不同呼气末正压水平对绵羊急性呼吸窘迫综合征模型肺复张效果及血流动力学的影响

目的观察在绵羊急性呼吸窘迫综合征（ARDS）模型上利用控制性肺膨胀（SI）实施肺复张策略后不同呼气末正压（PEEP）水平对复张效果及血流动力学的影响，以找到理想的PEEP压力范围。方法12只绵羊在麻醉后，行纤维支气管镜温生理盐水肺泡灌洗复制ARDS模型，低流速法描记准静态压力-容积（P-V）曲线，寻找P-V曲线的上拐点（UIP），并以UIP下5cm H2O（1cm H2O=0．098kPa）作为SI的峰压进行肺复张，肺复张后根据不同的PEEP水平分为PEEP5、PEEP10、PEEP15、PEEP20组。记录肺复张后2h内的血流动力学参数及氧代谢指标，实验后进行肺组织活检，观察SI后不同的PEEP水平对血流动力学及复张效果的影响。结果PEEP5组和PEEP10组在复张后2h内对血流动力学没有影响，但PEEP5组氧合呈现下降趋势，病理显示肺泡组织仍轻度萎陷，伴灶性肺泡塌陷；PEEP≥15cm H2O时中心静脉压（cVP）明显升高，心排血指数（CI）明显降低，氧合指数、肺机械参数均较复张前明显改善并保持2h以上。结论ARDS肺复张后，PEEP设定在10-20cm H2O可以明显改善氧合，对正常心功能状态下的血流动力学影响并不显著。     

急性呼吸窘迫综合征绵羊肺复张容积测定方法的比较

目的　比较压力容积 (P V)曲线法与等压法测定肺复张容积的差异。方法　内毒素持续静脉注射复制绵羊急性呼吸窘迫综合征模型 ,分别用 P V曲线法与等压法测定相同呼气末正压 (PEEP)的肺复张容积。结果　等压法测定肺复张容积可以立即得出结果 ;而 P V曲线法测定肺复张容积所需时间为5～ 6 min。随着 PEEP从 5 cm H2 O(1cm H2 O=0 .0 98k Pa)增至 15 cm H2 O,两种方法测定的肺复张容积均显著增加 (P均 <0 .0 5 ) ;PEEP为 5 cm H2 O时 ,等压法与 P V曲线法所测的肺复张容积分别为 (2 5 .79±2 0 .4 8) m l和 (6 3.2 6± 5 4 .5 7) m l,两组比较无明显差异 (P>0 .0 5 ) ;当 PEEP为 10和 15 cm H2 O时 ,等压法所测肺复张容积分别为 (4 8.6 4± 30 .5 1) m l、(71.5 0± 5 8.0 9) ml,P V曲线法测得肺复张容积分别为 (14 8.14±85 .4 2 ) m l、(32 2 .86± 14 8.4 2 ) m l,等压法所测值明显小于 P V曲线所测值 (P均 <0 .0 5 )。结论　虽然等压法较为简便 ,但由于准确性较差 ,因此不能代替 P V曲线法来测定肺复张容积     

肺泡灌洗对肺源性急性呼吸窘迫综合征肺复张容积和肺力学的影响

目的评价肺泡灌洗(BAL)对肺原性急性呼吸窘迫综合征(ARDSp)肺复张和肺力学的影响,以探讨BAL对ARDSp的治疗作用。方法以9例血液动力学稳定、接受机械通气的ARDSp患者为研究对象,采用压力-容积曲线法分别测定BAL前与后呼气末正压(PEEP)为5、10和15cmH2O(1cmH2O=0.098mmHg)时的肺复张容积,并对BAL前后气道峰压(PIP)、气道平台压(Pplat)、平均气道压(Pm)和静态顺应性(Cst)在不同PEEP下的趋势变化进行比较。结果BAL前PEEP至5、10和15cmH2O时肺复张容积分别为([35.89±3.93)mL(、124.56±9.68)mL和(161.70±8.50)mL,P<0.01],BAL后分别为[(42.27±4.27)mL、(139.70±17.59)mL和(160.16±9.43)mL,P<0.01]。但BAL前后组间趋势变化差异无显著性(F=2.749,P=0.079)。不同PEEP条件下BAL后PIP、Ppla和Pm较BAL前趋势有显著下降(P<0.05),Cst在BAL前后比较差异无显著性(P>0.05)。结论BAL对肺复张容积无显著影响,但显著降低ARDSp的气道压力,改善通气功能。     

