Perrigault P F, Pouzeratte Y H, Jaber S, Capdevila X J, Hayot M, Boccara G, Ramonatxo M, Colson P
Departement d'Anesthésie Réanimation B, Hopital St Eloi et Lapeyronie, Montpellier, France.
Thorax. 1999 Feb;54(2):119-23. doi: 10.1136/thx.54.2.119.
The purpose of this study was to investigate changes in breathing pattern, neuromuscular drive (P0.1), and activity of the sternocleidomastoid muscles (SCM) during a gradual reduction in pressure support ventilation (PSV) in patients being weaned off controlled mechanical ventilation.
Eight non-COPD patients recovering from acute respiratory failure were included in this prospective interventional study. All patients were unable to tolerate discontinuation from mechanical ventilation. Each patient was evaluated during a period of spontaneous breathing and during PSV. Four successive levels of PSV were assessed in the following order: 20 cm H2O (PS20), 15 cm H2O (PS15), 10 cm H2O (PS10), and 5 cm H2O (PS5).
When pressure support was reduced from PS20 to PS10 the respiratory rate (f) and the rapid shallow breathing index (f/VT) significantly increased and tidal volume (VT) significantly decreased. These parameters did not vary when pressure support was reduced from PS10 to PS5. Conversely, P0.1 varied negligibly between PS20 and PS15 but increased significantly at low PSV levels. P0.1 values were always greater than 2.9 cm H2O (4.1 (1.1) cm H2O) when SCM activity was present. When contraction of the SCM muscles reappeared the P0.1 was the only parameter that changed significantly.
In postoperative septic patients the value of P0.1 seems to be more useful than breathing pattern parameters for setting the optimal level of pressure assistance during PSV.
本研究旨在调查在接受控制机械通气撤机的患者中，压力支持通气（PSV）逐渐降低期间呼吸模式、神经肌肉驱动（P0.1）和胸锁乳突肌（SCM）活动的变化。
本前瞻性干预研究纳入了8例从急性呼吸衰竭中恢复的非慢性阻塞性肺疾病（COPD）患者。所有患者均无法耐受机械通气的中断。在自主呼吸期间和PSV期间对每位患者进行评估。按照以下顺序评估PSV的四个连续水平：20 cm H₂O（PS20）、15 cm H₂O（PS15）、10 cm H₂O（PS10）和5 cm H₂O（PS5）。
当压力支持从PS20降至PS10时，呼吸频率（f）和快速浅呼吸指数（f/VT）显著增加，潮气量（VT）显著降低。当压力支持从PS10降至PS5时，这些参数没有变化。相反，P0.1在PS20和PS15之间变化可忽略不计，但在低PSV水平时显著增加。当存在SCM活动时，P0.1值始终大于2.9 cm H₂O（4.1（1.1）cm H₂O）。当SCM肌肉再次出现收缩时，P0.1是唯一显著变化的参数。
在术后脓毒症患者中，P0.1值似乎比呼吸模式参数在设定PSV期间的最佳压力辅助水平时更有用。
