呼吸力学监测临床应用

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,呼吸力学监测临床应用,呼吸力学监测,监测指标,气道压力(Pressure),吸气峰压(PIP),平台压(Pplat),呼气末正压(PEEP),气流流速(Flow),吸气流速,呼气流速,气体容积(Volume),反映指标,顺应性(Compliance),呼吸系统顺应性,肺顺应性,胸廓顺应性,气道阻力(Resistance),吸气阻力,呼气阻力,呼吸功(WOB),呼吸力学监测的意义,没有自主呼吸的患者应用定容通气模式,timeVtTiPEEPPpeakPplat,10.50.502520,20.50.504540,究竟出了什么问题?,顺应性,顺应性,C =,V / P,P,V,t,t,Vt,Pplat PEEP,PIP PEEP,呼吸系统顺应性,动态顺应性,Crs, dyn =,静态顺应性,Crs, st =,呼吸系统顺应性,新生儿 3 - 5 ml/mmHg/kg BWt,婴儿10 - 20 ml/mmHg/kg BWt,儿童20 - 40 ml/mmHg/kg BWt,成人70 - 100 ml/mmHg/kg BWt,呼吸系统顺应性,静态顺应性,无肺部疾患的气管插管患者,50 - 70 ml/mmHg,动态顺应性,极少应用,呼吸系统顺应性,导致顺应性下降的原因,肺实质改变,ARDS, (支气管)肺炎, 肺水肿, 纤维化,表面活性物质功能障碍,ARDS, 肺泡肺水肿, 肺不张, 误吸,肺容量减少,气胸, 膈肌抬高,气道阻力,阻力,R =,P / flow,Pin,Pout,flow,R,吸气阻力,PIP,Pplat,吸气阻力,Raw =,吸气阻力,Hagen-Poiseuille定律,P = flow x 8,l/,r,4,层流,Venturi定律,P = flow,2,x K,l/,r,2,湍流,层流,R =,P / flow = 8,l/,r,4,气道阻力,新生儿30 - 50 mmHg/L/sec,婴儿20 - 30 mmHg/L/sec,儿童 20 mmHg/L/sec,成人 2 - 4 mmHg/L/sec,吸气阻力,导致气道阻力增加的原因,分泌物过多 分泌物潴留,粘膜水肿(哮喘, 气管炎, 肺水肿),肺气肿(气道压迫),异物,肿瘤所致狭窄,呼吸力学监测的意义,没有自主呼吸的患者应用定容通气,timeVtTiPEEPPpeakPplat,10.50.502520,20.50.504540,Raw,(Ppeak - Pplat),Crs, st,1/(Pplat - PEEP),病例 1,ZBQ, F/52岁, C761332, 入院日2004/07/21,既往史:,高血压 x 3年, 130/110 mmHg,AML-M5 x 1,+,年, 13程化疗,主诉: 发热腹痛 x 3天,2004-07-17: WCC 1.3, Hb 83, plt 37,2004-07-18: BT 40,C, 右下腹疼痛, 头孢哌酮治疗无效,病例 1,2004-07-20: ER,恶心, 呕吐, 腹泻,C, HR 140, RR 30, BP 67/27, SpO,2,82%,气管插管机械通气 x 7小时,SpO,2,96 100% (鼻导管O,2,7 lpm),CBC: wcc 0.1, Hb 56, plt 13,Tx:,GCSF300,g ih qd,亚胺培南0.5 gm iv q8h,IVIG10 g iv drip qd,病例 1,2004-07-22,定向力障碍, 发热,CT: 右额叶小面积高密度影,超声: 腹水,2004-07-25,ABG: 7.265/73.9/71.4气管插管及机械通气,DA 6,g/kg/min,2004-07-26,昏迷抽搐,HR 140, BP 110/70 (NE 6 10,g/min, DA 3 16 g/kg/min),病例 1,2004-07-30,Vt,吸痰, 氨茶碱无效,PIP 57 58,更换ETT后仍无明显改变,CBC: wcc 0.35, Hb 126, plt 31,初步印象,腹腔感染引起膈肌升高导致胸廓顺应性降低,肺部感染导致肺顺应性降低,病例 1,2004-07-31: 收入ICU,Vt 250, inspiratory flow 30, FiO,2,1.0, PEEP 5,RR 40, PIP 63, Pplat 20,PEEPi on ZEEP 9,E,1,V,T,M,2,BP 80/40 (DA 10,g/kg/min),O/E: 双肺轻度喘鸣音, 呼气相延长,病例 1,初步诊断,Raw明显升高, 顺应性降低,Raw 70 90, Crs 15,Tx,镇静肌松,甲强龙40 mg + 氨茶碱40 mg/hr + 