较高水平呼气末正压对俯卧位通气重度ARDS病人氧合状况、肺复张指标及血清炎性因子水平的影响

目的:探讨较高水平呼气末正压(PEEP)对俯卧位通气重度急性呼吸窘迫综合征(ARDS)病人氧合状况、肺复张指标及血清炎性因子水平的影响.方法:选取医院2018年7月—2020年7月103例重度ARDS病人为研究对象,依据干预方式不同分为低PEEP组和高PEEP组.两组病人在治疗原发病基础上均给予肺保护性通气策略及俯卧位通气,低PEEP组51例给予较低水平PEEP(8～12 cmH2 O,1 cmH2 O=0.098 kPa),高PEEP组52例给予较高水平PEEP(13～17 cmH2 O),比较两组病人氧合指标、肺复张指标、血清炎性因子水平.结果:两组病人通气24 h、48 h末动脉血氧分压(PaO2)、血氧饱和度(SpO2)、氧合指数(OI)水平较干预前均升高,且高PEEP组明显高于低PEEP组(P<0.05).两组病人通气48 h末肺动态顺应性(Cdyn)水平较干预前均升高,且高PEEP组明显高于低PEEP组;肺驱动压(DP)、心率(HR)、血乳酸(Lac)水平较干预前均降低,且高PEEP组明显低于低PEEP组(P<0.05).两组病人通气48 h末血清白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)及超敏C-反应蛋白(hs-CRP)水平较干预前均升高,且高PEEP组明显高于低PEEP组(P<0.05).结论:采用较高水平PEEP对俯卧位通气重度ARDS病人进行干预,通过扩张萎缩肺泡以改善氧合状态,调控肺复张指标,调节炎症因子水平,提高临床疗效.     

不同呼气末正压对ARDS犬肺复张后氧输送的影响

目的 探讨在急性呼吸窘迫综合征(ARDS)肺复张(RM)后不同呼气末正压(PEEP)对氧输送(DO2)影响.方法 复制15只犬油酸ARDS模型,低流速法描记静态压力容积(p-V)曲线,双向回归法计算吸气支低位拐点(LIP),压力控制法行RM,RM后按随机表调整PEEP分别为8(A),12(B),16 cmH2O(C)组(大致相当P-V曲线低位拐点以下4 cmH2O、拐点处和+4 cmH2O水平)(1 cmH2O=0.098 kPa).监测15 min时呼吸力学和P-V曲线法测定复张容积.同时观察RM前、RM完成后0,5,10和15 min时动脉血气、血流动力学,计算DO2.多组间单因素比较采用单因素方差分析,两独立样本间比较用t检验.结果 A组PaO2在RM后5,10和15 min[(257±23)mmHg,(253±21)mmHg,(255±19)mmHg]较0 min(322±20)mmHg(1 mmHg=0.133 kPa)有显著下降(P＜0.05);B和C组PaO2在RM后差异无统计学意义,两组间相比差异无统计学意义,但均显著高于A组(P＜0.05).静态顺应性在A,B组[(14.3±2.2)mL/cmH2O vs.(17.2±1.4)mL/cmH2O]之间差异无统计学意义(P＞0.05),但C组的静态顺应性(10.5±0.9)mL/cmH2O比其他组显著降低.复张容积则随PEEP水平的增高而增加[(50±12)mL,(124±15)mL,(157±10)mL],相对于PEEP A升到B组,从B到C组复张容积增加量明显降低(P＜0.05).以RM后与RM前氧输送的比值变化反映RM后不同PEEP水平对DO2的影响,复张后B组0,5,10,15 min时DO2(1.15±0.11),(1.14±0.12),(1.14±0.12),(1.16±0.11)较RM前DO2(1.00±0.09)显著增加(P＜0.05),而在其他组与RM前相比DO2无显著增加(P＞0.05).结论 LIP附近压力为ARDS RM后的PEEP比较合适,可以维持肺复张后氧合与复张容积,并改善肺顺应性,增加氧输送.

