《《ards肺复张的测定》ppt课件》由会员分享，可在线阅读，更多相关《《ards肺复张的测定》ppt课件（87页珍藏版）》请在金锄头文库上搜索。
1、急性呼吸窘迫综合征肺复张的测定与应用,内容提要,ARDS病理生理 ARDS肺复张容积测定 P-V曲线法 等压法 CT法：Gattinonis vs Roubys ARDS肺复张测定应用 明确肺不张的分布与特点 评价SI or Sigh的肺复张作用 评价PEEP维持肺复张的作用 指导PEEP选择,Lung volume decreased markedly (TLC, VC, TV, FRC) -alveolar edema -pulmonary surfactant -Interstitial pumonary edema depress brochiole and induce spasm
2、Compliance reduced significantly Ventilation/perfusion mismatch -intrapulmonary shunt and dead space like effects,ARDS病理生理特点,ARDS病理生理,CT scan 70-80% 的肺野呈现高密度区 分布：下垂部位(dependent field) 提示： 参与通气肺泡明显减少(20-30%) 肺损伤具有不均一性,肺容积减少Small lung Baby Lung,ARDS病理生理,A and C finding in the acute or exudative phase,
3、B and D Finding in the fibrosing-alveolitis phase,ARDS病理生理,肺容积/顺应性明显降低,ARDS病理生理,Reduced range of volume excursion: Low compliance Flattening at low and high volumes: Lower and upper inflection points Bigatello: Br J Anaest 1996,Volume,Pressure,NORMAL,ARDS,顺应性曲线明显右下移位,肺顺应性明显降低,ARDS病理生理,Upper and Lowe
4、r Inflection Points,Lower 呼气末肺泡塌陷 吸气早期肺泡再开放 Upper 吸气末肺泡顺应性明显 降低，肺泡过度膨胀,ARDS病理生理,Volume,Pressure,Lower Inflection Point,Upper Inflection Point,通气/血流失调,肺泡塌陷：ARDS重力依赖区，炎症或不张区 生理性低氧缩血管反应：障碍,ARDS病理生理,Imagine the Hardness to Blow up a Ballon .,easy,hard,spatial & elastic limitations,Laplacian Law,It needs
5、 higher initial pressures to overcome the surface tension to open up a bubble to wider diameters!,ARDS病理生理,Sustain inflation Sigh 小潮气量通气PHC, 避免肺泡过度膨胀 最佳PEEP避免剪切力(Shear force)性损害,Volume,Pressure,肺开放与保护性通气策略的基本内容,ARDS病理生理,Lung volume decreased markedly,Atelectrauma,Keep the lung open,Open the lung,Pre
6、vent volutrauma,SI and Sigh,PEEP,ARDS病理生理,内容提要,ARDS病理生理 ARDS肺复张容积测定 P-V曲线法 等压法 CT法：Gattinonis vs Roubys ARDS肺复张测定应用 明确肺不张的分布与特点 评价SI or Sigh的肺复张作用 评价PEEP维持肺复张的作用 指导PEEP选择,PV曲线法,Step 1: 测量PEEP所致的FRC(吸气末撤掉PEEP并延长呼气时间) FRCVE(ZEEP) VE(PEEP),肺复张容积测定,PV曲线法,Step 2: 分别描计ZEEP和PEEP的PV曲线 Step 3: 肺复张容积： RV= V20
7、(PEEP) + FRC V20(ZEEP),肺复张容积测定,等压法,呼吸模式：BIPAP 条件：Ph 20 cmH2O， PEEP分别为0 、5 、 10、15 cmH2O，Ti 6S 测定：延长呼气时间，测定ZEEP呼出气量。在不同PEEP时吸气末撤掉PEEP，延长呼气时间，测定呼气量,肺复张容积测定,等压法,肺复张容积测定,P-V曲线法与等压法的比较,肺复张容积测定,肺复张容积测定P-V曲线法,等压法虽然简单，但准确性较差 不能代替P-V曲线法 目前肺复张容积的测定仍宜采用 P-V曲线法,肺复张容积测定,CT method,膈顶上1cm CT层面 PEEP与ZEEP比较 Gattinon
8、i L. Am J Respir CCM, 1995, 151: 1807 全肺扫描 区别过度膨胀，膨胀，部分复张和塌陷区 Luiz M, Rouby JJ. Am J Respir CCM, 2001,163:1444,肺复张容积测定,CT法-Gattinoni,肺复张容积测定,原理 CT空气=0Hu，CT水=1000 Hu CT值=500Hu，肺组织50%空气+50%水 ARDS塌陷肺CT值100Hu100Hu，塌陷肺泡复张 后，100Hu+100Hu内肺组织减少 方法 ZEEP和PEEP通气呼气末CT扫描 膈肌顶上1cm 计算CT值在100 Hu 100 Hu范围内体素结果之差,Gatt
