制。方法将24例风湿性心脏病患者采用随机数字表法分为两组,处理组(n=13)CPB期间每5min间断肺通气一次;对照组(n=11)CPB期间不通气。所有患者均在术前留取血液标本,术后2h行支气管肺泡灌洗,分别测定支气管肺泡灌洗液(BALF)中的中性粒细胞、总蛋白(TP)、肿瘤坏死因子-α(TNF-α)含量、血清总蛋白以及术前、CPB后1h、4h肺氧合指数(OI)。结果处理组BALF中的中性粒细胞、TP、TNF-α含量较对照组显著降低(P<0.01,P=0.02,0.02),CPB后OI较对照组显著降低(P<0.05);两组CPB后1h、4h其OI均较同组CPB前显著增高(P<0.05)。结论间断肺通气可通过减少白细胞与血管内皮的黏附,减轻肺部炎症反应、内皮细胞损伤等,对CPB所致的肺损伤有保护作用。     

利多卡因对离体肺再灌注损伤保护作用的实验研究

目的通过离体肺再灌注模型观察利多卡因对肺再灌注损伤的保护作用.方法将12只兔随机分为两组Ⅰ组,低钾右旋糖酐(LPD)液灌洗兔肺后10℃保存,18 h后复灌;Ⅱ组,含利多卡因的LPD液灌洗后10℃保存,18 h后复灌.再灌注过程中测定氧分压(PO2)、二氧化碳分压(PCO2),灌注结束后测定肺组织湿干比(W/D)、髓过氧化物酶(MPO)活性以及支气管肺泡灌洗液(BALF)内中性粒细胞(PMN)计数,并观察肺组织形态学改变.结果Ⅱ组肺气体交换功能[PO2为(11.33±1.14)kPa(kPa=7.5 mm Hg)]、W/D(7.31±0.59)及BALF内PMN计数(0.39±0.05)情况显著优于Ⅰ组[(6.64±0.90)kPa、5.79±0.44、6.07±0.71],Ⅱ组MPO活性低于Ⅰ组,形态结构改变则明显优于Ⅰ组.结论灌洗液中加入利多卡因能明显改善肺气体交换功能,减少肺泡腔和间质内中性粒细胞浸润,减轻肺组织形态结构改变.     

部分液体通气与吸入NO对急性肺损伤动物疗效的对比研究

目的对肺灌洗(Lavage)诱导的急性肺损伤(ALI)家猪实施以氟碳(PFC)为媒介的部分液体通气(PLV)及吸入20ppm的一氧化氮(NO),比较二者对肺气体交换及血液动力学的影响.方法24头健康家猪,麻醉后经气管导管肺内以生理盐水反复灌洗,直至动脉氧分压(PaO2)<100mmHg达1h,记录气体交换及血液动力学各参数作为急性肺损伤的基础值.随机分为PLV组、NO组及对照组,PLV组肺内灌以相当于肺功能余气量(30ml/kg)的PFC,然后以普通呼吸机行常规气体通气,补充PFC4ml·kg-1·h-1以弥补蒸发损失;NO组吸入20ppmNO,对照组不给予其它治疗,各组每小时记录气体交换及血液动力学各参数的变化.结果PLV组实施PLV1h后,PaO2即从ALI时的(53±11)mmHg升高至(142±133)mmHg,4h后达(318±109)mmHg,与ALI时比较差异有显著性(P＜0.01),亦显著高于对照组(P＜0.05).实施PLV1h后Qs/Qt从ALI时的(57±9)%降至(42±13)%,4h后降至(26±10)%,较ALI时差异有显著性(P＜0.01),并于2h后显著低于对照组(P＜0.05).NO组的MPAP在整个实验过程中显著低于对照组(P＜0.01).NO组吸入NO1h后,PaO2即呈上升趋势,4h后从ALI时的65±14升至(114±36)mmHg,与对照组比较差异有显著性(P＜0.05).同时肺内分流(Qs/Qt)及肺泡-动脉氧压差(AaDO2)降低.MAP及体循环血管阻力(SVR)与对照组比较无显著性改变.结论以氟碳为媒介的部分液体通气及吸入20ppm的NO均能有效的改善ALI动物肺气体交换.吸入NO能显著降低MPAP,而PLV更能显著的升高PaO2.     

