vandaag 13 jaar geleden - NVvA · PDF fileValse verhoging van Hb-CO –Niet in zelfde...
Transcript of vandaag 13 jaar geleden - NVvA · PDF fileValse verhoging van Hb-CO –Niet in zelfde...
vandaag 13 jaar geleden
19/09/2014 Wetteren case 1
Patient Management of the Acrylonitrile-Disaster in Wetteren
I. Demeyer, MD, An, CCM Onze Lieve Vrouw Hospital
Aalst, Belgium
Some hints and pitfalls about..
• Beginners mistakes
• Communication errors
• “Waste of money”- story
• (non?)-experience experts
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This presentation only reflects the author’s personal opinion and neither the official
report nor public authority
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Not every presentation is successful
Definitions
• Disaster
• Disaster Relief Team
– Tasks of medical task force
• CP- Ops
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Disaster ?
• Starts with the ‘perception’ of a disaster
• Retrospective view of the event(s)
The Dendermonde day care center ‘Fabeltjesland’ assault
(jan 29, 2009) – 10 victims
– But 5 medical teams at the scene < 20 min
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Wetteren
Disaster or not?
“An occurrence of a natural catastrophe,
technological accident, or human caused
event that has resulted in severe property
damage, deaths, and/or multiple injuries.” USA Federal Emergency Management Agency (FEMA)
NOT: 1 death and 1 severely injured victim
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Disaster or not?
“The result of a vast ecological breakdown in
the relations between man and his
environment, a serious and sudden (or slow,
as in drought) disruption on such a scale
that the stricken community needs
extraordinary efforts to cope with it, often
with outside help or international aid.” WHO definition
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Wetteren case a Disaster?
YES
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Disaster Relief Team in Belgium
Team Discipline 1: Fire Dept
Discipline 2: Medical Dept
Discipline 3: Police Services
Discipline 4: Technical Support Services
Discipline 5: Communication Services
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Disaster Relief Team in Belgium
Discipline 2
Medical Dept.
East Flanders
4 Medical Directors
16 Deputy Medical Directors
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Discipline 2
Medical Director
At the scene
CP-Ops: operational command center
Co-organizer of the disaster relief with specific attention towards the safety (mental & physical) of all rescueworkers, the care for the victims and the population …
Reports to the Crisis Center (Provincial), (representative of the Government Discipl 2)
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Discipline 2: Medical
Victims
Implicated, not wounded
Population Wetteren, Schellebelle, Serskamp, Wichelen, …
Rescue workers (fire dept., civil protection, police services …)
Wounded
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Victims
Duration & number
19 days (May 4 – 21) provincial phase
1.979 evacuated civilians
(May 18: “all – 1” habitants < 250 m back home)
1 dead victim
397 hospital visitors
1 severely injured victim (case report)
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Time Lines
May 4 2 a.m.: Derailment and fire of train
9:42 a.m.: high values arylonitrile in sewer system
May 7 7 a.m.: High values acrylonitrile in sewer system miles away ….
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First communication
2:02 a.m. “Locomotive on fire”
2:08 a.m. 7 fire men at the scene
In the middle of nowhere: no access possible
Communication Cut the power transmission lines
Up scaling “fire dept.” zonal alert
Evacuation of neighborhood (150 m)
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Victims
2:00 a.m. Evacuation perimeter 150 m
± 300 people (towards festival hall and fire station)
Based on? Explosion risk?
Toxic – chemical risk?
Gut feeling
2:45 a.m. Decision taken at “hood mutual agreement” (discipl 1,2 &3)
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Decision making
• Based on:
– Hazardous substance database:
http://toxnet.nlm.nih.gov/
• Intikken: acrylonitrile
• HSDB als keuze aanklikken
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Evacuation
‘no worries…’
‘no worries, it’s all right ‘
First Communication
Police: summons people to leave their house from door to door & P.A.
But “feelings” within policemen
People refuse to leave their house!
Discussion vs. urgency
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Safety circles
CP-Ops
Decision making
Based on textbooks, databases,
Based on experience (Toxicologists!!)
Acrylonitrile: toxicity
Tri-Ethyl-Aluminium explosion risk
Ethylaluminiumdichloride
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explosion risk
28
Airway protection??