Abstract：

Objective To explore the effect of different positive end expiratory pressures (PEEP) on oxygen delivery (DO2) after recruitment maneuvers (RM) in dogs with acute respiratory distress syndrome (ARDS). Method After ARDS models established in 15 dogs by oleic acid, static P-V (pressure-volume) curves were determined by low flow technique. Lower inflection point (LIP) was set by two-way linear regression methods. RM was operated with the pressure control method. ARDS dog models were randomly divided into three groups, namely PEEP 8 cmH2O group (group A), 12 cmH2O group (group B) and 16cmH2O group (group C) after RM (equivalent to pressure at4 cmH2O under LIP, 4 cmH2O near LIP, and 4 cmH2O above LIP, respectively). Hemodynamics and arterial blood gas analysis were monitored before RM, 0, 5, 10 and 15 min after RM. The recruited volume was measured by P-V curve method 15 min after RM and respiratory mechanics was also observed at the same time. Then DO2 was calculated. The quantitative variables were summarized as the mean and SD. The t-test was used to compare continuous variables between the two independent samples. One-way analysis of variance was used to compare variables among three groups. The level of significance was set at P＜0.05 for all the tests. Results In group A, the levels of PaO2 were significantly reduced 5 min, 10 min and 15 min after RM[(257 ± 23 )mmHg, (253±21)mmHg, and (255±19)mmHg] compared with PaO2 at 0 min [(322 ± 20) mmHg] (P＜0.05).But in group B and group C, the levels of PaO2 5 min, 10 min and 15 min after RM were not lower than level of PaO2 at 0 min after RM (P＞0.05 ). The levels of PaO2 in groups B and C were higher than that in group A at the same time (P＜0.05). The recruited volume distinctly increased with PEEP levels escalated [(50±12 ) mL, (124 ±15) mL, and ( 157 ±10)mL](P＜0.05). However, the increment in the recruited volume from PEEP 8 cmH2O to 12 cmH2O was dramatically greater than that from PEEP 12 cmH2O to 16 cmH2O.There was no significant difference in static compliance between group A and B [(14.3 ± 2.2) mL/cmH2O vs. (17.2±1.4)mL/cmH2O] (P ＞ 0.05 ). But compared with groups A and B, the static compliance in the group C significantly reduced(10.5 ± 0.9) mL/cmH2O ( P ＜ 0.05 ). The ratios of DO2 after RM to DO2 before RM were different at different levels of PEEP. The levels of DO2 after RM[( 1.15 ± 0. 11 ),( 1. 14 ± 0.12), ( 1.14 ± 0. 12) and ( 1.16 ± 0.11 )] increased more greatly than that before RM ( 1.00 ±0.09) in the group B (P ＜ 0.05 ). It did not occurred in the groups A and C. Conclusions The PEEP 12 cmH2O set at near the LIP after RM could be the optimal PEEP. Not only can it improve DO2 and the static compliance, but also maintain oxygenation and the recruited volume after RM.     

