ARDS机械通气策略的评估.ppt

1、ARDS机械通气策略的评估,北京协和医院 杜斌,ARDS的回顾,1967年Ashbaugh提出 1985年病理生理研究 1990年肺保护性通气策略 1998年Amato 2000年NHBLI的ARDSnet多中心研究 1995年首次报道ARDS病死率降低,内容,什么是ARDS,1,如何选择潮气量,2,如何设定PEEP,3,4,是否需要肺复张,内容,如何选择潮气量,2,如何设定PEEP,3,4,是否需要肺复张,什么是ARDS,1,什么是ALI / ARDS,ALI 急性起病 PaO2/FiO2 300 CXR: 双侧浸润影 PAWP 18 mmHg,ARDS 急性起病 PaO2/FiO2 200

2、 CXR: 双侧浸润影 PAWP 18 mmHg,什么是ARDS,ARF发病率(1994) 137.1例/100,000人口/年 ALI发病率(1996 1999) 22.4 64.2例/100,000人口/年,Behrendt CE. Acute respiratory failure in the United States incidence and 31-day survival. Chest 2000; 118: 1100-5 Goss CH, Brower RG, Hudson LD, et al. Incidence of Acute Lung Injury in the Uni

3、ted States. Crit Care Med 31(6):1607-1611, 2003,ARDS在中国,上海12所大学医院15个ICU 2001 2002年间5320名患者收入ICU 108名(2%)发生ARDS PaO2/FiO2111.3 40.3 APACHE II17.3 8.0 肺源性38% (41), 肺外源性62% (67) 肺炎34.3%, 其他部位感染30.6% 住院病死率68.5%,Lu Y, Song Z, Zhou X, Huang S, Zhu D, Yang C, Bai X, Sun B, Spragg R; Shanghai ARDS Study Gro

4、up. A 12-month clinical survey of incidence and outcome of acute respiratory distress syndrome in Shanghai intensive care units. Intensive Care Med. 2004 Dec; 30(12):2197-203,什么是ARDS,Moss M, Mannino DM. Race and gender differences in acute respiratory distress syndrome deaths in the United States: a

5、n analysis of multiple-cause mortality data (1979-1996). Crit Care Med 2002; 30(8): 1679-1685,什么是ARDS,Moss M, Mannino DM. Race and gender differences in acute respiratory distress syndrome deaths in the United States: an analysis of multiple-cause mortality data (1979-1996). Crit Care Med 2002; 30(8

6、): 1679-1685,什么是ARDS,Herridge M, Cheung AM, Tansey CM, et al. One-year outcomes in survivors of the acute respiratory distress syndrome. N Engl J Med 2003; 348: 683-93.,什么是ARDS,Herridge M, Cheung AM, Tansey CM, et al. One-year outcomes in survivors of the acute respiratory distress syndrome. N Engl

7、J Med 2003; 348: 683-93.,什么是ARDS,ARDS病死率40 60% 病因学未知 治疗支持性 机械通气肺损伤,如何对ARDS患者进行机械通气, 而不导致或加重肺损伤?,内容,什么是ARDS,1,如何选择潮气量,2,如何设定PEEP,3,4,是否需要肺复张,如何选择潮气量,充分的气体交换 减少呼吸机相关性肺损伤的危险 低容量: 周期性肺泡塌陷和复张 高容量: 牵张/过度膨胀,VALI 动物试验证据,Dreyfuss DP. AJRCCM 1988; 137:1159,肺过度膨胀与肺炎克氏菌菌血症,目的: 检验PIP和PEEP对菌血症发生的影响 方法: 80只大鼠, 气道内

8、植入肺炎克氏菌 植入细菌22小时后进行机械通气3小时 4种通气策略(13/3; 13/0;30/10;30/0) 血培养,Verbrugge, Lachmann Intens Care Med 1998;24:172-7,VALI 临床试验证据,ARDS潮气量的选择 临床试验, measured body weight; ideal body weight = 25 x (height in meters)2; Dry weight measured weight minus estimated weight gain from salt and water retention; Predic

