呼吸困难的鉴别诊断

Step-by-stepdiagnosticapproachofdyspnea.ClinicalhistoryCarefulhistory-takingisthemostusefulfirststepinelucidatingtheaetiologyofdyspnoea.Severalfactorsneedtobeaddressedintheclinicalhistorywhenconstructingtheinitialdifferentialdiagnosis.TimecourseAcutedyspnoeaappearssuddenlyorinamatterofminutes.Ittypicallyindicatesacuteandsevereconditionsthatmaybelife-threatening.Examplesofconditionscausingsudden-onsetdyspnoeaincludeacutepulmonaryembolism,myocardialinfarction,acuteheartvalveinsufficiency,pneumothorax,anaphylaxis,foreignbodyaspiration,pulmonaryoedema,orcardiactamponade.[16]Subacutedyspnoeadevelopsoverhourstodays.Commoncausesincludeacuteasthma,exacerbationofCOPD,orpulmonaryoedema.Lesscommoncausesincludemyocarditis,superiorvenacavasyndrome,acuteeosinophilicpneumonia,orcardiactamponade.[16][17][18]Chronicdyspnoeadevelopsoverweekstomonths.Itisassociatedwithchronicpathology,suchascongestiveheartfailure,COPD,cardiomyopathy,idiopathicpulmonaryfibrosis,pulmonaryvasculardisease,pulmonaryhypertension,valvularheartdisease,oranaemia.[19]Lesscommoncausesincludemusculardystrophies,kyphoscoliosis,amyotrophiclateralsclerosis,pulmonaryalveolarproteinosis,chroniceosinophilicpneumonia,uraemia,orconstrictivepericarditis.[18][20][21][22][23]Recurrentdyspnoeamayindicateparoxysmaltachycardiasorintermittentcompleteheartblock.SeverityThereisnouniversallyagreedmeasureofdyspnoea;severalscalesareavailableinbothresearchandclinicalpractice.[24]Dyspnoeaishighlysubjective,and,foragivenleveloffunctionalimpairment,severityvarieswidely.Severedyspnoeaistypicallyaccompaniedbyassociatedsymptomsandismorelikelytobelife-threatening.Itmaybeassociatedwithacuteasthma,tensionpneumothorax,acuteupperairwayobstruction,massivepulmonaryembolism,ormyocardialinfarction.Milddyspnoeamaybeasolesymptomandmayindicateabenignaetiology.ItmaybecausedbystableCOPD,deconditioning,non-criticalairwayobstruction,ornormalageing.AssociatedsymptomsDyspnoeaoftenoccurswithothersymptoms,andtheirco-existencemayhelptolocalisetheoriginofdyspnoeatotheinvolvedorgansystemandhelptonarrowthedifferentialdiagnosis.Fevermanifestswithdyspnoeainmanyinfectiousandinflammatoryconditions,includingpneumonia,bronchitis,laryngitis,viralsyndromes(e.g.,Hantaviruspulmonarysyndromeandsevereacuterespiratorysyndrome[SARS]),vasculitides,andsepsis.[25][26]Dyspnoeaplusfeverandcoughmayindicatecommunity-acquiredpneumoniaoropportunisticinfectioninimmunocompromisedhosts.ACXRisnecessarytoexcludepneumonia.Post-obstructivepneumoniaispossibleinpatientswithforeignbodyaspirationorachestmalignancy.Centralchestpainmaysuggestcoronaryarterydisease,pulmonaryembolism,pneumothorax,pneumomediastinum,orforeignbodyaspiration.[27]Pleuriticchestpainmayindicatepneumonia,pneumothorax,pulmonaryembolism,asolitaryfibroustumourofthepleura,orpleuritis.[28]Pericardialconstrictionandeffusionsarecharacterisedbytypicalpericardialpainthatisreferredtothescapularregion,worsenedbypositionandchangesinintrathoracicpressure,andrelievedbyleaningforwards.Palpitationsmaybepresentinparoxysmaltachyarrhythmias,pulmonaryembolism,valvularheartdisease,oranxietyattacks.Syncopemayaccompanydyspnoeaassociatedwithtachyarrhythmiasorpulmonaryembolism.[29]Wheezingmayindicateasthma,COPD,pulmonaryoedema,bronchiolitis,oraspirationofaforeignbody.Coughmaybepresentinbronchitis,acuteinfectiouspneumonia,acuteeosinophilicpneumonia,interstitiallungdisease,COPD,asthma,bronchiectasis,orchronicpneumonitis.[18]ChronicsputumproductionmayindicateCOPDorbronchiectasis,whilelargeamountsofclearsecretionsmaybepresentinbronchoalveolarcarcinoma.[30]Changeinthepitchofthevoicemayaccompanydyspnoeaassociatedwithpneumomediastinum,gastro-oesophagealreflux,retropharyngealhaematoma,aorticaneurysm,orlungcancer.[31]Haemoptysismayaccompanydyspnoeainpatientswithbronchitis,exacerbationofbronchiectasis,chestmalignancies,vasculitides,acuteinfectiouspneumonia,cryptogenicorganisingpneumonia,pulmonaryembolism,cocainetoxicity,tuberculosis,ordiffusealveolarhaemorrhage.[32][33][34][35][36][37]Dysphagiaorodynophagiamaybepresentinadyspnoeicpatientwithgranulomatouslaryngitis,pneumomediastinum,foreignbodyaspiration,tetanus,andepiglottitis.[38][39][40]Inepiglottitis,dyspnoeamaybeadditionallyaccompaniedbydrooling.Vomitinganddiarrhoeamayaccompanydyspnoeainthyrotoxicosisorbotulism.[41][42]Heartburnmaybepresentingastro-oesophagealrefluxwithaspiration.Muscleweaknessormyalgiasassociatedwithdyspnoeamayindicatedeconditioning,adverseeffectsofmedications,musculardystrophies,amyotrophiclateralsclerosis,acutepolioorpost-poliosyndrome,Guillain-Barresyndrome,WestNileandotherviralinfections,leptospirosis,Cushing'smyopathy,orbotulism.[20][26][43][44][45][46][47][48][41]Visualdisturbancesmayoccurwithdyspnoeainmyastheniaandtetanus,andheadachemaybepresentincarbonmonoxidepoisoning.[39][49][50]Bonepainmaybeassociatedwithacutechestsyndromeduetosicklecellanaemiaorfatembolismassociatedwithlong-bonefractures.[51]Anxietymaybeareactiontodyspnoeaofanyaetiologybutmayalsocausedyspnoeainacutepanicoranxietyattacks.[52]Dyspnoea