不同呼气末正压对ARDS犬肺复张后氧输送的影响

Objective To explore the effect of different positive end expiratory pressures (PEEP) on oxygen delivery (DO2) after recruitment maneuvers (RM) in dogs with acute respiratory distress syndrome (ARDS). Method After ARDS models established in 15 dogs by oleic acid, static P-V (pressure-volume) curves were determined by low flow technique. Lower inflection point (LIP) was set by two-way linear regression methods. RM was operated with the pressure control method. ARDS dog models were randomly divided into three groups, namely PEEP 8 cmH2O group (group A), 12 cmH2O group (group B) and 16cmH2O group (group C) after RM (equivalent to pressure at4 cmH2O under LIP, 4 cmH2O near LIP, and 4 cmH2O above LIP, respectively). Hemodynamics and arterial blood gas analysis were monitored before RM, 0, 5, 10 and 15 min after RM. The recruited volume was measured by P-V curve method 15 min after RM and respiratory mechanics was also observed at the same time. Then DO2 was calculated. The quantitative variables were summarized as the mean and SD. The t-test was used to compare continuous variables between the two independent samples. One-way analysis of variance was used to compare variables among three groups. The level of significance was set at P＜0.05 for all the tests. Results In group A, the levels of PaO2 were significantly reduced 5 min, 10 min and 15 min after RM[(257 ± 23 )mmHg, (253±21)mmHg, and (255±19)mmHg] compared with PaO2 at 0 min [(322 ± 20) mmHg] (P＜0.05).But in group B and group C, the levels of PaO2 5 min, 10 min and 15 min after RM were not lower than level of PaO2 at 0 min after RM (P＞0.05 ). The levels of PaO2 in groups B and C were higher than that in group A at the same time (P＜0.05). The recruited volume distinctly increased with PEEP levels escalated [(50±12 ) mL, (124 ±15) mL, and ( 157 ±10)mL](P＜0.05). However, the increment in the recruited volume from PEEP 8 cmH2O to 12 cmH2O was dramatically greater than that from PEEP 12 cmH2O to 16 cmH2O.There was no significant difference in static compliance between group A and B [(14.3 ± 2.2) mL/cmH2O vs. (17.2±1.4)mL/cmH2O] (P ＞ 0.05 ). But compared with groups A and B, the static compliance in the group C significantly reduced(10.5 ± 0.9) mL/cmH2O ( P ＜ 0.05 ). The ratios of DO2 after RM to DO2 before RM were different at different levels of PEEP. The levels of DO2 after RM[( 1.15 ± 0. 11 ),( 1. 14 ± 0.12), ( 1.14 ± 0. 12) and ( 1.16 ± 0.11 )] increased more greatly than that before RM ( 1.00 ±0.09) in the group B (P ＜ 0.05 ). It did not occurred in the groups A and C. Conclusions The PEEP 12 cmH2O set at near the LIP after RM could be the optimal PEEP. Not only can it improve DO2 and the static compliance, but also maintain oxygenation and the recruited volume after RM.     

膈肌紧张性电位指导急性呼吸窘迫综合征呼气末正压选择的实验研究

目的 探讨利用膈肌紧张性电位(tonic diaphragm electrical activity EAdi,Tonic EAdi)选择急性呼吸窘迫综合征( ARDS)呼气末正压(PEEP)的可行性.方法 盐酸吸入法复制兔ARDS模型,充分肺复张后随机(随机数字法)分为Tonic EAdi组和氧合法组,分别利用TonicEAdi法或氧合法选择PEEP,观察Tonic EAdi组与氧合法组PEEP及其对呼吸力学以及气体交换的影响.两独立样本的比较用t检验,以P ＜0.05表示差异具有统计学意义.结果 (1) PEEP:Tonic EAdi组为(10.7::1.4) cm H2O(1 cm H20 =0.098 kPa),氧合法组为(10.0±2.8)cm H2O,组间比较差异无统计学意义(P＞0.05);(2)呼吸力学:PEEP选择后,与氧合法组比 较,Tonic EAdi组在潮气量(VT)、气道峰压(Ppeak)、气道平均压(Pmean)方面差异均无统计学意义(均P＞0.05);(3)气体交换:PEEP选择后,与氧合法组比较,Tonic EAdi组在氧合指数( PaO2/FiO2)、动脉血二氧化碳分压(PaCO2)方面差异无统计学意义(均P＞0.05).结论 TonicEAdi可以用来指导ARDS PEEP的选择.     