9、ted body weight 50 (for males) or 45.5 (for females) + 2.3 (height in inches) - 60,ARDS潮气量的选择 临床试验,组间潮气量差异大 ARDSnet: 6.2 vs 11.8; Steward: 7.2 vs 10.8; Brochard: 7.1 vs 10.3 大样本量(n= 861)足以检测组间的差异 酸中毒的治疗 与其他临床试验相比, 采用增加RR以及输注碳酸氢钠的方法纠正轻至中度酸中毒, 因此组间PaCO2和pH值差异较小 ARDSnet: PaCO2: 41.5 vs 35.5; pH: 7.38 v

10、s 7.41 (目标: 7.3 7.45); Steward: 54.4 vs 45.7; 7.29 vs 7.34 (下限: 7.0); Brochard: 59.5 vs 41.3; 7.28 vs 7.4 (下限: 7.05),ARDS小潮气量临床试验的差异,还有其他的原因吗?,临床试验的差异性,平台压的改变,荟粹分析的提示,2项阳性试验的对照组潮气量与临床情况存在差异, 因而不能确定试验组是否优于临床治疗 大潮气量(12 ml/kg)组气道压高( 34 cm H2O), 患者预后差,荟粹分析的提示,3项阴性试验的对照组与临床情况非常接近 只要气道压力介于28 32 cmH2O, 进一步

11、降低潮气量(6 7 ml/kg), 患者不会额外受益,荟粹分析的提示,气道平台压力作为主要指标 一致的治疗指标 与VALI密切相关,Amato的研究还有哪些提示,Parshuram C and Kavanagh B. Meta-analysis of tidal volumes in ARDS. Am J Respir Crit Care Med 2003; 167: 798,ARDSNet研究中最初的潮气量,ARDSNet研究中符合入选标准但未参与试验患者的生存率,P = 0.002,Krishnan JA, Hayden D, Schoenfeld D, Bernard G, Brower

12、 R. (for the NHLBI ARDSNetwork Investigators). Outcome of participants vs. eligible nonparticipants in a clinical trial of critically ill patients Abstract. Am J Respir Crit Care Med 2000;161:A210,有关机械通气的世界性调查结果,1992年的情况 超过1,000名受调查者 45%表明会将潮气量限制在5 9 ml/kg(实际体重) 96%表明潮气量的选择受到气道压力的影响,Carmichael LC, D

13、orinsky PM, Higgins SB, Bernard GR, Dupont WD, Swindell B, Wheeler AP. Diagnosis and therapy of acute respiratory distress syndrome in adults: an international survey. J Crit Care 1996; 11: 918,1994年的教科书,Assuming that inflating the lungs to volumes above TLC is unsafe, it has become common practice

14、to reduce VT to no more than 7 cm3/kg actual body weight in the management of ARDS,Hubmayr RD. Setting the ventilator. In: Tobin MJ, editor. Principles and practice of mechanical ventilation. New York: McGraw-Hill; 1994, p. 191206.,NIH研究中6 ml/kg和12 ml/kg潮气量组患者病死率与第1天平台压的关系,1.0,0.8,0.6,0.4,0.2,0,Lowe

15、ss smoother, bandwidth = .8 12 ml/kg group. Proportion discharge dead,0,20,26,31,37.3,60,Mean Pplat on day 1,1.0,0.8,0.6,0.4,0.2,0,Lowess smoother, bandwidth = .8 6 ml/kg group. Proportion discharge dead,0,20,25,32,60,Mean Pplat on day 1,NIH研究中6 ml/kg和12 ml/kg潮气量组患者病死率与第1天平台压的关系,1.0,0.8,0.6,0.4,0.2,

16、0,0,20,26,31,37.3,60,Mean Pplat on day 1,Petrucci, Lacovelli. Meta-analysis Small Vt Cochrane Database 2003: 3,所有5项研究, 共1,202名患者 小潮气量组病死率降低 216/605 (35.7%) vs. 249/597 (41.7%) p 0.05 RR0.85 (CI 0.74 0.98) 然而, 如果平台压 31 cmH2O, 小潮气量与大潮气量组患者间并无显著差异 RR1.13 (CI 0.88 1.45),对ARDS病死率的影响,Pplat 30 cmH2O, 无论潮气量

