Poisoning/Overdose

General Management

Poisoning is Exposure to substance that is toxic in any amount

Overdose

Exposure to substance in excess amount

resulting in toxic effects

1998 TESS* Data1998 TESS* Data

• 2,241,082 reported human exposures

• 97.9 % at home

• Peak volume 4pm-10pm

• 91% of calls 8pm-midnight

*The Toxic Exposure Surveillance System (US based)

Exposures by Age

• < 6 years old 52.7%

• < 3 years old 39.6%

• 775 fatalities

• 0.03% of total exposures

• ages 20 - 49 years = 56%

• >6 years = 2.1%

Fatalities

Number of Substances

• 92.8% of all cases--one substance

• 44.7% of fatal cases-->2 substances

Management Location

• Managed on site 75.2%

• Treated, released at ER only 12.3%

• Admitted to critical care 2.7%

• Refused referral * 2.0%

Therapy

• No therapy 11.9%

• Observation only 12.7%

• Decontamination only 59.6%

• Activated charcoal 6.8%

• Ipecac 1.2%

Most Common Substances

• Cleaning substances 10.2%

• Analgesics 9.6%

• Cosmetics 9.4%

• Plants 5.5%

• Foreign bodies 4.6%

• Cough, cold 4.5%

• Bites, stings 4.1%

• Insecticides, pesticides, rodenticides 3.9%

• Sedative, hypnotics, antipsychotics 3.2%

• Antidepressants 3.0%

• Hydrocarbons 3.0%

• Alcohols 2.5%

Largest Number of Deaths

• Analgesics 264

• Antidepressants 152

• Stimulants, street drugs 118

• Cardiovascular medication 118

• Sedatives, hypnotics 89

• Alcohols 56

Indicators

• Sudden onset of CNS signs:– Seizures– Coma– Decreased LOC– Bizarre behavior

• Sudden onset of:– Abdominal pain– Nausea– Vomiting

Indicators cont

• Sudden onset of unexplained illness

• Bizarre, incomplete, evasive history

• Trauma (>50% of adult trauma EtOH, drug-related)

• Pediatric patient with arrhythmias

History

• What?• How much?• How long?• Multiple substances?• Treatment attempted? How?

Whose advice?• Psychiatric history?• History of suicide?

Scene Survey

• Check out scene for :– 1– 2– 3– 4

• Where do you look for clues?

General Management

• Support ABC’s– Secure airway, secure with advanced airway

if needed– Ensure adequate oxygenation, ventilation– Maintain adequate circulation

• Monitor ECG• Obtain vascular access• Manage hypotension initially with volume• Use vasopressors cautiously

General Management

• Keep patient calm • Maintain normal body temperature• Evaluate nature/toxicity of poison

– Check container, package insert, poison center information

– Treat the patient, not the poison

General Management

• Rule out (differential diagnosis)– Trauma– Neurological disease– Metabolic disease

• Base general management on route of poison entry

Poison Entry

• Ingestion

• Slow movement from injection site throughout body

• Remove from skin surface

• Remove from exposure; Support oxygenation, ventilation

• Prevent absorption from GI tract

• Inhalation

• Absorption

• Injection

Ingested Poisons

Objective

Remove from GI tract before absorption occurs

Ipecac

• RARELY used anymore

• If used, has to have been initiated within few minutes after ingestion

• Vomiting in 20-30 minutes

• Only removes about 32% of contaminate

• Many contraindications

Ipecac

• Dose– 15 cc if 12 months to 12 years old– 30 cc if >12 years old

• Follow with 2-3 glasses of water

• Keep patient ambulatory if possible

Ipecac

• If no vomiting after 20 minutes, repeat

• When emesis occurs, keep head down

• Collect, save vomitus for analysis

Ipecac

• Contraindications– Comatose or no gag reflex– Seizing or has seized– Caustic (acid or alkali) ingestion– Low viscosity hydrocarbon ingestion– Late term pregnancy

Ipecac

• Contraindications– Severe hypertension, cardiovascular

insufficiency, possible AMI– Ingestion of:

