呼气末正压通气对阻塞性睡眠呼吸暂停综合征肥胖患者全麻术中呼吸功能的影响

目的 评价呼气末正压通气对阻塞性睡眠呼吸暂停综合征(OSAS)肥胖患者全麻术中呼吸功能的影响.方法 择期行悬雍垂腭咽成形术的OSAS患者40例,性别不限,年龄26 ～ 57岁,ASAⅠ或Ⅱ级,按照体重将患者分为2组(n=20):正常体重组(A组),BMI＜ 26 kg/m2;肥胖组(B组),BMI＞ 32 kg/m2.静脉注射咪达唑仑、异丙酚、舒芬太尼和顺阿曲库铵麻醉诱导,气管插管后先行非呼气末正压通气60 min,再行呼气末正压通气60 min,PEEP为8 cm H2O,维持PETCO2 35 ～ 45 mm Hg和气道峰压＜ 28 cm H2O.分别于气管插管后5 min(T1)、60min(T2)和120 min(T3)时记录胸肺顺应性(CL)和气道阻力(Raw).于清醒状态未吸纯氧前(T0)和T1-3时,采集足背动脉血样进行血气分析,计算氧合指数(PaO2/FiO2)、呼吸指数(RI)和生理无效腔(VD/VT).记录术后24h内不良反应的发生情况.结果 与T0时比较,B组T1和T2时PaO2/FiO2降低,RI升高(P＜0.05);与T1时比较,B组T3时PaO2/FiO2、CL升高,RI降低(P＜0.05);与A组比较,B组T1和T2时PaO2/FiO2和CL降低,T1-3时Raw,RI和VD/VT升高(P＜0.05).两组患者术后24 h内均未见心脑血管意外、气胸或肺水肿等不良反应的发生.结论 呼气末正压通气(PEEP 8 cm H2O)可抑制OSAS肥胖患者全麻术中肺不张,改善气体交换和胸肺顺应性.     

高渗氯化钠对单肺通气时呼吸力学的影响

目的 探讨高渗氯化钠对单肺通气患者呼吸力学参数的影响.方法 选择拟单肺通气剖胸手术患者60例,随机均分为高渗氯化钠治疗组(H组)和对照组(C组).在单肺通气30 min后经中心静脉导管输注7.5％氯化钠溶液(H组)或生理盐水(C组)2 ml/kg.观察单肺通气前(T1)、单肺通气后30 min(T2)、输注后30 min(T3)、60 min(T4)、单肺通气结束时(T5)的动态肺顺应性(Cdyn)、气道峰压(Ppeak)、气道平均压(Pmean)、动脉血氧分压(PaO2)、血清Na+浓度.结果 与T1时比较,两组患者T2时的Cdyn、PaO2明显降低,Ppeak、Pmean明显升高(P＜0.05).与T2时比较,T3～Ts时H组Cdyn、PaO2逐渐升高,Ppeak、Pmean逐渐下降(P＜0.05),且Cdyn、PaO2明显高于C组,Ppeak明显低于C组(P＜0.05).T4、T5时H组Pmean明显低于C组(P＜0.05).结论 7.5％氯化钠溶液对单肺通气患者的各呼吸力学参数有改善作用,对肺通气功能具有保护作用.     

双相正压通气治疗急性呼吸窘迫综合征

目的探讨双相气道正压(BIPAP)通气模式治疗急性呼吸窘迫综合征(ARDS)患者的疗效及其对血流动力学和气道力学的影响.方法随机将20例ARDS患者分为BIPAP通气模式组(BIPAP组)和间歇正压通气模式组(IPPV组),行机械通气治疗,每组各10例.观察两组血流动力学、血气分析、呼吸力学指标.结果BIPAP组机械通气时间平均为13天,显著低于IPPV组的21天(P＜0.05).BIPAP组患者安定、吗啡和万可松用量显著低于IPPV组(P＜0.05);IPPV组吸气峰压、平台压和呼气末正压均显著高于BIPAP组(P＜0.05).心率、平均动脉压、平均肺动脉压、体循环阻力和心脏指数两组差别无显著性意义(P＞0.05),但IPPV组肺血管阻力显著高于BIPAP组(P＜0.05).两组间动脉血氧分压、二氧化碳分压和pH值差别无显著性意义(P＞0.05),BIPAP组混合静脉血氧分压显著高于IPPV组(P＜0.05).结论BIPAP通气模式人机关系协同性好,能够降低肺血管阻力,增加混合静脉血氧分压,缩短了ARDS治疗的机械通气时间.     