吸痰联合肺复张后不同呼气末正压水平对急性呼吸窘迫综合征患者肺气体交换的影响

目的 探讨吸痰联合肺复张后不同的呼气末正压(PEEP)水平对急性呼吸窘迫综合征(ARDS)机械通气患者肺气体交换的影响.方法 以22例ARDS机械通气患者为研究对象,吸痰后给予肺复张,在原有PEEP水平(P0)基础上调整.于调整后10、30、60 min监测患者在各压力水平氧分压(PaO2)、二氧化碳分压(PaCO2)、静脉血氧饱和度(SpO2)、氧合指数(PaO2/FiO2)及肺泡-动脉血氧分压(PA-aO2)变化.结果 与基础水平比较,PaO2、SpO2及PaO2/FiO2在各PEEP水平均显著升高(P<0.05).随着应用PEEP水平的不断增加,PaO2、SpO2、PaO2/FiO2也随之升高,其中设置P0+4 cm H2O和P0+6 cm H2O的压力水平PaO2、SpO2、PaO2/FiO2显著高于其他水平(P<0.05).与其他四组比较,P0+4 cm H2O和P0+6 cm H2O在30～60 min监测时段PaO2、SpO2及PaO2/FiO2下降趋势较小(P<0.05).应用不同PEEP水平测得的PA-aO2不同,随PEEP水平增加逐渐下降.与其他水平比较,应用P0+4 cm H2O和P0+6 cm H2O时PA-aO2显著降低.不同PEEP水平PaCO2比较差异无统计学意义(P>0.05).结论 ARDS机械通气患者在吸痰联合肺复张后选择在原有PEEP水平(P0)上增加4～6 cm H2O时,有利于维持患者复张后肺气体交换功能.     

最佳呼气末正压对急性呼吸窘迫综合征猪模型肺内分流的影响

目的:探讨最佳呼气末正压(PEEP)对急性呼吸窘迫综合征(ARDS)猪模型肺内分流(Qs/Qt)的影响。方法:选择油酸静脉注射法复制猪ARDS模型(n=11),应用压力控制法进行肺复张,并根据最佳氧分压+二氧化碳分压法(PaO2+PaCO2)确定最佳PEEP。记录在基础状态、ARDS状态及最佳PEEP水平下,ARDS猪模型的Qs/Qt,气道平台压(Pplat)、静态顺应性(Cst)及动态顺应性(Cdyn)、动脉氧分压(PaO2)、混合静脉血氧分压(PvO2)、动脉血氧饱和度(SaO2)、混合静脉血氧饱和度(SvO2)等参数。并评估PaO2、PvO2、SaO2、SvO2对Qs/Qt的影响。结果:最佳PEEP可明显降低ARDS动物模型的Qs/Qt,P<0.05);Qs/Qt的影响因素大小依次为:SaO2(r2=0.953,P<0.05)、PaO2(r2分别为0.387,P<0.05)、SvO2(r2=0.273,P<0.05),而PvO2对Qs/Qt的影响(P>0.05)无统计学意义。结论:最佳PEEP可有效改善ARDS动物模型的肺内分流,动脉血氧饱和度是影响肺内分流的最主要因素。     

高呼气末正压加肺复张治疗急性呼吸窘迫综合征

目的 评价高呼气末正压(PEEP)加肺复张(RM)治疗急性呼吸窘迫综合征(ARDS)的临床疗效和安全性.方法 选择2008年6月至2010年5月贵阳医学院附属医院内科重症监护病房(MICU)收治的ARDS患者38例,按信封法随机分为RM组和非RM组,每组19例.两组均采用压力支持通气(PSV)模式行机械通气,尽可能在吸入氧浓度(FiO2)＜0.60时达到目标氧合的最小PEEP水平,限制平台压≤30 cm H2O(1 cm H2O=0.098 kPa).RM时FiO2调至1.00,压力支持水平调至0,将PEEP升至40 cm H2O,持续30 s后再降低,8 h 1次,连续5 d.记录基础状态和5 d内的机械通气参数、血气分析结果及生命体征,比较两组氧合改善和肺损伤指标变化,观察RM的不良反应和气压伤发生率.结果 ①两组患者基础状态及机械通气参数均无明显差异.②两组动脉血氧分压(PaO2)和氧合指数(PaO2/FiO2)均明显改善,且RM组明显优于非RM组[PaO2(mm Hg,1 mm Hg=0.133 kPa)2 d:85.8±21.3比73.5±18.7,3 d:88.6±22.8比74.3±19.8,4 d:98.8±30.7比79.3±19.3,5 d:105.5±29.4比84.4±13.8;PaO2/FiO2(mm Hg)4 d:221.8±103.5比160.3±51.4,5 d:239.6±69.0比176.8±45.5,均P＜0.05].③两组呼出气冷凝液(EBC)中过氧化氢(H2O2)和白细胞介素-6(IL-6)水平均呈下降趋势,RM组下降幅度更明显[5 d时H2O2(μmol/L):0.04±0.02比0.10±0.03;IL-6(ng/L):4.12±2.09比9.26±3.47,均P＜0.05].④两组均无气压伤发生,心率无明显变化,无心律失常发生,中心静脉压和平均动脉压无明显变化.结论 高PEEP加RM可增加气体交换,改善氧合,减少呼吸机相关性肺损伤(VALI).应用RM比较安全,耐受性好,临床观察未见低氧血症、气压伤和血流动力学异常.

