气道压力释放通气应用于急性肺损伤/急性呼吸窘迫综合征患者的研究

目的评价气道压力释放通气(airway pressure release ventilation,APRV)对急性肺损伤(acute lung injury,ALI)/急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)患者的疗效,评估其对患者呼吸机相关性肺损伤(Ventilator-Induced Lung Injury,VILI)程度,并探讨可能的机制。方法采用前瞻性研究方法,入组患者随机分为APRV组、小潮气量肺保护通气组。描记肺准静态压力-容积曲线(pressure-volume curve,P-V曲线),并据此设置呼吸机参数,通气24h、48h观察效果。结果两组患者氧合明显改善,血流动力学指标无明显变化,APRV组Pmean明显高于SIMV+PEEP组,准静态P-V曲线三角区Pflex容积(Vdelta)增加明显,血清SP-D浓度呈升高趋势。结论 APRV应用于急性肺损伤/急性呼吸窘迫综合征患者,相对于小潮气量肺保护性通气策略,氧合改善、呼吸力学类似;较高的平均气道压,能更有效地肺复张,未对血流动力学产生影响,但加重了肺损伤,导致呼吸机相关性肺损伤。     

小潮气量加叹气通气对外源性和内源性急性肺损伤疗效的对比研究

目的对比研究小潮气量加叹气通气对外源性和内源性急性肺损伤（ALI）的治疗效果及对血流动力学的影响。方法 20例ALI患者分为肺外源性组8例和肺内源性组12例。两组患者均在小潮气量通气及适宜的呼气末正压基础上,在镇静及肌松条件下,行叹气法肺复张。结果通气后两组患者的氧合状态明显改善,静态顺应性明显提高,肺外源性组升高较为明显;通气前后两组PaCO2、pH、心率、平均动脉压及中心静脉压变化无统计学差异,两组患者均未发生胸、纵隔气肿、皮下气肿等并发症。结论小潮气量加叹气通气能明显改善患者的氧合状态及胸肺顺应性,安全易行,对血流动力学干扰较小,对肺外源性ALI效果更明显。     

微创二尖瓣置换术中单肺通气策略

目的 探讨微创二尖瓣置换术中不同肺通气策略对呼吸功能和呼吸力学的影响。方法 纳入60例择期行微创二尖瓣手术的患者,根据术中采用不同的单肺通气策略分为两组：容量控制性单肺通气组（60例）及保护性单肺通气+肺复张组（60例）。两组患者均采用双腔气管插管进行单肺通气,容量控制性通气组采用传统容量控制性通气策略（6-8ml/kg）;保护性肺通气组采用低潮气量(5 ml/kg)+5cm H2O PEEP肺通气+肺复张技术。记录两组患者单肺通气前、体外循环停用后15分钟、30分钟以及术后双肺通气四个时间点的气道峰压、气道阻力、胸肺顺应性,氧合指数,以及术后低氧血症的发生,机械通气时间,ICU时间,肺不张和肺部感染等的发生情况。结果 与容量控制性单肺通气组相比较, 保护性单肺通气+肺复张组患者在CPB及双肺通气时氧合指数明显升高（P<0.01）;CPB后15min、30min时肺顺应行明显增加,气道阻力、气道峰明显降低,（P<0.05）,保护性单肺通气+肺复张组患者术后低氧血症、肺不张及延迟拔除气管导管的发生率均明显降低（P<0.05）;肺部感染两组比较无统计学意义(P=0.68)。结论：微创二尖瓣手术中采用低潮气量(5 ml/kg)+5cm H2O PEEP+肺复张保护性肺通气策略是安全可行的,不仅可明显提高肺顺应性,降低围术期低氧血症的发生,还可以减少术后机械通气时间及ICU时间,降低肺部并发症的发生。     