压力-容积曲线指导开胸手术患者个体化保护性单肺通气的效果

目的 评价应用动态压力-容积曲线(P-V曲线)设定开胸手术患者个体化的潮气量(VT)和呼气末正压(PEEP)行单肺通气(OLV)的效果.方法 择期行肺叶切除术患者25例,性别不限,年龄44～64岁,体重57～75 kg,ASA分级Ⅰ或Ⅱ级.常规双肺通气30 min后(T0)行OLV,按照动态P-V曲线低位拐点对应的压力(PLIP) +0.196 kPa设定PEEP,根据动态P-V曲线高位拐点对应的容量(VUTP)设定VT,通气30 min后(T1)将VT降至80％ VUIP,通气30 min后(T2)再将VT降至60％ VUIP,然后再通气30 min (T3).OLV期间吸呼比1∶1 ～2,通气频率14～20次/min,维持PETC02 4.67～6.00kPa.分别于T0-3时记录MAP、HR、CVP和气道峰压(Ppeak)、气道阻力(Rsw)、胸肺顺应性(CL),同时采集动脉和中心静脉血样,进行血气分析,记录pH值、PaO2和PaCO2,计算肺内分流率(Qs/Qt).结果 与T0时比较,T1-3时HR、Ppeak、Rsw和Qs/Qt升高,CL和PaO2降低,T1.2时CVP升高,T3时MAP和PaCO2升高(p＜0.05);与T1时比较,T2.3时Ppeak和Rsw降低,T1.2时Pa02升高,Qs/Qt降低,T3时CVP降低,MAP和PaC02升高(P＜0.05).结论 根据80％ VUU确定VT,PuP +0.196 kPa确定PEEP,有助于改善开胸手术患者的氧合,对血液动力学无明显影响,是实现个体化保护性OLV的有效手段.     

反复肺复张联合肺保护性通气对急性呼吸窘迫综合征家兔肺损伤的影响

目的 评价反复肺复张联合肺保护性通气对急性呼吸窘迫综合征(ARDS)家兔肺损伤的影响.方法 家兔24只,雌雄各半,体重2.5～3.5 kg,采用随机数字表法,将兔随机分为4组(n=6):正常对照组(Ⅰ组)、ARDS模型组(Ⅱ组)、肺保护性通气组(Ⅲ组)和反复肺复张联合肺保护性通气组(Ⅳ组).麻醉下进行机械通气,Ⅱ组、Ⅲ组和Ⅳ组采用静脉输注油酸0.1 ml/kg(经15 min输注)的方法 制备ARDS模型,模型制备成功后经3 min确定静态压力.容积曲线低位转折点.Ⅰ组和Ⅱ组的通气参数为:VT12 ml/kg,通气频率30次/min,呼气末正压(PEEP)0,FiO2 1.0,氧流量1 L/min,吸气时间0.6 s,吸呼比1.0∶2.3;Ⅲ和Ⅳ组通气参数为:VT6 ml/kg,PEEP为静态压力-容积曲线低位转折点对应气道力+2 cm H2O,其他通气参数同Ⅰ组和Ⅱ组,Ⅳ组分别在确定静态压力-容积曲线低位转折点后即刻、1、2和3 h时实施肺复张.肺复张的方法:吸气压力为30 cm H2O,吸气时间为30 s.分别于每次肺复张后采集动脉血样,测定PaO2,计算氧合指数.最后一次肺复张后1 h处死动物,取肺组织,测定TNF-α和IL-10的含量、髓过氧化物酶(MPO)活性、丙二醛(MDA)含量和湿/干重比(W/D比),计算TNF-α与IL-10的比值(TNF-α/IL-10),光镜下观察肺组织病理学结果.结果 与Ⅰ组比较,Ⅱ组氧合指数降低,肺组织TNF-α/IL-10、MPO、MDA和W/D比升高(P＜0.05);与Ⅱ组比较,Ⅲ组氧合指数升高,肺组织TNF-α/IL-10、MPO、MDA和W/D比降低(P＜0.05);与Ⅲ组比较,Ⅳ组氧合指数升高,肺组织TNF-α/IL-10、MPO、MDA和W/D比降低(P＜0.05).Ⅳ组肺组织损伤程度轻于Ⅲ组.结论 与肺保护性通气比较,肺保护性通气期间反复肺复张可进一步减轻ARDS家兔肺损伤,其机制与抑制肺组织炎性反应有关.