Abstract：

Objective To investigate the clinical effects and safety degree of high positive endexpiratory pressure (PEEP) combined with lung recruitment maneuver (RM) in patients with acute respiratory distress syndrome (ARDS). Methods Thirty-eight patients in medical intensive care unit (MICU) of Affiliated Hospital of Guiyang Medical College suffering from ARDS admitted from June 2008 to May 2010 were enrolled in the study. With the envelope method they were randomized into RM group and non-RM group, with n= 19 in each group. All patients received protective ventilation: pressure support ventilation (PSV) with plateau pressure limited at 30 cm H2O (1 cm H2O=0. 098 kPa) or lower. PEEP was set at the minimum level with fraction of inspired oxygen (FiO2) ＜0. 60 and partial pressure of arterial oxygen (PaO2) kept between 60 and 80 mm Hg (1 mm Hg=0. 133 kPa). RM was conducted by regulating FiO2 to 1.00, support pressure to 0, PEEP increased to 40 cm H2O and maintained for 30 seconds before lowering, and this maneuver was repeated every 8 hours for a total of 5 days. Base status, ventilation parameters, blood gas analysis and vital signs were obtained at baseline and for the next 5 days. Oxygenation status and lung injury indexes were compared between RM group and non-RM group, the adverse effects of (PaO2/FiO2) were both increased in RM group and non-RM group, but the values were higher in RM group [PaO2 (mm Hg) 2 days: 85.8± 21.3 vs. 73. 5± 18. 7, 3 days : 88. 6± 22. 8 vs. 74. 3 ±19. 8, 4 days : 98. 8 ±30. 7 vs. 79. 3±19. 3, 5 days: 105.5±29.4 vs. 84. 4±13. 8; PaO2/FiO2(mm Hg) 4 days: 221.8±103. 5 vs.interleukin-6 (IL-6) concentration in exhaled breath condensate (EBC) decreased in both groups but lower in RM group with significant difference [5 days H2O(μmol/L): 0. 04 ± 0. 02 vs. 0.10 ± 0.03 ; IL-6 (ng/L):No significant changes in heart rate were found during RM. Central venous pressure and mean arterial pressure remained unchanged after RM. Conclusion High level PEEP combined with RM can improve gas exchange and oxygenation, decrease ventilator associated lung injury (VALI). RM was safe and had good tolerance, no hypoxemia, barotrauma and hemodynamic instability were observed.     

俯卧位通气联合呼气末正压治疗急性呼吸窘迫综合征家猪的疗效研究

目的 探讨俯卧位通气联合呼气末正压(PEEP)治疗急性呼吸窘迫综合征(ARDS)的疗效及其机制.方法 12头家猪静脉注射油酸建立ARDS模型,分为仰卧位组和俯卧位组,均给予0(ZEEP)、10(PEEP10)、20 cm H2O(PEEP20,1 cm H2O=0.098 kPa)PEEP的机械通气15 min,监测家猪血流动力学、肺气体交换和呼吸力学指标;处死动物观察肺组织病理学变化.结果 俯卧位组ZEEP、PEEP10时氧合指数(PaO2/FiO2)明显优于仰卧位组[ZEEP:(234.00±72.55)mm Hg比(106.58±34.93)mm Hg,PEEP10:(342.97±60.15) mm Hg比(246.80±83.69)mm Hg,1 mm Hg=0.133 kPa,P均<0.05];PEEP20时两组PaO2/FiO2差异无统计学意义(P>0.05).PEEP10时两组肺复张容积(RV)差异无统计学意义(P>0.05);但PEEP20时俯卧位组RV显著高于仰卧位组[(378.55±101.80)ml比(302.95±34.31)ml,P<0.05].两组间心率(HR)、平均动脉压(MAP)、心排血指数(CI)、呼吸系统顺应性(Cst)及动脉血二氧化碳分压(PaCO2)差异均无统计学意义(P均>0.05);仰卧位组背侧肺组织的肺损伤总评分明显高于俯卧位组[(12.00±1.69)分比(6.03±1.56)分,P<0.05].结论 俯卧位通气联合合适的PEEP可改善ARDS家猪氧合,并且不影响血流动力学和呼吸力学,肺组织损伤的重新分布可能是其机制之一.     

