Badet Michel, Bayle Frédérique, Richard Jean-Christophe, Guérin Claude
Service de Réanimation Médicale et Assistance Respiratoire, Hôpital de la Croix Rousse, 69004 Lyon, France.
Respir Care. 2009 Jul;54(7):847-54. doi: 10.4187/002013209793800448.
In patients with acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), the use of alveolar-recruitment maneuvers to improve oxygenation is controversial. There is lack of standardization and lack of clinical studies to compare various recruitment maneuvers. Recruitment maneuvers are closely linked to the selection of positive end-expiratory pressure (PEEP), which is also a subject of debate.
With 12 intubated and mechanically ventilated patients with early ALI/ARDS we conducted a recruitment maneuver (sustained inflation at 40 cm H(2)O for 30 s), then set PEEP at 24 cm H(2)O, and then we reduced PEEP stepwise, by 4 cm H(2)O every 10 min. We kept the fraction of inspired oxygen (F(IO(2))) at 0.8. After each PEEP decrement step we measured P(aO(2)). We defined the "optimal" PEEP as the PEEP step above which P(aO(2)) decreased by > or = 20%. All the patients then underwent a period of ventilation on the same settings: tidal volume 6 mL/kg, PEEP at the level set by the physician before the experiment, plateau pressure < 30 cm H(2)O. Then each patient underwent 3 ventilation strategies, each applied for one hour: optimal PEEP alone; optimal PEEP plus one sustained inflation (40 cm H(2)O for 30 s); and optimal PEEP plus sigh breaths (ie, twice the baseline tidal volume, plateau pressure < 40 cm H(2)O) every 25 breaths. After the application of each PEEP strategy we measured arterial blood gas values and the static compliance of the respiratory system.
The mean +/- SD optimal PEEP was 12 +/- 4 cm H(2)O. The measurements from the standardization periods were comparable between the 3 PEEP groups. In the optimal-PEEP-plus-sighs group the changes in P(aO(2)) (85 +/- 96%) and static compliance (14 +/- 20%) were significantly greater than in the 2 other groups.
Sighs superimposed on lung-protective mechanical ventilation with optimal PEEP improved oxygenation and static compliance in patients with early ALI/ARDS.
在急性肺损伤（ALI）/急性呼吸窘迫综合征（ARDS）患者中，使用肺泡复张手法改善氧合存在争议。缺乏标准化且缺乏比较各种复张手法的临床研究。复张手法与呼气末正压（PEEP）的选择密切相关，而PEEP的选择也是一个有争议的话题。
对12例早期ALI/ARDS且已行气管插管并机械通气的患者进行一次复张手法（40 cm H₂O持续充气30秒），然后将PEEP设置为24 cm H₂O，接着每10分钟将PEEP逐步降低4 cm H₂O。维持吸入氧分数（FIO₂）为0.8。在每次PEEP降低步骤后测量动脉血氧分压（P(aO₂)）。将“最佳”PEEP定义为P(aO₂)下降≥20%的上一步PEEP值。随后所有患者在相同设置下进行一段时间的通气：潮气量6 mL/kg，PEEP为实验前医生设定的水平，平台压<30 cm H₂O。然后每位患者接受3种通气策略，每种策略应用1小时：仅使用最佳PEEP；最佳PEEP加一次持续充气（40 cm H₂O持续30秒）；最佳PEEP加每25次呼吸进行一次叹息呼吸（即两倍基线潮气量，平台压<40 cm H₂O）。在应用每种PEEP策略后测量动脉血气值和呼吸系统的静态顺应性。
平均±标准差的最佳PEEP为12±4 cm H₂O。3个PEEP组在标准化时期的测量结果具有可比性。在最佳PEEP加叹息呼吸组中，P(aO₂)的变化（85±96%）和静态顺应性的变化（14±20%）显著大于其他2组。
在早期ALI/ARDS患者中，在肺保护性机械通气的最佳PEEP基础上叠加叹息呼吸可改善氧合和静态顺应性。