Abstract：

Objective To evaluate the effect of alveolar recruitment maneuvers (ARM) combined with lung protection mechanical ventilation on lung injury in a rabbit model of acute respiratory distress syndrome (ARDS) .Methods Twenty-four rabbits of both sexes weighing 2.5-3.5 kg were randomly divided into 4 groups (n=6 each):normal control group(group Ⅰ);ARDS group(group Ⅱ);ARDS+lung protection mechanical ventilation group (group Ⅲ) and ARDS + lung protection mechanical ventilation + ARM group (group Ⅳ). The animals were anesthetized with iv pentobarbital 20 mg/kg, tracheostomized and mechanically ventilated. Anesthesia was maintained with iv gammahydroxybutyrate infusion 100 mg·kg-1·h-1 and intermittent iv boluses of vecuronium. ARDS was induced with oleic acid 0.1 ml/kg injected iv over 15 min in Ⅱ ,Ⅲ and Ⅳ groups. In Ⅰand Ⅱ groups VT = 12 ml/kg, RR=30 bpm, I∶E=1.0=2.3, PEEP=0, FiO2=1, while in Ⅲ and Ⅳ groups VT=6 ml/kg, RR=30 bpm, I∶E=1.0=2.3, PEEP=airway pressure at lower inflection point+2 cm H2O, FiO2=1.ARM was performed by increasing the airway pressure to 30 cm H2O for 30 s once an hour in group Ⅳ. Arterial blood gas analysis was performed after each ARM. The animals were sacrificed at 1 h after the 3rd ARM. The lungs were removed for microscopic examination and determination of W/D lung weight ratio, TNF-α, IL-10 and MDA contents and MPO activity. TNF-α/IL-10 ratio was calculated. Results ARDS significantly decreased PaO2/FiO2 and increased TNF-α/IL-10 and W/D lung weight ratio, MPO activity and MDA content in the lung tissue. Lung protection mechanical ventilation significantly increased PaO2/FiO2 and decreased TNF-α/IL-10 and W/ D lung weight ratio, MPO activity and MDA content in the lung tissue. Lung protection mechanical ventilation + ARM significantly increased PaO2/FiO2 and decreased TNF-α/IL-10, W/D lung weight ratio, MDA content and MPO activity in group Ⅳ. Conclusion ARM combined with lung protection mechanical ventilation can further attenuate ARDS-induced lung injury by inhibiting inflammatory response.     

全麻诱导期持续正压通气策略对肥胖患者诱导后肺不张的影响

目的评价全麻诱导期采用持续气道正压通气(CPAP)策略对肥胖患者诱导后肺不张的影响。方法选取择期全麻下行脑血管介入术的患者86例, 性别不限, 年龄30～60岁, BMI 28～35 kg/m2, ASA分级Ⅱ或Ⅲ级。采用随机数字表法分为2组(n=43):CPAP组(C组)和常规组(R组)。C组在自主呼吸预充氧及自主呼吸消失后设置CPAP 5 cmH2O辅助通气。于入室后(T1)、气管插管后5 min(T2)时行胸部CT断层扫描及动脉血气分析, 计算肺不张面积百分比及记录PaO2;T2时记录肺动态顺应性(Cdyn)和平台压(Pplat);记录控制呼吸下平均分钟通气量(MV)、PETCO2以及诱导过程中血管活性药物使用情况。记录面罩通气期间反流、误吸的发生情况。记录术后3 d内肺部并发症发生情况。结果与R组比较, C组T2时肺不张面积百分比降低, PaO2、Cdyn和Pplat升高(P<0.05), MV、PETCO2、血管活性药物使用率、肺部并发症发生率差异无统计学意义(P>0.05) 。面罩通气期间均未见反流、误吸发生。结论麻醉诱导期CPAP(5 cmH2O)策略可减轻肥...     