呼气末正压在治疗急性呼吸窘迫综合症中的应用及护理

综述在治疗急性呼吸窘迫综合症病人时使用呼气末正压的理论基础,以及近年来急性呼吸窘迫综合症机械通气策略中呼气末正压的应用。提出选择最佳呼气末正压的方法、最新观点和需要解决的问题。阐述运用呼气末正压在治疗急性呼吸窘迫综合症中的护理监护。     

呼气末正压在治疗急性呼吸窘迫综合症中的应用及护理

综述在治疗急性呼吸窘迫综合症病人时使用呼气末正压的理论基础，以及近年来急性呼吸窘迫综合症机械通气策略中呼气末正压的应用。提出选择最佳呼气末正压的方法、最新观点和需要解决的问题。阐述运用呼气末正压在治疗急性呼吸窘迫综合症中的护理监护。     

无创正压通气治疗急性呼吸窘迫综合征的前瞻性队列研究

目的 观察和评价无创正压通气(NPPV)对急性呼吸窘迫综合征(ARDS)的疗效和安全性.方法 采用前瞻性队列研究,分析2004年1月-2007年12月北京朝阳医院呼吸重症监护病房(RICU)使用NPPV治疗ARDS患者的临床资料.结果 ①31例患者纳入本研究,其中男23例,女8例;年龄20～76岁,平均(49±17)岁;NPPV前急性生理学与慢性健康状况评分系统Ⅰ(APACHE Ⅰ)评分(14±8)分,氧合指数(PaO2/FiO2)(123±32)mm Hg(1 mm Hg=0.133 kPa).②NPPV成功率为74.2%(23/31),非肺部感染所致ARDS的成功率显著高于肺部感染所致ARDS(100%比60%,P=0.017).③与NPPV前相比,成功组NPPV治疗后2 h及24 h的心率(HR)、呼吸频率(RR)及PaO2/FiO2均有显著改善(P均<0.01),而失败组上述指标不但无显著改善,尚伴有动脉血二氧化碳分压(PaCO2)逐渐升高(P<0.05).患者均无NPPV相关的严重并发症.结论 对于无NPPV禁忌的ARDS患者,NPPV可作为一线呼吸支持手段;但对于在短期应用NPPV后生命体征及动脉血气无显著改善者,尤其是肺部感染诱发ARDS时应及早改为有创通气.     

