TrainingtoPreventLineofDutyDeathsDuetoStress

andOverexertion

March1,2019

JustinC.Dickstein

www.BlastMask.com|Justin@BlastMask.com

Anunsolvableproblem?

Firefightingisandalwayshasbeenaninherentlyriskyprofession,whether

paidorvolunteer.InfactaccordingtotheU.S.DepartmentofLabor,firefightersare

threetimesmorelikelytodieonthejobthananyotheroccupation(1,2).Thisis

largelyaknownandacceptedriskbyanyonewhoisapartofthefireservice.We

willallwillinglyriskourlivestosavealife.Whatisabsolutelyunacceptable,

especiallyinthisageofawarenessandrapidinnovation,isthatthesame

preventableriskfactorshavebeentheleadingcauseofon-dutydeathsfordecades.

Onaverageoverthelast25+yearsmorethanhalfoflineofdutydeaths(LODDs)can

beattributedtostressoroverexertioncausingsuddencardiacdeath(1,3).The

InternationalAssociationofFireFighters(IAFF)hascategorizedthesedominant

contributingfactorstolineofdutydeathsashealth/wellness/fitness(4).

Despitesubstantialeffortstosolvethisongoingproblem,thestatistics

remainunchanged.Andwhenexpandedtoincludenon-fatalcardiacevents,theyare

considerablymorealarming.Anestimated765firefightersexperiencedheart

attacksin2005,withonly8.1%,or62,resultinginsuddendeath(1,2,5).That

combinationoffatalandnon-fatalon-dutycardiovasculareventsaffectsalmost1in

1,000U.S.firefighterseverysingleyear(6).Additionalresearchhasshownthatfor

everyfatalcardiacevent,17additionalnon-fatalcardiaceventsoccuramong

firefighters(7,8).Furthermore,thesefatalcardiaceventsareoccurringinfirefighters

whoareyoungerthanthoseinthegeneralpopulationexperiencingthesameevents

(1,3).Thesetrendshaveremainedconstantfordecades.Itistimeforanimmediate

andmonumentalchangeinthefireservice.Itistimetosaveourselves.

Whathappenswhenweanswerthebell?

Everyfirefighterintuitivelyknowswhathappenswhenthefirealarmgoes

offanditistimetogetreadytofightfire;orwhenyoupullupon-sceneandthefire

andsmokeareraging.Thecardiovascularandrespiratorystressoffightingfire

beginswithanincreaseinheartrateandminuteventilation,causedbya

sympatheticnervoussystem-triggeredadrenalinerelease,assoonasthealarm

sounds(1).Themostphysiologicallyandpsychologicallydemandingtasksare

usuallyassociatedwithfiresuppressionandsearchandrescue(1,7).Accordingly,the

greatestnumberoffatalcardiaceventsoccursonthefireground.Andriskofafatal

heartattackis10-100timeshigherduringfiresuppressioncomparedtonon-

emergencytasks(4,7).Intherelativelyrareinstanceoffindingandremovinga

victim,thecombinedphysicalandemotionalstressdrivethefirefightersheartrates

wellabove100%oftheirpredictedmaximumandkeepsitatthatlevelforextended

timeperiods(1).

Arewepreparedforthatstress?

TheIndianaUniversityresearchemphaticallystates,“Thediscrepancy

betweenthephysicalpreparednessoffirefightersandthehighdemandoffirefighting

standsatthecenteroffireservicelineofdutydeaths(1).”Awiderangeofstudieshave

shownthatapproximately75%ofallfirefightersareoverweight,withupto40%

beingclassifiedasobese–including33%ofnewrecruits(6,9-12).Thesearenumbers

thatexceedthegeneralpopulationoftheUS,inaprofessionthatiscountedonto

physicallyperformatmaximumlevelsofexertion(13).

Inactivefirefightershavea90%greaterriskofmyocardialinfarction(heart

attack)thanthosewhoareaerobicallyfit(13).Andfirefighterswithlowaerobic

capacityare2.2timesmorelikelytosustaininjurythantheirmorefitpeers(14).