9、inoni L. Am J Respir CCM, 1995, 151: 1807,原理 充气不良区(100Hu500Hu)、正常充气区(500Hu 900Hu)、无充气区(100Hu+100Hu)和过度充气区(900Hu1000Hu)。肺泡复张，充气不良和正常充气肺区体积增加 方法 ZEEP和PEEP呼气末螺旋CT，根据层面厚度计算不同CT值肺体积，肺复张后充气不良与正常充气肺组织体积增加值,肺复张容积测定,CT法- Rouby,Luiz M, Rouby JJ. Am J Respir CCM, 2001,163:1444,Gattinonis vs Roubys CT法比较,肺复张容积测
10、定,CT methods: Rouby vs Gattinoni,Luiz M, Rouby JJ. Am J Respir CCM, 2001,163:1444,肺复张容积测定,内容提要,ARDS病理生理 ARDS肺复张容积测定 P-V曲线法 等压法 CT法：Gattinonis vs Roubys ARDS肺复张测定应用 明确肺不张的分布与特点 评价SI or Sigh的肺复张作用 评价PEEP维持肺复张的作用 指导PEEP选择,ARDS肺不张的影响因素-附加静水压,Hydrostatic pressure = (1 CT/-1000) Height Maximum sternoverte
11、bral dimention of human thorax: 20cmH2O PEEP 20cmH2O不能使ARDS患者肺泡完全复张 动物ARDS,Mean Airway pressure 25 cm H2O,ARDS肺复张应用,ARDS下肺气体含量明显降低,CT scan ARDS study group. AJRCCM, 2000,161:2005,ARDS肺复张应用,CT section lcated 5 cm below the carina No differences were observed in the percentage of lower lobes located b
12、eneath the heart in two groups,CT scan ARDS study group. AJRCCM, 2000,161:2005,ARDS肺不张的影响因素 -heart lung interdependence,ARDS肺复张应用,Cardiac mass and volume in ARDS,Cardiac mass was increased by 27% vs NS Mechanism of cardiac mass: Edema of cardiac wall RV dilation secondary to pul hypertension Hyperki
13、netic state related to SIRS,CT scan ARDS study group. AJRCCM, 2000,161:2005,ARDS肺复张应用,心脏下肺叶气体量明显降低 ARDS 73% vs NS 21%,Closed bar: Fraction of gas in lower lobes located beneath the heart Open bar: lower lobes located outside the heart,CT scan ARDS study group. AJRCCM, 2000,161:2005,ARDS肺复张应用,塌陷肺泡的分布
14、,Local: Loss of aeration predominating in lower lobes Diffuse: Equal loss of aeration to the upper and lower lobes,ARDS肺复张应用,Lung morphology pattern,Local Diffuse LIP No Yes Normally aerated 5512% 24 12% Poorly aerated 23 8% 40 12% Distribution modal Bimodal Unimodal Peak of CT distr -727Hu/27Hu 7Hu
15、 Compltot 57 5 46 11,Vieira SRR. AJRCCM, 1999, 159: 1612,ARDS肺复张应用,Diffuse distribution,ARDS肺复张应用,ARDS肺复张应用,local distribution,内容提要,ARDS病理生理 ARDS肺复张容积测定 P-V曲线法 等压法 CT法：Gattinonis vs Roubys ARDS肺复张测定应用 明确肺不张的分布与特点 评价VT和SI or Sigh对肺复张的影响 评价PEEP维持肺复张的作用 指导PEEP选择,SI前后绵羊复张容积的变化,*,*,与SI前相比，*P 0.05,ARDS肺复张
16、应用,SI有效组绵羊肺气体交换变化,*,*,与SI前相比，*P 0.05,ARDS肺复张应用,潮气量对肺复张的影响,A:PEEP=0, B:PEEP=Pflex, C:at the end of inspiration, D:PEEP=Pflex as in C during expiration,Pelosi P, Goldner M, Mckibben A, et al. Am J Respir Crit Care Med, 2001, 164, 131-140,ARDS肺复张应用,小潮气量通气的局限性,Cretti S, Mascheroni D, Caironi P, et al. Am J Respir Crit Care Med, 2001,
