ARDS肺复张的实施课件.ppt
,ARDS肺复张的实施,科学与艺术的困惑,内容提要,肺保护性通气策略不能解决解决的问题肺泡塌陷的病理生理后果肺复张的临床实施Prone positionSpontaneous breathingHigh VT and sighRM,ARDSnet: 小潮气量通气,ARDS Net. N Engl J Med. 2000 May 4;342(18):1301-8.,Low tidal volume: more alv collapse,小Vt不能复张塌陷肺泡，加重低氧血症实施肺保护性通气策略至少1525%患者需提高FiO2,邱海波, 刘大为, 陈德昌等. 中华麻醉学杂志, 1998, 18: 202-205,LIP：塌陷肺泡开始复张的压力 不是全部塌陷肺泡复张的压力,PEEP not enough: more alv keep collapse,30 kg PigPost LavagePCVPaw 13 cmH2O PEEP 5 cmH2O,Experimental study-Pig with ARDS,许红阳，邱海波. ARDS绵羊肺复张容积测定方法的比较. 中国危重病急救医学， 2004, 16: 413.邱海波. PEEP对ARDS肺复张容积及氧合影响的临床研究. 中国危重病急救医学，2004, 16: 399.,Clinical Trial11 ARDS pats,A. Hypoxamia B. Shear forcesC. Surfactants inactivate D. Biotrauma and MODS,Pathophysiology Consolidation and alv collapse,A .低氧血症,肺泡塌陷：ARDS重力依赖区 炎症或不张区生理性低氧缩血管反应：障碍,How Does Excessive Mechanical Stress Inflame the Lung?,“Shear”,Verbrugge et al. Crit Care Med 1999;27：779,Ventilator-associated lung injury,Purine: a marker of ATP breakdown and VILI42 SD ratsPCV 6minPCV Pre/PEEPBALF purine and protein,Lachmann. ICM, 1994; 20:6-11,Intra-alveolar proteins inactivate alv surfactant in a dose-dependent way1mg surfactant = inhibitory effect of 1mg plasma protein,C. Surfactant 灭活,Surfactant move away,When lung regions collapse at end expiration, surfactant molecules move away from the alv surface toward terminal bronchioles and cannot be reused during next inflation,Rouby JJ. Am J Respir Crit Care Med, 2001, 165: 1182,D. 预防Biotrauma和MODS,Marini JJ, Gattinoni L. Ventilatory management of acute respiratory distress syndrome: a consensus of two Crit Care Med. 2004 Jan;32(1):250-5.,“Stretch”,“Shear”,Airway Trauma,俯卧位通气的病理生理特征,改善通气过程 胸膜腔压力梯度 顺应性胸壁促进分泌物的清除,Closingpressure,Closing pressure,Time course of Prone on PaO2/FiO2 between ARDSp vs ARDSexp,Time response of Prone position on PaO2/FiO2 between ARDSp vs ARDSexp,黄英姿, 邱海波. 肺内外源性ARDS实施俯卧位通气时间的选择.中华内科杂志2004, 43(12):883-887,保留自主呼吸的优点,Paw cmH2O,%,Opening and Closing Pressures,0,5,10,15,20,25,30,35,40,45,50,0,10,20,30,40,50,5 patients,ALI / ARDS,From Crotti et alAJRCCM 2001.,Some units cantbe kept open by any reasonable PEEP!,Amato: CT + PV Curve,Heart,Sp,P,V,LIP,UIP,Insp recruit,Larger Vt/Sigh: Pressure must be high enoughEven up to UIP,许红阳，邱海波. ARDS绵羊肺复张容积测定方法的比较. 中国危重病急救医学， 2004, 16: 413.邱海波. PEEP对ARDS肺复张容积及氧合影响的临床研究. 中国危重病急救医学，2004, 16: 399.,Clinical Trial11 ARDS pats,Recruitment is Time-Dependent, 40 SECONDS,Recruitment mannuvers,Basic PrinciplesMethods for RecruitmentExperimental Studies and Clinical TrialsEfficacyHazards,1. 控制性肺膨胀(SI)法2. PEEP递增法3. 压力控制(PCV)法,Methods for Recruitment,CPAP模式: PS 0, PEEP 30-40 cmH2O, 20-50s 2. BIPAP: Ph /PL 30-40cmH2O, 20-50s 3. Insp Hold: 将吸气保持键按住，持续20- 40s,控制性肺膨胀(SI)法,Multiple Maneuvers May Be Needed For Optimum RM Effect,Fujino et al, Crit Care Med 2001; 29(8):1579-1586,Post-RM PEEP Determines PaO2,Post-RM-PEEP肺开放效应持续时间的决定因素,CCM, 2004, 32: 2371-2377,28 mixed-breed pigsModels of ARDS:OAVILIPneumonia(PNM)RMSIIncreased PEEPPCV,肺开放后的PEEP选择-PaO2/FiO2,1. RM后 PEEP: 20cmH2O2. PEEP递减: 2cmH2O/5min3. PEEP阈值: PaO2/FiO25%4. PEEP: PEEP阈值 +2cmH2O,BASELINE VENTILATIONTidal volume=6ml/kgPEEP=5cmH2O,Modify PEEP to get a1.10.9,recruiting maneuver,Measure,1.10.9Leave PEEP unchanged,stress index 0.9,1.1Decrease PEEP until 1.1stress index 0.9,Crit Care Med, 2004, 32: 1018-1027,肺开放后的PEEP选择- Stress index,Implications,RM 的有效性ALI的病因 (direct vs in direct)Post RM PEEPMethod in certain settingsRM hazards are greatest and effectiveness least in pneumonia-caused acute lung injuryPCV may be better tolerated than SI,Recommendations,Use PCV in preference to SISafer, “multiple”, effective, maintains ventilation, simpleMonitor hemodynamics during recruiting interval.以下情况需重复作RM: 体位改变, 管路断开, 呼吸力学特征或PaO2明显恶化对于顽固性难治性ARDS患者, 可考虑反复RM和更高的压力Employ Prone Position and/or PEEP to consolidate RM benefit.,
