Unknown Ingestion

Aka: Unknown Ingestion, Toxin Ingestion, Drug Ingestion, Medication Overdose, Poisoning, Acute Poisoning, Accidental Ingestion, Intentional Drug Overdose, Overdose

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II. Epidemiology

  1. Poison Control had 2.1 Million telephone cases of human Poisoning in 2019 (across 55 U.S. centers)
  2. Age
    1. Half of Poisonings occur in children under age 6 years (esp. under age 2 years)
    2. Teen Overdoses are also common

III. History: Approach

  1. Talk to Paramedics and family who were at scene
  2. Review pill bottles including OTC agents
  3. Review drug paraphernalia as well as unusual wrappers and containers

IV. History (Mnemonic: History MATtERS)

  1. Materials or Medications
    1. Substance ingested, inhaled or touched
    2. Consider coingestions (complicates Toxidrome diagnosis)
  2. Amount and concentration
    1. Dosage or strength of substance
    2. Number of pills (or number remaining in bottle) or liquid volume ingested
  3. Time taken
    1. Exposure onset
  4. Emesis
  5. Reason
  6. Signs and Symptoms

V. Exam

  1. Obtain full set of Vital Signs including Temperature
  2. Identify immediate life threatening conditions
    1. ABC Management
    2. Primary Trauma Survey
    3. Secondary Trauma Survey
    4. Thorough Neurologic Exam (especially prior to RSI, sedation and paralysis)
      1. Obtain history of baseline mental status and cognitive status from family
      2. Glasgow Coma Scale (GCS)
      3. Evaluate pupil size and reactivity
      4. Observe for Agitation, Seizures, Hallucinations
    5. Other key exam components
      1. Evaluate skin for dryness or moisture
      2. Evaluate mucous membranes
      3. Evaluate for Urinary Retention
  3. Evaluate for toxin induced changes (including Toxidromes)
    1. See Toxidrome
    2. Toxin Induced Odors
    3. Toxin Induced Skin Changes
      1. Dry, hot, red skin is associated with Anticholinergic Toxicity
        1. Distinguishes Anticholinergic Toxicity from Sympathomimetic Toxicity
      2. Diaphoretic Skin (Mnemonic: SOAP)
        1. Sympathomimetic Toxicity (contrast with Dry Skin with Anticholinergic Toxicity)
        2. Organophosphate Poisoning
        3. Aspirin (Salicylate Poisoning)
        4. Phencyclidine (PCP)
    4. Toxin Induced Vital Sign Changes
      1. Tachycardia or Hypertension
        1. Sympathomimetic Toxicity
        2. Anticholinergic Toxicity (NOT diaphoretic)
        3. Drug Withdrawal
      2. Bradycardia or Hypotension
        1. Beta Blocker Overdose or Calcium Channel Blocker Overdose
        2. Clonidine Overdose
        3. Organophosphate toxicity (and Pesticides)
    5. Toxin Induced Neurologic Changes
      1. See Toxin Induced Altered Level of Consciousness Causes
      2. Seizures
        1. Tricyclic Antidepressants
        2. Isoniazid
        3. Organophosphates
        4. Sympathomimetics
      3. CNS Depression
        1. Benzodiazepines
        2. Opioids
        3. Carbon Monoxide Poisoning
        4. Alcohol Intoxication or Toxic Alcohols (Ethylene Glycol Poisoning, Methanol Poisoning)
        5. Oral Hypoglycemics or Insulin Reaction
    6. Pupil changes
      1. See Eye Examination Signs of Chemical Dependency
      2. Altered Pupil Reactivity
      3. Miosis (Pupil Constriction)
        1. Cholinergic Toxicity (e.g. Organophosphate Poisoning, Nerve Agent Exposure)
        2. Clonidine
        3. Opioids
        4. Benzodiazepines
      4. Mydriasis (Pupil Dilation)
        1. Anticholinergic Toxicity
        2. Sympathomimetic Toxicity
        3. Serotonin Syndrome
  4. Evaluate for associated findings
    1. Sexual Assault
      1. See Date Rape Drug
      2. Intoxication accompanies Sexual Assault in 40% of cases

