呼吸力学的知识.ppt

呼吸机波形与参数 压力－pressure 近端压力 远端压力 气管内压力 食管压力，内源性PEEP 容量－volume，压力-容量环 流量－flow，流速-容量环 呼吸做功，等 基本图形 各压力参数 吸气峰压（PIP） PIP = PRAW + Pplateau 平台压（ Pplateau） Pplateau = VT/CRS 呼气末压（EEP） 气道阻压（PRAW） PRAW = RAW ×（flow rate） 呼吸力学监测 顺应性（Compliance） 静态顺应性（Cst ） Cst = VT/（Pplateau — PEEP） 动态顺应性(Cdyn) Cdyn = VT/（PIP — PEEP） 气道阻力(RAW) RAW = PRAW/(flow rate) : 2~3 (cmH2OL/s) 包括呼吸道与气管导管的阻力 Airway Pressure (VCV) Airway Pressure (VCV) 压 力 Why Spontaneous Breath Should Be Needed Better cardiac output Better ventilation/perfusion Better end expiratory lung volume (EELV) Better clinical outcome Christian Putensen Fabry Chest 1995:107:1387 Asynchrony is still a problem Patient-ventilator asynchrony during assisted mechanical ventilation ArnaudW. Thille Pablo Rodriguez Belen Cabello Fran?ois Lellouche Laurent Brochard Intensive Care Med (2006) 32:1515–1522 Ti in PSV Inspiration termination Criteria (Esens) 压力上升时间与吸气终止 Intrathoracic pressures Resp Lab @ MGH Asia Vent Forum @ Shanghai TCI 亚洲通气论坛 Our study settings Pressure Support P circuit P eso P plural Rise time 1% P circuit P eso P plural Rise time 1% P circuit P eso P plural Rise time 100% P circuit P eso P plural Esens 1% P circuit P eso P plural Esophageal Balloon Approximates pleural pressure Polyethylene 10 cm long balloon 100 cm long tubing Positioned in the lower 1/3 of the esophagus Filled with 0.5-1.0cc air Calculations based on differential pressures Tracheal Pressure Measurements Tracheal Pressures Measures pressure at distal end of endotracheal tube 5 Fr polyethylene tube PAW-PTR/Flow (L/s) = Resistance of ETT Advance Tracheal Pressure catheter to 1 cm less than ET plus adapters Withdraw 1-2cm if patient continues to cough TC,气道阻力与流速的关系 TC/ATC ATC Haberthur ICM 1999;25:514 Does the tube-compensation function of two modern mechanicalventilators provide effective work of breathing relief? TC 100%, ETT 6.5mm Pcircuit Peso Pplural 气管压力监测 Ptr (tracheal pressure) 作为压力控制呼吸的向导 在压力控制通气时，由于气管内插