肺动脉漂浮导管的临床应用

肺动脉漂浮导管的临床应用Starling定律：心脏的每搏搏出量取决于心脏舒张期的心室内容量〔preload〕在一定限度内，舒张期心室内容量越大，收缩期每搏量越大最适宜的左心室充盈压为15mmHg(1.99kPa),此时心搏出量最高因此，测定左心的前负荷是理想的指标：左心室舒张未容量〔LVEDV〕左心室舒张未压力〔LVEDP〕但临床测定较困难理论根底

LVEDP4~12mmHgMean:8mmHgLAP4~12mmHgMean：8mmHgPVPPCWP5~15mmHgMean:10mmHg1970年以前，肺动脉导管是“猪尾巴样〞从粗到细很长正常的思维1970年，Ｈ.Ｊ.ＣＳwan和WilliamGanz创造了带套囊的肺动脉漂浮导管，即Ｓwan-Ganz导管

Pressuresintherightsideoftheheartandpulmonarycapillarywedgecanbeobtainedbycardiaccatheterizationwithouttheaidoffluoroscope.ANO.5Frdouble-lumencatheterwithaballoonjustproximaltothetipisinsertedintotherightatriumunderpressuremonitoring.Theballoonistheninflatedwith0.8mlofair.Theballooniscarriedbybloodflowthroughtherightsideoftheheartintothesmallerradiclesofthepulmonaryartery.Inthispositionwhentheballoonisinflatedwedgepressureisobtained.Theaveragetimeforpassageofthecatheterfromtherightatriumtothepulmonaryarterywas35secondsinthefirst100patients.Thefrequencyofprematurebeatswasminimal,andnootherarrhythmiasoccurred.

NewEnglandJournalofMedicine

(1970)

Table6NORMALINTRACARDIACPRESSURES(mmHg)TypeMeanRangeRightatrialpressure51-10Rightventricularend-systolic/end-25/515-30/0-8diastolicpressurePulmonaryarterialsystolic/diastolic23/915-30/5-15pressureMeanpulmonaryarterialpressure1510-20Pulmonarycapillarywedgepressure105-15Leftatrialpressure84-12Leftventricularend-diastolicpressure84-12Leftventricularsystolicpressure13090-140Table7DERIVEDHEMODYNAMICPARAMETERSFormulaNormalValuesCI=CO/BSA2.8~4.2L/min/m2SV=CO·1000/HR50~110ml/beatSI=SV/BSA30~65ml/beat/m2LVSWI=1.36·(MAP-PCWP)·SI/10045~60g·m/m2RVSWI=1.36·(PAP-CVP)·SI/1005~10g·m/m2SVR=(MAP-CVP)·80/CO900~1400dyne·sec·cm-5SVRI=(MAP-CVP)·-5.m2-5-5.m2

Table8OXYGENDELIVERYPARAMETERSFormulaNormalValuesArterialO2contentCaO2=(1.39.Hb.SaO22)18~20ml/dLMixedvenousO2contentCvO2=1.39.Hb.SvO2213~16mL/dlArteriovenousO2contentdifferenceavDO2=CaO2-CvO24~5.5mL/dLPulmonarycapillaryO2contentCcO2=1.39.Hb.ScO2219~21mL/dLPulmonaryshuntfractionQs/Qt=100.(CcO2-CaO2)/(CcO2-CvO2)2~8percentO2deliveryDO22800~1100mL/minO2consumption

VO2=10.CO.(CaO2-CvO2)150~300mL/min心输出量测定为温度稀释法thermodilutionmethod连续温度稀释法〔1992〕continuousthermodilutionmethod适应证左心功能不全(EF＜40％或CI＜2.0L/min.m2)心源性、低血容量感染性休克或多脏器功能衰竭严重缺血性心脏病近期心肌堵塞或心绞痛不稳定严重休克〔心源性休克、感染性休克和严重创伤性休克〕大量失血或体液改变低心排综合征心脏大血管手术估计伴大出血或大量体液丧失右心衰、肺动脉高压、严重腹水和慢性阻塞性肺疾患血流动力学不稳定需用强心药或LABP维持主动脉手术需钳闭主动脉者Table1INDICATIONSFORPACMONITORINGMajorproceduresinvolvinglargefluidshiftsand/orbloodlossinpatientswithcoronaryarterydiseaseProceduresrequiringcardiopulmonarybypassPatientswithrecentmyocardialinfarctionsorunstableanginaPatientswithpoorleftventricularfunction(congestiveheartfailure)Patientsinhypovolemic,cardiogenic,orsepticshock,orwithmultipleorganfailureMassivetraumacasesPatientswithrightheartfailure,COPD,pulmonaryhypertension,orpulmonaryembolismPatientsrequiringhighlevelsofpositiveend-expiratorypressureHemodynamicallyunstablepatientsrequiringinotropesorintra-aorticballooncounterpulsationPatientsundergoingsurgeryoftheaortarequiringcross-clampingPatientsundergoinghepatictransplantationPatientswithmassiveascitesrequiringmajorsurgery

