II. Epidemiology

  1. Leading cause of toxin related death in United States

III. Sources: Carbon Monoxide

  1. Gas powered engine
    1. Propane fueled forklifts
    2. Ice skating rink Zamboni
    3. Indoor tractor pulls
  2. Home
    1. Furnace
    2. Indoor Heaters
      1. Home water heaters
      2. Gas heaters
      3. Pool heaters
      4. Kerosene heaters
    3. Indoor Flames
      1. Wood stoves
      2. Indoor charcoal fires
      3. Sterno fuel
    4. Tobacco smoke
      1. Smokers
        1. Carboxyhemoglobin levels may reach 9-20%
      2. Nonsmokers exposed to passive smoke
        1. Cigarette tip 2.5 fold greater CO than inhaled
  3. Industrial or Occupational
    1. Steel foundry
    2. Pulp paper mill
    3. Formaldehyde and coke producing plants
    4. Fire fighters
  4. Fire
    1. Building or structure fire
    2. Wilderness fire

IV. Pathophysiology

  1. Carbon Monoxide Properties
    1. Colorless
    2. Odorless
    3. Non-irritating gas
    4. Small molecule that crosses through some barriers into closed spaces (e.g. drywall)
  2. Carbon Monoxide inhalation
    1. High affinity for Hemoglobin
    2. Displaces Oxygen and produces Carboxyhemoglobin
      1. Functional Anemia is however not responsible for Carbon Monoxide's lethal effects
  3. Direct toxin effects of Carbon Monoxide
    1. Sodium channel activation
    2. Nitric oxide levels increase
    3. Neurotoxic

V. Symptoms

  1. Headache (88%)
  2. Dizziness (83%)
  3. Nausea (75%)
  4. Drowsiness (75%)
  5. Dry Mouth (44%)

VI. Signs

  1. Cherry-red skin and mucosa
  2. Bounding Pulse
  3. Hypertension
  4. Muscular fasciculations
  5. Stertorous breathing
  6. Dilated pupils
  7. Convulsions
  8. Altered Mental State to coma
  9. Do not rely on Oxygen Saturations (not accurate see below)

VII. Findings: Carboxyhemoglobin level

  1. Carboxyhemoglobin: 10%
    1. Frontal Headache
  2. Carboxyhemoglobin: 20%
    1. Throbbing Headache
    2. Dyspnea on exertion
      1. Severe Hypoxemia requiring intubation may occur at this level
  3. Carboxyhemoglobin: 30%
    1. Impaired judgment
    2. Nausea or Vomiting
    3. Dizziness
    4. Visual disturbance
    5. Fatigue
  4. Carboxyhemoglobin: 40%
    1. Confusion
    2. Syncope
  5. Carboxyhemoglobin: 50%
    1. Coma
    2. Seizures
  6. Carboxyhemoglobin: 60%
    1. Hypotension
    2. Respiratory failure
  7. Carboxyhemoglobin: 70%
    1. Death

VIII. Labs

  1. Blood grossly appears abnormal red color
  2. Venous Blood Gas
  3. Carboxyhemoglobin
    1. Carboxyhemoglobin elevated (see above)
  4. Complete Blood Count
    1. Leukocytosis

IX. Precautions

  1. Oxygen Saturation data is inaccurate
    1. Does not distinguish Carboxyhemoglobin from oxygenated Hemoglobin
  2. Drywall does not deter Carbon Monoxide
    1. Carbon Monoxide diffuses across drywall and may permeate separated rooms in multi-tenant housing
  3. Consider concurrent Cyanide toxicity in structure fires
    1. Smoke Inhalation and Lactic Acid >8 suggests cyanide Poisoning (especially with Altered Level of Consciousness)

X. Management: Mild Poisoning

  1. Criteria
    1. Carboxyhemoglobin <30%
    2. No Neurologic or Cardiovascular Impairment
  2. Management
    1. Oxygen 100% Non-Rebreathing Mask
      1. Continue until Carboxyhemoglobin <5%
      2. Carbon Monoxide decreases 50% in 6 hours on room air
      3. Carbon Monoxide decreases 50% in 60 minutes on non-rebreather mask
      4. Carbon Monoxide decreases 50% in 30 minutes on 100% oxygen while intubated
    2. Admission criteria
      1. All patients with Carboxyhemoglobin >25%
      2. Underlying heart disease

