Case-basedVetBLUE®andIts6LungUltrasoundSigns
GregoryR.Lisciandro,DVM,Dipl.ABVP,Dipl.ACVECCHillCountryVeterinarySpecialists&FASTVet.com,Spicewood,TexasUSA
Websitewww.FASTVet.com
TextFocusedUltrasoundTechniquesfortheSmallAnimalPractitioner,Wiley©2014availableinSpanish,www.intermedica.com.ar,Greek,Chinese,JapaneseandPolish
UseofLungUltrasoundinSmallAnimals-TheVetBLUE® Thereluctance topro-activelyapply lungultrasound (LUS) tosmallanimalswith respiratorydistress is irrational inmanyrespects. The overriding belief that air-filled lung creates insurmountable obstacles, and the continued belief in smallanimalmedicinethatimaginglungisdifficulttoperformleadingtomistakes,perpetuateLUSdelayeduseinsmallanimalveterinarymedicine.ThoracicFASTcalledTFAST®(2008)wasthefirststandardizedabbreviatedveterinaryultrasoundexamof the thorax that included the Chest Tube Site (CTS) for lung surveillance for detection of PTX and lung contusions.However, becauseof the findingof lungpathology foundduring TFAST, the author extended lung surveillance from theTFASTCTSwiththeadditionof6morelungviewsappliedtonon-traumasubsetsofsmallanimals.Thenameofthisnovelregionally-basedLUSexamhasbeenstudiedandpublishedbyLisciandroandcolleaguesin2014astheVetBLUEProtocol(“Vet”forveterinaryand“BLUE”blueforcyanosisandbedsidelungultrasoundexamorinemergency).TheBasicsofVetBLUE®PatientPreparationGenerallynoVetBLUEsitesareshaved!Allimagesshownbytheauthorareunshavedsitesatwhichthefur ispartedandalcohol isappliedtotheskinandasmallamountofacousticgeloralcohol-basedhandsanitizer totheprobe head. No images from cases in this talk were shaved. Patient Positioning Vet BLUE is performed in sternalrecumbencyorstandingand issaferfordogsandcats inrespiratorydistress. Arolloftowelsorpapertowelsundertheforelegsof a cat is aneasy toleratedmaneuver to gain access to the lowerventralVetBLUEandTFASTPeriCardial Siteviews. Vet BLUE may also be performed in dogs and cats in lateral recumbency. Probe Orientation and Type LUSorientation is always the same with the visualization of the “Gator Sign” to properly identify the pulmonary-pleuralinterfaceorthe“LungLine”,actualsurfaceofthelung.Theprobeisheldperpendiculartothelong-axisoftheribs;depthisgenerallysetbetween4-7cm;frequencyisgenerallysetbetween5-10MHz;andamicroconvexprobeispreferredoveralinearprobebecause theprobe is acceptable forall 3 formats -AFAST®, TFAST® andVetBLUE® – combinedcalledGlobalFAST®. Aphase-arrayorsectorprobe isgenerallynot recommendedbecause its focalpoint is toosmall,althoughthis isunknown.Alinearprobemaybeused,however,itisgenerallynotidealfortheAFASTandTFASTportionsofGlobalFAST.The“GATORSIGN”–BasicLungUltrasoundOrientation
Figure.Theroundedribheadsarelikenedtotheeyes,andthepulmonary-pleural(PP-line)interfacetothebridgeofitsnose,asapartiallysubmergedgator(alligator)peersatthesonographer.TheproximalwhitelineisthefocusofallLUS.ThismaterialisreproducedwithpermissionofJohnWiley&Sons,Inc,FocusedUltrasoundTechniquesfortheSmallAnimalPractitioner,Wiley©2014andFASTVet.com©2014
HowtoPerformtheVetBLUE®-9AcousticWindows
ThismaterialisreproducedandmodifiedwithpermissionofJohnWiley&Sons,Inc.,FocusedUltrasoundTechniquesforthe
SmallAnimalPractitioner,Wiley©2014andFASTVet.com©2014HowtoPerformTheVetBLUElungexaminationisascreeningtestperformedidenticallyastheprobeispositionedattheCTSviewofTFAST.Theprobeisthenmovedthroughregionallocationsthatarebilaterallyappliedasfollows:caudodorsallung region (Cd - same as the TFAST3 CTS view, upper third, 8-9Th intercostal space), perihilar lung region (Ph – 6-7thintercostalspace,middlethird),middlelungregion(Md–4-5thintercostalspace,lowerthird),andcraniallungregion(Cr–2nd-3rdintercostalspace,lowerthird).