两种肺复张策略治疗先心病术后呼吸窘迫综合征的疗效比较

目的比较两种肺复张策略(LRM)治疗全身麻醉先心病术后呼吸窘迫综合征(ARDS)患儿的疗效。方法选取2012年12月~2014年12月我院收治的先心术后ARDS患儿40例作为研究对象,将其随机分为控制性肺膨胀(SI)组和呼气末正压递增(IP)组,各20例。在机械通气(24~48 h)内分别应用SI和PI进行LRM,并比较两组患儿治疗前后的氧合指数、肺顺应性、心率、平均动脉压、中心静脉压的变化。结果 LRM前后患儿的氧合指数、肺顺应性比较,差异均有统计学意义(P0.05);组间比较平均动脉压(MAP)、中心静脉压(CVP)及心率变化,差异无统计学意义(P0.05);复张后MAP、CVP及心率均很快恢复到复张前水平。结论 LRM对先心术后ARDS患儿的早期应用,可提高其肺顺应性和氧合指数。     

肺复张策略对防止纤支镜治疗后肺泡塌陷的作用观察

目的:探讨肺复张策略对防止纤支镜治疗后肺泡塌陷的效果.方法:将机械通气需纤维支气管镜检查的60例患者随机分为治疗组及对照组,治疗组采用肺复张策略,对照组行常规机械通气.比较2组动脉血气和氧代谢、血流动力学指标.结果:治疗组纤维支气管镜检查前PaO2(114.25±24.75) mmHg,PaCO2 (32.56±7.73) mmHg,肺复张30 min后PaO2(112.12±20.41) mmHg,PaCO2(31.56±6.63) mmHg,PaO2及PaCO2肺复张前后无明显差异(均P ＞0.05);对照组纤维支气管镜检查前PaO2(116.11±26.53) mmHg,PaCO2(30.12±5.53) mmHg,常规机械通气30 min后PaO2(86.21±16.23)mmHg,PaCO2(31.56±6.63) mmHg,常规机械通气治疗前后PaO2有显著性差异(P＜0.01),而PaCO2无明显差异(P＞0.05).结论:支气管镜检查后采用肺复张策略能复张塌陷的肺泡,减少低氧血症对机体的危害,并对血流动力学影响较小.     

急性呼吸窘迫综合征肺复张时机探讨

目的:在急性呼吸窘迫综合征(ARDS)治疗过程中,探索肺复张的时机。方法:选取3例并发ARDS的甲型H1N1流感患者,设置呼吸机基本参数:通气模式压力调节-容量控制(PRVC),潮气量(Vt)6～8mL/kg,较高呼气末正压(PEEP),根据氧合目标是否达到,平台压是否急速增加和>40cmH2O,是否出现CO2潴留,决定是否使用肺复张。结果:患者均存活,均未出现气胸,行肺复张1例,颈部出现皮下气肿,在肺复张过程中需要用血管活性药物保证血压稳定。结论:ARDS时,如果在增加PEEP后,PaO2有改善,平台压<30cmH2O(肥胖者<40cmH2O),应保持在这个水平直至持续30h。肺复张动作的适应症是:ARDS时,PEEP已经达到较高水平仍然存在的顽固性低氧血症。肺复张动作的时机是:如果PEEP已经达到较高水平,氧合仍不稳定,平台压越来越高,降低潮气量不能阻止平台压增加,特别是PaCO2突然增加,血流动力学尚稳定。去复张后,调整PEEP可以达到氧合目标的患者,不再作肺复张操作。     

肺开放/复张的机械通气策略的研究进展

广泛性、小灶性肺不张和肺泡萎陷是急性肺损伤(acute lung injury,ALI)/急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)的主要病理改变,也是引起肺容量减少、肺内分流(QS/QT)增加、顺应性下降和顽固性低氧血症的主要原因.机械通气能有效纠正缺氧,减少肺损伤,是治疗ALI/ARDS的重要措施,但也可因正压通气和肺泡反复萎陷/复张产生的剪切力,引起机械通气相关性肺损伤(ventilator associated lung injury,VALI),包括气压伤、容积伤、生物伤等.针对VALI致伤因素,一系列保护性肺通气策略(lung protective ventilatory strategy,LPVS)被提出,本文就近年来肺开放/复张的机械通气策略的研究进展作一综述.     