VI. Evaluation: Mass Casualty Exposure

  1. Consider Exposure possibilities
    1. Biological Weapon
    2. Chemical Weapon
  2. Mnemonic: Asbestos
    1. Agents
      1. Type and toxicity of agent
      2. Potential Lethality of exposure
    2. State
      1. Solid or Liquid
      2. Gas, Vapor, or Aerosol
      3. State combination
    3. Body Site
      1. Where exposure occurred
      2. Routes of entry and absorption
    4. Effects
      1. Local
      2. Systemic
    5. Severity
      1. Mild, moderate or severe effects and exposure
    6. Time course
      1. Past: When did symptom onset occur
      2. Present: Getting better or worse?
      3. Future: Prognosis
    7. Other diagnoses
      1. Differential diagnosis
      2. Additional or combination diagnoses
    8. Synergism
      1. Combined effects of multiple exposures

VII. Causes

  1. See Accidental Poisoning Causes

VIII. Labs

  1. Bedside Glucose
  2. Complete Blood Count
  3. Comprehensive Metabolic Panel
    1. See Metabolic Acidosis with Anion Gap
    2. Anion Gap calculation is critical
  4. Arterial Blood Gas (ABG) or Venous Blood Gas (VBG)
  5. Serum Osmolality (where available)
    1. Alerts to possible Toxic Alcohol ingestion (e.g. Polyethylene Glycol)
    2. May indicate starting antidote (e.g. Fomepizole) empirically
  6. Urinalysis
  7. Urine Tox Screen (Urine superior to blood)
    1. Limited value in toxicology (poor Test Sensitivity, Test Specificity), but obtained in most cases
  8. Serum or Urine Pregnancy Test (in all genetic females of child bearing age)
  9. Carboxyhemoglobin
    1. Obtain immediately if Carbon Monoxide Poisoning suspected (and empiric High Flow Oxygen until resulted)
  10. Creatinine Phosphokinase (CPK)
    1. Indicated if Rhabdomyolysis suspected
    2. Also consider myoglobin
  11. Drug Levels in all Overdose cases
    1. Serum Salicylate Level (obtain baseline and 6-12 hours after ingestion)
    2. Serum Acetaminophen Level (obtain baseline and 4 hours after ingestion; also consider at 2 hours)
    3. Blood Alcohol Level (obtain baseline or 0.5 to 1 hour after ingestion)
  12. Drug levels when indicated
    1. Serum Theophylline Level
    2. Serum Digoxin Level (obtain baseline and 2-4 hours after ingestion)
    3. Serum Amitriptyline Level
    4. Serum Iron level (obtain baseline and 2-4 hours after ingestion)
    5. Antiepileptic medication levels
    6. Lithium level
  13. Consider evaluation for serious infection
    1. See Septic Shock
    2. See Meningitis
    3. See Bacterial Endocarditis (e.g. IV Drug Abuse)
    4. Consider Blood Cultures and Serum Lactic Acid
    5. Consider Lumbar Puncture

IX. Labs: Red Flags

  1. Metabolic Acidosis with elevated Anion Gap
  2. Elevated Osmolar Gap

X. Diagnostics: Electrocardiogram

  1. Indicated in all cases (esp. if Tricyclic Antidepressant or Antipsychotic Overdose suspected)
  2. Obtain serial EKGs as indicated during emergency department evaluation
  3. Monitor continuous telemetry
  4. Findings suggestive serious cardiotoxicity (and risk of Ventricular Tachycardia or Torsades)
    1. Prolonged QT interval
      1. See Prolonged QT Interval due to Medication
      2. Causes include Antipsychotics, Anticholinergics, Sympathomimetics, Antidepressants
    2. Wide QRS (e.g. Tricyclic Antidepressant Overdose)
      1. See Sodium Channel Blocker Toxicity
      2. Causes include Tricyclic Antidepressants, Cocaine, Diphenhydramine, Antiarrhythmics
      3. P Waves may be subtle
      4. Treated with repeated doses of Sodium Bicarbonate until QRS narrows
    3. Bradycardia
      1. See Bradycardia
      2. Narrow Bradycardia
        1. Seen with Beta Blocker Overdose, Calcium Channel Blocker Overdose, Digoxin Poisoning, Opioids
      3. Wide Bradycardia
        1. Seen with Sodium Channel Blocker Toxicity, Hyperkalemia