小潮气量结合肺复张术对食管癌开胸术后早期急性呼吸窘迫综合征患者的疗效

目的 观察小潮气量(VT)结合肺复张术对食管癌开胸术后早期急性呼吸窘迫综合征(ARDS)患者的疗效与可能出现的不良反应.方法 2007年1月1日至2009年9月30日收治食管癌开胸术后早期ARDS患者26例,男性20例,女性6例;年龄51～76岁,平均65.5岁.患者术后循环稳定,因ARDS而不能脱离机械通气.监测并持续记录无创血压、脉搏氧饱和度,实行小VT通气结合呼吸末正压(PEEP)递增法进行肺复张.记录肺复张前及两次肺复张后30 min的PEEP水平及吸入氧浓度(FiO2);监测静态肺顺应性(CLS)及动脉血气分析.结果 26例患者共实施肺复张术52次,全部患者在肺复张术后,FiO2减低,CLS增加,动脉血气分析改善.所有病例均顺利出院,未发生气压伤或其他并发症.结论 小VT结合肺复张策略可以有效改善食管癌开胸术后早期ARDS患者的低氧血症.     

单肺通气期间连续气道正压通气对胸腔镜房间隔缺损修补术患者肺功能的影响

目的 探讨单肺通气期间连续气道正压通气(CPAP)对胸腔镜房间隔缺损修补术患者肺功能的影响.方法 拟行房间隔缺损修补术的患者20例,年龄16～30岁,体重41～64 kg,性别不限,ASA分级Ⅱ级,随机分为2组(n=10):对照组和CPAP组.两组单肺通气时VT 8 ml/kg,呼吸频率12～16次/min,吸呼比1:2,维持PET CO2 35～40 mm Hg.CPAP组单肺通气期间,非通气侧肺采用CPAP,压力为6 cm H2O.术中监测氧合指数、肺顺应性和气道压,记录拔管时间、单肺通气期间心血管事件和低氧血症的发生情况.结果 与对照组比较,CPAP组氧合指数和肺顺应性升高,拔管时间缩短,低氧血症发生率低(P＜0.01),两组患者气道压力在正常范围且未发生心血管事件.结论 单肺通气期间行CPAP(6 cm H2O)可改善胸腔镜房间隔缺损修补术患者的肺功能.     

俯卧位通气下急性呼吸窘迫综合征患者氧合的变化

目的探讨俯卧位通气下急性呼吸窘迫综合征(ARDS)患者氧合的变化及其机制。方法23例早期ARDS患者(病程<72 h),在镇静、肌松下持续俯卧位通气2 h。呼吸机参数设定为潮气量6-8 ml/kg,吸气时间1.0-1.2 s,吸气流速40 L/min,呼吸频率12-20次/min。吸入氧浓度0.4- 1.0,呼气末正压6-18 cm H2O。观察俯卧位前即刻、俯卧位0.5、2 h及恢复仰卧位2 h的氧合指数(PaO2/FiO2)、呼吸系统静态顺应性(Cst)、心率(HR)、平均动脉压(MAP)、中心静脉压(CVP)、平均肺动脉压(MPAP)。肺动脉楔压(PAWP)、心脏指数(CI)、气道峰压(PIP)及气道阻力(Paw)。俯卧位后PaO2/FiO2比俯卧位前上升超过20%作为氧合改善的判断标准。结果与俯卧位前比较,87%患者俯卧位0.5、2 h、恢复仰卧位2 h时PaO2/FiO2和PaO2升高(P<0.01);Cst HR、MAP、CVP、MPAP、PAWP、CI、Raw、PaCO2、PIP差异无统计学意义;87%氧合改善的患者在俯卧位0.5、2 h时Cst差异无统计学意义, 恢复仰卧位2 h时Cst升高(P<0.05)。结论俯卧位通气可改善早期ARDS患者的氧合,且恢复仰卧位后氧合改善持续存在。     