不同模式通气治疗对颅脑损伤合并ARDS患者的影响

目的探讨不同通气模式在颅脑损伤合并急性呼吸窘迫综合征(ARDS)患者治疗中的应用效果。方法将62例颅脑损伤合并ARDS患者纳入研究对象,在统一初始通气治疗6~8h后,随机分为Ⅰ、Ⅱ两组,每组31例,分别再给予不同机械通气模式实验,Ⅰ组采用同步间歇指令通气(SIMV)+压力支持通气(PSV)模式,而Ⅱ组采用适应性支持通气(ASV)+肺复张策略(LRM)模式;实验期分别对两组血气分析指标、呼吸力学参数及相关血流动力学指标进行观察记录。结果实验过程中,在相同PEEP水平下,两组间在MAP、Pa CO2及PH值方面比较差异无显著性(P0.05);而采用ASV+LRM模式的Ⅱ组患者在RR、CVP、PIP、Pplat及Qs/Qt水平较Ⅰ组患者降低(P0.05),在Pa O2/Fi O2、Pa O2则较Ⅰ组患者增高(P0.05)。结论在颅脑损伤合并ARDS患者通气治疗中,ASV+LRM模式与SIMV模式对患者的血流动力学影响相同,但ASV+LRM模式下人机协调性好,在预防肺气压伤及改善氧合方面具有优势。     

PEEP肺复张术治疗心脏手术后早期ALI—ARDS（附20例报告）

目的观察应用呼气末正压（PEEP）递减方式进行肺复张治疗心脏术后早期急性肺损伤—急性呼吸窘迫综合征（ALI-ARDS）的疗效。方法20例符合ALI-ARDS诊断标准并接受机械通气的心脏术后患者,将PEEP逐渐增加至20cmH2O,吸气压35cmH2O,呼吸频率为12次／min并保持2min,以后以2cmH2O／5min递减,直至恢复到肺复张术前PEEP水平,观察患者生命体征、肺静态顺应性、氧合指数以及血流动力学变化。结果所有患者均能够较好耐受肺复张术,在肺复张后氧合指数明显高于术前（P〉0．05）,且能够保持2h。患者血流动力学以及肺静态顺应性治疗前后均无显著差异（P〉0．05）。结论心脏术后早期发生ALI—ARDS患者,采用PEEP递减进行肺复张可以有效地改善肺氧合功能,同时对血流动力学影响较小。     

喉罩联合不同压力肺复张肺保护性通气策略在老年患者全麻腹腔镜手术中的应用

目的探讨喉罩联合不同压力肺复张肺保护性通气策略在老年患者全麻腹腔镜手术中的应用。方法根据实验入选要求筛选合乎条件的自愿参加实验的手术患者,随机分为两组:对照组(C):喉罩联合常规保护性通气〔潮气量6 ml/kg,最佳呼气末正压(PEEP)<5 cmH 2O〕,实验组(E):喉罩联合驱动性压力肺复张压力通气(潮气量6 ml/kg,PEEP 5~10 cmH 2O)。比较两组全麻恢复期各组患者的血流动力学、呼吸功能指标、术后的肺部并发症(PPCs)及全身并发症发生情况。结果E组老年患者在全麻恢复期中各个血流动力学及呼吸功能指标皆优于C组。结论对于老年患者而言,全麻手术中采用喉罩联合驱动性压力肺复张压力通气肺复张肺保护性通气策略有提高肺功能恢复和降低并发症的可能。     

Prone position augments recruitment and prevents alveolar overinflation in acute lung injury