急性呼吸窘迫综合征机械通气时不同呼气末正压水平对每搏量变异度的影响

目的 观察急性呼吸窘迫综合征患者机械通气时逐渐升高呼气末正压(PEEP)水平对每搏量变异度(stroke volume variation,SVV)的影响,预测心前负荷及血液动力学变化,以指导临床治疗.方法 选择2012年9月～ 2013年10月符合2012年欧洲柏林ARDS新定义诊断标准的急性呼吸窘迫综合征危重患者30例,排除入院死亡及心衰患者,最终入选8例.给予机械通气治疗,逐渐升高PEEP水平,即PEEP 5 mmHg,PEEP 7 mmHg,PEEP 9 mmHg,PEEP 11 mmHg,PEEP 13 mmHg,PEEP 15 mmHg(1 mmHg =0.133 kPa).入选者均给予左侧桡动脉置入动脉导管,使用Vigileo系统监测血液动力学指标SVV及CO的值,同时记录MAP.入选者同时给予右侧锁骨下中心静脉置管,记录CVP.数据统计采用SPSS 17.0统计软件,结果以均数±标准差((x)±s)表示,组间比较用方差分析,组间两两比较采用SNK-q检验.结果 ①随着PEEP的变化,CO、SVV的变化均差异具有统计学意义(P＜0.01),而MAP的变化差异无统计学意义(P =0.933).②随着PEEP的升高,SVV总体呈S型升高趋势,但PEEP 5与PEEP 7之间、PEEP 13与PEEP 15之间SVV差异无统计学意义(P＜0.05).CO随着PEEP的升高成下降趋势.③在PEEP设置13 mmHg及以上时,SVV提示机体前负荷不足;PEEP 11 mmHg及以上时CO提示出现心输出量降低.CVP不能准确预测前负荷变化.结论 高水平PEEP可明显降低心脏前负荷,而SVV可作为高PEEP下心脏前负荷减少的参考指标用于指导临床液体治疗.     

无创正压通气治疗急性肺损伤/急性呼吸窘迫综合征的观察

目的 评价无创正压通气(NPPV)治疗急性肺损伤(ALI)／急性呼吸窘迫综合征(ARDS)患者的临床效果。方法 对18例ALI/ARDS患者实施NPPV治疗结果进行回顾性总结，分析NPPV治疗前后动脉血氧分压／吸氧浓度(PaO2／FiO2)、呼吸频率(RR)和心率(HR)的变化。结果 NPPV治疗成功率为55.6％(10／18)，8例NPPV治疗失败患者中7例改用气管插管有创通气。总死亡率为33．3％(6／18)。NPPV成功组50％(5／10)为ALI患者，治疗后1～2h PaO2／FiO2、RR和HR较治疗前有显著改善。NPPV失败组均为ARDS患者，治疗后1-2h PaO2／FiO2、RR和HR无明显变化。结论 NPPV对部分ALI／ARDS患者是有效的支持治疗手段，尤其是ARDS早期的ALI阶段可考虑选用NPPV。如NPPV治疗失败，应及时转换为气管插管有创通气。     

无创正压通气治疗急性呼吸窘迫综合征的研究

目的：探讨无创正压通气(NIPPV)治疗急性呼吸窘迫综合征(ARDS)改善疗效的因素。方法：23例ARDS患者按诱发因素分为肺内因素组(A组)和肺外因素组(B组)。选择不同呼吸机和鼻(面)罩行NIPPV，采用双相压力支持通气(BiPAP)；多功能呼吸机采用压力支持通气(PSV) 呼气末正压(PEEP)或同步间歇指令通气(SIMV) PSV PEEP。通气3—10h，不适合NIPPV的患者改建人工气道通气。结果：全程进行NIPPV治疗的患者A组5例，B组12例；NIPPV治愈A组为55．6％(5／9)；B组为85．7％(12／14)，P＜0．05。结论：选择合适的适应证，合理选择呼吸机、呼吸模式和治疗参数，并改善对NIPPV不利的影响因素，可以减少人工气道的使用。     

无创正压通气治疗创伤性湿肺的临床研究

目的 观察无创正压通气（NIPPV）治疗创伤性湿肺的疗效。方法 选择30例行无创正压通气治疗的创伤性湿肺患者为治疗组，24例未用NIPPV治疗的创伤性湿肺患者为对照组，通过对2组患者进行心电监测、血氧饱和度、呼吸频率、血气分析等指标的监测，比较2组患者呼吸频率和动脉血气参数、肺部病变吸收时间、气管插管率、ICU住院时间及预后。结果 30例创伤性湿肺患者经NIPPV治疗后动脉血气指标与临床表现明显改善（P〈0．01）；与对照组相比，NIPPV治疗组患者临床症状改善时间、肺部病变吸收时间、ICU住院时间明显缩短（P〈0．01），肺实变率显著减低（P〈0．05），但2组患者气管插管率和病死率差异却无显著性。结论 NIPPV通过调节压力支持与呼吸末正压水平，早期应用可明显改善创伤性湿肺患者病情及缩短病程，但并不能改善其预后。