GregLisciandro,DVM,Dipl.ABVP,Dipl.ACVECCandFASTVet.comandHillCountryVeterinarySpecialists©2015,2016,2017,2018
KeyPoint:BestwaytoperformVetBLUE®accuratelyistolocatetheleftTFASTChestTubeSitedirectlyabovethexiphoidintheareaofthe8-10thintercostalspaceintheupper1/3rdofthethorax,findthetransitionzonewherelungandabdomeninterface, then bymove 2 intercostal spaces cranially tomake sure the probe is over lung/pleural space and not overliver/stomach/abdominalcontents.FromtheleftTFASTCTS,whichisthesameastheleftVetBLUECdview(point1),drawalinewithyouralcoholoracousticcouplinggeltotheelbow,andhalfwaytotheelbowistheVetBLUEPhview(point2),andneartheelbowistheVetBLUEMdview(point3).IftheheartisinviewattheVetBLUEMdview,slideabovetheheartuntilyouseethelungline.ThefinalsiteistheVetBLUECrview(point4),whichrequiresextendingtheforelegcraniallytogettheprobeplacedinthe1st-2nd-3rd intercostalspaces. DefinetheCrviewbyfinding itstransitionzoneofthethoracicinlet and lung then sliding caudally over intercostal spaces 1, 2, and 3. If too ventral at the Cr view, you will see thestriationsofthepectoralmuscles.Noweachoftheviewshasaprimary,andthensecondaryviewsbyslidinganintercostalspacecaudallyandanintercostalspacecraniallyfromtheprimaryviewsothat3intercostalspacesaresurveyedateachVetBLUEview.Theauthor’spreferenceistostarthigh(dorsal)ontheleftmovingfromCdtoCr,andthendothesameontherighthemithorax.Byalwaysperforminginthesamemanner,findingsarebetterremembered;andifyoudonothavetheGatorSignOrientation,thenyouarenotoverlung. *Notethediaphragmatic-hepaticview(DH)isALSOpartofVetBLUEprovidingadeepwindowintolungnotevidentonthetransthoracicVetBLUEviewsnotshownintheimagesabove.VetBLUE®forRespiratoryDistress–The6VetBLUE®SignsWetvs.DryLung–BasicLungUltrasound.BasiceasilyrecognizableLUSfindingsarecategoriazedintotheWetLungvs.DryLungconcept. LungSliding(alsocalledGlideSign)withA-lines(reverberationartifact)atthe lung line isconsidered“DryLung”only tobeconfoundedwithPTX (A-linesandnoLungSliding [alsocalledGlideSign]). A-linesarehorizontal lines.
However,manypatientsinwhichtheprobabilityofPTXisverylow,thenspendingadditionaltimefindingtheLungSliding(Glide Sign) becomes less important and A-lines alone suffice. Ultrasound Lung Rockets (ULRs) also called B-lines areconsidered“WetLung”andoscillatetoandfrowithinspirationandexpirationandmustextendtothefarfieldobliteratingA-linesandarevertical lines. ShredSign,TissueSign,andNoduleSign (plusWedgeSign)–AdvancedLungUltrasound.Thesearethe3moreadvancedLUSsignswehavecreatedinprogressiveorderofincreasingconsolidation/infiltration.TheShred Sign is an air bronchogramon TXR or rather consolidationwith aeration of the lung; the Tissue Sign is similar tohepatization of lung or rather consolidation withOUT aeration; and the Nodule Sign or rather organizedconsolidation/infiltrationindiscreetnodules(nodule<3cm,mass>3cm).TheWedgeSignisasubsetoftheShredSignandrepresents pulmonary thrombo-embolism (PTE) or rather vascular infarcts at the lung periphery. See Figure descriptionbelow.