Amongunconditionedpersons,stressfulsituationsresultinginsympatheticand

cardiovascularactivation,suchasfirefighting,can“trigger”acuteheartdisease

events(6,15).Therearetickingtimebombsinyourfiredepartmentrightnow.And

youaredoingthem,theirfamilies,andyourfellowfirefighters,thegreatest

disservicebyallowingthemtobecomplacentintheircurrentstate,whichisatbest

unfitforduty.

WhatisVO2maxandwhyisitthekeytosavingfirefighterslives?

VO2maxisthemaximaloxygenuptakeorthemaximumvolumeofoxygen

thatcanbeutilizedduringmaximalorexhaustiveexercise;itisconsideredthebest

indicatorofcardiorespiratoryendurance(16).VO2maxhasbeenconsistently

identifiedasanimportantfactorintheassociationoffirefightingdemandsand

physiologicalrequirements(1,17,18).VO2maxismeasuredinmL/kg/min,withthe

minimumlevelrecommendedforfirefightersbytheIAFFsetat42mL/kg/min(7).It

hasbeenshownthatindividualswithVO2maxvaluesbelow33.5mL/kg/minare

unabletocompleteastandardfiresuppressionprotocol(1,19).Mostimportantlyof

all–researchfromtheUniversityofSouthCarolinahasshownthatalowVO2maxis

agreaterriskfactorforcardiovascularmortalitythanobesity,hypertension,

diabetes,highcholesterol,orsmoking(7,16).

DeniseSmithetal.explainthatlowerlevelsofcardiorespiratoryfitnessare

associatedwithamarkedlyincreasedriskofpathologicalchangesduringpeak

exercise,including:STsegmentchange,dysrhythmia,andabnormalheartrate

recovery(20,21).Theythengoontostatedirectlythathighfitnesslevelsandaerobic

capacityhavea“likelyprotectiveeffectagainstsuddencardiacdeath…”infirefighters

(20).

HowdoesyourSCBA,specificallyyourregulator,affectyourVO2max?

Operatinginyourself-containedbreathingapparatus(SCBA)mightbe

havingamoredramaticeffectonyourabilitytoworkthanyourealize,inmoreways

thanyouthink.ResearchhasshownthatduringheavyworktheSCBAgreatly

reducesmaximalexerciseperformance(22-25).ClinicaldatashowsthatafullSCBA

systemlowersVO2maxby14.9%(22).Toshowhowsignificantthis14.9%is,letus

lookatsomeVO2maxvaluescommontofirefighters.Asampleofpaidfirefighters

wasfoundtohaveameanVO2maxof40.57mL/kg/min(1,26).Whenthatisreduced

14.9%bytheSCBA,itgetsloweredto34.52mL/kg/min–orjust1mL/kg/minover

theminimumrequiredforcompletingthestandardfiresuppressionprotocol

discussedearlier.75%ofvolunteerfirefighterstestedwerefoundtohaveaVO2max

between20-39mL/kg/min(1,26).ThatmeanswhentheirVO2maxvaluesare

adjustedfortheSCBA,75%ormoreofvolunteerfirefightersdonotmeetthe

minimumleveltoperformafiresuppressionprotocol.

In2005Evesetal.publishedquantitativedatashowingthatthesingle

biggestfactorcontributingtotheSCBAloweringoverallworkloadwasthe

regulator,nottheweightofthepack.Theregulatoritself,withnoweightfromthe

SCBApack,wasresponsiblefora13.1%reductioninVO2max(22).Theregulator

alonedecreasesVO2maxalmostthesameamountasthefullSCBA.Theweightof

theSCBApackwasonlyresponsiblefora4.8%decreaseinVO2max(22).Further

researchfromButcheretal.showedthattheregulator,byitself,increasedactive

expiratoryresistiveworkby59%,inspiratoryelasticworkby26%,andtotalwork

ofbreathingby13%(27).Thepotentialconsequenceofthisincreasedworkof

breathingisthecompetitionforavailablecardiacoutput(27).Evesetal.clearlystate,

“ThemodernSCBAwornbyfirefightersdecreasesVO2maxandpeakpoweroutputdue

toaventilatorlimitationimposedbytheaddedexpiratorybreathingresistanceofthe

SCBAregulator.”Everyfirefighterknowsthatitismoredifficulttoworkandbreathe

intheirSCBA.Thedatareinforcesandexplainsthecauseofthatworn-out,

breathlesssensationthateveryonehasexperiencedafteranaggressiveinterior

attack,oranystrenuousassignmentcompletedinanSCBA.