绝对禁忌证绝对禁忌证指PAC操作困难，或可能发生严重并发症，甚至引起死亡。三尖瓣或肺动脉瓣狭窄PAC不能通过狭窄的瓣膜，即使偶尔通过狭窄部位，也可加重阻碍血流通过。右心室或右心室内肿块〔肿瘤或血栓形成〕插管时不慎，可致肿块脱落而引起肺栓塞。法乐四联症右心室流出道十分敏感，PAC通过肺动脉时，常可诱发右心室漏斗部痉挛而使紫绀加重。相对禁忌证严重心律失常正常情况下，PAC置管时，常可诱发一过性房性或室性心律失常，因此，手术病人伴有失常时，插管过程中可引起严重心律失常。此类病人是否选用PAC，需权衡其利弊。凝血障碍经大静脉穿刺插管时，可能会发生出血、血肿。因此，手术病人伴凝血异常者应慎用。近期置起搏导管者施行PAC插管或拔管时不慎，可能使起搏导线脱落。表2PAC不同途径进入右心房深度插管途径右颈内静脉肘前静脉股静脉导管深度15－20左6070〔cm〕右50表3PAWP与LVEDP差异的各种情况PAWP＞LVEDPPAWP＜LVEDP1.正压通气1.主动脉瓣返流2.PEEP2.左心室顺应性降低3.胸内压↑3.肺动脉分支减少4.PAC不在肺III区〔全肺切除术、肺栓塞〕5.慢性阻塞性肺疾患6.心动过速7.肺血管阻力↑8.二尖瓣阻塞〔狭窄〕9.肺静脉受压〔肿瘤〕10.二尖瓣返流11.心内左向右分流PCWP>LVEDP

Positive-pressureventilationPEEPIncreasedintrathoracicpressureNon-WestLungZoneIIIPACplacementChronicobstructivepulmonarydiseaseIncreasedpulmonaryvascularresistanceLeftatrialmyxomaMitralvalvedisease(stenosis,regurgitation)

PCWP<LVEDPNoncompliantLV(ischemia,hypertrophiedLV)Aorticregurgitation(prematureclosureofthemitralvalve)LVEDP>25mmHg

并发症〔1〕中心静脉穿刺引起的并发症误入动脉血肿神经损害气胸气栓并发症〔2〕插管过程中引起的并发症一般心律失常严重心律失常〔室速、室颤〕右束支传导阻滞完全性传导阻滞〔主要指原有RBBB〕并发症〔3〕导管留置过程中肺动脉破裂、肺出血气囊破裂感染血栓形成和栓塞：血栓性静脉炎，静脉栓塞，心内膜血栓形成，瓣膜赘生物等肺梗死并发症〔4〕导管扭曲、打结、折断心脏机械性损伤Table4PRACTICEGUIDELINESFORPULMONARYCATHETERUSE(ASATASKFORCEONPULMONARYARTERYCATHETERIZATION)OpinionsPAcathetermonitoringcanreducetheincidenceofperioperativecomplications,primarilybyprovidingimmediateaccesstocriticalhemodynamicdataHavingimmediateaccesstoPAcatheterdataallowsimportantpreemptivemeasuresforthatsubsetofpatientswhoencounterhemodynamicdisturbancesthatrequireimmediateandprecisedecisionsaboutfluidmanagementanddrugtreatment.ExperienceandunderstandingarethemajordeterminantsofPAcathetereffectivenessPAcatheterizationisinappropriateasaroutinepracticeinsurgicalpatientsandshouldbelimitedtocasesinwh