肺牵张指数指导不同原因急性呼吸窘迫综合征复张后呼气末正压选择的实验研究

目的研究以肺牵张指数指导不同原因急性呼吸窘迫综合征(ARDS)肺复张后呼气末正压(PEEP)的选择。方法通过静脉注射油酸、生理盐水肺灌洗和盐酸吸入建立三种犬ARDS模型。容量控制通气,回归法计算肺牵张指数(b)。调整PEEP使b=1,肺复张后再次调整PEEP,分别使b=1、<1与>1。稳定通气30 min后测定肺复张容积,同时观察呼吸力学和肺气体交换。结果盐水灌洗组复张后b=1时的PEEP为(12．8±1．8)cm H2O,显著高于盐酸吸入组[(9．2±1．8)cm H2O,P<0．05],但与油酸组比较无显著差异。与复张前b=1相比,三组复张后b=1时的氧合指数均显著升高。复张后b=1时,油酸组氧合指数为(399±61)mm Hg,较b<1[(307±71)mm Hg]时显著增加(P<0．05),与b>1时比较无显著差异。复张后b=1时,盐水灌洗组氧合指数显著高于盐酸吸入组(P<0．05),但与油酸组比较无显著差异(P>0．05)。三组动物复张后b=1时肺复张容积无明显差异,但均显著高于复张前b=1时的复张容积(P<0．05)。与复张后b>1比较,三组动物复张后b=1时均具有较高的肺顺应性和明显较低的气道平台压。结论肺牵张指数可指导不同原因ARDS复张后的PEEP选择。     

Adult respiratory distress syndrome: improved oxygenation during high-frequency jet ventilation/continuous positive airway pressure

The role of high-frequency jet ventilation (HFJV)/continuous positive airway pressure (CPAP) and HFJV/intermittent mandatory ventilation (IMV) in the treatment of surgical patients with the adult respiratory distress syndrome were evaluated. To compare the efficacy of HFJV to IMV at a constant FiO2 and positive end-expiratory pressure, patients in surgical intensive care were randomized to receive IMV/CPAP therapy or one of three modes of HFJV: (1) HFJV/CPAP alone, (2) HFJV/CPAP + IMV (1), or (3) HFJV/CPAP + IMV (2). Each patient served as his own control. During comparison of HFJV/CPAP + IMV (1) to HFJV/CPAP + IMV (2) (n = 9) and HFJV/CPAP to HFJV/CPAP + IMV (1) (n = 7), cardiac output, PaCO2, PaO2, PvO2, and variables consisting of intrapulmonary shunt fraction (Qsp/Qt), PaO2/FiO2 ratio, and A-a gradient were calculated. The subgroup placed on HFJV/CPAP demonstrated a fall in PaO2 of 13 torr (p = NS; n = 5). HFJV/CPAP + IMV (1) compared with HFJV/CPAP significantly (p less than 0.005) increased PaO2 by 52 +/- 24 torr and decreased Qsp/Qt by 8.9 +/- 1.0 (p less than 0.025). Cardiac output remained unchanged. Comparison of HFJV/CPAP + IMV (2) to HFJV/CPAP + IMV (1) demonstrated a significant improvement in oxygenation (p less than 0.025), but of lesser magnitude (8.4 +/- 11 torr). PaO2/FiO2 ratio and A-a gradient improved in both IMV (1) and IMV (2) subgroups. Oxygenation and ventilation/perfusion (V/Q) matching significantly improved with HFJV/CPAP + IMV (1), to a greater magnitude than with HFJV/CPAP + IMV (2) or HFJV/CPAP alone, and was the preferred method of ventilatory support.     

