机械通气的血流动力学效应.ppt

氧供需平衡氧耗量氧需量血流动力学常用参数压力参数流量参数容积参数氧输送相关参数前负荷压力指标：临床常用充盈压力评价前负荷CVP、PAWP容积指标：容积是判断前负荷的“最好”指标RVEDV、LVEDV、GEDV流量指标静脉回流量压力指标

——讨论基础压力不是容量压力不代表容量压力与容量有关压力只是压力!中心静脉压容易测量、ICU病人常规与右心房之间几乎没有阻力测量原因：了解心脏功能了解容量状态？CVP心脏功能从静脉把血抽出降低CVP回流功能从循环血池到心脏增加CVP正常范围：8-12cmH2O“安全范围”病人个体化容量=前负荷临床已经可以直接测量VentriclesizeGEDV学术上多年期盼判断前负荷的“最好”指标右室舒张末容积(RVEDV/CEDV)肺动脉漂浮导管左室舒张末面积(LVEDA)超声心动图Globalend-diastolicvolume(GEDV)全心舒张末容积胸腔内血液容积(ITBV)热－染料双指示剂法容积及容量反应性容量的组成应激容量（Stressvolume）与压力有关影响静脉回流影响心输出量非应激容量（Unstressvolume）与压力无关不直接影响静脉回流ModelofthesystemiccirculationEurRespirJ.,2019;10:226–237.流量指标通常情况下:心输出量=回心流量CVP的相关因素循环充盈压力中心静脉压力PQ心功能曲线心输出量足够吗?组织灌注是否合适？否！心输出量可否提高？容量（前负荷）反应性组织需求可否降低？LVStrokeVolumeLVEnd-DiastolicVolume容量反应性决定于：初始容量和心肌收缩力DLShockA43-year-oldmanpresentedtotheemergencyroominrespiratorydistressaftera3-weekillness.Hehadahistoryofalcoholismbutnootherseriousillness.Hehadarespiratoryrateof34breathsperminute,aheartrateof120beatsperminute,abloodpressureof80/50mmHg,andoxygensaturationof86%whilebreathingambientair.Onexamination,hisneckveinsweregrosslydistended(PanelA)andbreathsoundswereabsentontherightside.Chestradiographyrevealedcompleteopacificationoftherightlungfield(PanelB).Therightsideofthediaphragmwasinvertedandcompressingtheliverinferiorly,andtheheartwashyperkineticandseverelycompressed.Computedtomographyshowedalargecollectionofliquidintherightpleuralspacewithamarkedmediastinalshiftandcompressionoftheheartandgreatvesselstowardtheleftsideofthechestwall(PanelC).Sixlitersofpuswasdrainedwiththeuseofa24-Frenchchesttube,andtheheartratedecreasedto90beatsperminute,thebloodpressurenormalizedto110/60mmHg,andtheelevatedjugularvenouspressureimmediatelyresolved(PanelD).Themicrobiologiccul