Acrylonitrile
(monomere in polymereproduction: lego)
At room temp: good water soluble
Mixture with air: highly explosive
Highly exothermic reaction during polymerisation
Density > air Sewing system, waterholes, lowlands
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Acrylonitrile
Skin, inhaled (toxic level < smell border)
Short T 50% (20 min) quickly eliminated, metabolised to cyanide
Incomplete combustion HCN
Respiratory protection for rescue workers
Hazmat equipment
Urgent need for antidote (Cyanokit®)
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Cyanide intoxicatie
• Waterstofcyanide (HCN): acute cyanide intoxicatie
• Aanpak/Therapie?
– Geen internationale richtlijnen
– EuSEM:
• pre & in-hospitaal richtlijnen
• literatuurreview
Europese consensus 2013
HCN
• Polyurethaan
• Verf, acryl
• Nylon
• Plastiek
• Papier,hout, wol,katoen
May 4
02:02 a.m. Call from 112 to fire dept. Wetteren
02:08 a.m. Fire dept. at the scene
02:14 a.m. Upscaling for fire dept. alert
Medical disaster plan initiated
02:45 a.m. Council phase
03:40 a.m. Provincial phase
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CN intoxicatie
• Afhankelijk van wijze van besmetting, concentratie en duur van blootstelling
• LD50 = 1mg/kg
• Ingestie
• Transdermaal
• Rookinhalatie bij brand (4-12u later cyanide)
CN
• 1704: Pruisisch blauw: synthetisch pigment (ijzer(III)hexacyanoferraat(II))
• 1783: Blauwzuur: Vloeibaar – gasvormig vanaf 26°C
• WO II: Zyklon B • Geur van bittere amandelen
• Toepassingen anno 2014
– Metaalreiniging – Mijnindustrie (goudextractie uit erts) – Plastics industrie
CN intoxicatie
• Literatuur: blootstelling tot 14 dagen = acuut
• Acute Exposure Guidelines Levels (AEGL)
– AEGL – 1: ongemak, irritatie snel voorbijgaand
– AEGL – 2: duidelijk en ernstig gezondheidseffect
– AEGL – 3: levensbedreigend/overlijden
• Belgische werknemers: max 2 ppm/8u
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Waarden in ppm
Classificatie Duur van blootstelling
10 min 30 min 1 uur 4 uur 8 uur
AEGL – 1 4.6 4.6 4.6 4.6 4.6
AEGL – 2 290 110 57 16 8.6
AEGL – 3 480 180 100 35 19
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HCN toxiciteit
Symptomen – Mild: neurologisch/respiratoir:
• Hoofdpijn, verwardheid, duizeligheid, nausea, braken, palpitaties, tachypnee/dyspnee, amandelgeur, branderige droge keel, kersrode huid, mydriasis.
– Ernstig: neuro/resp/cardiovasculaire depressie: • Epilepsie, coma • Initieel hyperdynamisch, nadien cardiovasculair falen:
bradycardie, hypotensie, cardiorespiratoir arrest, †
† Seconden / minuten afhankelijk van blootstelling – 100 ppm: † > 60 min – 300 ppm † > sec/min
HCN toxiciteit
Cyanide ion affiniteit
1. Cobalt
2. Fe3+ in methemoglobine
3. Cytochrome aa3 oxidase mitochondriaal
4. Fe2+ in hemoglobine
Cytochrome aa3 oxidase mitochondriaal
Cytochrome oxidase:
– Op celniveau: mitochondriaal
– Hersenen/hart/lever
– Pyruvaat via acetyl-coA in aerobe Kreb cyclus ATP productie.
– Fe houdend enzyme, essentieel voor NADH
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2. HCN toxiciteit
• Niet competitieve inhibitie met cyt.oxidase Kreb //
• Pyruvaat Lactaat (anaeroob) metabole (lactaat) acidose.
• Andere mechanismen: ?
– Coronaire art VC Cardiac output zakt
– Longoedeem via onduidelijk mechanisme
• Afbraak: leverenzyme: rhodenase (S-donor): CN thiocyanaat renale
klaring
– trage reactie.
CN-
• Inhibeert 40tal enzymesystemen
• Inhibeert oxidatieve fosforylatie
– Bindt aan cytochroom aa3 oxidase
– Aeroob nr anaeroob metabolisme
• Cellulair ATP tekort: lactaatacidose
CN vs CO
Information
Exchange info between Operational Centre and Crisis Centre
6 press communications between 3:40 and 9:38 a.m.
