Embed Size (px)
Citation preview
4/23/17
1
SmokeinhalationinjuryArmelledeLaforcadeDVM,DACVECC
GarretPachtinger,VMD,DACVECC
COO,VETgirl
Introduction
JustineA.Lee,DVM,DACVECC,DABTCEO,VETgirl
Introduction VETgirl…On-The-Run• Thetech-savvywaytogetonlineveterinaryCE!• Asubscription-basedpodcastandwebinarservice
offeringveterinaryRACE-approvedCE
VETgirlELITE
50-60podcasts/yearplus30+hoursofwebinars!– $199/year– 40+hoursofRACE-CE
Up to 5 members: $599/year
Up to 10 members:$999/year
> 10 members:Ping us
4/23/17
2
VideoArchives!Newandimproved
video!
DownloadouriTunespodcastsfree!
Socialmediaandourblog!
n 4/24– 10:30amESTn 4/28– 6pmESTn 5/2– 3pmEST
4/23/17
3
Logistics:CECertificatesn Typeinquestionsn Emailedtoyou48hoursafterthewebinarn Activeparticipation=noquizn Watchingvideolater,mustcompletequiz
n ELITEmembersonlyn Email/contactwithANYquestions
n [email protected] [email protected]
ArmelleM.deLaforcade-DVM,DACVECC
AssociateProfessor,TuftsUniversity
Introduction
Introduction
• Smoke• Pathophysiology• Diagnosis• Treatment• Complications
Epidemiology
• Frequentlyaccompaniesburninjury• Increasesmortalityby20%inburnpatients• Increasesriskofpneumonia,ARDS
– Increasedmortalityto60%
Literature
• Studiesinpeople– Burnstudies,burnsepsis
• Animalmodels– Histopathology,immunechanges
• Veterinarystudies– Largelycasereports
Smokeinjury
• Directheatdamage– Upperairway,nasopharyngealmucosa
• LowFi02• Inhaledparticulates/irritants• Inhaledtoxins
• Complicatedby– Inflammatorychanges,secondarypneumonia
4/23/17
4
Systemsaffected
• Respiratory• Centralnervoussystem
– Acute– Delayed
• Cardiovascular• Ocular• Cutaneous
Constituentsofsmoke• Whatisburning,howmuchoxygen,temperature
• Particulatematter:Soot,tar,ash,metaloxides
• Carbon: Carbonmonoxide,carbondioxide
• Nitrogen:Hydrogencyanide,ammonia,nitrogenoxides
• Halogens:hydrogenchloride,halocarbons• Fluorocarbons:hydrogenfluoride• Sulfur:hydrogensulfide,sulfurdioxide,thiols• Hydrocarbons:aldehydes
Constituentsofsmoke• Whatisburning,howmuchoxygen,temperature
• Particulatematter:Soot,tar,ash,metaloxides
• Carbon: Carbonmonoxide,carbondioxide
• Nitrogen:Hydrogencyanide,ammonia,nitrogenoxides
• Halogens:hydrogenchloride,halocarbons• Fluorocarbons:hydrogenfluoride• Sulfur:hydrogensulfide,sulfurdioxide,thiols• Hydrocarbons:aldehydes
Directthermalinjury
• Upperairway– MouthtoGlottis– Thermalinjury
• Lowerairway– Belowglottistolungparenchyma
– Chemicalinjury– Toxiccompounds
https://www.vetmed.wsu.edu
Particulatematter• Cough
– Vagalreceptorsinthroatandproximalairway– Paroxysmal/intractable
• Cellularedema,destruction– Carbonaceousaccumulation
• Reflexbronchoconstriction• Highviscositysecretions
– Lowhumidity
• Impairedmucociliaryclearance
Hypoxia
• Atelectasis• Surfactantinactivation• Obstructivecasts
– Cellulardebris,fibrinclots,leukocytes,mucus
• Pulmonaryedema– Proteinrich– Reducedcompliance,increasedresistance– Increasedworkofbreathing
4/23/17
5
Carbonmonoxide:“thesilentkiller”
• Highlylinkedtofirerelateddeaths– Autopsystudies
• Imaging:Pulmonaryedema– Interstitial&interalveolar
• Postmortem:Pulmonaryedema&hemorrhage
COandgasexchange
• Rapidlyabsorbed• CombinationwithHb
– CO+Hbè COHb (carboxyhemoglobin)– 200-250xgreateraffinityofHb forCOthanoxygen