XI. Imaging

  1. CT Head
    1. Consider in all patients with Altered Level of Consciousness
  2. CT Cervical Spine
    1. Consider at time of CT Head if suspicion for Cervical Spine Injury
    2. Maintain spine precautions until cleared by exam in a CNS intact patient
  3. Chest XRay Indications (indicated in most Altered Level of Consciousness patients)
    1. Chemical pneumonitis (Aspiration Pneumonitis)
    2. Toxin Induced Pulmonary Edema
    3. Pneumothorax
    4. Acute Respiratory Distress Syndrome
  4. Abdominal XRay (KUB) Indications
    1. See Radiopaque Toxins

XII. Differential Diagnosis: Toxidromes

  1. Sympathomimetic Toxicity (e.g. Amphetamine, Cocaine, Ephedrine)
    1. Tachycardia
    2. Hypertension
    3. Hyperthermia
    4. Arrhythmia (primarily Tachycardia)
    5. Mydriasis
    6. Agitation
    7. Diaphoresis
      1. Differentiates from Anticholinergic Toxicity
      2. Anticholinergic Toxicity and Sympathomimetic Toxicity otherwise share similar presentations (see below)
        1. Hypertension, Tachycardia, Hyperthermia, Agitation and Mydriasis are present in both conditions
  2. Cholinergic Toxicity (e.g. Organophosphate, Pesticide)
    1. SLUDGE Mnemonic: Salivation, Lacrimation, urination, Defecation, gastrointestinal, Emesis
  3. Anticholinergic Toxicity (e.g. Diphenhydramine, Atropine, Scopolamine, Jimson weed)
    1. Mad as a hatter (altered)
    2. Blind as a bat (Mydriasis)
    3. Red as a beet (flushed)
    4. Hot as a hare (hyperthermia)
    5. Dry as a bone
      1. Contrast with diaphoresis in Sympathomimetic Toxicity
      2. Urinary Retention and ileus are also suggestive of Anticholinergic Toxicity
  4. Opioid Toxicity (e.g. Heroin, Morphine)
    1. Central Nervous System depression (sedation to coma)
    2. Respiratory depression (apnea)
    3. Miosis
  5. Sedative-Hypnotic Toxicity (e.g. Benzodiazepine Toxicity, Barbiturates, anticonvulsants, Alcohol)
    1. Central Nervous System depression (sedation to coma)
    2. Respiratory depression (apnea)
    3. Confusion, Delirium, Hallucinations
  6. Other presentations
    1. Serotonin Syndrome
    2. Drug Withdrawal
    3. Club Drug or Date Rape Drug
    4. Serious Infection ( Septic Shock, Bacterial Meningitis, Bacterial Endocarditis)
  7. References
    1. ACLS (2013) Provider Manual, AHA, p. 282

XIII. Differential Diagnosis: Specific medications in Overdose

  1. Beta Blocker Overdose
  2. Calcium Channel Blocker Overdose
  3. Clonidine Overdose
  4. Acetaminophen Overdose
  5. Salicylate Overdose (Salicylism)
  6. Sulfonylurea Overdose
  7. Tricyclic Antidepressant Overdose
  8. Valproate Toxicity

XIV. Differential Diagnosis: Drugs of Abuse (Intoxication and withdrawal)

  1. See Date Rape Drug
  2. Precautions
    1. Substances of abuse are difficult to distinguish by sight
    2. White powder could be Cocaine, Methamphetamine, synthetic Opioids, NBOMe or bath salts
    3. Crystals could be Crystal Meth, U-47700
    4. Many substances of abuse are reformulated into tablets
      1. Fentanyl may be formed in tablets similar to Oxycodone or Hydrocodone
  3. Alcohol
    1. See Alcohol Abuse
    2. Ethanol-based hand sanitizer (especially in health care centers)
      1. Hand sanitizer can cause significant Alcohol Intoxication (60% Alcohol)
      2. Some abusers of hand sanitizer extract the Alcohol with salt
  4. Cannabinoids (Marijuana, K2, Spice)
    1. See Marijuana (includes Synthetic Cannabinoids such as K2)
    2. Most common drug of abuse in U.S. and progressively increasing annually among grades 8-12
  5. Opioids (e.g. Oxycodone, Morphine, Heroin)
    1. See Opioid Abuse
    2. Opioid Overdose (Narcotic Overdose)
  6. Sedative-Hypnotics
    1. Benzodiazepine Abuse
    2. Benzodiazepine Overdose
    3. Gamma Hydroxybutyrate (GHB)
  7. Stimulants (Sympathomimetics)
    1. Cocaine
    2. Methamphetamine
    3. Synthetic Cathinones (Psychoactive Bath Salts)
    4. Methylenedioxymethamphetamine (MDMA, Ecstasy)
  8. Volatile Inhalants (Sniffing, Huffing, Bagging)
    1. More common drug of abuse in ages 10-14 years old
    2. Risk of Sudden Sniffing Death Syndrome
  9. Hallucinogens
    1. Ketamine Abuse (and Methoxetamine)
    2. Phencyclidine (PCP)
    3. Dextromethorphan Abuse