6 a.m. first press conference
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Communication
Lack of “experience”
Crisis Centre & Operational centre
Disaster Time span, > 48 hrs vs 19 days
E 40: Gas leak pipeline rupture: 48 hrs
E 413: H2 gas transport collision: 48 hrs
Mass communication
Avoid highways during traffic jams
Decision making and political consequences
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Decision making
• 1 PPM measured: evacuation
• Case definition acrylonitrile intox:
– Mucosa irritation: proves contact acrylonitrile
– Other symptoms: metabolized towards CN
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Behandeling
• Bron wegnemen
• 100% O2
• Ondersteunende maatregelen
• Antidoot:
– Methaemoglobine vorming (nitraten, 4-DMAP)
– Sulfaatdonoren (thiosulfaat)
– Cobaltverbindingen (hydroxycobalamine)
Cyanokit
• Dosis 70mg/kg (5g) over 15-20 min, te herhalen zo arrest/aanhoudende cardiovasculaire instabiliteit. Max 10g
• 0 tot >99 jaar (max 140mg/kg in totaal), ook bij zwangerschap
• Reeds prehospitaal: zo meerdere patiënten ter plaatse: geef 2,5 g IV per persoon, restdosis in hospitaal.
• Nadelen:
– ! Valse verhoging van Hb-CO
– Niet in zelfde leiding als thiosulfaat.
– Foutieve probleemmelding bij hemodialyse (blood leak)
– Erytheem moeilijke beoordeling brandwonden nadien
Biochemie
• Cyanideconcentratie in bloed correleert zeer goed met plasmalactaat (> 90 mg/dl)
• Geen snelle detectietechniek voor HCN (bloed)
Lactaatbepaling
• Omweg om ernst HCN intox te bepalen
Lessons learned (1)
PREPARE YOURSELVE to deal with negative press/public comments
DOCUMENT / REPORT ALL EVENTS
TIME REGISTRATION
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Upscaling disaster planning
2:14 a.m. Medical Disaster Plan (MIP)
2:45 a.m. Council phase
3:40 a.m. Provincial phase
6:21 a.m. Telephone Information Centre
What kind of information?
Close doors, windows, stay inside, avoid Wetteren centre
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Lessons learned (2)
Inform your citizens a.s.a.p.
- Updates through website/Facebook/twitter/domino
- Telephone Information Centre (TIC)
. Started at 06:21 a.m.!!!
. 3000 calls/day
Update your citizens
Give correct information
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Lessons learned (3)
Towards Decision makers (Crisis center):
Don’t take your whishes for real
Message: return home
vs.
Message: Wait another day (May 9 – 12)
Local population “aggressive” towards the CP-Ops staff
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Home or not?
Lessons learned (4) – Case 1
“Acrylonitrile is carcinogenic”
TV news interviews Prof. XXX, MD, toxicologist at
University XXX
“No carcinogenic effects retrieved from literature”
Toxicologists at different Universities & Industrial MDs (follow up > 20 yrs.)
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Lessons learned (4) – Case 2
“Large numbers of dead fish washing up on the shores of the Schelde
downstream of Wetteren”
TV broadcasts
“Not confirmed”
By river police: waste of money, time …
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How to handle this evil?
Deny first message of carcinogenic effect?
- My answer: don’t do this
- Public opinion: “they are hiding the truth”
CC is “running behind the facts”
- Inform the news broadcasting media
- Provide them with experts able to explain “lay people” the risks
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Lessons learned (5)
Beginners mistake: when you see a camera
- Think twice before expressing your “feelings”
Circumstances
- 3 days requesting for sanitary facilities, no feedback from the CC
- May 8 visit from important politicians and the Mayors of the neighbouring villages: STOP of all activities… till 14 hrs: no decisions at the CC
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Wat hebben we vandaag geleerd?
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Lessons learned (6)
• Occupational medicine: no collaboration (Belgium)
– Fire dept: each unit has his own occup. Med.
– Fire dept: fire fight unit doctor
• Police: own medical dept.
• Civil protection
• Hospitals
• GP’s
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Lessons learned (6)
• > 20 different occupational doctors
• > 10 General practioners
Different approach in follow up:
minimizing vs maximizing
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Ongoing problems
Mr J. Haek, CEO, announces: “Infrabel will pay all costs: ship, cleaning, civilians…”
Blood collections/results: communicated “not clearly” to the public
Epidemiologic follow-up of the local population and rescue workers
Large evacuation planning
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QUESTIONS ?? (& ANSWERS …?)
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Take home
• Denk aan CN intoxicatie naast CO, ook bij minder gekende stoffen/chemische rampen acrylonitril in Wetteren
• Behandel zo snel mogelijk
– Bij grote waarschijnlijkheid van intoxicatie (brand met polymeren), tachypnee, hypotensie, bradycardie, epilepsie, cardiovasculaire collaps, cardiorespiratoir arrest.