支气管扩张剂(雾化),Vt 400, Flow 25 (减速气流), FiO,2,0.8, PEEP 7, f 15,NE 0.08,g/kg/min,结果,RR 15 (没有自主触发),BP 100 110/60 70, UO 70 80 ml/hr,支气管痉挛?,无显著效果,病例 1,严重呼吸功能衰竭的可能原因,除外支气管痉挛,腹腔内感染?,腹水: 细胞数668, wcc 146, 单核44%,肺部感染?,痰涂片(07/26),GNB大量,真菌菌丝可见,痰培养(07/26),Stenotrophomonas对替卡西林/克拉维酸, 头孢他啶或环丙沙星敏感,病例 1,抗生素: 头孢他啶 + 环丙沙星,是否有其他致病菌?,支气管镜检查,隆突及所有支气管开口均可见白斑,组织活检涂片: 大量有隔菌丝,真菌培养:,Aspergillus flavus,病例 1的教训,更换气管插管的错误决定,使患者不必要地承担缺氧的风险,排除不可能的感染灶,原发感染灶没有明显的器官功能障碍, 而远隔器官即出现严重功能衰竭的情况非常罕见,重视微生物学检查,鉴别可能的致病菌以及污染菌(定植菌),及时采样以便正确诊断,病例 2,YJC, M/58岁, C812258, 入院日2004/07/27,2003/12食道癌,2004/02/19择期手术,术后并发反复吸入性肺炎,既往史,慢性支气管炎 x 20,+,年,1976年因胃穿孔行胃大部切除手术,病例 2,07/12呼吸困难及发热,ABG: 7.47/48/186 (FiO,2,0.45),07/15CT: 气管狭窄, 纵隔多发淋巴结,07/23呼吸困难加重,气管插管(ETT 6.5)及机械通气,07/27T管 (3 lpm) x 24小时,/110,病例 2,PIP 34,Pplat 10,PEEP 5,Time (sec),Pressure (cmH,2,O),Raw = (PIP Plat) / Flow,= 32 cmH,2,O sec / L,Crs= Vt / (Pplat PEEP),= 300 / (10 5),= 60 mL / cmH,2,O,病例 2,吸气阻力明显增加, 原因包括,气管狭窄?,气管插管口径过小?,病例 2,气管狭窄,CT可见病变,气管插管前高碳酸血症,COPD不能解释CO,2,潴留,气管插管口径过细,气管仅有一半狭窄,号气管插管阻力很高,疾病进展迅速,气管插管导致的压力差,Flow rate = 0.75 L/sec,Delta P =,272.36 x e,-0.5396 *,ETT ID,For 6.5# ETT,Delta P = 8.17 cmH,2,O,气管插管导致的附加阻力,Flow rate = 0.75 L/sec,Resistance =,363.42 x e,-0.5396 *,ETT ID,For 6.5# ETT,Resistance = 10.9 cmH,2,O sec/L,压力差及阻力的鉴别,ETT,气道,总计,压力差,8.2,15.8,24,阻 力,10.9,21.1,32,治疗的结果,因患者不能耐受及配合, 不能进行呼吸力学监测,ABG,/96(FiO,2,0.37),/87.9(FiO,2,0.37),/109(FiO,2,0.37),病例 2的经验,导致气道峰压过高的原因很多, 包括医源性因素,了解呼吸力学有助于推理分析及正确的治疗,时间常数,时间常数(,), = R x C,测定肺组织充盈或排空的速度,反映肺组织对压力变化的反应速度,时间常数(,),Time/Tau,吸气相,呼气相,Pressure,时间常数(,),P,A,(t) = (Pplat - PEEP) e,-kt,k = 1/ =1/(R x C),V(t) = Vt x e,-kt,k = 1/ =1/(R x C),时间常数(,),时间常数,成人(正常值),2 x 0.10 = 0.20”,术后气管插管成人患者,5 x 0.06 = 0.30”,COPD成人患者,15 x 0.06 = 0.90”,ARDS成人患者,8 x 0.03 = 0.24”,ARDS患儿,5 x 0.01 = 0.05”,Tau,呼出气容积,残余容积,0,0%,100%,1,63%,37%,3,95%,5%,5,99.9%,0.1%,时间常数(,),肺泡的呼吸力学分类,快反应肺泡,时间常数较小,慢反应肺泡,时间常数较大,C,c,R,r,为何需要设置吸气末暂停,Pressure,Flow,Peak,Plateau,PEEP,inspiration,expiration,Compliance,low,high,PENDELLUFT,during the,Plateau Phase,为何需要设置吸气末暂停,Pressure,Flow,Peak,Plateau,PEEP,inspiration,expiration,Compliance,low,high,No