2022年医学专题-ARDS呼吸功能监测与通气策略抉择

1、ARDS呼吸功能监测与通气(tng q)策略抉择 邱海波(hi b) 刘玲东南大学附属中大医院ICU第一页，共六十六页。内容提要(ni rn t yo) Physiopathologic course of ARDS and the dilemma in Mechanical ventilationOxygenation and ShuntRespiratory mechanicsCompliance (Elastance) and ResistanceStress indexEsophageal PressureVd / Vt第二页，共六十六页。Therapeutic target of M

2、V in ARDSBecome evident over the past two decadesMV itself can augment or cause pulmonary damageShift of therapeutic target of MV in ARDS 1970sNormal gas exchange1980-1990Protection of thelung from VILIN Engl J Med 1972;287:799-806.Lancet 1980;2:292-4.Am Rev Respir Dis 1987; 135:312-5.Intensive Care

3、 Med 1990;16:372-7.第三页，共六十六页。The lung-protection strategyLung recruitment-open the lung Use of higher PEEP-keep lung open (avoid collapse/recruitment) Low tidal volumes (Pplat 30cmH2O)- avoid overdistension Prevent regional and global stress and strain on the lung parenchymaAm J Respir Crit Care Med

4、. 2022, 178: 346355.第四页，共六十六页。Same MV strategy sutiable for every ARDS pat ?May be No.Physiological effects of RM and PEEP associated with patients individual characteristics Inflamattion spreading from core diseasePercentage of potentially recruitable lungDifferent stages of ARDSN Engl J Med. 2006,

5、 354; 1775-86 .JAMA. 1994, 271, 1772-79. 第五页，共六十六页。Inflamattion spreading from core diseasePossible modelLowerHigherHigher severity mortalityCore disease 24%Inflammation spreading 1Lower severity mortality第六页，共六十六页。Potentially recruitable lungLower percentage of potentially recruitable lungHigher pe

6、rcentage of potentially recruitable lungN Engl J Med. 2006, 354; 1775-86第七页，共六十六页。Mortality in Relation to the Percentage of potentially Recruitable Lung (Panel A) Pulmonary anatomy according to CT Findings in patients with Healthy Lungs, Patients with Unilateral Pneumonia,and Patients with Acute Lu

7、ng Injury or ARDS (Panel B).N Engl J Med. 2006, 354; 1775-86第八页，共六十六页。Lower VS Higher percentage of potentially recruitable lungHigher percentage of potentially recruitable lungGreater total lung weights Poorer oxygenation Respiratory-system compliance Higher levels of dead spaceHigher rates of deat

8、hN Engl J Med. 2006, 354; 1775-86第九页，共六十六页。Different stages of ARDSPathologic stagesEarly exudative phase edema, bleeding, atelactasis, PMN and plt embolus, and microembolusProliferative phase proliferation of tive II epithelium cellFibrotic phase Proliferation of fibroblastHeterogeneity ：location,

9、time courseVersatility : Pathologic changes第十页，共六十六页。Difficult to assessGattinoni L (1994)Early ARDS (MV up to 1 week): prevalent edemaIntermediate ARDS (between 12 weeks): a transition period during edema begins to be reabsorbed and proliferative processes begin to occurLate ARDS (more than 2 weeks

10、): fibrous processesClinical stages of ARDSJAMA. 1994, 271, 1772-79. 第十一页，共六十六页。Early VS Late ARDS 84 sever ARDS for underwent extracoresl support (1979-1992)JAMA. 1994, 271, 1772-79. 第十二页，共六十六页。Early VS Late ARDS JAMA. 1994, 271, 1772-79. 第十三页，共六十六页。CT scan, early VS late ARDS Gattinoni L Type 1Ear

11、ly ARDSWeek 1Intermediate ARDSWeek 2Late ARDSWeek 7d)RM: PCV 2min at PIP 50cmH2O/PEEP PUIPAm J Respir Crit Care Med, 2002, 165:165170第十六页，共六十六页。Summary-Early and Late ARDSEarly ARDS is characterized by edema and intact lung structureRecruitability is function of the extent of edemaWith time lung str

