机械通气技术原理与进展介绍.pptVIP

机械通气技术原理与进展 2010.04 杭州 Effective management of synchrony requires:同步有效管理机制要求 ? A reliable trigger 可靠的触发 ? Adequate flow to be patient demand 适合患者需要足够的流速  ? Well timed transition from inspiration to expiration 吸气相转呼气相精确性 ? Low expiratory resistance 低呼气阻力 New ventilators provide controls to better manage synchrony:新型呼吸机最佳同步管理 ? Leak compensation 漏气补偿 ? Rise time control 上升时间控制  ? Inspiratory termination control 吸气中止控制 ? Electronic high speed low resistive valve 电控高速低阻力阀 Time Constant Range of threshold Supra-plateau Pressure Pressure support breath Flow Cycling-off Threshold Selector Automatic Pressure Support Cycling-off Threshold Adjustment 自动压力支持切换调节 时间常数 标准域值 超平台压 流速切换标准 压力支持呼吸 ? Basis for the Pressure Support Flow Cycling Logic System Automatic Pressure Support Cycling-off Threshold Adjustment 自动压力支持切换调节 Logic system is based on the known characteristics of the human respiratory system. 逻辑系统基于人类呼吸系统的特点 Flow deceleration is largely a function of the resistance and compliance of the respiratory system. 流速递减是由于呼吸系统阻力和顺应性作用的原理 The product of resistance and compliance is the respiratory time constant. 阻力与顺应性的乘积是呼吸时间常数 Measuring time constant is a way of determining how fast or slow the flow will decelerate during a pressure support breath. 测定到时间常数可以决定在压力支持呼吸时流速下降的快和慢 Identifying how fast or slow flow will decelerate determines how a given flow cycling threshold will affect (1) the duration of inspiration for the breath and (2) the degree of breath cycle-off synchrony. 识别快和慢流速递减来决定流速切换标准将影响(1)吸气周期(2)呼吸切换同步的等级 压力支持流速切换逻辑系统 ? An Example: COPD患者 Automatic Pressure Support Cycling-off Threshold Adjustment 自动压力支持切换调节 Patients with long time constants, like those with COPD, need a high flow cycling threshold (i.e. high % of peak flow) to provide good expiratory synchrony because it takes a long time for their flows to drop during pressure support and cycling-off at a higher % threshold will allow the breath to end when they are rea