Service de Réanimation Médicale et d'Assistance Respiratoire, Hôpital de la Croix Rousse, France.
Respir Care. 2012 Jul;57(7):1129-36. doi: 10.4187/respcare.01344. Epub 2012 Jan 23.
Intermittent positive pressure breathing (IPPB) is used in non-intubated patients to increase lung volume and to enhance coughing. Alpha 200 (Salvia Lifetec, Kronberg, Germany) is a specific IPPB device. CoughAssist (Respironics France, Carquefou, France) is a mechanical insufflator-exsufflator used to remove secretions in patients with inefficient cough. Both can also be used for intubated or tracheotomized patients. We assessed the impact of various artificial airways on the ability of the Alpha 200 and CoughAssist to generate insufflated volume.
We measured the insufflated volume and pressure at the airway opening in a lung model under 2 conditions of compliance (30 or 60 mL/cm H(2)O) at single resistance of 5 cm H(2)O/L/s. The devices were used at 2 set pressures: 30 and 40 cm H(2)O. The Alpha 200 was set at 2 inflation flows: 0.5 and 1 L/s, whereas CoughAssist was set at its highest value of 10 L/s. Measurements were done without (control) and with different size endotracheal tubes and tracheostomy cannulae. The relationships between insufflated volume and measured pressure were analyzed using linear regressions.
The slopes and intercepts of the control relationship between insufflated volume and pressure were significantly greater with Alpha 200 at each set flow than with CoughAssist. As artificial airways were used, the insufflated volume did not differ from the control with CoughAssist, while with Alpha 200 it increased at each flow setting and for all mechanical conditions. The largest differences in insufflated volume between the 2 devices were observed for the largest endotracheal tubes and tracheostomy cannulas and for the lowest inflation flow setting in Alpha 200. These results can be explained in terms of how the devices function, as CoughAssist adapts by increasing flow, while Alpha 200 adapts by increasing inspiratory time.
This bench study has shown that in the presence of artificial airways the value of the insufflated volume generated by the CoughAssist device was significantly lower than that generated by the Alpha 200 device.
间歇性正压通气（IPPB）被用于非插管患者以增加肺容量并增强咳嗽。Alpha 200（Salvia Lifetec，德国 Kronberg）是一种特定的 IPPB 设备。CoughAssist（Respironics France，法国 Carquefou）是一种机械通气-呼气装置，用于清除无效咳嗽患者的分泌物。两者也可用于插管或气管切开患者。我们评估了不同人工气道对 Alpha 200 和 CoughAssist 产生充气量的影响。
我们在肺模型中，在顺应性为 30 或 60 mL/cm H(2)O 时，在单一阻力为 5 cm H(2)O/L/s 的情况下，测量了两种条件下气道开口处的充气量和压力。设备设置在 30 和 40 cm H(2)O 的两个设定压力下。Alpha 200 设置为 0.5 和 1 L/s 的两种充气流量，而 CoughAssist 设置为其最高值 10 L/s。在没有（对照）和不同尺寸的气管内导管和气管造口套管的情况下进行测量。使用线性回归分析充气量和测量压力之间的关系。
在每个设定流量下，与 CoughAssist 相比，Alpha 200 的充气量与压力之间的控制关系的斜率和截距都显著更大。随着人工气道的使用，CoughAssist 的充气量与对照相比没有差异，而在 Alpha 200 中，在每个流量设置下和所有机械条件下都增加。在这两种设备中，最大的充气量差异出现在最大的气管内导管和气管造口套管以及 Alpha 200 中最低的充气流量设置。这些结果可以根据设备的工作原理来解释，因为 CoughAssist 通过增加流量来适应，而 Alpha 200 通过增加吸气时间来适应。
本台架研究表明，在存在人工气道的情况下，CoughAssist 设备产生的充气量值明显低于 Alpha 200 设备。