不同水平呼气末正压通气对头低位腹腔镜手术患者肺顺应性及肺氧合的影响

目的 观察不同呼气末正压通气(positive end-expiratory pressure,PEEP)对头低位腹腔镜手术患者的肺顺应性及肺氧合的影响,探讨在头低位腹腔镜手术施行PEEP的合适水平. 方法 选择ASA分级Ⅰ、Ⅱ级,择期行腹腔镜直结肠手术患者45例,根据随机数字表法分成3组(每组15例):Ⅰ组,PEEP=0;Ⅱ组,PEEP=4 cmH2O(1 cmH2O=0.098 kPa);Ⅲ组,PEEP=8 cmH2O.术中采用容量控制通气,维持PETCO2 35～45 mmHg(1 mmHg=0.133 kPa),记录麻醉诱导后即刻(T0)、手术开始后10 min(T1)、各组实施不同水平PEEP干预后30 min (T2)和60 min(T3)、手术结束拔管前10 min(T4)的PETCO2、肺动态顺应性(pulmonary dynamic compliance,Cdyn),并同时抽取动脉血和深静脉血行血气分析,计算死腔通气比(dead space ventilationratio,Vd/Vt)和肺内分流率(intrapulmonary shunt,Qs/Qt). 结果 3组患者一般资料、HR及MAP差异无统计学意义(P＞0.05).3组患者Cdyn在T1时较T0时均降低(P＜0.05),Ⅱ组和Ⅲ组在T2时上升,在T4时[Ⅱ组(50.9±9.8) ml/cmH2O,Ⅲ组(58.8±13.4) ml/cmH2O]高于T0时[Ⅱ组(47.6±10.6) ml/cmH2O,Ⅲ组(51.3±10.8) ml/cmH2O](P＜0.05),Ⅲ组在T2、T3时高于Ⅰ组[T2:Ⅲ组(42.8±9.9) ml/cmH2O,Ⅰ组(29.3±8.0) ml/cmH2O;T3:Ⅲ组(42.9±10.3) ml/cmH2O,Ⅰ组(29.3±8.6) m]/cmH2O] (P＜0.05).3组的Vd/Vt在T1时均增大(P＜0.05),Ⅰ组和Ⅲ组在T4时[Ⅰ组(21.5±7.6)％,Ⅲ组(24.2±6.8)％]高于T0时[Ⅰ组(9.5±5.8)％,Ⅲ组(10.7±5.2)％](P＜0.05),而Ⅱ组在T4时[(12.2±6.8)％]同T0时[(9.9±7.8)％]比较,差异无统计学意义(P＞0.05),且低于同一时点Ⅰ组和Ⅲ组(P＜0.05).Ⅱ组的Qs/Qt在T4时低于Ⅰ组[Ⅱ组(12.3±6.3)％,Ⅰ组(26.2±20.8)％](P＜0.05).中心静脉血氧分压(central venous partial pressure of oxygen,PvO2)3组均逐渐上升(P＜0.05).Ⅱ组在T4时PaO2和PvO2均高于其他两组(P＜0.05). 结论 PEEP有利于头低位腹腔镜手术患者的肺顺应性及肺氧合.4 cmH2O PEEP不仅能改善肺顺应性,更有利于降低Vd/Vt和Qs/Qt,增加肺氧合.     

多脏器功能障碍综合征患者连续性血液净化的效果

目的 探讨连续性血液净化（CBP）用于多脏器功能障碍综合征（MODS）患者的效果。方法 MODS患者20例，男性13例，女性7例，年龄40—87岁，ASA分级Ⅱ级7例、Ⅲ级13例，均符合MODS和急性呼吸窘迫综合征的诊断标准。经右侧股静脉置管，使用持续性肾脏替代治疗机以高容量连续性静脉．静脉血液滤过（HV—CVVH）模式治疗。于第1次CBP前、CBP开始后2、4、6h及CBP停止后6h测定心率（HR）、平均动脉压（MAP）、中心静脉压（CVP）、pH、动脉血氧分压（PaO2）、动脉血二氧化碳分压（PaCO2）、氧合指数（PaO2／FiO2）、肺动态顺应性（Cdyn）、气道阻力（Raw），同时抽取静脉血2ml测定血液BUN、Scr、Glu、Na^＋、K^＋、Cl^-的浓度。结果 与第1次CBP前比较，pH、PaCO2、Na^＋、Cl^-、G1u差异无统计学意义（P〉0．05）；PaO2、PaO2／FiO2和Cdyn在CBP开始后2、4、6h时明显升高（P〈0．05）；Raw、BUN、Scr和K^＋明显降低（P〈0．05）；HR于CBP开始后2、4、6h以及CBP停止后6h时降低（P〈0．05）。结论 CBP能促进MODS患者的氧合功能，改善血液生化指标，维持内环境稳定，对血液动力学无明显影响。     