GregLisciandro,DVM,Dipl.ABVP,Dipl.ACVECCandFASTVet.comandHillCountryVeterinarySpecialists©2015,2016,2017,2018andIllustrationbyHannahHey,SanAntonio,Texas
Figure. A) Dry Lung B) Wet Lung, ULRS (alveolar-interstitial edema) C) Shred Sign (air bronchogram) D) Tissue Sign(consolidationwithOUTaeration,hepatization)E)NoduleSign (organized infiltration, consolidation)andF)WedgeSign -triangulatedShred-TissueSignrepresentingvascularinfarction.ThismaterialisreproducedandmodifiedwithpermissionofJohnWiley&Sons,Inc.,FocusedUltrasoundTechniquesfortheSmallAnimalPractitioner,Wiley©2014andFASTVet.com©2014
GregoryLisciandro,DVM,Dipl.ABVP,Dipl.ACVECCandFASTVet.comandHillCountryVeterinarySpecialists©2015,2016,2017,2018
Figure.A)Noultrasoundlungrockets(ULRs)B)AsingleULR(alsocalledB-lines)scoredas“1”or"2"or"3"or">3"and"∞"orinfinity.ThemaximumnumberofULRsoverasinglerepresentativeintercostalspaceateachrespectiveVetBLUEview(3intercostalspacesperview)isrecorded.Thecountingsystemisasfollows:0;1;2;3;>3,whenULRsarestillrecognizedas
individuals; and∞ or infinity, when the ULRs blend into one another becoming confluent. ULRs also called B-lines arevertical laser-likehyperechoic lines thatdonot fadeextending fromthe lung line to the far fieldobliteratingA-linesandswinginsynchronywiththephasesorrespiration.ULRsalsocalledB-linesandmustbeplacedinclinicalcontextwithaVetBLUEpattern-basedapproach.WeknowfromourresearchtoexpectALLVetBLUEviewstobedry(absentB-lines)inthevast majority of pateints (adult dogs, adult cats, puppies and kittens > 6 weeks of age) (Lisciandro et al. VRUS 2014;Lisciandroetal.JVECC2017;Lisciandroetal.JVECC2018[Abstract]).FASTVet.com©2015,2016,2017,2018Regionally-BasedPatternApproachofVetBLUE®
ThismaterialisreproducedwithpermissionofJohnWiley&Sons,Inc.,LisciandroGRChapter10:TheVetBLUEScan,InFocusedUltrasoundTechniquesfortheSmallAnimalPractitioner
Figure.ClinicalCasesExamplesofVetBLUERegionally-basedPatterns.A)DryLungallfieldsrulesoutclinicallyrelevantLeft-sidedCongestiveHeartFailure(L-CHF),suggestsupperairwayobstruction,FelineAsthma,COPD,PTEandnon-respiratorylook-a-likes.B)WetLungorULRsindorsal,perihilar,andmiddlelungregionssuggestsCardiogenicLungEdema(left-sidedcongestiveheart failure,volumeoverloadfromintravenousfluids). C)WetLung indorsal lungregionssuggests formsofNon-cardiogenicLungEdemamakingTFASTechoviewshelpfultodistinguishfromCardiogenicLungEdema.D)WetLungsinventralfieldswithorwithoutsignsofconsolidation(ShredSign/TissueSign),suggestPneumonia.E)Solitarynodule.F)Multiple nodules suggestMetastatic Disease orGranulomatousDisease. KEY: D=Dry lung;W=Wet lung; Sh=Shred Sign;Ti=TissueSign;Nd=NoduleSign.WedgeSign(PTE)notshown.ThismaterialisreproducedwithpermissionofJohnWiley&Sons,Inc,FocusedUltrasoundTechniquesfortheSmallAnimalPractitioner,Wiley©2014andFASTVet.com©2014VetBLUE®DiagnosticAlgorithmforFindingsandPatterns
ThismaterialisreproducedwithpermissionofJohnWiley&Sons,Inc.,LisciandroGRChapter10:TheVetBLUEScan,InFocusedUltrasoundTechniquesfortheSmallAnimalPractitioner
RuleOutsforAbsentB-lines(DRY)AllViewsonVetBLUE®
RESPIRATORYPulmonaryThromboembolism(PTE)
AdvantageofVetBLUE®OverThoracicRadiographyUltimatelyproactiveVetBLUE lungultrasoundwillprove itselfasamoresensitivetestthanradiographyfor lungsurfacepathology(anddiagnosingpneumothorax),alveolar-interstitialedema(UltrasoundLungRockets,alsocalledB-lines), lungconsolidation (Shred Sign, Tissue Sign, Wedge Sign for PTE) and nodules (Nodule Sign) and most common respiratoryconditions. We have several clinical studies accepted, in the process of being written, that support this statement(Lisciandro et al VRUS 2014; Lisciandro et al. JVECC 2017; Kulhavy and Lisciandro JVECC 2015 [Abstract]), Kulhavy andLisciandroJVECC2018[Abstract]),Wardetal.JAVMA2017,Wardetal.JVECC2018,Wardetal.JVIM2018).AlwaysStriveforTheGLOBALFAST®APPROACHWehavebeenadvocatingforVetBLUEasbothascreeningtestandacomplimentarytesttobetter interpretpulmonaryradiographyandrefertothelatteras"RADBLUE";however,theGlobalFAST®avoidsmistakes,forexample,adogwithadrycoughfrommainstembronchialcompressionfromdilatedcardiomyopathy(DCM)mayverywellhaveabsentB-linesallVetBLUE views, and an unremarkable cardiac silhouette on thoracic radiographs, but have easily detected DCM by TFASTrecognizinganenlargedleftventricleandverypoorcontractilityattheTFASTrightpericardialshort-axisview.WithouttheGlobalFAST®Approach,seriousdiseasewouldhavebeenmissedandthedrycoughmisdiagnosed.Moreover,thedogmayhaveabdominalco-morbiditieslikeright-sidedcongestiveheartfailure(FATcaudalvenacavaandascites),orasplenicmassthatismissed,byonlyperformingpoint-of-careultrasoundexaminationsorfocusedultrasoundandfallingintothetrapof"satisfaction of search error." The author advocates for the Global FAST Approach® on ALL patients having throughexperienceseenthedangerofnotdoingsotothepatient'sdetriment.