17、如何, 病死率均降低 Pplat越低, 预后越好 与10 12 ml/kg相比, 5 8 ml/kg潮气量降低病死率? 调整呼吸频率以纠正PaCO2 (只要没有内源性PEEP, 35 40 bpm),内容,什么是ARDS,1,如何选择潮气量,2,如何设定PEEP,3,4,是否需要肺复张,PEEP Story: 1936 2005,Minimal PEEP Best PEEPSuter (1975) Super PEEPKirby (1975) DiRusso (1995) Optimal PEEPMatamis (1984) CT ScanGattinoni (1993),最小PEEP,在可接

18、受的FiO2下维持充分氧合(PaO2)所需的PEEP水平 如何定义最小PEEP? 充分氧合SpO2 88%1 可接受FiO2FiO2 0.602,Brower RG, Lanken PN, MacIntyre N, et al. Higher versus lower positive endexpiratory pressures in patients with the acute respiratory distress syndrome. N Engl J Med 2004; 351:327336. Amato MBP, Barbas CSV, Medeiros DM, Magaldi

19、 RB, Schettino G, Lorenzi-Fihlo G, Kairalla RA, Deheinzelin D, Munoz C, Oliveira R, Takagaki TY, Carvalho CRR. Effect of protective-ventilation strategy on mortality in the acute respiratory distress syndrome. N Engl J Med 1998; 338: 347-354,最佳PEEP,保证氧输送(DO2)达到最大值的PEEP水平,Peter M Suter, et al. N Engl

20、 J Med 1975; 284,超高PEEP: Qs/Qt 0.20,PEEP up to 25 cmH2O well tolerated in healthy rhesus monkeys with Intermittent mandatory ventilation Intravascular volume expansion Careful cardiovascular monitoring,Kirby RR, Perry JC, Calderwood HW, Ruiz BC, Lederman DS. Cardiorespiratory effects of high positiv

21、e end-expiratory pressure. Anesthesiology. 1975 Nov; 43(5):533-9.,如何选择PEEP,ARDS肺形态学,重力依赖区域的肺不张,重力依赖区域的肺不张,重力依赖区域的肺不张,Control: VT 7; PEEP 3 MVHP: VT 15; PEEP 10 MVZP: VT 15; PEEP 0 HVZP: VT 40; PEEP 0,Tremblay L. J Clin Invest 1997; 99:944,PEEP 动物试验证据,病死率的比较,Villar (待发表),RCT 严重ARDS P/F 200 mmHg 高PEEP

22、, 小潮气量 vs. 低PEEP, 中等潮气量 对照组: Vt 9 11 ml/kg PBW, PEEP 5 cmH2O 治疗组: Vt 5 8 ml/kg PBW, PEEP Pflex + 2 cmH2O 目标: PCO2 35 50 mmHg, PO2 70 100 mmHg 通过调整呼吸频率纠正PCO2 治疗: 氧合恶化 增加PEEP 氧合改善 降低FiO2,Villar (待发表) 第1天,Villar (待发表),Villar (待发表),对照组治疗组 N = 50N = 53 病死率54%病死率30% 在最终的数据分析期间发现, 一个研究中心的随机分组存在问题, 因而需要删除该中

23、心入选患者的相关数据 N = 45N = 50 病死率53.3%病死率32% P = 0.04 (0.017),Villar (待发表),高PEEP能否改善ARDS患者的预后?,Amato NEJM 1998; 338: 347 (n = 53) Absolute mortality difference33% NNT3.03 Villar, Kacmarek (待发表) (n = 95) Absolute mortality difference21.3% NNT4.7 ARDSnet NEJM 2000; 342: 1305 (n = 861) Absolute mortality dif

24、ference8.9% NNT11.2,ALVEOLI试验 假设,对于接受限制容量和压力的 ALI/ARDS患者, 更高的PEEP可能改善临床预后,NHLBI ARDS Clinical Trial Network. Higher versus Lower Positive End-Expiratory Pressures in Patients with the Acute Respiratory Distress Syndrome. N Engl J Med 2004; 351: 327-36.,ALVEOLI试验设计,动脉氧合:SpO2 = 88 - 95% PaO2 = 55 - 80