• Haldaneeffect– LeftshiftofoxyHb curve– Impairedoxygenrelease– Tissuehypoxia
CO:systemiceffects
• Cardiac:COaffinityformyoglobin– Myocardialdepression– Arrhythmias– Hypotension– Perpetuatestissuehypoxia
• Neurologic:demyelination– Impairedcellularuptakeofoxygen– Freeradicalformation– Coma,seizures
COtoxicity:diagnosis
• Co-oximetry– Carboxyhemoglobin levels– Heparinizedblood
• MRIlesions• Pulseoximetry
– Falselyelevated
COHb (%) Symptoms
0-5 Normal
15-20 Headache, confusion
20-40 Hallucination
40-60 Coma
60+ CPA
• 3chihuahuas,housefire• 30minutesinsmoke
• Seizures3-4daysfollowingfire– Difficulttocontrol
• Brainpathology– Neuronalnecrosis,demyelination– SupportacuteCOtoxicity
JAAHA 2010
COpoisoning:treatment
• ShortenhalflifeofCOHb– 100%oxygenadministration– Hyperbaricoxygentherapy(CoHb>25-30%)
• Slowcorrectionoflacticacidosis– Providingsomeoxygendiffusiontotissues
• Delayedeffects– Personality,behavior,memorychanges
4/23/17
6
• 4dayspostsmokeexposure– Mentationchanges– Walkingintowalls,ataxic– Progressedtotetraparesis– Tachypnea,pneumonia
• Therapy– Antibiotics,N-acetylcysteine,supportivecare
• Followup:34months
HydrogenCyanide(CN):“thetoxictwin”
• Combustionofsynthetics– Plastics,rubber,foam,varnish,paints– Wool,silk,paper
• 1960’s-1980’s– recognizedrolesmokeinhalationinjury
• LevelsmaybebetterpredictoroflethalityinsmokeinhalationvictimsthanCO– Protocolsforprophylactictreatment
HydrogenCyanide(CN)
• Inhibitscytochromecoxidase– aerobicmitochondrialrespiration– Anaerobicrespiration
• Lacticacidosis• Cellulardamage,death
• Bindshemoglobin– Reducedoxygencarryingcapacityofblood
• Heart,brain,CNSmostaffected– Mostreliantonoxygen
CN:clinicalsigns
• CanbesimilartoCO• Firefightershavereported
– Headache,weakness,fatigue,shortnessofbreath,cough,disorientation,arrhythmias
– Heartattack
CN:clinicalsigns
• CanbesimilartoCO• Firefightershavereported
– Headache,weakness,fatigue,shortnessofbreath,cough,disorientation,arrhythmias
– heartattack
Cyanidetoxicity:diagnosis
• Oftenmissed– ‘Inlineofdutydeaths’ (LODDs)– Suddencardiacillness
• Bloodtesting:shorthalflife,sendouttest• Airmonitoring• Lactateconcentration
– IndicatoroftoxicCNlevels– Lactate>10mmolindicatesCN>39umol/L
4/23/17
7
Cyanidetoxicity:treatment
• Hydroxocobalamin– OnlyFDAapprovedantidote– Combineswithcyanidetoformcyanocobalamin– VitaminB12precursor– Controversial
• 2017study– Safe– Reducedhospitallengthofstay,ventilatordays– Incidenceofpneumonia
ParisFireBrigade
• Criteriaforhydroxocobalaminadministration
• Extricatedfromanenclosed-spacefirescenewithsmoke
• Sootinthenose,mouth,orthroatorsootyexpectoration
• Anyalterationsinconsciousness• Hypotension
Smokeinhalation:clinicalsigns• None!• Respiratory
– Tachypnea– Cough– Harshlungsounds– Pulmonarycrackles– Nasaldischarge– Laryngeal/trachealsounds
• Mucousmembranes– Cyanosis– Hyperemic
Smokeinhalation:clinicalsigns• Neurologic
– Depressed– Ataxia– Stupor– Coma
• Dermatologic– Smokysmell– Singedhair– Burnedskin– Sootonskin
Firstassessment
• Airwaypatency– Intubateifnecessary– Lossofconsciousness
• Oxygentherapy• IVaccess
Pointofcaretesting
• Lactateconcentration• Co-oximetry
– Carboxyhemoglobinemia
• Pulseoximetry?