Infact,thismaybemorethanjustapreviouslyinexplicablefeeling.Smithet

al.proposethat,“Ischemia(duetoanincreaseinmyocardialoxygendemand)may

exceedmyocardialdemand,resultinginelectrical,mechanical,andbiochemical

dysfunctionofthecardiacmuscle,precipitatingfatalarrhythmias.”(20)

Howcanwegetfitforthefire?

Dr.JimBrown,DirectorofFirefighterHealth&SafetyResearchatIndiana

University–Bloomington,states,“Developmentofaneffectivephysicaltraining

programbeginswiththeidentificationofdemandlevelsajoboreventpresents.”And

ofcourse,thereisnoalternativetowearingSCBAsinanimmediatelydangerousto

lifeorhealth(IDLH)atmospheres.So,ourbestchancetoreduceLODDsfrom

overexertionistobecomeaccustomtotheireffectsonourcardiorespiratorysystem.

Thatmeanstrainingasfrequentlyandrealisticallyaspossible.Thatmeanstraining

“on-air”,notjustinmasksandcylinderweight.Becauseastheresearchclearly

shows,itistheregulatorthatisresponsibleforthedecreaseinafirefighter’s

VO2max.BenMauti,fireservicemarketmanagerforMSANorthAmericadescribes

thenewG1SCBAsystemasfollows,“There’soneairflowpathwhentheregulatoris

hookeduptothefacepieceandasecondaryflowpath,anopenportdesign,toallow

thefirefightertobreathewithoutexhalationresistancewheninstandbymode(28).”

Thatisanecessaryandbeneficialfeatureforrecoveryonthefireground,but

unfortunatelyitdoesnotleadtothephysiologicalandpsychologicaladaptations

neededtoperformadequatelyandsurvivethemassiveworkloadoffightingfire.In

fact,theexhalationresistanceisonekeycontributingfactorinreducingthewearer’s

VO2max(22).

Unfortunately,manydepartmentsdonothavetheresourcestotrain

consistentlyandfrequently“on-air”.Evenlarge,well-fundeddepartmentshave

difficultiesallowingthattypeoftrainingatthestationlevel.Oritmayevenbean

issueoftime,wherefirefightersarespendingmoretimewaitinginlineatthe

cascadesystemthantheyarelearningthecoordinatedmotionsandrepetitive

musclememoryofthedrill.Forthispurpose,wehavecreatedtheBreathingLimited

AirSituationalTraining(Blast)Mask.BlastMasktrainingregulatorsattachtoyour

facepieceandsimulatereal-worldSCBAbreathingwithoutdrainingyourcylinders,

soyoucantrainlikeitisreal.NFPA14046.7,A.5.1.8,andA.6.7.2givetheauthority

havingjurisdictiontheauthorizationtoselectandproviderespiratorsthatare

applicableandsuitableforthepurposeintendedandexplaintheuseofsimulated

stressorsforbeneficialtraining(29).BlastMaskisnotforIDLHatmospheres,butisan

applicableandsuitablerespiratorandsimulatedstressorforavarietyofdrills,

including:SCBAmazes,forcibleentry,verticalventilation,RITandotherrescue

training,dummydrags,theKaisersled,highrisedrills,ladderthrows,hosedrags,

CPATandotherphysicalagilitytesting,andanykindofgeneralfitnesstraining.

Researchersevaluatedthereturnoninvestmentforimplementingapeer-led

wellnessprogramandcalculatedacostsavingsof$2,765perfirefighter,anda

returnoninvestmentof$4.61savedforevery$1invested(30).Thesesavingsonly

accountforareductioninworkerscompensationclaimsandmedicalcost,they

notedthatthecostsavingswouldhavebeenmuchhigherwithexpenseslikelost

workdaysandovertimepayincluded(30).TheBlastMaskwillnotjustsaveyour

departmentmoney,time,andresources;itverywellmightsaveyourfirefighters’

lives.KerriganandMossmighthavesaiditbestforFireEngineering,“Beingfitfor

dutyisthemostbasicrequirementforeveryfirefighter–careerorvolunteer(31).”Itis

timetobetacticallyfitwhenitcounts.Itistimetosaveourselves.

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