Rationale: Mechanical ventilation in the prone position may be an effective means of recruiting nonaerated alveolar units and minimizing ventilation-induced lung injury. Objectives: To evaluate and quantify regional lung volume alterations when patients with lobar or diffuse acute lung injury (ALI) were turned prone after a recruitment maneuver. Methods: In 21 patients with ALI, a recruitment maneuver was applied in the supine position followed by a multislice spiral computed tomography (CT) scan; then, patients were turned prone and a second CT scan was performed. Main Results: Both the recruitment maneuver and prone position resulted in improved oxygenation in patients with lobar ALI. Prone position also resulted in increased respiratory system compliance and decreased Pa(CO(2)) in lobar ALI. In lobar ALI, the proportion of overinflated and nonaerated areas declined, whereas the proportion of well-aerated areas increased in the prone position. The decrease in overinflated areas was observed mainly in the ventral areas. The dorsal regions showed a decrease in nonaerated areas and an increase in well-aerated areas. Recruitment maneuver and prone position improved oxygenation but had no effect either on Pa(CO(2)) or on the respiratory system compliance of patients with diffuse ALI. These patients responded to prone position with a decrease in nonaerated areas. Conclusions: Prone position recruited the edematous lung further than recruitment maneuvers and reversed overinflation, resulting in a more homogeneous distribution of aeration. The effects of the prone position were more pronounced in patients with lobar ALI.     

肺复张策略对肺内、外源性损伤大鼠模型的肺保护作用

目的探讨肺复张策略对肺内、外源性损伤大鼠模型的肺保护作用。方法清洁级SD大鼠60只,雌雄各半,随机均分为6组;空白对照组(K组)、肺复张对照组(F组)、肺内源性损伤组(AN组)、肺复张内源性损伤组(RN组)、肺外源性损伤组(AW组)、肺复张外源性损伤组(RW组)。采用逐步提高压力的控制性膨肺的肺复张策略。机械通气4 h后,使用酶联免疫分析法(ELISA法)检测大鼠肺泡灌洗液(BALF)中Fas、TNF-α、SP-A的浓度及肺损伤Smith评分。结果 BALF中的Fas、TNF-α、SP-A浓度:与AN组比较,RN组Fas和TNF-α水平较低,SP-A水平较高(P0.05);与AW组比较,RW组的Fas和TNF-α水平较低,SP-A水平较高(P0.05);与RN组比较,RW组的Fas和TNF-α水平低,SP-A水平较高(P0.05)。肺损伤评分,RN组和RW组肺损伤评分低于AN组和AW组,且RW组低于RN组(P0.05)。结论肺复张策略可以减轻肺组织病理损伤,增加肺内SP-A水平并降低Fas和TNF-α水平;对肺内、外源性损伤大鼠模型具有肺保护作用。肺复张策略对肺外源性急性肺损伤的疗效优于肺内源性急性肺损伤。     

A decremental PEEP trial for determining open-lung PEEP in a rabbit model of acute lung injury

A positive end-expiratory pressure (PEEP) above the lower inflection point (LIP) of the pressure-volume curve has been thought necessary to maintain recruited lung volume in acute lung injury (ALI). We used a strategy to identify the level of open-lung PEEP (OLP) by detecting the maximum tidal compliance during a decremental PEEP trial (DPT). We performed a randomized controlled study to compare the effect of the OLP to PEEP above LIP and zero PEEP on pulmonary mechanics, gas exchange, hemodynamic change, and lung injury in 26 rabbits with ALI. After recruitment maneuver, the lavage-injured rabbits received DPTs to identify the OLP. Animals were randomized to receive volume controlled ventilation with either: (a) PEEP = 0 cm H2O (ZEEP); (b) PEEP = 2 cm H2O above OLP (OLP + 2); or (c) PEEP = 2 cm H2O above LIP (LIP + 2). Peak inspiratory pressure and mean airway pressure were recorded and arterial blood gases were analyzed every 30 min. Mean blood pressure and heart rate were monitored continuously. Lung injury severity was assessed by lung wet/dry weight ratio. Animals in OLP + 2 group had less lung injury as well as relatively better compliance, more stable pH, and less hypercapnia compared to the LIP + 2 and ZEEP groups. We concluded that setting PEEP according to the OLP identified by DPTs is an effective method to attenuate lung injury. This strategy could be used as an indicator for optimal PEEP. The approach is simple and noninvasive and may be of clinical interest.     