右外侧小切口行法洛四联症根治术中的肺保护

目的加强右外侧小切口行法洛四联症根治术中的肺保护.方法58例法洛四联症的病儿中,行右外侧小切口矫治术加肺保护组18例,行常规正中剖胸矫治术的对照组40例.肺保护组术中肺动脉灌注低温保护液.术中和术后监测血流动力学、呼吸功能(氧指数、肺泡-动脉血氧分压差、气道峰压)和血浆脂质过氧化物MDA指标.结果肺保护组呼吸机辅助通气时间(24.1±15.3) h和ICU监护时间(2.5±1.4) d均短于对照组呼吸机辅助通气时间(30.1±15.4) h和ICU监护时间(3.9±2.0) d(P＜0.05).两组术后气道峰压差异无显著性(P＞0.05),而术后24 h和48 h的肺泡-动脉血氧分压差肺保护组显著低于对照组(P＜0.05),术后12 h和24 h氧指数肺保护组显著高于对照组(P＜0.05);术后24 h和48     

部分液体通气用于家猪肺灌洗诱导的急性肺损伤的疗效观察

目的 对肺灌洗诱导的急性肺损伤家猪实施以氟碳（PFC）为媒介的部分液体通气（PLV）,观察其对肺气体交换及血液动力学的影响。方法 16头体重为（25±3）kg的健康幼猪,麻醉后经气管导管注入生理盐水反复肺内灌洗,直致动脉氧分压（PaO2）<100 mm Hg达1h,记录肺气体交换及血液动力学各参数作为肺损伤基值。随机分为PLV组及对照组。对照组以呼吸机仅行常规机械通气,PLV组动物经气管导管肺内灌以30ml/kgPFC,然后以与对照组同样的呼吸参数行机械通气,每小时补充4ml/kg的PFC以弥补蒸发损失量。每小时记录各肺气体交换及血液动力学参数的变化。结果 实施PLV1h后,PaO2即从 ALI的（53.2±10.81）mm Hg升高至（14.07±133.42）mmHg,4h后高达（318.51±108.97）mm Hg,显著高于对照组。实施PLV1h后Qs/Qt从ALI的57.10％±8.88％降至42.3％±12.78％,4h后降至26.05％±10.56,并于2h后显著低于对照组。与对照组比较,PLV组血液动力学无显著性的改变。结论 以PFC为媒介的PLC可明显地改善急性肺损伤的肺气体交换,对血液动力学无明显影响。     

白细胞过滤不能减轻心脏瓣膜置换术病人炎症反应

目的　探讨循环血白细胞过滤对体外循环(CPB)心脏瓣膜置换术病人炎症反应的影响。方法　连续选取5 2例行心脏瓣膜置换术病人,随机分成试验组和对照组。试验组在动脉旁路上并行安装PallLG 6白细胞滤器,在心肺复灌前5～10min至CPB结束开放滤器;对照组仅用常规动脉滤器。结果　白细胞过滤可显著降低心肺复灌前循环血总白细胞、中性粒细胞和单核细胞计数;白细胞介素6在各观察时点组间差异无统计学意义;白细胞介素8在心脏复灌前和复灌15min试验组分别为(3.7±2. 8)pg/ml和(13.8±2.0 0 )pg/ml显著高于对照组(1.6±1.1)pg/ml和(3. 5±3.5 )pg/ml,P分别为<0.0 1和<0 .0 5 ;肿瘤坏死因子α在心脏复灌前试验组和对照组分别为(11.1±2. 9)pg/ml和(8.9±3.9)pg/ml,P <0. 0 5 ;各观察时点试验组与对照组补体C3 水平差异无统计学意义;两组病人术后静脉使用抗生素无差异。结论　再灌注前及再灌注早期循环血白细胞过滤不能减轻心脏瓣膜置换术病人的炎症反应     

己酮可可碱在肺缺血-再灌注损伤中的作用

目的　探讨己酮可可碱 (PTX)对肺缺血 -再灌注损伤的保护作用。　方法　 72只大鼠随机分为 3组 ,每组 2 4只。 组 :未行缺血及再灌注处理 ; 组 :行左肺缺血和再灌注处理 ; 组 :行左肺缺血和再灌注处理 ,并给予己酮可可碱。采用在体肺温缺血 -再灌注损伤的模型 ,于缺血 45分钟、再灌注 1小时、2小时和 4小时进行动脉血气分析、肺组织含水量、支气管肺泡灌洗液白蛋白含量、血浆和左肺组织丙二醛、左肺组织和支气管肺泡灌洗液髓过氧化物酶(MPO)活性测定。　结果　 组再灌注 2小时和 4小时动脉血氧分压显著降低 ,各时间点左肺含水量、支气管肺泡灌洗液白蛋白含量、血浆丙二醛、左肺组织、支气管肺泡灌洗液中髓过氧化物酶均显著升高 ,PTX可改善上述指标变化。结论　 PTX通过抑制中性粒细胞肺内聚集 ,减轻肺血管内皮细胞损伤程度 ,而防止损伤的发展     

