同濟(jì)醫(yī)學(xué)院診斷學(xué)-呼吸障礙課件

Dyspnea

1Definition:

Dyspneaisdefinedasanawarenessofdifficultyinbreathing

Itisthereforeasymptom,usuallydescribedbythepatientas“shortofbreath,”whetherthesensationisduetoactualdifficultyinbreathingorisessentiallyanawarenessofhyperventilation.Ifthesymptombecomesstriking,italwayscompanieswithdilatationofnares,cyanosis,useofaccessorymusclesofrespirationandabnormalitiesofrespiratoryrate,depthorrhythm.Definition:2RespiratorydiseasesCirculatorydiseasesPoisoningHematologyNeuropsychogenicfactorsEtiologyRespiratorydiseasesEtiology3RespiratorydyspneaCausedbyabnormalventilationandgasexchange,reductioninventilatorycapacity,hypercapniaandhypoxemiaresultingfromrespiratorydisease.Threeclininaltypes:InspiratorydyspneaExpiratorydyspneaMixeddyspneaRespiratorydyspneaCausedbya4InspiratorydyspneaTendstooccurprimarilywhenthereisobstruction(suchasinflammation,edema,tumorandforeignbody)inlarynx,tracheaandmajorbronchi.Characterizedbythedepressionsigh,inwhichvisibleindrawingoverthesternalnotch,thesupraclavioularspaces,theintercostalspacesandtheepigastriumintheinspirationcanbeseen.Oftenaccompaniedbyacoarse,lowpitchedinspiratorywheezinganddrycough.InspiratorydyspneaTendstooc5ExpiratorydyspneaExpiratorydyspneaisduetothedecreaseoflungelasticityandspasmnarrowingofthebronchiolesandsmallerbronchiasinemphysema,bronchialasthmaandasthmaticbronchitis.Expirationisprolongedandlabouredwithwheezing.ExpiratorydyspneaExpiratoryd6MixeddyspneaOccurswiththeextensivelungdisease,suchasseverepneumonia,pulmonaryfibrosis,massiveatelectasis,pleuraleffusionandpneumothorax.Resultsinthedecreaseofventilatorsandgasexchangecapacity.Breathingisdifficultduringbothinspirationandexpiration.MixeddyspneaOccurswiththee7Cardiacdyspnea

Cardiacdyspneaisusuallyattributabletopulmonaryvascularcongestionresultingfromtheleftand/orrightheartfailure.CardiacdyspneaCardiacdysp8CardiacdyspneaInLeft-sidedheartfailure,complianceisreduced,andtherefore,ventilationisdecreasedtotheedematouslungregionsandvitalcapacityreduced.Alveoliarestiffandmoreworkisneededtoovercomeelasticrecoil,thehighalveolarpressurewillstimulatestretchreceptorandinitiatetheinflationreflexresultinginearlyturningoffofinspirationandanincreaseinrespiratoryrate.CardiacdyspneaInLeft-sidedh9Cardiac

dyspneaThedyspneacausedbyright-sidedheartfailureislessseverethanthatonecausedbyleft-sided.Mechanism:(1)Thepressureofrightatrialandsuperiorvenacavaisthenaturalstimulusofrespiratorycenter.(2)Thedecreaseofoxygencontentandtheaccumulationoftheacidmetabolites,suchaslactic,stimulaterespiratorycenter.(3)Therestrictionoftherespiratorymovementcausedbyenlargementofliverresultingfromcongestion,ascitesandpleuraleffusion.CardiacdyspneaThedyspneacau10Cardiac

dyspneaSymptomsofcongestiveheartfailurecancauseorthopneaandparoxysmalnocturnaldyspneawhenelevated-fillingpressureispresent.CardiacdyspneaSymptomsof11orthopneaOrthopneaisdifficultyinbreathinginthesupineposition,thismayberelivedbysittingup,whichreducesthedegreeofpulmonarycongestionbypoolingbloodinthelowerextremitiesandloweringleftventricularfillingpressures,improvingthediaphragmaticmovement,increasingvitalcapacity.orthopneaOrthopneaisdifficul12paroxysmalnocturnaldyspneaSymptoms:Thepatientawakesshortofbreathatnight,butoftenobtainreliefbysittingupforaperiodoftime.Inthemostadvancedcases,thepatientsbecomeacutelydyspneic,cyanoticandveryfrequentlyproducefoamysputumtingedwithblood.Signs:Moistralesatthebothlungbases,tachycardia,wheezingandbronchospasm,themarkedlyaccentuatedsecondheartsoundinthepulmonicarea.paroxysmalnocturnaldyspneaSy13Mechanism:Supinepostureforsleepresultsinresorbtionofextracellularfluidintotheintravascularspace,causingariseinfillingpressure.

Theparoxysmaldyspneaistermedascardiacasthma.Itcanbeseeninthehypertensiveheartdiseaseandcoronaryheartdisease.paroxysmalnocturnaldyspneaMechanism:Supineposturefor14Toxic

dyspneaInthemetabolicacidosis(uremiaanddiabeticketosis),theacidmetabolitesstimulatetherespiratorycenter,causingdeepandregularrespirationwithsnoring.TheoverdoseofmorphineandpentobarbitalcandepressrespiratorycentercausingdeeprespirationorCheyne-StokessrespirationToxicdyspneaInthemetabolic15

Neuro-Psychogenic

dyspneaInpatientssufferingfromcerebrovasculardiseases(intracranialhemorrhage,elevatedintracerebralpressure),therespiratorycenterlosesthebloodsupplyoriscompressed.Therespirationbecomesdeep,slowandirregular.Insomecasesthedyspneamaybepsychogenic,whichischaracterizedbyrepetitivedeep,sighingrespirationwithnumbnessofextremitiesorlips,cheiropedalspasm.Thesearealsomanifestationsofacutehypocapniaandrespiratoryalkalosis.Neuro-PsychogenicdyspneaInp16Hematological

dyspnea

Insevereanemia,sulfhemoglobinemia,methaemoglobinemiaorcarbonmonoxidepoisoningthedecreaseofoxygen-carryingcapacityandoxygencontentdevelopabnormalrespirationandincreasedheartrate.Therespirationratealsoincreasesinshockwhichstimulatesrespirationcenterbecauseofhypotension.HematologicaldyspneaInsever17AccompaniedSymptomParoxysmaldyspneawithwheezing.Dyspneawithchestpain.Dyspneawithfever.Dyspneawithcoughandpurulentsputum.Dyspneawithcoma.

AccompaniedSymptom18Paroxysmaldyspneawithwheezing

Itispresentinbronchialasthmaandcardiacasthma.Paroxysmalseveredyspneaisoftenseeninacutelarynxedema,foreignbodyinbronchi,massivepulmonaryembolism,andspontaneouspneumothorax.Paroxysmaldyspneawithwheezi19Dyspneawithchestpain.

Itisfrequentlyobservedinlobarpneumonia,pulmonaryinfarction,spontaneouspneumothorax,acuteexudativepleurisy,acutemyocardialinfarction,andbronchialcarcinoma.