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, 25: 1297-1301.
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 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
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
Editorial
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
ARDS肺部形态学的改变
GATTINONI - 3 ZONES
HEART SP
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): 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%
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
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
ARDS患者的肺复张 nursing
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
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: 968-975
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
– 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
ARDS肺部形态学的改变
ARDSபைடு நூலகம்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
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
– 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
Gattinoni 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
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.
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.
– 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
肺复张与ARDS
ARDS的肺复张
• CPAP
• CPAP 30 – 45 cmH2O
• PCV
• PC 15 cmH2O • PEEP 30 – 45 cmH2O