肺复张手法与单纯小潮气量机械通气治疗急性呼吸窘迫综合征

目的观察肺复张手法对急性呼吸窘迫综合征（ARDS）患者的治疗作用,并与小潮气量辅助／控制通气方式比较。方法20例ARDS患者,平均年龄（58±8）岁。分为两组：（1）试验组10例：采用肺复张手法机械通气;（2）对照组10例：采用小潮气量辅助／控制通气（潮气量设为6ml／kg,体重为标准体重）。分别观察两组患者上机后0、48和72h的氧合指数、中心静脉压、镇静药物的用量以及28d的病死率和并发症等。结果试验组与对照组比较,氧合指数48h分别为（297±15）及（211±12）cmH20,72h为（305±18）及（247±16）cmH2O;带机时间缩短为（15±2）及（21±2）d;48h中心静脉压分别为（14．1±0．5）及（19．2±1．0）cmH2O,72h分别为（11．3±0．8）及（17．1±1．1）cmH2O。28d病死率和并发症的发生率两组比较差异无统计学意义（P〉0．05）。结论肺复张手法比单纯小潮气量容量控制／辅助通气具有改善氧合迅速、带机时间短、血流动力学稳定及所用镇静药物少等优点。     

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...     

Changes in lung volume and work of breathing: A comparison of two variable-flow nasal continuous positive airway pressure devices in very low birth weight infants

Variable flow nasal continuous positive airway pressure (VF-NCPAP) recruits lung volume more effectively and reduces work of breathing (WOB) compared to constant-flow NCPAP (CF-NCPAP) in very low birth weight (VLBW) infants. Because different VF-NCPAP devices have somewhat different flow patterns, whether different VF-NCPAP devices function similarly is unknown. We compared two VF-NCPAP devices: the Infant Flow trade mark (EME, Ltd.) and the Arabella(R) (Hamilton Medical) to assess whether lung volume recruitment and WOB were similar in VLBW infants requiring NCPAP. Eighteen infants <1,500 g were studied on both NCPAP devices applied in random order. All infants required NCPAP for mild respiratory distress. Calibrated DC-coupled respiratory inductance plethysmography (RIP) was used to assess lung volume changes. NCPAP was first increased to 8 cmH(2)O to allow comparable recruitment in all infants, and then was slowly decreased to 6, 4, and 0 cmH(2)O, with data collection at each level. Mean birth weight (+/-SD) was 1,107 +/- 218 g, gestational age was 27.9 +/- 2.0 weeks, weight at study was 1,092 +/- 222 g, and age at study was 4.6 +/- 4.3 days. There were no differences in lung volume recruitment overall or at any NCPAP level (P = 0.943). No differences were found in either inspiratory WOB (P = 0.468) or in resistive WOB (P = 0.610) between devices. Compliance, tidal volume, respiratory rate, and minute ventilation were also similar. Despite differences in flow characteristics between the two VF-NCPAP devices we studied, lung volume recruitment and WOB were similar.     

急性呼吸窘迫综合征小潮气量肺保护通气策略的预后分析

目的：探讨急性呼吸窘迫综合征应用小潮气量肺保护性通气策略的预后情况。方法：急性呼吸窘迫综合征患者80例根据入住病床单双号分为治疗组40例与对照组40例,两组都给予常规治疗,治疗组采用小潮气量辅助/控制机械通气治疗,对照组采用肺复张/机械通气治疗。结果：两组治疗前Pa02、Pa02/Fi02和PaC02对比无明显差异,治疗后各时间点Pa02和Pa02/Fi02值明显上升,PaC02值显下降(P<0.05),同时组间对比无统计学差异。治疗组的机械通气时间与住院时间都明显少于对照组,差异有统计学意义(P<0.05)。两组都无死亡患者,治疗组呼吸机相关肺炎、恶心呕吐和肺出血并发症发生率明显低于对照组(P<0.05)。结论：小潮气量肺保护性通气策略应用于呼吸窘迫综合征的治疗能有效保持动脉血气的稳定,加快患者的恢复,减少并发症,值得推广应用。     