• Strychnine• Phenothiazines (Thorazine, Stellazine, Compazine)• Tricyclic antidepressants• Iodides• Silver Nitrate

Lavage

• Commonly used in ED’s• Removes about 31% of substance• Helps get activated charcoal in

patient, especially if patient is unconscious

• Not helpful for sustained release tablets

• Will not remove large tablets

Activated Charcoal

• Adsorbs compounds, prevents movement from GI tract

• Very effective at adsorbing substances

• Binds about 62% of toxin

• Dose– 5 - 10X estimated weight of ingested

chemical

Activated Charcoal

• Inactivates Ipecac

• Do not give until vomiting stops

• Do not give with – Cyanide– Methanol– Tylenol (+)

• Containers must be kept airtight

• Can be given PO via slurry or by NG

Inhaled Poisons

Objective: Move to fresh air; optimize ventilation and protect

personnel from exposure

Absorbed Poisons

Objective: Remove poison from skin

Liquid: Wash with copious amounts of water

Powder: Brush off as much as possible, then wash with copious

amounts of water

Protect personnel from exposure

Dilute / Irrigate / Wash

• Use soap, shampoo for hydrocarbons

• No need for chemical neutralization - heat produced by reaction could be harmful

Eye Irrigation

• Wash for 15 minutes

• Use only water or balanced salt solutions

• Remove contact lenses

• Wash from medial to lateral

Examples of Specific Toxins

Acids

• Examples– Toilet bowl cleaner– Rust remover– Phenol (carbolic acid)– Hydrochloric acid

• Severe burning of stomach

• Absorption, systemic acidemia

Acids

• Loss of airway = most immediate threat

• Secure airway against edema

• IV with RL, NS for volume loss

• Emesis, gastric lavage contraindicated

• Dilution with water, milk NOT recommended

Alkalis

• Examples– Drain cleaner– Washing soda– Ammonia– Lye (sodium hydroxide)– Bleach (sodium hypochlorite)

• Severe burning of esophagus, stricture formation

Alkalis

• Loss of airway = most immediate threat

• Secure airway against edema

• IV with LR, NS for volume loss

• Emesis, gastric lavage contraindicated

• Dilution with water, milk NOT recommended

Hydrocarbons

• Examples– Kerosene– Gasoline– Lighter fluid– Turpentine– Furniture polish

Hydrocarbons

• Signs/Symptoms– Choking, coughing, gagging– Vomiting, diarrhea, severe

abdominal pain– Chemical pneumonitis, pulmonary

edemaIf the patient is coughing, aspiration has occurred

Methanol

methyl alcohol

wood alcohol

wood naphtha

Methanol

• Sources– Industry– Household solvents– Paint remover– Fuel, gasoline additives– Canned heat– Windshield washer antifreeze

Methanol

• Toxic dose– Fatal oral: 30-240ml– Minimum: 100 mg/kg– Example

• Windshield washer fluid 10% Methanol• 10 kg child needs only 10 cc to be toxic

Methanol

• Mechanism of toxicity– Methanol slowly metabolized to

formaldehyde– Formaldheyde rapidly metabolized

to formic acid• Acidosis• Ocular toxicity

Methanol Metabolism

OC

OH

H+_

HOC

OH

Formic Acid

CH

OH

Formaldehyde

HOHH

HC

Methanol

Alcohol dehydrogenase

Aldehyde dehydrogenase

Cyanide

But first…• A little review of

biochemistry and biophysics

Staying alive requires energy...

• The natural tendency of the universe is for things to become more disorderly.

• This trend toward disorder is called entropy.

• Complex systems (including us) don’t tend to last long, unless…

• They have a constant supply of energy to combat entropy.

Organisms capture and store the energy they need in the form of...

• The “currency” cells use to pay off the energy debt built up fighting entropy.

• Formed by capturing energy released as the cell breaks down large molecules through glycolysis and the Krebs Cycle.