压力控制通气模式在合并轻度阻塞性通气功能障碍老年患者腹腔镜胆囊手术中的通气效果

目的评价压力控制通气(PCV)模式用于合并轻度阻塞性通气功能障碍的老年患者行腹腔镜胆囊切除术中的通气效果。方法选择择期拟行腹腔镜胆囊切除术患者40例,男23例,女17例,年龄65~75岁,ASAⅡ或Ⅲ级,合并轻度阻塞性通气功能障碍,BMI 18.5~23.9kg/m~2,采用随机数字表法,均分为两组:容量控制通气(VCV)组(V组)和PCV组(P组)。新鲜气流量均为2L/min,FiO_260%,VT_8~12ml/kg(P组调整吸气压),I∶E 1∶2,RR 12~16次/分。调整通气参数维持PET_CO2 35~45mm Hg。直至手术结束后气管导管拔除期间两组均分别维持以上通气模式及呼吸参数。于气管插管后5min(气腹前)(T_1)、气腹开始后30min(T_2)、气腹结束后10min(T_3)时记录气道峰压(Ppeak)、气道平台压(Pplat)、吸气阻力(Raw)和动态肺顺应性(Cdyn),采集桡动脉和混合静脉血行血气分析,计算氧合指数(PaO_2/FiO_2)、呼吸指数(RI)、死腔通气率(VD/VT_)和肺内分流率(Qs/Qt)。记录拔管时间、复苏室停留时间和拔管后2h内高碳酸血症、低氧血症等不良反应的发生情况。结果与V组比较,T_1~T_3时P组Ppeak、Pplat和Raw明显降低,Cdyn、PaO_2/FiO_2明显升高,RI、VD/VT_、Qs/Qt和拔管后低氧血症发生率明显降低(P0.05)。两组拔管时间、复苏室停留时间及高碳酸血症发生率差异无统计学意义。结论 PCV模式可安全用于合并轻度阻塞性通气功能障碍的老年腹腔镜胆囊切除术患者,其通气效果好,低氧血症发生率降低。     

不同压力持续气道正压对单肺通气氧化应激反应的影响

目的比较不同压力持续气道正压(CPAP)对单肺通气氧化应激反应的影响。方法择期行食管癌根治术患者48例,随机均分为双肺通气组(A组)、单肺通气组(B组)、单肺通气非通气肺给予2cmH2OCPAP组(C组)及5cmH2OCPAP组(D组)。分别于开胸前(T0)、单肺通气后(A组于开胸后)30min(T1)、90min(T2)、150min(T3)、手术结束(T4)时测定血清超氧化物歧化酶(SOD)活性、丙二醛(MDA)、NO浓度。结果 T1～T4时B、C组及T2～T4时D组的SOD活性明显低于A组,T1～T4时B、C、D组MDA及NO浓度高于A组(P0.05)。T1～T4时C、D组MDA及NO浓度均显著低于B组(P0.05),T3时C、D组SOD活性显著高于B组(P0.05);T3时D组MDA及NO浓度高于C组(P0.05)。结论 CPAP能减轻单肺通气氧化应激反应,且2cmH2OCPAP优于5cmH2OCPAP。     

Operative lung constant positive airway pressure with the Univent bronchial blocker tube.

Constant positive airway pressure (CPAP) to the operative lung during one-lung ventilation (1-LV) with a double-lumen tube increases PaO2; there have been no reports of application of CPAP to the operative lung during 1-LV with the Univent bronchial blocker (BB) tube. This study determined the method of administration and the effect on PaO2 of 10 cm H2O of CPAP to the operative lung during 1-LV (1-LV + 10 CPAP) produced by the Univent BB system. We designed our CPAP system for the Univent BB using an in vitro lung model so that low O2 flow rates (2-4 L/min) yielded clinically relevant levels of CPAP (5-20 cm H2O) over a wide range of lung compliance. The CPAP system simply consisted of placing a resistance to a variable oxygen flow distal to the operative lung. Seven consenting patients who required thoracotomy and 1-LV were anesthetized and their tracheas were intubated with the Univent BB tube; the BB was inserted into the appropriate mainstem bronchus until the proximal surface of the BB cuff was just distal to the tracheal carina. PaO2 was measured in the seven patients during 12 sequences of two-lung ventilation (2-LV), one-lung ventilation (1-LV), and 1-LV with 10 cm H2O CPAP (1-LV + 10 CPAP). 1-LV + 10 CPAP was always instituted on the deflation phase of a previous single tidal inhalation. We found in our patients with a lung compliance of 32 +/- 4 mL/cm H2O that 2.4 +/- 0.2 L/min of oxygen flow produced 1-LV + 10 CPAP.(ABSTRACT TRUNCATED AT 250 WORDS)     