肺泡巨噬细胞活化在急性坏死性胰腺炎大鼠肺损伤中的作用

目的　探讨肺泡巨噬细胞活化在急性坏死性胰腺炎 (ANP)肺损伤中的作用。　方法30只成年SD大鼠随机分为正常对照组、ANP后 1、3、6、12h组 ,每组 6只。逆行性胰胆管注射 3%牛磺酸钠建立ANP大鼠模型 ,正常对照组大鼠自胆胰管内逆行注入生理盐水。经支气管肺泡灌洗获取肺泡巨噬细胞 ,检测支气管肺泡灌洗液中蛋白含量、肺组织髓过氧化物酶 (MPO)水平、肺泡巨噬细胞分泌肿瘤坏死因子α(TNFα)及一氧化氮 (NO)水平。以反转录聚合酶链反应 (RT PCR)法测定肺泡巨噬细胞TNFαmRNA、诱导型一氧化氮合酶 (iNOS)mRNA表达情况。行肺、胰腺组织病理学检查并评分。结果　ANP大鼠肺损伤随着病情进展而逐渐加重 ;肺组织MPO及支气管肺泡灌洗液中蛋白含量逐渐升高 ,12h达最高值 ,分别为 (10 78± 0 5 8)U/g和 (2 0 11 0± 10 5 5 ) μg/ml;肺泡巨噬细胞分泌TNFα、NO水平逐渐升高 ,至 6h达到高峰 ,分别为 (16 2 4 2± 149 2 )pg/ml和 (88 8± 6 5 ) μmol/L ,12h又回落。ANP发生后 ,肺泡巨噬细胞TNFαmRNA、iNOSmRNA的表达情况与TNFα、NO的变化趋势相似。ANP大鼠各组指标与正常对照组相比差异均有显著性意义 (P <0 0 5 )。组织学评分结果表明 ,随着胰腺损伤的加重肺损伤也逐渐加重。肺泡巨噬细胞TNFαmRNA、iNOSmRNA     

盐酸戊乙奎醚不同给药方式对大容量肺灌洗患者术后呼吸动力学的影响

目的 探讨盐酸戊乙奎醚不同给药方式对大容量肺灌洗患者术后呼吸动力学的影响.方法 择期行左全肺大容量肺灌洗术患者40例,采用完全随机分组法分成静脉注射盐酸戊乙奎醚组(A组)与雾化吸入盐酸戊乙奎醚组(B组),每组20例.灌洗开始前30 min A组静脉注射盐酸戊乙奎醚0.01 mg/kg,B组给予灌洗侧肺雾化吸入盐酸戊乙奎醚0.01 mg/kg(用生理盐水稀释至5 ml),15 min.记录插管后(T0)、灌洗开始前(T1)、灌洗结束(T2)及灌洗结束后30 min(T3)、60 min(T4)、90 min(T5)、120 min(T6)灌洗侧肺气道峰压(peak airway pressure,Ppeak)及肺动态顺应性(lung dynamic compliance,Cdyn).统计灌洗液总量、灌洗液残留量、灌洗时间,收集术中患者口腔分泌物.结果 与T0比较,两组患者T1时Cdyn[A组(30.3±1.9) ml/cmH2O,B组(30.5±1.8) ml/cmH2O(1 cmH2O=0.098 kPa)]均明显升高,Ppeak[A组(18.8±1.2) cmH2O,B组(17.9±1.4) cmH2O)]均明显降低(P＜0.05).T4、T5时与A组比较,B组Cdyn[(22.8±1.7)、(26.8± 1.7) ml/cmH2O)]明显升高,Ppeak[(25.2±1.5)、(20.2±1.2) cmH2O)]明显降低(P＜0.05).结论 大容量肺灌洗术患者灌洗侧肺术前雾化吸入戊乙奎醚有利于患者术后Cdyn的恢复,能改善患者通气,缩短术后呼吸力学指标的恢复时间.     

Non-invasive ventilation in surgical patients in a district general hospital

We have retrospectively audited the use of non-invasive ventilation (NIV) in surgical patients. We analysed the case notes of 38 surgical patients who received NIV over a 9-month period. Twenty-three patients received NIV following emergency surgery, eight after elective surgery, and seven did not have an operation. Co-morbidity was common. The commonest reasons for starting NIV were chest infection, acute respiratory distress syndrome and pulmonary oedema. NIV was often only one aspect of treatment in surgical patients with complex medical problems. With intensive support from the critical care outreach team, NIV can be safely delivered on a surgical ward, and may sometimes prevent intensive care unit admission. Use of NIV on the intensive care unit may obviate the need for tracheal intubation in some patients. In very ill surgical patients with a poor prognosis, NIV was frequently used as the ceiling of respiratory support.     

