Transcript Diapositiva 1

Death By Smoke:
Cyanide Poisoning & Cyanokits ®
Amy Gutman MD
EMS Medical Director
[email protected] / www.TEAEMS.com
Introduction
• Review cyanide toxicity, assessment &
emergency management
• A full presentation on the “Toxic Twins” of
carbon monoxide and hydrogen cyanide is
available for review as the lecture “Toxic
Smoke” on www.TEAEMS.com, but is
beyond the scope of this brief presentation
Rescuer Morbidity & Mortality
• 80% fire scene injuries due to smoke inhalation
• 50% firefighter line-of-duty deaths from cardiovascular
stressors
• >4,000 fire-related deaths & >20,000 smoke inhalation
injuries occur in the US annually
• Rescuers & fire victims have a high mortality from
enclosed space burns due to the chemical composition
of modern manufactured materials
Toxic Smoke
• Toxic smoke inhalation is a major cause of rescuer
morbidity & mortality, causing acute critical injuries
with long-term cardiovascular & neurological effects
• Many toxic products released during a typical
building & contents fire
• Many toxins are difficult to rapidly detect, yet must be
immediately treated based upon clinical exam and a
high degree of suspicion
Toxic Smoke “Anatomy”
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Particulates (dust, soot)
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Irritants
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Hydrochloric acid
Sulfur dioxide
Nitrogen oxides
Ammonia
Formaldehyde
Benzene
Asphyxiants/Toxicants
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Carbon dioxide
Hydrogen cyanide
Carbon monoxide
Hydrogen sulfide
Acrolein Aldehyde
Phosgene
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Structural fires often involve
polyvinyl chloride, used to
make upholstery, wire, pipes &
wall coverings
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Burning pvc creates hydrogen
chloride & phosgene
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Polyethylene & pvc more
dangerous when smoldering
than during the high heat of a
working fire, emitting carbon
monoxide, hydrogen cyanide,
hydrochloric acid & other toxins
“Toxic Twins”
• Carbon monoxide (CO) & hydrogen cyanide (HCN) are
"toxic twins" of smoke inhalation
– Released from rubber, plastics, synthetics, laminates & other
materials with deadly synergistic effects
• HCN exposure compounds CO injuries
– Cyanide 35 times more toxic than CO
– Cyanide toxicity additive with CO as minimal levels often lethal
causing rapid AMS, hemodynamic instability & death
• CO & HCN so rapidly lethal that other toxins rarely
found on autopsy blood analysis
Cyanide Poisoning
• Accidental exposure
– Inhalation (occupational, fire smoke)
– Ingestion (household products)
– Dermal (industrial materials)
• Intentional exposure
– Terrorism (Saddam Hussain)
– Intentional poisoning via suicide or tampering with
commercial products (Tylenol in 1980s)
• Smoke inhalation is most common route
exposure
Hydrogen Cyanide (HCN)
• Odorless, colorless
• Inhalation results in loss of consciousness in 30 secs,
apnea in 3-5 mins, cardiac arrest in 5-8 mins
– In a low-O2 environment, cyanide 10 X more toxic
– In a closed room, cyanide released from combustion of one seat
cushion can kill all occupants w/i minutes
• Prevents cells from using O2 in energy production
causing acidosis, cell death & cardiopulmonary arrest
• As death occurs within minutess, there may be no
other evidence of smoke inhalation
HCN Mechanism of Action
• Cyanide binds & deactivates mitochondrial
cytochrome a3, inhibiting cellular O2 utilization
• No amount of supplemental oxygen can
overcome this O2 deficit
• Inhibition of cellular respiration results in
accumulation of toxic byproducts of anaerobic
metabolism (i.e. lactic acid) & depletion of
cellular adenosine triphosphate (ATP)
• Tissues with highest O2 requirements (brain &
heart) rapidly affected
Acute Cyanide Poisoning
• HCN poisoning presumptive,
(no rapid diagnostic test)
• Toxicity suggested by:
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Holstege CP, et al. Goldfrank’s Toxicologic Emergencies. 8th ed.
AMS
Dilated pupils (mydriasis)
Bradypnea
Hypotension, tachycardia
Confirmed CO poisoning
HCN Poisoning Management
• Treatment decisions must be made immediately
based upon history, SSX, exam & clinical suspicion
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Supportive care, rapid transport
– Establish airway, administer 100% O2
– Cardiopulmonary resuscitation often necessary
– Administer Cyanokit antidote during resuscitation (carried by
selective Region V / CIEMSS ALS ambulances)
– Additional management dependant on symptoms (i.e.