面罩双水平气道正压无创通气在腹腔镜胆囊切除术中的应用

【摘要】〓目的〓探讨面罩双水平气道正压(BiPAP)无创通气在腹腔镜胆囊切除手术全身麻醉中应用的安全可行性。方法〓40例行腹腔镜胆囊切除手术的患者,随机分为面罩BiPAP通气组(I组)和气管内插管间歇正压通气(IPPV)组(Ⅱ组),每组20例,术中监测平均动脉血压(MAP)、心率(HR)、脉搏血氧饱和度(SpO₂)以及Narcotrend指数(NI),并在麻醉前(T0)、麻醉诱导后(T₁)、插管或上面罩后(T₂)、机械通气后5 min(T₃)、气腹后5 min(T₄)、手术结束(T₅)、拔管或去面罩后(T₆)时点记录其数值;两组患者在T₀、T₃、T₄、T₅时点做血气分析,记录PaO₂、PaCO₂、pH值。结果〓I组MAP、HR在T₂和T₆时点低于Ⅱ组(P<0.05),而I组NI在T₁时点高于Ⅱ组(P<0.05);组内比较Ⅱ组在T₂、T₆时点MAP、HR显著升高(P<0.05),而I组在这两个时点无变化。PaO₂、PaCO₂、pH值在T₀、T₃、T₄、T₅时点组间比较差异均无统计学意义。结论〓面罩BiPAP无创通气应用于腹腔镜胆囊切除手术全身麻醉能够进行有效通气,且能维持患者血流动力学平稳,是一种安全有效的通气方式。     

Prospective,randomized, controlled evaluation of the preventive effects of positive end-expiratory pressure on patient oxygenation during one-lung ventilation

BACKGROUND AND OBJECTIVE: This prospective, randomized, controlled study evaluated the effects on oxygenation by applying a selective and patient-specific value of positive end-expiratory pressure (PEEP) to the dependent lung during one-lung ventilation. METHODS: Fifty patients undergoing thoracic surgery under combined epidural/general anaesthesia were randomly allocated to receive zero PEEP (Group ZEEP, n = 22), or the preventive application of PEEP, optimized on the best thoracopulmonary compliance (Group PEEP, n = 28). Patients' lungs were mechanically ventilated with the same setting during two- and one-lung ventilation (FiO2 = 0.5; VT = 9mL kg(-1), inspiratory :expiratory time = 1 : 1, inspiratory pause = 10%). RESULTS: Lung-chest wall compliance decreased in both groups during one-lung ventilation, but patients of Group PEEP had 10% higher values than patients with no end-expiratory pressure (ZEEP) applied--Group ZEEP (P < 0.05). During closed chest one-lung ventilation, the PaO2 : FiO2 ratio was lower in Group PEEP (232 +/- 88) than in Group ZEEP (339 +/- 97) (P < 0.05); but no further differences were reported throughout the study. No differences were reported between the two groups in the need for 100% oxygen ventilation (10 patients of Group ZEEP (45%) and 14 patients of Group PEEP (50%) (P = 0.78)) or re-inflation of the operated lung during surgery (two patients of Group ZEEP (9%) and three patients of Group PEEP (10%) (P = 0.78)). Postanaesthesia care unit discharge required 48 min (25th-75th percentiles: 32-58 min) in Group PEEP and 45 min (30-57 min) in Group ZEEP (P = 0.60). CONCLUSIONS: The selective application of PEEP to the dependent, non-operated lung increases the lung-chest wall compliance during one-lung ventilation, but does not improve patient oxygenation.