Adenosine Triphosphate (ATP)

Putting It All Together• Cells have to have energy to stay alive.• Cells get energy by breaking down glucose in two phases: glycolysis and

the Krebs Cycle.• Glycolysis yields 2 ATP and pyruvate.• Pyruvate is changed to acetate (acetyl-CoA) and sent to the Krebs Cycle.• The Krebs Cycle strips hydrogen and electrons off acetate and feeds them

into the electron transport chain.• Movement of electrons down the transport chain releases energy which is

trapped as ATP.

• At the end of the chain, the electrons combine with hydrogen and oxygen to

form water.

• CN messes with this !

Cyanide

• Chemical, plastic industries• Metallurgy, jewelry making• Blast furnace gases• Fumigants, pesticides• Present in various plants

– apples, pears, apricots, peaches, bitter almonds

• Remember there is CN gas released by BURNT plastics (e.g fire!!)

Cyanide Antidote Kit

• Amyl nitrite, sodium nitrite – Only be used in serious cyanide poisonings– Can induce life-threatening tissue hypoxia

secondary to methemoglobinemia

• Sodium thiosulfate – Can be used by itself– Is relatively benign

Salicylates

Salicylates

• Examples– Aspirin– Oil of wintergreen

• Uses– Analgesics– Antipyretics– Anti-inflammatories– Platelet function inhibitors

Salicylates

• Mechanism of Toxicity– Direct stimulation of respiratory center,

causing respiratory alkalosis– Irritation of gastrointestinal tract, causing

decreased motility, pylorospasm, nausea, vomiting, hemorrhagic gastritis

– Decreased prothrombin levels/platelet dysfunction, causing prolonged clotting times

– Uncoupling of oxidative phosphorylation

Results of Oxidative Phosphorylation Uncoupling

• ATP production decreases, resulting in CNS and cardiovascular failure.

• Cells attempt to compensate by increasing the rate they process glucose anaerobically through glycolysis.

• Lactic and pyruvic acids accumulate, leading to metabolic acidosis.

• Hypoglycemia results as liver sugar stores are depleted.• In absence of sugar cells begin to metabolize lipids, ketone

bodies are produced, acidosis worsens.• Energy normally trapped as ATP is wasted as heat, causing

a rise in body temperature.• The rise in body temperature accelerates metabolism,

increasing tissue oxygen demand and worsening acidosis.

Salicylates

– Vomiting– Lethargy– Hyperpnea– Respiratory

alkalosis– Metabolic

acidosis

– Coma– Seizures– Hypoglycemia– Hyperthermia– Pulmonary

edema

Clinical Presentation: Acute Toxicity

Salicylates

• Clinical Presentation: Chronic Toxicity– Usually young children, confused

elderly– Confusion, dehydration, metabolic

acidosis– Higher morbidity, mortality than acute

overdose– Cerebral, pulmonary edema more

common

Salicylates

• Acute Toxicity Management– Oxygen, monitor, IV– GI tract decontamination– Activated charcoal– Replace fluid losses, but do NOT

overload– Control hyperthermia

Salicylates

• Acute Toxicity Management– Bicarbonate for metabolic acidosis– D50W for hypoglycemia– Diazepam for seizures

Acetaminophen

Acetamophen

• Examples– Tylenol– Tempra– Many drugs contain this also

• Uses– Analgesic– Antipyretic

Acetaminophen

• Mechanism of toxicity– N-acetyl p-benzoquinonimine,

normal product of acetaminophen metabolism, is hepatotoxic

– Normally is detoxified by glutathione in liver

– In overdose, toxic metabolite exceeds glutathione capacity, causes liver damage

Acetaminophen

• Management– Induce emesis– Do NOT give activated charcoal in

general– Give specific acetaminophen

antidote

Acetaminophen

• The specific antidote for acetaminophen toxicity.

Mucomyst

• N-acetylcysteine Another sulfur-containing amino acid Substitutes for glutathione. Allows continued detoxification of NAPBQI. 140mg/kg initially followed by 70mg/kg every 4 hours

17 times. Tastes, smells like rotten eggs Mix with chilled fruit juice to decrease odor, taste

More to come

• Review – Cocaine OD– TCA OD– Opoid OD– MDMA - E– GHB