XV. Management: General

  1. See Altered Level of Consiousness
  2. Involve poison control early
    1. http://www.aapcc.org/
    2. U.S. Phone: 1-800-222-1222
  3. Supportive Care
    1. ABC Management
      1. Advanced Airway (as indicated) with Rapid Sequence Intubation (RSI)
        1. Rocuronium is preferred paralytic in ingestions
        2. Risk of Hyperkalemia (which would contraindicate Succinylcholine)
          1. Overdosage with ACE Inhibitors or Digoxin
          2. Rhabdomyolysis associated with unconscious from Overdose
    2. Cardiac Monitor
      1. Control Dysrhythmias
      2. QRS Widening on EKG
        1. Sodium Bicarbonate 1-2 ampules IV push (requires numerous back-to-back doses until QRS narrows)
    3. IV Access and appropriate hydration
    4. Oxygen Delivery as needed
    5. Control Seizures (see Status Epilepticus)
  4. Consider Decontamination (e.g. aerosolized toxins, topical contaminants)
    1. See Decontamination After Toxin Exposure
    2. Protect medical personnel
      1. Liquid toxin
      2. Vapor off-gassing from patient
    3. Protect patient from further injury
      1. Remove all clothing
      2. Consider Skin Decontamination (e.g. irrigation)
  5. Consider Coma cocktail (consider for unknown Drug Ingestion with Altered Level of Consciousness)
    1. Dextrose 25% to 50% (for Hypoglycemia demonstrated by Glucometer)
    2. Naloxone 0.4-2 mg IV (for possible Opioid Overdose)
      1. Indicated in apnea
      2. Caution in Opioid Dependence (may precipitate Opioid Withdrawal and Agitation)
      3. Caution in pregnancy (risk of Preterm Labor, Hypertensive Crisis, neonatal abstinence syndrome)
    3. Other agents to consider
      1. Thiamine (Alcoholic or malnourished patients)
      2. Flumazenil (for possible Benzodiazepine Overdose)
        1. Uncommon emergency use due to the risk of severe Benzodiazepine Withdrawal (e.g. Seizures)
        2. Use only with caution (due to risk of serious withdrawal in Benzodiazepine addiction)
  6. Consider Gastric Decontamination with charcoal if presentation within 1-2 hours of poison ingestion
    1. See Activated Charcoal for indications and contraindications
      1. Drugs must be bound by charcoal and patient must be alert or with protected airway
    2. Activated Charcoal given within 30 minutes after ingestion: Decreases absorption by 70%
    3. Activated Charcoal given within 30-60 minutes after ingestion: Decreases absorption by 30%
    4. Do not use Gastric Lavage
  7. Other measures
    1. Consider Toxin Antidotes
    2. Consider Hemodialysis for Dialyzable Drugs
      1. https://www.extrip-workgroup.org/
      2. See Dialyzable Drug (low molecular weight, low Protein binding, low volume of distribution)