PENDELLUFT,because of constant,flow flow,时间常数与呼吸模式,Adaptive Support Ventilation,Automatic closed-loop control system on expiratory trigger sensitivity,Adaptive Support Ventilation (ASV) Hamilton Galileo,ASV所独特的呼吸机设置,最低(目标)分钟通气量,患者的理想体重(IBW),男性50.0 + 2.3 身高(inch) 60,女性45.5 + 2.3 身高(inch) 60,分钟通气量% (范围25 350%),IBW 15 kg% Min Vol x IBW / 1000,IBW 15 kg,22 x % Min Vol / 100,IBW 15 kg,45 x % Min Vol / 100,吸气时间,RCexp or 0.5 sec,2 x RCexp or 3 sec,呼气时间,2 x RCexp,12 sec,I:E比,1:4,1:1,Adaptive Support Ventilation (ASV) Hamilton Galileo,RR,V,T,固定MV,目标RR,目标V,T,安全范围,安全范围,Adaptive Support Ventilation (ASV) Hamilton Galileo,RR,V,T,气压伤/容积伤,浅快呼吸,窒息,内源性PEEP,目标V,T,目标RR,固定MV,安全范围,Adaptive Support Ventilation (ASV) Hamilton Galileo,概念,最适呼吸形式 = 分钟通气量固定时呼吸功最低,RR,V,T,WOB最低,Adaptive Support Ventilation (ASV) Hamilton Galileo,Otis AB, Fenn WO, Rahn H. Mechanics of breathing in man. J Appl Physiol 1950; 2: 592-607,WOB,f,弹性,阻力,总计,最适呼吸频率,Adaptive Support Ventilation (ASV) Hamilton Galileo,最适呼吸形式的计算(Otis公式),2,2,RCe,MV f x V,D,V,D,1 + 4,2,RCe, 1,f =,RCeexpiratory time constant,MVminute ventilation,ftotal respiratory rate,V,D,dead space,Otis AB, Fenn WO, Rahn H. Mechanics of breathing in man. J Appl Physiol 1950; 2: 592-607,Adaptive Support Ventilation (ASV) Hamilton Galileo,最低WOB的确定(Otis公式),RR,V,T,固定MV,目标RR,目标V,T,死腔:,1 mL/pound BWt (Radford nomogram),呼气时间常数:,测定参数,分钟通气量:,预先设置,Adaptive Support Ventilation (ASV) Hamilton Galileo,预先设置,监测参数,ASV输出,% MinVol,T,I,(sec),Mandatory Rate (bpm),P,HIGH, Alarm (cmH,2,O),T,E,(sec),T,I,(sec),Body Weight (kg),Total Rate (bpm),P,Control, P,Support,(cmH,2,O),V,Tinsp,(ml),RCexp (sec),V/P (ml/cmH,2,O),Adaptive Support Ventilation (ASV) Hamilton Galileo,RR,V,T,设定MV,目标RR, 指令通气频率, 指令通气频率,最适呼吸形式的实现,Adaptive Support Ventilation (ASV) Hamilton Galileo,RR,V,T,设定MV,目标V,T, 吸气压力, 吸气压力,最适呼吸形式的实现,Adaptive Support Ventilation (ASV) Hamilton Galileo,RR,V,T,设定MV,目标RR,目标V,T, 吸气压力, 指令通气频率, 吸气压力, 指令通气频率, 吸气压力,指令通气频率, 吸气压力, 指令通气频率,最适呼吸形式的实现,呼气触发灵敏度,Ventilator,ETS,Fixed ETS,Siemens 300,5%,Bird 