4/23/17
8
Diagnostics
• Thoracicradiographs– 80%– Interstitialtoalveolar
• Bronchoscopy– Obstruction
• Arterialbloodgas– PaO2:FiO2
Diagnosticsinpeople• Bronchoscopy• Pulmonaryfunctiontesting• Pulmonaryscan
Treatment
• Oxygentherapy– Firstresponders!– Respiratoryfailure– MetabolismofCO
• Mechanicalventilation– Failuretomaintainairway– Progressiverespiratoryfailure– Unconsciousness
Hyperbaricoxygentherapy
• Deliveryofoxygenunderpressure• Oxygendiffusesintoareasoflowoxygen
– Helpischemictissues– Reducesrelianceonhemoglobin
• UsefulwithCOandCNpoisoning– DisplacesCOfromintracellularstores– Improvemitochondrialfunction
• Consideredif– Carboxyhemoglobin>25%,unconsciousness
N-acetylcysteine
• Mucolytic• People
– NebulizedN-acetylcysteine/heparin/albuterol– Attenuatelunginjury– ReduceprogressiontoARDS– Reducemortality– Somestudiesshownobenefit
• Continued5-7daysinhospital
Albuterol
• Beta-2agonist• Relaxesbronchialsmoothmusclereceptors• Reducesairwayresistance• Usefulwithseverebrochospasm
4/23/17
9
AlphaTocopherol
• VitaminE– SuperoxideScavenger
• Smokeexposurecausesoxidativestress• VitEdepletedinburn&smokeinjury
– Sheepmodels
• Fewstudies,somesuggestimprovedgasexchangewithsupplementation
Antibiotictherapy
• Bacterialcolonizationpeaks2-3dayspostexposure
• Prophylactic:No– Promoteantibioticresistance
• Withinfection:Yes– Organismcanbedifficulttopredict– Alteredairwaymicrobiome– Broadspectrumpendingcultureresults
• Anaerobes,facultativeanaerobes
Corticosteroids
• Anti-inflammatory• MayreducepulmonaryedemaBut..• Increasedriskofpulmonaryinfection• Delayedwoundhealing• Lackofdemonstratedbenefit
• Notrecommended
Adjunctivetherapy
• Atropineophthalmic– Reduceciliaryspasm,pain
• Treatmentofburns
Complications
• ARDS– Bilateralinfiltrates Acuteonset– Severehypoxemia Absenceofheartfailure
• Pneumonia– 2-4daysafterexposure– Longtermsusceptibilitytorespiratoryinfections
• Animalmodel,people
• Sepsis– Cutaneousburns
Outcome
• 11complicated,16uncomplicated– 4died,4euthanized,3survivedintensivecare– Ifnoworseafter1day,likelyuncomplicated
• 15uncomplicated,7complicated• 20catssurvived
4/23/17
10
Conclusion
• Smokeinhalationinjuryiscomplex• Airwaysupportiskey• Impactofdirectinjuryandtoxicgases
– Paramounttosuccessfultherapy
• Expectcomplications• Progressionofrespiratorysignsmaybeprognostic
• Greatcriticalcarecases!
Thankyou!
n 4/24– 10:30amESTn 4/28– 6pmESTn 5/2– 3pmEST
This material is copyrighted by VETgirl, LLC. None of the materials provided may be used, reproduced or transmitted, in whole or in part, in any form or by any means, electronic or otherwise, including photocopying, recording or the use of any information storage and retrieval system, without the consent of VETgirl, LLC. Unless expressly stated otherwise, the findings, interpretations and conclusions expressed do not necessarily represent the views of VETgirl, LLC. Medical information here should be references by the practitioner prior to use. Under no circumstances shall VETgirl, LLC. be liable for any loss, damage, liability or expense incurred or suffered that is claimed to have resulted from the use of the information provided including, without limitation, any fault, error, omission, interruption or
delay with respect thereto. If you have any questions regarding the information provided, please contact [email protected]
