ARDS患者的肺复张 -

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.
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.
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
GATTINONI - 3 ZONES
过度膨胀, “干”, “婴儿肺"
HEART
湿, PEEP可使其复张
塌陷或实变区域
SP
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%
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
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
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
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.
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
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
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
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.
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
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0要镇静以保证肺复张过程中无自
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
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
2/3 (V0/V)ARD Nhomakorabea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