Principles of artificial ventilation

The application of intermittent positive pressure ventilation (IPPV) during the 1952 Copenhagen polio epidemic led to the development of the world's first intensive care unit. The requirement for ventilatory support is the most common indication for intensive therapy unit (ITU) admission and is a defining feature of the specialty. Ventilator technology continues to develop and there are many ways to deliver IPPV. The variety of modes of ventilation is increasingly complex and expanding, without evidence that any one mode is associated with improved outcome. Ventilatory support is part of the treatment for a range of conditions including acute respiratory failure, raised intracranial pressure (ICP) and circulatory shock. Ventilator-associated lung injury is reduced by using low tidal volumes and limiting plateau airway pressure to less than 30 cmH₂O. Prolonged artificial ventilation has an associated morbidity and mortality and thus should be reviewed by an expert clinician on a daily basis. Weaning aims to identify those patients who will be able to breathe spontaneously. Protocols exist to facilitate timely extubation without the need for re-intubation.     

单肺通气时机械通气模式的研究进展

背景 单肺通气(one lung ventilation,OLV)实施过程中最常见的并发症是低氧血症,也是麻醉医师遇到的最严重的挑战. 目的 近来研究表明OLV本身能够引起低氧血症和急性肺损伤(acute lung injury,ALI).因此,如何实施OLV时机械通气模式,降低肺内分流率(pulmonary shunt fraction,Qs/Qt)、预防低氧血症一直是临床研究的热点. 内容 综述提高吸入氧分数(fraction of inspiration O2,FiO2)、控制通气模式、高频通气(high frequency ventilation,HFV)、潮气量(tidal volume,Vt)、反比通气、部分液体通气(partial liquid ventilation,PLV)、持续气道正压通气(continuous positive airway pressure,CPAP)、呼气末正压通气(positive end-expiratory pressure,PEEP)等通气模式,以及实施联合多种模式的保护性肺通气策略. 趋向 综合运用多种预防OLV期间低氧血症的通气模式取得良好的效果,但应针对患者和手术情况制定OLV时机械通气模式.     

A clinical trial of volume- versus pressure-controlled intraoperative ventilation during laparoscopic bariatric surgeries

BackgroundIntra-operative ventilation is often challenging in patients with morbid obesity undergoing bariatric surgery.ObjectivesTo test the noninferiority of pressure-controlled ventilation (PCV) to volume-controlled ventilation (VCV) in respiratory mechanics.SettingBariatric Surgery Center, Iran.MethodsIn a randomized open-labeled clinical trial, 66 individuals with morbid obesity undergoing laparoscopic bariatric surgeries underwent intraoperative ventilation with either PCV or VCV. The measurements taken were peak and mean airway pressures (H₂O), partial pressure of arterial oxygen (PaO₂), partial pressure of arterial carbon dioxide (PaCO₂) and end-tidal carbon dioxide (CO₂). We additionally collected pulse-oximetric oxygen saturation, inspiratory concentration of oxygen (FiO₂), and hemodynamic variables. Data were analyzed with repeated measures over the time of intubation, after peritoneal insufflation, and every 15 minutes, thereafter up to one hour.ResultsPCV mode was successful to sustain adequate ventilation in 97% of the patients, which was similar to the 94% success rate of the VCV mode. Peak airway pressure increased 6 cmH₂O and end-tidal CO₂ rose by 5 mm Hg after abdominal insufflation in both groups (P = .850 and .376). Alveolar-arterial oxygen gradient similarly increased within 30 minutes after tracheal intubation both in PCV and VCV groups, with small trend of being higher in the VCV group. The ratio of dead space to tidal volumes (VD/VT) did not have a meaningful change (P = .724).ConclusionPCV was noninferior to VCV during laparoscopic bariatric surgery. Either mode of ventilation could be alternatively used during the anesthesia care of these patients.     

