1、ARDS患者的肺复张 ALI/ARDS的定义 ALI 急性起病 胸片对称的侵润影 PaO2/FiO2 300 mmHg PAWP 18 mmHg或没有左心衰的证据 ARDS 急性起病 胸片对称的侵润影 PaO2/FiO2 200 mmHg PAWP 18 mmHg或没有左心衰的证据 ARDS肺部形态学的改变 Puybasset L,et al.Regional distribution of gas and tissue in acute respiratory distress syndrome.I.Consequences for lung morphology.Intensive Car
2、e Med 2000;26:857-69.ARDS肺部形态学的改变 ARDS患者 健康对照 CT平均密度(HU)-256 21-654 8 组织容积(ml/m2 BSA)31.6 1.7 16.7 0.8 气体容积(ml/m2 BSA)11.5 1.2 32.2 1.8 胸腔内总容积(ml/m2 BSA)43.0 2.3 49.0 2.5 Gattinoni L,et al.Relationships between lung computed tomographic density,gas exchange and PEEP in acute respiratory failure.Anes
3、thesiology 1988;69:824-32.ARDS肺部形态学的改变 Patroniti N,Bellani G,Maggioni E,Manfio A,Marcora B,Pesenti A.Measurement of pulmonary edema in patients with acute respiratory distress syndrome.Crit Care Med 2005;33:2547-2554 ARDS肺部形态学的改变 GATTINONI -3 ZONES 过度膨胀,“干”,“婴儿肺 湿,PEEP可使其复张 塌陷或实变区域 HEARTSPGattinoni
4、L.J Thorac Imag 1986;1(3):25 ARDS肺部形态学的改变 婴儿肺(BABY LUNG)的概念 通气的肺仅相当于正常肺的20 30%ARDS患者肺容积的减少并非意味胸腔内总容积的减少 仅仅是实变组织替代了气体 Gattinoni L,et al.Relationships between lung computed tomographic density,gas exchange and PEEP in acute respiratory failure.Anesthesiology 1988;69:824-32.气压伤(barotrauma)机械通气导致肺过度牵张所引
5、起的肺损伤 容积伤(volutrauma)Normal rat lungs PIP 45,5 min PIP 45,20 mins 剪切力损伤(atelectrauma)指由于肺泡反复塌陷和复张所造成的损伤 肺泡塌陷时的剪切力损伤 驱动压力30 cmH2O时 通气肺泡与不通气肺泡交界处的剪切力可高达140 cmH2O(Mead 1970)F=PL x(V0/V)2/3 ARDS保护性肺通气策略 机械通气时有两个肺损伤区域 肺容积过低可导致剪切力损伤 肺容积过高可导致肺泡过度牵张，引起容积伤 Froese AB,Crit Care Med 1997;25:906 肺开放与ARDS Editori
6、al Open up the lung and keep the lung open B.Lachmann Dept.of Anesthesiology,Erasmus University Rotterdam,The Netherlands (1992)18:319-321 肺泡通气与吹气球 肺复张与ARDS ARDS的肺复张 CPAP CPAP 30 45 cmH2O PCV PC 15 cmH2O PEEP 30 45 cmH2O 叹气(Sigh)肺复张操作 肺复张前5 10分钟将FiO2提高到1.0 通常需要镇静以保证肺复张过程中无自主呼吸 首先用CPAP 30 cmH2O共30 40
7、秒 之后仔细评估效果 肺复张操作 如果效果不明显，但患者耐受较好 应在15 20分钟后用更高水平的CPAP(35 40 cmH2O)进行肺复张 如果第二次肺复张操作效果也不佳 应当进行第三次肺复张操作 CPAP 40 cmH2O 肺复张操作 部分患者可能需要进行多次肺复张操作才能显示效果 Fujino et al,AJRCCM 1999 肺复张操作 尚不清楚是否需要使用40 cmH2O以上的压力 动物试验表明 高达60 cmH2O的压力是安全的 尽管这样高的压力仍处于试验阶段，且需要在密切监测的条件下谨慎实施 Fujino et al AJRCCM 1999 肺复张操作 如果CPAP 40 c
8、mH2O 30 40秒不足以使肺复张 PCV 20 cmH2O,PEEP 30 cmH2O,I:E 1:1,f 10 bpm for 2 min 如果仍然无效 PCV 20 cmH2O,PEEP 40 cmH2O,I:E 1:1,f 10 bpm for 2 min 一些动物可能出现CO轻度下降，PAP升高 所有试验动物在10分钟内血流动力学均恢复到肺复张前的状态 Fujino et al AJRCCM 1999 如果判断肺复张成功?PaO2/FiO2 300 mmHg 或 PaO2+PaCO2 400 mmHg 肺复张能够改善ARDS氧合 Lapinsky SE,Aubin M,Mehta