DynamicUpperAirwayConditions(e.g.,CollapsingTrachea,LaryngealParalysis)UpperAirwayObstruction(e.g.,Mass,OropharyngealSwelling)ChronicObstructivePulmonaryDisease(COPD),Bronchitis
FelineAsthmaTracheobronchitis(e.g.,Infectious,Inflammatory,Irritant)
PleuralEffusionCentrallylocatedlungpathologyawayfromthelungline(missedbyVetBLUE)
CARDIACPericardialEffusion/CardiacTamponade
CardiacArrhythmiaDilatedCardiomyopathy(DCM)
Right-sidedCongestiveHeartFailure(CHF)PulmonaryHypertension
UNDIFFERENTIATEDHYPOTENSIONCanineAnaphylaxisHemoabdomenHemothorax
HemoretroperitoneumCavitary(orSpacial)Effusion
GDV/BloatSepsis
OTHERNON-RESPIRATORYPyrexia/HeatStroke
HighFeverSevereMetabolicAcidosis
SevereAnemia
NOTE:DryLungsALLFieldsalsocalledAbsentB-linesALLViews(ABAV)isRapid(<90sec),Point-of-care,MinimalRestraint-HighlySensitiveTestRulingOutLeft-sidedCHF(Dogs88-96%,Cats96%)
GregoryLisciandro,DVM,DABVP,DACVECCandFASTVet.comandHillCountryVeterinarySpecialists©2015,2016,2017,2018
Lisciandroetal.JVetEmergCritCare2016;26(S1):S8
References&FurtherReading
1. LisciandroGR.Abdominal(AFAST)andthoracic(TFAST)focusedassessmentwithsonographyfortrauma,triage,andtracking(monitoring)insmallanimalemergencyandcriticalcare.JVetEmergCritCare2011;21(2):104-119.
2. LisciandroGR,etal.Frequencyandnumberofultrasoundlungrockets(B-lines)usingaregionallybasedlungultrasoundexaminationnamedvetblue(veterinarybedsidelungultrasoundexam)indogswithradiographicallynormallungfindings.VetRadiolandUltrasound2014;55(3):315-22.
3. LisciandroGR,etal.Frequencyandnumberofultrasoundlungrockets(B-lines)usingaregionallybasedlungultrasoundexaminationnamedvetblue(veterinarybedsidelungultrasoundexam)incatswithradiographicallynormallungfindings.JVetEmergCritCare2017;27(3):267-277.
4. WardJL,LisciandroGR,TouSP,KeeneBW,DeFrancescoTC.Accuracyofpoint-of-carelungultrasound(VetBLUEprotocol)forthediagnosisofcardiogenicpulmonaryedemaindogsandcatswithacutedyspnea.JAmVetMedAssoc2017250(6):566-579.
5. WardJL,LisciandroGR,DeFrancescoTD,etal.EvaluationofPoint-of-careThoracicUltrasoundandNT-proBNPfortheDiagnosisofCongestiveHeartFailureinCatswithRespiratoryDistress.JVetInternMed2018.
6. WardJL,LisciandroGR,WareWAetal.Lungultrasoundfindingsin100dogswithvariousetiologiesofcough.JAmVetMedAssocinpress,acceptedMay2018.
7. LisciandroGR,etal.AbsenceofB-linesonLungUltrasound(VetBLUEprotocol)toRuleOutLeft-sidedCongestiveHeartFailurein368CatsandDogs.Abstract,JVetEmergCritCare2016.
8. WardJL,LisciandroGR,DeFrancescoTC.Distributionofalveolar-interstitialsyndromeindyspneicveterinarypatientsassessedbylungultrasoundversusthoracicradiographs.JVetEmergCritCare,inpress,acceptedNovember2016.
9. LisciandroGR.Chapter55:UltrasoundinAnimals.InCriticalCareUltrasound(humantextbook),EditorsLumbandKarakitsos.Elsevier:St.Louis,MO2014.
10. LisciandroGR.Chapter10:TheVetBLUELungScan.InFocusedUltrasoundfortheSmallAnimalPractitioner,Editor,LisciandroGR.WileyBlackwell:AmesIA2014.
11. LisciandroGR.Chapter9:TheThoracic(TFAST)Exam.InFocusedUltrasoundfortheSmallAnimalPractitioner,Editor,LisciandroGR.WileyBlackwell:AmesIA2014.
12. LisciandroGRandArmeniseA.Chapter16:FocusedorCOAST3-CPR,GlobalFASTandFASTABCDE.InFocusedUltrasoundfortheSmallAnimalPractitioner,Editor,LisciandroGR.WileyBlackwell:AmesIA2014.