– Veranderd bewustzijn (desoriëntatie, verwardheid, mydriasis)
– Lactaatacidose, zeker zo >8 mmol/L
• 100% O2 + antidotum: cyanokit 5g, ook pre-hospitaal., te herhalen bij aanhoudend verhoogd lactaat na controle.
Diagnose
Labo-analyse
– Sterke correlatie tussen cyanide waardes en lactaat, echter aspecifiek
– Cyanide bepaling op bloed
• Korte t ½ (60’)
• Duurt 2u in labo
– Arterieel/ Veneus bloedgas: hoge Pv02, hoge veneuze 02 sat Pa02 – Pv02 klein, echter door R/ met 100% 02 moeizame interpretatie.
Besluit:
– Behandel meteen zo
• Verdacht op CN intoxicatie: omstandigheden, veranderd bewustzijn, forse lactaatacidose
• Zeker zo bradycard/hypotens.
Behandeling
• Safety first! – Bron verwijderen.
• BLS
• 100% 02
– 1. Zowel bij vermoeden CO als CN.
– 2. Vermoedelijk directe reactivatie van mitochondriale enzymes.
• Supportief:
– Vasopressie
– Convulsieve therapie
• Antidota
– 3 types
• Hyperbare 02 geen bewezen meerwaarde
Antidota
1. Vorming van methemoglobine:
– 4 - DMAP
– Nitriten
2. S-donoren
– Natriumthiosulfaat
3. Cobaltgroepen
– Dicobaltedetaat
– Hydroxycobolamine
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HCN detoxificatie
• Conversie naar thiocyanaat
• Conversie naar cyanocobalamine (via hydroxycobalamine)
1. Methemoglobinevorming
• 4-DMAP (4-dimethylaminophenol ) / nitrieten
– Vorming van methemoglobine (Hb-Fe3+) snelle chelatie met cyanide cyanomethemoglobine trage disscociatie in cyanide omzetting via rhodenase in thiocyanaat renale klaring.
– Nevenwerkingen:
• VD met hypotensie, hemolyse, nefrotoxiciteit.
• Reeds bestaande hypoxemie + methemoglobinemie: methemoglobinemie -> centrale cyanose, dyspnee, zo > 30% Fe3+-Hb: cardiovasculaire collaps/ †.
hydroxycobalamine
• Chelator cyanide: vormt vit B 12 (cyanocobalamine), via nieren uitgescheiden
• Urticaria, huidverkleuring
• Bloeddrukstijging
• Lang halfleven (1 dosis genoeg)
• 70 mg/kg (5 gr)
2. Natriumthiosulfaat
• S – donatie: versnelt rhodenase x 3: acceleratie van enzymwerking/renale klaring.
• Eerder add-on therapie: werkt traag, add-on bij 1 of bij 3.
• Dosis: 12,5g traag IV (0,5g/kg IV)
3. Cobalt (Cyanokit, ...)
• Cyanide ion hoogste affiniteit voor cobalt.
• 2 vormen:
– Dicobalt edetaat: 2e lijnstherapie (anaphylaxis, vrij cobalt is toxisch)
– Hydroxycobalamine (Cyanokit)
• + cyanide cyanocobalamine (vorm van vit B12) renale excretie.
• Voordelen: – Minimale nevenwerkingen: urticaria, angioneurotisch
oedeem, uiterst zeldzaam anaphylaxis,photosensiviteit, erythema (tot 15 dagen), chromaturie (48u tot 30 dagen).
– Verminderd zuurstof-transport capaciteit niet, itt DMAP/nitriet
– NO-scavenging Hypertensie (werkt tendens tot hypotensie bij CN tegen)
– Snelle werking, vlot transport tot in weefsels.
– Veilig in hemodynamisch instabiele patiënten, bij arrest.
Welk antidotum?
• Elke regio eigen algoritmes
• In VS: 4-DMAP/nitrieten en thiosulfaat.
• Frankrijk: cyanokit, ook pre-hospitaal
• Vergelijking tussen 1 – 2 en 3: tendens tot meerwaarde voor cyanokit,
voornamelijk door sneller herstel van de MAP.
• Geen bewezen survival benefit/ invloed op metabole acidose.
• Prijs:
– cyanokit € 681 voor 2 vials van 2,5g.
– Nithiodote (Nanitriet – natriumthiosulfaat): $ 422