9、S,Boiteau P,Slutsky AS:Safety and efficacy of a sustained inflation for alveolar recruitment in adults with respiratory failure.Intensive Care Med 1999,25:1297-1301.肺复张能够改善氧合 Schreiter D,Reske A,Stichert B,Seiwerts M,Bohm SH,Kloeppel R,Josten C.Alveolar recruitment in combination with sufficient pos
10、itive endexpiratory pressure increases oxygenation and lung aeration in patients with severe chest trauma.Crit Care Med 2004;32:968-975 肺复张能够维持肺泡稳定 Schreiter D,Reske A,Stichert B,Seiwerts M,Bohm SH,Kloeppel R,Josten C.Alveolar recruitment in combination with sufficient positive endexpiratory pressur
11、e increases oxygenation and lung aeration in patients with severe chest trauma.Crit Care Med 2004;32:968-975 PEEP能够有效维持氧合 Lapinsky SE,Aubin M,Mehta S,Boiteau P,Slutsky AS:Safety and efficacy of a sustained inflation for alveolar recruitment in adults with respiratory failure.Intensive Care Med 1999,
12、25:1297-1301.反复肺复张的作用 Fujino Y,Goddon S,Dolhnikoff M,Hess D,Amato MBP;Kacmarek RM.Repetitive high-pressure recruitment maneuvers required to maximally recruit lung in a sheep model of acute respiratory distress syndrome.Crit Care Med 2001;29:1579-1586 肺复张对脑氧代谢的影响 Bein T,Kuhr LP,Bele S,Ploner F,Keyl
13、C,Taeger K.Lung recruitment maneuver in patients with cerebral injury:effects on intracranial pressure and cerebral metabolism.Intensive Care Med 2002;28:554-558 肺复张对内脏血流的影响 Nunes S,Rothen HU,Brander L,Takala J,Jakob SM.Changes in Splanchnic Circulation During an Alveolar Recruitment Maneuver in Hea
14、lthy Porcine Lungs.Anesth Analg 2004;98:1432-8 肺复张的副作用 血流动力学紊乱 延迟到血流动力学稳定后再进行 发生气压伤 需对以下患者评估利弊 既往肺部囊性或大泡性疾病 既往肺部漏气 肺复张期间对患者的监测 动脉血压 脉搏和心律 SpO2 如果出现并发症 立即终止肺复张操作 肺复张对护士的要求 了解肺复张的目的 密切监测生命体征的变化 肺复张后不要轻易脱开呼吸机 吸痰 吸痰对氧合及肺容积的影响 Dyhr T,Bonde J,Larsson A:Lung recruitment maneuvers are effective to regain lu
15、ng volume and oxygenation after open endotracheal suctioning in acute respiratory distress syndrome.Crit Care 2003,7:55-62 吸痰管大小与压力改变 Morrow BM,Futter MJ,Argent AC.Endotracheal suctioning:from principles to practice.Intensive Care Med 2004;30:1167-1174 吸痰导致氧合下降 Lasocki S,Lu Q,Sartorius A,Fouillat D,
16、Remerand F,Rouby J-J.Open and Closed-circuit Endotracheal Suctioning in Acute Lung Injury:Efficiency and Effects on Gas Exchange.Anesthesiology 2006;104:39-47 吸痰对氧合的影响 Lindgren S,Almgren B,Hgman M,Lethvall S,Houltz E,Lundin S,Stenqvist O.Effectiveness and side effects of closed and open suctioning:an experimental evaluation.Intensive Care Med 2004;30:1630-1637 肺复张防止吸痰导致的肺容积减少 SWIVELpsv CLOSEDpsv CLOSED SWIVEL DISCONNECTION Prevention of Endotracheal Suctioning-induced Alveolar Derecruitment in A
