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 mmHgPAWP 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 mmHgPAWP 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 Care 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 1.716.7 0.8气体容积(ml/m2 BSA)11.5 1.232.2 1.8胸腔内总容积(ml/m2 BSA)43.0 2.349.0 2.5Gattinoni L, et al. Relationships between lung computed tomographic density, gas exchange and PEEP in acute respiratory failure. Anesthesiology 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: 2547-2554ARDS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Gattinoni L. J Thorac Imag 1986; 1(3): 25ARDS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起的肺损伤容积伤(volutrauma)Normal rat lungsPIP 45, 5 minPIP 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)2/3ARDS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ARDSEditorialOpen up the lung and keep the lung openB. LachmannB. LachmannDept. of Anesthesiology, Erasmus University Rotterdam, The NetherlandsDept. of Anesthesiology, Erasmus University Rotterdam, The Netherlands(1992) 18:319-321(1992) 18:319-321肺泡通气与吹气球肺复张与ARDSARDS的肺复张CPAPCPAP 30 45 cmH2OPCVPC15 cmH2OPEEP 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0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 cmH2O 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 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 positive 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 pressure increases oxygenation and lung aeration in patients with severe chest trauma. Crit Care Med 2004; 32: 968-975PEEP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, 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 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 Healthy 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 lung 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, 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SWIVELpsvCLOSEDpsvCLOSEDSWIVELDISCONNECTIONPrevention of Endotracheal Suctioning-induced Alveolar Derecruitment in Acute Lung Injury Maggiore SM, Lellouche F, Pigeot J, Taille S, Deye N, Durrmeyer X, Richard J-C, Mancebo J, Lemaire F, Brochard L. Am J Respir Crit Care Med 2003; 167: 1215-1224肺复张能够防止吸痰导致的氧合下降Lasocki S, Lu Q, Sartorius A, Fouillat D, 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肺复张: 总结ARDS患者有效肺容积缩小肺泡反复塌陷与开放导致剪切力损伤肺复张是保护性通气策略的重要组成肺复张的成功取决于足够的压力与时间合适的PEEP医务人员的理解