8400,25%,Star,25% or 4 lpm,Evita 4,25% (Adult),6% (Paediatric),Bear 1000,25%,Adjustable ETS,Galileo,10 40%,NPB 840,1 45%,Servo,i,1 40%,Cardiopulmonary Venturi,5 80%,呼气触发灵敏度,吸气峰流量,25%,15%,45%,Tinsp,呼气触发灵敏度的影响,ETS 40%,ETS 5%,潮气量(L),0.51,0.17,0.61,0.25,吸气时间(sec),1.04,0.29,1.66,0.62,呼吸频率(bpm),25.0,12.1,21.5,12.6,Chiumello D, Pelosi P, Taccone P, et al. Effect of different inspiratory rise time and cycling off criteria during pressure support ventilation in patients recovering from acute lung injury. Crit Care Med 2003; 31: 2604-10.,呼气触发灵敏度与时间常数,Yamada Y, Du H. Analysis of the mechanisms of expiratory asynchrony in pressure support ventilation: a mathematical approach. J Appl Physiol 2000; 88: 2143-50,压力支持通气中呼气触发灵敏度的闭环控制系统,时间常数,ETS范围,平台上压力,压力支持,通气,呼气触发灵敏度与吸气终止延迟,Yamada Y, Du HL. Effects of different pressure support termination on patient-ventilator synchrony. Respiratory Care 1998; 43: 1048-1057,PIF 60 lpm,呼气触发灵敏度与吸气终止延迟,Yamada Y, Du HL. Effects of different pressure support termination on patient-ventilator synchrony. Respiratory Care 1998; 43: 1048-1057,PIF 30 lpm,严重气流梗阻,内源性PEEP过高,肺泡过度膨胀,胸腔内压过高, 回心血量减少 休克,降低内源性PEEP的方法,延长呼气时间,增加吸气流量,降低呼吸频率,外源性PEEP ?,严重气流梗阻患者的处理,增加流量不能显著延长呼气时间T,E,VtRRflowT,E,提示降低分钟通气量,对于减少内源性PEEP的重要作用,延长呼气时间治疗哮喘持续状态,目的: 评价哮喘持续状态患者降低呼吸频率对动态过度充盈(DHI)的影响,气道平台压,患者: 12名因严重哮喘接受机械通气患者,设置: 定容通气, 潮气量613,100 mL, 吸气流速 79,4 L/min, 分钟通气量约10 L/min,干预: 呼吸频率18, 12 ,6 bpm,Leatherman JW, McArthur C, Shapiro RS.,Effect of prolongation of expiratory time on dynamic hyperinflation in mechanically ventilated patients with severe asthma.,Crit Care Med 2004 Jul;32(7):1542-5.,延长呼气时间治疗哮喘持续状态,18 bpm,12 bpm,6 bpm,呼气时间延长(sec),1.7,6.7,气道峰压(cmH,2,O),66.8,8.7,66.4,9.5,67.8,11.1,气道平台压(cmH,2,O),25.4,2.8,23.3,2.6,21.3,2.9,呼气末流速(mL/sec),61.4,12.6,38.6,4.5,23.1,5.8,Leatherman JW, McArthur C, Shapiro RS.,Effect of prolongation of expiratory time on dynamic hyperinflation in mechanically ventilated patients with severe asthma.,Crit Care Med 2004 Jul;32(7):1542-5.,总结,呼吸力学是机械通气患者的重要监测参数,呼吸力学监测有助于病理生理异常的诊断及治疗效果监测,呼吸力学有助于理解新的呼吸模式,谢谢！,