12、ucture is altered associated with increased dead space and PCO2第十七页，共六十六页。Prognosis of ARDSInflammation spreadingPotentially recruitable lungLowerLower severity mortalityRM and higher PEEP may be harmfulHigherHigher severity mortalityRM and higher PEEP are neededCore diseaseAggravated Improved Early

13、 ARDSLate ARDSEffect of RM and higher PEEP?第十八页，共六十六页。QuestionsHow to know who will get benefit from RM and PEEPHow to set a suitable PEEP in ARDS patientCT scan may be one choiceBut not at bed sidePaO2 (P/F) may be another choiceBut our goal is not better gas exchangeHow about bedside respiratory m

14、echanical monitoring Reduce VILI第十九页，共六十六页。内容提要(ni rn t yo) Physiopathologic course of ARDS and the dilemma in Mechanical ventilationOxygenation and ShuntRespiratory mechanicsCompliance (Elastance) and ResistanceStress indexEsophageal PressureVd / Vt第二十页，共六十六页。Shunt is the fundamental cause of hypox

15、emia in ARDSRM and PEEPImprove oxygenation(P/F)Reduced Shunt Am J Respir Crit Care Med, 2001, 164:1701-1711第二十一页，共六十六页。肺泡(fipo)完全复张的临床标准-P/FPaO2/FiO2400 PaO2 + PaCO2 400 2.PaO2/FiO2 降低(jingd)5%第二十二页，共六十六页。PaO2 + PaCO2 400 (at 100% oxygen): 维持肺开放(kifng)的可靠指标到达PaO2 + PaCO2 400时： CT显示只有5% 的肺泡塌陷 PaO2 +

16、PaCO2 400对塌陷肺泡的预测： ROC曲线下面积 0.943Borges JB, , Amato MBP.Am J Respir Crit Care Med Vol 174. pp 111, 2006肺泡完全复张的临床(ln chun)标准-CT第二十三页，共六十六页。肺泡完全(wnqun)复张的临床标准-CTBorges JB, , Amato MBP.Am J Respir Crit Care Med Vol 174. pp 111, 2006动脉氧合与塌陷肺组织重量(zhngling)明显呈负相关 (R = 0.91)第二十四页，共六十六页。Methods of Qs/Qt cal

17、culationQc: 经肺毛细血管回心的血量(已气体(qt)交换)Qs: 经短路回心的血量(未经体交换)Qt= Qc+Qs 总回心血量计算公式：太复杂但比较准确正常肺Qs/Qt 4-5%ARDS Qs/Qt常30%第二十五页，共六十六页。简化(jinhu)公式吸空气(kngq)时：吸纯氧时：应用条件吸纯氧10-20min(最大限度(xind)纠正相对分流)PaO2150-200mmHg第二十六页，共六十六页。P/F and Qs/Qt change with lung recruitment Case 63 Y woman Guillain-Barre Syndrome, Pneumonia

18、, ALIPEEPPEEP第二十七页，共六十六页。内容提要(ni rn t yo)Physiopathologic course of ARDS and the dilemma in Mechanical ventilationOxygenation and ShuntRespiratory mechanicsCompliance (Elastance) and ResistanceStress indexEsophageal PressureVd / Vt第二十八页，共六十六页。Respiratory mechanics -Compliance (Elastance) and Resista

19、nce第二十九页，共六十六页。Concepts and FormulaE=P / VolC= Vol / PCst=Vt / (Pplat-PEEPtot)Cdyn=Vt / (PIP-PEEPtot)R= P / VC= 1 / E第三十页，共六十六页。Compliance and Resistance changes in ARDSCompliance decreased significantlyResistance may increase slightlyCompliance decreasedDue to alveolar collapse Resistance increased