肺复张手法联合双水平正压通气与小潮气量机械通气治疗急性呼吸窘迫综合征

目的观察肺复张手法联合双水平正压通气对急性呼吸窘迫综合征（ARDS）患者的治疗作用，并与小潮气量辅助／控制通气方式进行比较，以寻找更合理的机械通气方式。方法28例ARDS患者，男15例，女13例，平均年龄（37±9）岁。符合中华医学会呼吸病学分会制定的ARDS诊断标准。分为两组：（1）试验组14例：采用肺复张手法联合双水平正压机械通气；（2）对照组14例：采用美国ARDS协会推荐的小潮气量辅助／控制通气（潮气量设为6ml／kg，体重为标准体重）。分别观察两组患者上机后0、48和72h的氧合指数、肺顺应性（ml／cm H2O）、中心静脉压、镇静药物的用量以及28d的病死率和并发症等。结果试验组与对照组比较，氧合指数48h分别为（298±16）及（212±12）cm H2O（1cm H2O=0．098kPa），72h为（309±16）及（246±17）cm H2O；肺顺应性48h分别为（38．4±2．2）及（29．5±1．3）ml／cm H2O，72h为（42．0±1．3）及（29．0±1．0）ml／cm H2O；带机时间缩短为（14±3）及（19±3）d；试验组和对照组48h中心静脉压分别为（13．8±0．8）及（18．6±1．1）cm H2O，72h分别为（11．6±0．7）及（16．8±1．0）cm H2O。试验组仅在上机时应用少量镇静剂，而对照组则连续应用至通气方式转为自主通气方式。28d病死率和并发症的发生率两组比较差异无统计学意义（U=0．38，P〉0．05）。结论肺复张手法联合双水平正压通气方式比单纯小潮气量容量控制／辅助通气具有改善氧合迅速、肺顺应性增加明显、带机时间短、血液动力学稳定及所用镇静药物少等优点。     

Pressure-volume curve does not predict steady-state lung volume in canine lavage lung injury

To better understand strategies for recruiting and maintaining lung volume in acute lung injury, we examined relationships between steady-state lung volume and cumulative cyclic recruitment/derecruitment volume history and the quasi-static pressure-volume curve, in an animal saline lavage lung injury model. Small-volume tidal pressure-volume loops performed after inflation from functional residual capacity demonstrated incremental, cyclic recruitment only if the peak pressure achieved exceeded the pressure at which the compliance increased (Pflex) on the pressure-volume curve, whereas loops performed after deflation from total lung capacity remained close to the envelope deflation curve. Recruitment continued to occur up to and beyond a peak inspiratory airway pressure of 40 cm H(2)O, as demonstrated by both the tidal loops and by computed tomography-derived lung volume data. Tidal-specific compliance was relatively constant across positive end-expiratory pressure levels after inflation from functional residual capacity, but peaked at moderate positive end-expiratory pressure after deflation from total lung capacity, further demonstrating the effects of volume history and providing experimental validation of the recruitment models of Hickling (AJRCCM 2001;163:69-78). These results support the interpretation of Pflex as pressure threshold for recruitment, but otherwise do not suggest a role for the pressure-volume curve in predicting steady-state lung volume.     

容许性高碳酸血症对急性肺损伤动物心肺影响的观察

观察不同水平的容许性高碳酸血症对油酸型急性肺损伤模型的心肺功能影响。复制猪ＡＬＩ模型，四腔热稀释漂浮导管监测血液动力学不同潮气量致不同程度的ＰＨＣ。