anticonvulsants, antiarrhythmics)
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Clinical signs of HCN & CO toxicity similar
– Both have AMS, hypotension, confusion, anxiety, tachycardia,
tachypnea, respiratory distress
– High suspicion for HCN poisoning if suspected CO poisoning
or exposure to a closed space fire
– Oximetry may record normal SaO2 with CO poisoning
Hydroxycobalamin / Cyanokit ®
• Class:
– Vitamin B complex
• Therapeutic Class:
– Hematinic, vitamin
• Actions:
– Cyanide rapidly binds with cytochrome c-a3 oxidase mitochondrial
complex which inhibits cells from using O2 forcing anaerobic
metabolism
– Results in rapid lactate production, cellular hypoxia, metabolic
acidosis & cell death
– Effectiveness of hydroxycoblamin based on ability to bind cyanide
ions to form cyanocobalamin which is harmlessly secreted in urine
Hydroxycobalamin / Cyanokit ®
• Pharmacokinetics:
– Each mL contains hydroxocobalamin acetate equivalent to
1000mcg hydroxocobalamin & inert preservatives including cobalt
– Appears as dark red needles or red powder
– Hygroscopic while anhydrous, moderately water-soluble, unstable
in light
– Plasma-protein bound, stored in the liver, excreted in the bile after
enterohepatic recycling
– 50% disappears from injection site in 2.5 hours; within 72 hrs 1666% appears in the urine with the majority excreted within 24 hrs
• Indications:
– Smoke inhalation, known / suspected cyanide poisoning
• Contraindications:
– Hypersensitivity ro hydroxycobalamin or cyanocobalamin
Hydroxycobalamin / Cyanokit ®
• Precautions:
– Rare allergic reactions
– Pregnancy category C
– Blunted therapeutic response due to infection, uremia, drugs
having bone marrow suppressant properties such as
chloramphenicol, and concurrent iron or folic acid deficiency.
• Side Effects:
– Transient HA, hypertention, chromoaturia, N/V erythema, rash,
injection site reactions
Cyanokit®
• Only ancillary supply needed is
sterile water for reconstitution
• Takes effect in minutes
• Is only FDA approved emergency
antidote for treatment of known or
suspected cyanide poisoning
• Side effects usually minimal &
transient
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Allergic Reactions
Transient elevation in blood pressure
Photosensitivity
Transient urine red-coloration
Cyanokit ® Step 1:
Reconstitute
• Add 100cc of 0.9% saline to vial
using sterile transfer spike
• LR & 5% dextrose also compatible
• Diluent not included in the kit
• Fill to line, which represents 100cc
• Keep vial in upright position
Cyanokit (two 2.5-g vials) [package insert]. Columbia, MD: Meridian Medical Technologies, Inc.; 2011.
Cyanokit® Step 2: Mix
• Rock or rotate vial for 30
seconds to mix solution
• Do not shake
Cyanokit ® Step 3:
Infuse 1st Vial
• Use vented IV tubing
• Hang & infuse over 7.5 – 15
minutes
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Cyanokit® Step 4: Infuse 2nd
Vial (Medical Control)
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EMS must call Medical
Control for 2nd vial
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Repeat steps 1 & 2
before 2nd infusion
– Reconstitute
– Mix
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Use vented IV tubing
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Hang & infuse over
15-120 mins
Cyanokit® Considerations
• Inspect solution for particulate matter & color
– Discard if particulates present or solution not dark red
• Stored at 25°C (77°F)
• Use separate IV line for infusion as most resuscitation
drugs incompatible with Cyanokit
– If administering other antidotes, do not use same IV line
• In addition to Cyanokit, HCN treatment includes
aggressive airway management, cardiovascular
support, & seizure management
Cyanokit (two 2.5-g vials) [package insert]. Columbia, MD: Meridian Medical Technologies, Inc.; 2011.
References
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Cyanokit Project. California Department of Public Health, Emergency
Preparedness Office. 2010.
Eckstein M. JEMS. 2004;29:suppl 22-31
Guy JS, et al. Smoke inhalation injury. www.medscape.com. 2007
Lee-Chiong TL. Postgrad Med. 1999;105:55-62.
Cyanide Poisoning Treatment Coalition. 2007
Alcorta R. JEMS. 2004;29:suppl 6-15; CDC. MMWR. 2003;52:906-908;
RTI International. Clin Toxicol. 2006;44 Suppl 1:47-63
Guidotti T. Prehosp Disast Med. 2005;21:s40-s48.
www.masimo.com
www.Firerehab.com
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www.carbonmonoxidekills.com
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www.carbon-monoxide-poisoning.com
www.cdc.gov
www.nlm.nih.gov/medlineplus/carbonmonoxidepoisoning.html
www.emedicinehealth.com/carbon_monoxide_poisoning/article_em.htm
www.osha.gov/OshDoc/data_General_Facts/carbonmonoxidefactsheet.pdf
www.postgradmed.com/issues/1999/01_99/tomaszewski.htm
Goldfrank’s Toxicologic Emergencies. 8th ed. New York, NY: McGrawHill; 2006:1712
Eckstein M. JEMS. 2004;29:suppl 22-31
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Meridian Medical Technologies Training Presentation. 2011
Alarie Y. “Toxicity of Fire Smoke,” Critical Reviews in Tox, 2002;
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Borron, S. Emergency physician’s role in appropriate treatment of
cyanide poisoning in smoke inhalation. Oral presentation, Seattle, Wash.,
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Tuovinen H. ”Modeling of Hydrogen Cyanide Formation in Room Fires.”
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Baskin S. “Cyanide poisoning: Medical aspects of chemical and biological
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Baud FJ. “Elevated blood cyanide concentrations in victims of smoke
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Jon Marinaro, MD. Trauma-Surgical ICU Director. UNM Burn Center.
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Summary
[email protected] / www.TEAEMS.com
• Full presentation on “Toxic Smoke” including full
review of CO & HCN poisoning available at
www.TEAEMS.com
• With ANY suspicion of HCN poisoning, immediately
start treatment as a few minute delay can be lethal
• Cyanokit simple & easy to use, easy to store with
minimal side effects or contraindications