Principles of artificial ventilation

The application of intermittent positive pressure ventilation (IPPV) during the 1952 Copenhagen polio epidemic led to the development of the world’s first intensive care unit. The requirement for ventilatory support is the most common indication for intensive therapy unit (ITU) admission and is a defining feature of the specialty. Ventilator technology continues to develop and there are many ways to deliver IPPV. The variety of modes of ventilation is increasingly complex and expanding, without evidence that any one mode is associated with improved outcome. Ventilatory support is part of the treatment for a range of conditions including acute respiratory failure, raised intracranial pressure (ICP) and circulatory shock. Ventilator-associated lung injury is reduced by using low tidal volumes and limiting plateau airway pressure to less than 30 cmH₂O. Prolonged artificial ventilation has an associated morbidity and mortality and thus should be reviewed by an expert clinician on a daily basis. Weaning aims to identify those patients who will be able to breathe spontaneously. Protocols exist to facilitate timely extubation without the need for re-intubation.     

不同通气模式对单肺通气影响的Meta分析

目的 采用Meta分析的方法评价压力控制通气(pressure controlled ventilation,PCV)与容量控制通气(volume controlled ventilation,VCV)对术中单肺通气(one lung ventilation,OLV)患者呼吸力学及循环的影响. 方法 检索PubMed、Embase、Cochrane图书馆,检索时间从建库至2016年2月.收集术中OLV使用PCV与VCV的临床随机对照试验(randomizedcontrolled trim,RCT).采用Cochrane协作网系统评价法评价纳入文献的质量,采用RevMan 5.0软件对收集的患者资料进行Meta分析评价. 结果 共纳入14项研究,包括964例患者,其中PCV组480例,VCV组484例.与VCV组比较:在开胸前双肺通气时(T1),PCV组气道平均压(mean airway pressure,Pmean)比值比(odds ratio,OR)[0R=-0.22,95％CI(-0.42,-0.01),P＜0.05]较低;OLV时(T2),PCV组气道峰压(peak airway pressure,Ppeak)[加权均数差(weighted mean difference,WMD)=-1.37,95％CI(-1.69,-1.05)]及气道平台压(pause pressure,Plateau)较低[WMD=-0.29,95％CI(-0.51,-0.07)],而PaO2高[WMD=0.52,95％CI(0.08,0.95)];关胸后双肺通气时(T3),PCV组Ppeak较低[WMD=-0.63,95％CI(-1.09,0.17)]. 结论 与VCV比较,OLV期间PCV可提供较低的气道压,可能是一种较好的通气模式.     

Respiration: ventilation

Anaesthetists and intensivists directly manipulate pulmonary function, in particular ventilation. A sound and thorough working knowledge of applied pulmonary physiology of ventilation is essential to the safe conduct of anaesthesia and intensive care medicine. This article discusses pulmonary anatomy, gas exchange in the lung, the mechanics of ventilation, airway resistance, elastance and compliance, the work of breathing and ventilation/perfusion relationships including hypoxic pulmonary vasoconstriction. General anaesthesia has profound effects on the respiratory system including the ventilatory response to hypercapnia and hypoxia, upper airway muscle function, lung volumes and ventilation/perfusion matching. Many surgical procedures are facilitated by one-lung ventilation. When utilizing one-lung ventilation a key aim for the anaesthetist is to maintain adequate alveolar ventilation while minimizing the amount of shunt through the non-ventilated lung. A detailed understanding of one-lung ventilation is therefore vital if a logical approach to management is to be adopted.     

Pressure-controlled ventilation is superior to volume-controlled ventilation with a laryngeal mask airway in children

Background:  This prospective, randomized, crossover study had two purposes: first, to determine whether pressure-controlled ventilation (PCV) is safer than volume-controlled ventilation (VCV) by preventing gastric insufflation in children ventilated through an laryngeal mask airway (LMA); second, to assess whether the measurement of LMA leak pressure (P_leak) is useful for preventing leakage during positive pressure ventilation (PPV).
Methods:  Forty-one, 2 to 15-year-old children underwent general anesthesia with an LMA. The expiratory valve was set at 30 cmH₂O and P_leak was measured using constant gas flow. Children were randomly ventilated using PCV or VCV for 5 min in order to reach a P_ETCO₂ not exceeding 45 mm Hg, and then they were ventilated with the alternative mode. If the target P_ETCO₂ could not be obtained in one mode, we switched to the other. If both modes failed, children were intubated. Tidal volumes, P_ETCO₂ and airway pressures were noted and compared between modes. Gastric insufflation was checked by epigastric auscultation.
Results:  PCV provided more efficient ventilation than VCV, as targeted P_ETCO₂ was obtained without gastric insufflation using PCV in all cases except one, whereas VCV failed in three cases. No gastric insufflation occurred when ventilating below peak.
Conclusions:  These findings suggest that in the age group studied, PCV is more efficient than VCV for controlled ventilation with a laryngeal mask. Gastric insufflation did not occur with this mode.