20、第三十一页，共六十六页。Compliance decreasedP-V curve Reduced range of volume excursion: Low complianceFlattening at low and high volumes: Lower and upper inflection pointsVolumePressureNORMALARDS顺应性曲线明显(mngxin)向右下移位第三十二页，共六十六页。six pigletsvenous infusion of oleic acidPEEP titration (from 26 to 0 cmH2Owith a Vt

21、of 6 to 7 ml/kg) performed, following a RMCritical Care 2007, 11: R86.第三十三页，共六十六页。Ronitoring respiratory mechanics during a PEEP titration procedure may be a useful adjunct to optimize lung aerationCritical Care 2007, 11: R86.PEEP at min Ers corresponded to the greatest amount of normally aerated ar

22、eas第三十四页，共六十六页。%E2: Percentage of volume dependent elastancePercentage of non-linearity of the elastance of the Ers%E230%: tidal overdistensionIntensive Care Med. 2022, 34:22912299In non-injured animals第三十五页，共六十六页。Stress index and %E2 are useful in non-injured lungs onlyErs can be superior to the st

23、ress index and %E2 to guide PEEP titration in focal loss of lung aerationErs seems to be useful for guiding PEEP titration in non-injured and injured lungs第三十六页，共六十六页。Female pigsLung lavageCrs: computed using the occlusion techniqueRM: 45 cmH2O for 40 sPeep10 cmH2OPro and Post RM (CT scan)Gas exchan

24、ge Lung mechanics Amount and the changes in aerated andCritical Care. 2005, 9: R471-R482第三十七页，共六十六页。Vpoor: volume of poorly aerated lung; Vhap: volume of hyperinflated lungPmcd: pressure of maximum compliance decrease on inflation curve 第三十八页，共六十六页。Crs may be useful for guiding PEEP titrationChanges

25、 in aerated and nonaerated lung volumes were adequately represented by Crs Not by changes in oxygenation or shuntCritical Care. 2005, 9: R471-R482第三十九页，共六十六页。Case 79 y, man, 75 kg Pneumonia, ARDS, APACH II 27Sedation and nerve block Baiseline: VcV, Vt 500ml, PEEP 6cmH2O, RR 20 b/min, P/F Crs 56, Ppl

26、at 16cm H2O, PaCO2 35mmHg, P/F 121RM: SI 40cmH2O30s (P/F400 mm Hg or change1-b=1-b1RM again set the PEEP in b=1第四十七页，共六十六页。Case64 y, man, 70 kg Multiple trauma, ARDSBaiseline MV set: SIMV+PS (autoflow), Vt 420ml, PEEP10cmH2O, FiO2 50%, RR 20 b/minPplat 26cm H2O, PaCO2 47mmHg, P/F 155Change to VCV: V

27、T 420ml, RR 20 b/minRM: SI 40cmH2O30s (P/F400 or change134151316122第四十九页，共六十六页。Respiratory mechanics -MV Guided by Esophageal Pressure第五十页，共六十六页。MV Guided by Esophageal Pressurein ALIEsophageal pressurepleuralpressure pressureTranspulmonary pressure= pulmonary alveolar pressure -Esophageal pressure6

28、1 ARDS pats MVControl or esophagealpressureguided groupPrimary end pointimprovement in oxygenationSecondary end points:Respiratory-system compliancePatient outcomesN Engl J Med. 2022, 359; 2095第五十一页，共六十六页。第五十二页，共六十六页。第五十三页，共六十六页。第五十四页，共六十六页。As compared with the current standard of careSignificantly

29、improves oxygenation and complianceN Engl J Med. 2022, 359; 2095MV Guided by Esophageal Pressure第五十五页，共六十六页。内容提要(ni rn t yo) Physiopathologic course of ARDS and the dilemma in Mechanical ventilationOxygenation and ShuntRespiratory mechanicsCompliance (Elastance) and ResistanceStress indexEsophageal PressureVd / Vt第五十六页，共六十六页。Vd/Vt VS PEEP生理死腔与潮气量比率(bl)Vd/Vt 是肺泡通气效率的指标过高的