25、 mmHg,NHLBI ARDS Clinical Trial Network. Higher versus Lower Positive End-Expiratory Pressures in Patients with the Acute Respiratory Distress Syndrome. N Engl J Med 2004; 351: 327-36.,ALVEOLI试验结果 PEEP,*,*,*,*,*,Low PEEP,High PEEP,PEEP cm H2O,Study Day,NHLBI ARDS Clinical Trial Network. Higher versu

26、s Lower Positive End-Expiratory Pressures in Patients with the Acute Respiratory Distress Syndrome. N Engl J Med 2004; 351: 327-36.,ALVEOLI试验 平台压,*,*,*,NHLBI ARDS Clinical Trial Network. Higher versus Lower Positive End-Expiratory Pressures in Patients with the Acute Respiratory Distress Syndrome. N

27、 Engl J Med 2004; 351: 327-36.,ALVEOLI试验 住院病死率,P=0.56,NHLBI ARDS Clinical Trial Network. Higher versus Lower Positive End-Expiratory Pressures in Patients with the Acute Respiratory Distress Syndrome. N Engl J Med 2004; 351: 327-36.,ALVEOLI试验 总结,550名患者 试验中期结束 无显著差异: 病死率 脱离呼吸机天数 ICU以外住院日,NHLBI ARDS C

28、linical Trial Network. Higher versus Lower Positive End-Expiratory Pressures in Patients with the Acute Respiratory Distress Syndrome. N Engl J Med 2004; 351: 327-36.,高PEEP对病死率的影响,Favors Lower PEEP,Favors Higher PEEP,Mortality Difference,Unadjusted,(95% Confidence Intervals),NHLBI ARDS Clinical Tria

29、l Network. Higher versus Lower Positive End-Expiratory Pressures in Patients with the Acute Respiratory Distress Syndrome. N Engl J Med 2004; 351: 327-36.,ALVEOLI试验 高PEEP为何无效?,高PEEP的有益作用被副作用抵消? 需要进行肺复张? “低PEEP”足以防止低呼气末容积通气所导致的肺损伤? 低潮气量和气道平台压力减少了低呼气末容积通气所导致的肺损伤?,NHLBI ARDS Clinical Trial Network. Hig

30、her versus Lower Positive End-Expiratory Pressures in Patients with the Acute Respiratory Distress Syndrome. N Engl J Med 2004; 351: 327-36.,为什么评价PEEP对ARDS患者预后影响的研究存在差异?,设定PEEP的方法 ARDSnet 采用PEEP/FiO2表 Alveoli 采用PEEP/FiO2表 Ranieri PV曲线 Amato PV曲线 Villar PV曲线 Kacmarek 至少13 cmH2O,内容,什么是ARDS,1,如何选择潮气量,2

31、,如何设定PEEP,3,4,是否需要肺复张,有关呼吸力学的假设和现实,假设 PEEP可以使塌陷的肺泡复张 现实 PEEP并不能使肺泡复张 PEEP能够防止已经复张的肺泡再次塌陷,PV曲线: 吸气支和呼气支,呼气相肺泡塌陷与吸气相肺泡塌陷密切相关,Crotti S, Mascheroni D, Caironi P, Pelosi P, Ronzoni G, Mondino M, Marini JJ, Gattinoni L. Recruitment and derecruitment during acute respiratory failure: a clinical study. Am J

32、 Respir Crit Care Med 2001: 164: 131-140.,Decremental PEEP Associated With Best Compliance,Hickling KG. Best compliance during a decremental, but not incremental, positive end- expiratory pressure trial is related to open-lung positive end- expiratory pressure. A mathematical model of acute respirat

33、ory distress syndrome lungs. Am J Respir Crit Care Med 2001: 163: 69-78.,PEEP (cmH2O),Mean tidal PV slope (ml/cmH2O),Maximum PV slope at PEEP 16,Maximum PV slope at PEEP 20,Incremental PEEP,Decremental PEEP,Hickling的数学模型,The Pressure-Volume Curve Is Greatly Modified by Recruitment A Mathematical Model of ARDS Lungs KEITH G. HICKLING Intensive Care Unit and Department of Anaesthesia, Queen Elizabeth Hospital,