新一代机械通气机吸气上升时间和吸气终止标准的评估：一项肺模型研究

Evaluation of inspiratory rise time and inspiration termination criteria in new-generation mechanical ventilators: a lung model study.

作者信息

Chatmongkolchart S, Williams P, Hess D R, Kacmarek R M

机构信息

Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.

出版信息

Respir Care. 2001 Jul;46(7):666-77.

PMID:11403698

Abstract

INTRODUCTION

Inspiratory rise time adjustment during pressure ventilation and inspiration termination criteria adjustment during pressure support ventilation are available on some of the newest mechanical ventilators. Both are designed to improve patient-ventilator synchrony. However, the function of these adjuncts during pressure ventilation on these ventilators has not been evaluated.

METHODS

Three inspiratory rise times (minimum, medium, and maximum) were evaluated in 5 new-generation mechanical ventilators (Hamilton Galileo, Siemens 300A, Puritan Bennett 840, BEAR 1000, and Dräger Evita 4) during pressure support and pressure assist/control. Three inspiration termination criteria settings (minimum, medium, and maximum) were also evaluated in 2 mechanical ventilators (Hamilton Galileo and Puritan Bennett 840) during pressure support. All evaluations were performed with a spontaneous breathing lung model (compliance 50 mL/cm H2O, resistance 8.2 cm H2O/L/s, respiratory rate 12 breaths/min, inspiratory time 1.0 s, and lung model peak inspiratory flow 60 L/min). Throughout the evaluation, inspiratory pressure was set at 15 cm H2O and positive end-expiratory pressure at 5 cm H2O, resulting in a peak airway pressure of 20 cm H2O.

RESULTS

Significant (p < 0.05) and important (> 10%) differences were found among the ventilators at similar rise times (minimum, medium, and maximum) and for each ventilator as rise time was varied. Also, significant (p < 0.05) and important (> 10%) differences were observed between ventilators and within each ventilator when inspiration termination criteria were varied. There were significant (p < 0.05) differences between pressure support and pressure assist/control, but most were < 10%, except those associated with expiration.

CONCLUSIONS

Major differences exist for each ventilator as rise time or inspiration termination criteria are varied and among ventilators at similar settings. Inspiration termination criteria adjustment markedly affects transition to exhalation in the Puritan Bennett 840.

摘要

引言

一些最新的机械通气机具备在压力通气时调整吸气上升时间以及在压力支持通气时调整吸气终止标准的功能。这两者均旨在改善患者与通气机的同步性。然而，这些辅助功能在这些通气机进行压力通气时的作用尚未得到评估。

方法

在5台新一代机械通气机（汉密尔顿伽利略、西门子300A、伟康840、百瑞1000和德尔格Evita 4）上，于压力支持和压力辅助/控制模式下评估了3种吸气上升时间（最短、中等和最长）。还在2台机械通气机（汉密尔顿伽利略和伟康840）上于压力支持模式下评估了3种吸气终止标准设置（最小、中等和最大）。所有评估均使用一个自主呼吸肺模型（顺应性50 mL/cm H₂O，阻力8.2 cm H₂O/L/s，呼吸频率12次/分钟，吸气时间1.0秒，肺模型吸气峰值流速60 L/分钟）进行。在整个评估过程中，吸气压力设定为15 cm H₂O，呼气末正压设定为5 cm H₂O，从而使气道峰值压力达到20 cm H₂O。

结果

在相似的上升时间（最短、中等和最长）下，各通气机之间以及随着上升时间变化时每台通气机内部均发现了显著（p < 0.05）且重要（> 10%）的差异。此外，当吸气终止标准改变时，各通气机之间以及每台通气机内部也观察到了显著（p < 0.05）且重要（> 10%）的差异。压力支持和压力辅助/控制之间存在显著（p < 0.05）差异，但除了与呼气相关的差异外，大多数差异均小于10%。