XI. Management: Moderate Poisoning

  1. Criteria
    1. Carboxyhemoglobin: 30-40%
    2. No Neurologic Impairment
  2. Management
    1. Oxygen 100% Non-Rebreathing Mask
      1. Continue until Carboxyhemoglobin <5% (see above)
    2. Admission to telemetry (cardiovascular monitor)
    3. Venous Blood Gas
      1. Determine acid-base status

XII. Management: Severe Poisoning

  1. Criteria
    1. Carboxyhemoglobin: >40%
    2. Neurologic Impairment
  2. Management
    1. Oxygen 100% Non-Rebreathing Mask
      1. Continue until Carboxyhemoglobin <5% (see above)
    2. Admission to telemetry (cardiovascular monitor)
    3. Endotracheal Intubation may be required due to severe Hypoxemia
    4. Venous Blood Gas
      1. Follow acid-base status
    5. Hyperbaric oxygen chamber
      1. Efficacy
        1. Decreases risk of delayed neuropsychiatric effects
          1. Reduces risk of personality change, Parkinsonism, cognitive effects
        2. Better short-term and long-term cognitive outcome
        3. Weaver (2002) N Engl J Med 347:1057-67 [PubMed]
      2. Criteria
        1. Chamber immediately available OR
        2. No improvement in 4 hours
          1. Cardiovascular status
          2. Neurologic status

XIII. Prevention

  1. Adequate Ventilation
  2. Carbon Monoxide detectors

XV. References

  1. Moayedi and Swaminathan in Herbert (2016) EM:Rap 16(7): 13-14
  2. Reisdorf (1996) in Tintinelli (1996)
  3. (1995) MMWR Morb Mortal Wkly Rep 44:765-7 [PubMed]

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Ontology: Carbon Monoxide (C0007018)

Definition (MSHCZE) CO, jedovatý plyn, který je produktem neúplného spalování uhlíku (svítiplyn, kouření, výfukové plyny). Váže se na krevní barvivo hemoglobin asi 250krát silněji než kyslík a narušuje tak významně jeho přenos. Organismus při otravě CO trpí výrazným nedostatkem kyslíku (hypoxií). V průběhu otravy se objevují bolesti hlavy, závratě, nevolnost a zvracení, později jsou v popředí poruchy vědomí až kóma. Typické je třešňově červené zbarvení kůže a sliznic. V léčbě je nutné co nejrychleji zabezpečit přívod kyslíku do organismu (vynesení postiženého na čerstvý vzduch, podávání kyslíku, v těžkých případech přetlakem). Těžší otrava může i po vyléčení zanechávat některé trvalé následky na činnosti mozku. CO vzniká v malém množství také v lidském organismu, a to zejm. při přeměně hemu na bilirubin. Takto vzniklý CO je přenášen hemoglobinem z tkání do plic, kde je z těla vylučován. I za běžných podmínek je proto asi 1% hemoglobinu obsazeno CO. Již po vykouření jediné cigarety se však toto množství zvýší na několikanásobek. (cit. Velký lékařský slovník online, 2013 http://lekarske.slovniky.cz/ )
Definition (NCI_NCI-GLOSS) A poisonous gas that has no color or odor. It is given off by burning fuel (as in exhaust from cars or household heaters) and tobacco products. Carbon monoxide prevents red blood cells from carrying enough oxygen for cells and tissues to live.
Definition (NCI) An odorless, tasteless, poisonous gas, CO, that results from the incomplete combustion of carbon. Inhalation causes central nervous system damage and asphyxiation.
Definition (MSH) Carbon monoxide (CO). A poisonous colorless, odorless, tasteless gas. It combines with hemoglobin to form carboxyhemoglobin, which has no oxygen carrying capacity. The resultant oxygen deprivation causes headache, dizziness, decreased pulse and respiratory rates, unconsciousness, and death. (From Merck Index, 11th ed)
Definition (CSP) colorless, odorless, poisonous gas produced by incomplete fossil fuel combustion.
Concepts Hazardous or Poisonous Substance (T131) , Inorganic Chemical (T197)
MSH D002248
SnomedCT 51765001
English Carbon Monoxide, Monoxide, Carbon, CO, Carbon Monoxide [Chemical/Ingredient], co carbon monoxide, carbon monoxide, CARBON MONOXIDE, Carbon monoxide, CO - Carbon monoxide, Carbon monoxide gas, Carbon monoxide (substance)
French Monoxyde de carbone
Swedish Kolmonoxid
Czech oxid uhelnatý
Finnish Hiilimonoksidi
Italian Monossido di carbonio
Russian UGLERODA (IV) OKSID, UGLERODA MONOOKSID, UGLERODA OKIS', UGARNYI GAZ, UGLERODA MONOKSID, УГАРНЫЙ ГАЗ, УГЛЕРОДА (IV) ОКСИД, УГЛЕРОДА МОНОКСИД, УГЛЕРОДА МОНООКСИД, УГЛЕРОДА ОКИСЬ
Polish Tlenek węgla
Norwegian Kullos, Karbonmonoksid
Spanish gas monóxido de carbono, monóxido de carbono (sustancia), monóxido de carbono, Monóxido de Carbono
German Kohlenmonoxid
Portuguese Monóxido de Carbono

