Service de Réanimation Médicale et d'Assistance Respiratoire, Hôpital de la Croix Rousse, Lyon, France.
Respir Care. 2011 Aug;56(8):1108-14. doi: 10.4187/respcare.01121.
The CoughAssist is a mechanical insufflator-exsufflator designed to assist airway secretion clearance in patients with ineffective cough. The device may benefit intubated and tracheotomized patients. We assessed the impact of various artificial airways on peak expiratory flow (PEF) with the CoughAssist.
We measured PEF and pressure at the airway opening in a lung model during insufflation-exsufflation with the CoughAssist, at 3 set pressures: 30/-30, 40/-40, and 50/-50 cm H(2)O, first without (control), and then with different sizes (6.5 to 8.5 mm inner diameter) of endotracheal tube (ETT) and tracheostomy tube (6, 7, and 8 mm inner diameter), compliance settings of 30 and 60 mL/cm H(2)O, and resistance settings of 0 and 5 cm H(2)O/L/s). We analyzed the relationship between PEF and pressure with linear regression.
With compliance of 30 mL/cm H(2)O and 0 resistance the slope of the control relationship between PEF and pressure was statistically significantly greater than during any conditions with ETT or tracheostomy tube. Therefore, in comparison to the control, the relationship of PEF to pressure significantly went in the direction from top to bottom as the ETT or tracheostomy tube became narrower. The findings were the same with compliance of 30 mL/cm H(2)O and resistance of 5 cm H(2)O/L/s. With compliance of 60 mL/cm H(2)O the highest set pressure values were not achieved and some relationships departed from linearity. The control slope of the relationship between PEF and pressure with compliance of 60 mL/cm H(2)O and 0 resistance did not significantly differ with any ETT or tracheostomy tube.
The artificial airways significantly reduced PEF during insufflation-exsufflation with CoughAssist; the narrower the inner diameter of the artificial airway, the lower the PEF for a given expiratory pressure.
CoughAssist 是一种机械性通气-呼气装置，旨在帮助无效咳嗽的患者清除气道分泌物。该设备可能对插管和气管切开的患者有益。我们评估了不同人工气道对 CoughAssist 通气-呼气时呼气峰流量（PEF）的影响。
我们在肺模型中测量了 CoughAssist 通气-呼气时的气道开口处的 PEF 和压力，在 3 个设定压力下（30/-30、40/-40 和 50/-50 cm H2O），首先在没有人工气道（对照）的情况下，然后分别使用不同内径（6.5 至 8.5 毫米）的气管内导管（ETT）和气管造口管（6、7 和 8 毫米内径）、顺应性设置为 30 和 60 mL/cm H2O 以及阻力设置为 0 和 5 cm H2O/L/s。我们用线性回归分析了 PEF 与压力之间的关系。
在顺应性为 30 mL/cm H2O 和阻力为 0 时，PEF 与压力之间的对照关系斜率明显大于任何 ETT 或气管造口管条件下的斜率。因此，与对照相比，当 ETT 或气管造口管变窄时，PEF 与压力的关系明显从顶部到底部。在顺应性为 30 mL/cm H2O 和阻力为 5 cm H2O/L/s 时，结果相同。在顺应性为 60 mL/cm H2O 时，无法达到最高设定压力值，并且一些关系偏离了线性。在顺应性为 60 mL/cm H2O 和阻力为 0 时，PEF 与压力之间的对照关系斜率与任何 ETT 或气管造口管均无显著差异。
人工气道在 CoughAssist 通气-呼气时显著降低了 PEF；人工气道的内径越窄，给定呼气压力下的 PEF 越低。