Ontology: Carbon Monoxide Poisoning (C0007020)

Definition (MEDLINEPLUS)

Carbon monoxide (CO) is a gas that has no odor or color. But it is very dangerous. It can cause sudden illness and death. CO is found in combustion fumes, such as those made by cars and trucks, lanterns, stoves, gas ranges and heating systems. CO from these fumes can build up in places that don't have a good flow of fresh air. You can be poisoned by breathing them in. The most common symptoms of CO poisoning are

  • Headache
  • Dizziness
  • Weakness
  • Nausea
  • Vomiting
  • Chest pain
  • Confusion

It is often hard to tell if someone has CO poisoning, because the symptoms may be like those of other illnesses. People who are sleeping or intoxicated can die from CO poisoning before they have symptoms. A CO detector can warn you if you have high levels of CO in your home.

Centers for Disease Control and Prevention

Definition (MSH) Toxic asphyxiation due to the displacement of oxygen from oxyhemoglobin by carbon monoxide.
Definition (CSP) toxic asphyxiation due to the displacement of oxygen from oxyhemoglobin by carbon monoxide.
Concepts Injury or Poisoning (T037)
MSH D002249
SnomedCT 17383000
English Carbon Monoxide Poisonings, Monoxide Poisoning, Carbon, Monoxide Poisonings, Carbon, Poisoning, Carbon Monoxide, Poisonings, Carbon Monoxide, POIS CARBON MONOXIDE, CARBON MONOXIDE POIS, carbon monoxide poisoning, CO poisoning, poisoning by carbon monoxide (diagnosis), poisoning by carbon monoxide, Carbon Monoxide Poisoning [Disease/Finding], carbon monoxide poison, carbon monoxide toxicity, Carbon Monoxide Poisoning, CO Poisoning, Carbon monoxide poisoning
Italian Intossicazione da monossido di carbonio, Avvelenamento da monossido di carbonio
Swedish Kolmonoxidförgiftning
Japanese イッサンカタンソチュウドク, 中毒-一酸化炭素, 照明用ガス中毒, 灯用ガス中毒, CO中毒, 一酸化炭素中毒
Finnish Häkämyrkytys
Russian UGLERODA OKIS'IU OTRAVLENIE, SVETIL'NYM GAZOM OTRAVLENIE, СВЕТИЛЬНЫМ ГАЗОМ ОТРАВЛЕНИЕ, УГЛЕРОДА ОКИСЬЮ ОТРАВЛЕНИЕ
Czech Otrava oxidem uhelnatým, otrava kysličníkem uhelnatým, intoxikace oxidem uhelnatým, otrava oxidem uhelnatým, oxid uhelnatý - otrava
Croatian OTROVANJE UGLJIČNIM MONOKSIDOM
Polish Zatrucie gazem świetlnym, Zatrucie tlenkiem węgla
Hungarian Szén-monoxid mérgezés
Norwegian Karbonmonoksidforgiftning, Kullosforgiftning
Spanish Envenenamiento por Monóxido de Carbono, Envenenamiento por Gas del Alumbrado, intoxicación por monóxido de carbono, Intoxicación por monóxido de carbono, Intoxicación por Monóxido de Carbono
Portuguese Envenenamento por Monóxido de Carbono, Intoxicação por monóxido de carbono, Intoxicação por Monóxido de Carbono
Dutch koolmonoxidevergiftiging, Kolendampvergiftiging, Koolmonoxydevergiftiging, Vergiftiging, kolendamp-
French Intoxication par le monoxyde de carbone, Intoxication oxycarbonée, Intoxication au monoxyde de carbone, Intoxication par l'oxyde de carbone, Intoxication à l'oxyde de carbone, Oxycarbonisme
German Kohlenmonoxidvergiftung