XVI. Management: Specific Ingestions

  1. See Accidental Poisoning Causes
  2. See Intoxication
  3. Toxidrome Approaches
    1. See Hydrocarbon Ingestion
    2. See Caustic Ingestion (e.g. Acid Ingestion, Base Ingestion)
    3. See Anticholinergic Poisoning
    4. See Sympathomimetic Toxicity (Stimulant Overdose)
  4. Common Agents of Concern
    1. See Salicylate Poisoning
    2. See Acetaminophen Overdose
    3. See Alcohol Overdose
    4. See Beta Blocker Overdose
    5. See Benzodiazepine Overdose
    6. See Calcium Channel Blocker Overdose
    7. See Ethylene Glycol Poisoning
    8. See Isopropyl Alcohol Poisoning
    9. See Lithium Poisoning
    10. See Methanol Poisoning
    11. See Opioid Overdose
    12. See SSRI Overdose
    13. See Tricyclic Antidepressant Overdose
  5. Oher Specific Agents
    1. See Anticoagulant Overdose
    2. See Atypical Antipsychotic Overdose
    3. See Cardiac Glycoside Overdose
    4. See Dextromethorphan Overdose
    5. See Fluoride Poisoning
    6. See Histamine Fish Poisoning
    7. See Insulin Overdose
    8. See Loperamide Poisoning
    9. See Acute Iron Poisoning
    10. See Mushroom Poisoning
    11. See Nitrous Oxide Overdose
    12. See Organophosphate Poisoning
    13. See Strychnine Poisoning
    14. See Sulfuryl Fluoride Poisoning
    15. See Sulfonylurea Overdose
  6. Atypical Agents used as Suicide Attempt
    1. Sodium Nitrite Poisoning
      1. Results in Methemoglobinemia
      2. May also cause coma, Tachypnea, acidosis and Seizures
      3. ABC Management
      4. Administer methylene blue 1 to 2 g IV over minutes
    2. Carbon Monoxide Poisoning
      1. Ingestion of formic acid and sulfuric acid (sulphuric acid) yields Carbon Monoxide
      2. Strong acid fumes may also result in Burn Injury and lung injury
      3. Rescuers should don PPE and decontaminate patient
      4. See Carbon Monoxide Poisoning for management
    3. Hydrogen Sulfide Poisoning (Suicide attempt)
      1. Acid (e.g. toilet bowl cleaner) combined with sulfur-containing molecule (e.g. Pesticides, fungicide, lime sulfur)
      2. Results in release of Hydrogen Sulfide (H2S)
      3. Administer High Flow Oxygen by non-rebreather, Sodium Nitrite and consider hydroxocobalamin
    4. Carbon Dioxide Poisoning
      1. Patients combine citric acid and Baking Soda, and inhaled with bag overhead in a closed space
      2. Remove from source and administer High Flow Oxygen by non-rebreather
    5. References
      1. Swadron and Nordt (2022) EM:Rap 22(6): 5-7

XVII. Disposition

  1. See Clinical Sobriety
  2. Indications for emergency department discharge
    1. Return to baseline mental status and
    2. Minimal to no residual symptoms and
    3. Hemodynamically stable Vital Signs and
    4. No psychological safety concerns (not suicidal, and no intentional Overdose)
  3. Resources
    1. National Suicide Prevention lifeline: 1-800-273-TALK
    2. Substance Abuse and Mental Health Referral Hotline (SAMSHA): 1-800-662-HELP

XVIII. Prevention: Childhood Poisonings

  1. See Accidental Poisoning Causes for most common childhood Poisonings
  2. See Medication Dosing Errors in Children
  3. Background
    1. Medication Poisonings are responsible for two-thirds of deaths in children under age 5 years old
    2. U.S. and Canadian restrictions in 2008 on OTC Medications for infants and children
      1. Has effectively reduced childhood Poisonings
  4. Education
    1. Do not rely on child-resistant medications as sole protection against Poisoning
      1. However, keep the medication containers closed tightly, preferably with child resistant caps
    2. Store all medications including pill boxes in a safe place after every time they are accessed
      1. See One Pill Can Kill
      2. Purses containing medications should also be kept safely away from toddlers and children
      3. Place medication containers on high shelves, out of a child's sight
    3. Dispose of medications properly
      1. See Medication Disposal
    4. Talk to children about danger of household products
      1. Medications, laundry pods and dish detergent pods, household cleansers are absolutely not candy
      2. Hand sanitizer contains >60% Alcohol and may result in Alcohol Poisoning in young children
      3. Keep cleaners and disinfectants in their original containers (never store in water or soda bottles)
    5. Dispose of Ipecac syrup if still in household
      1. No longer recommended (risk of harm such as aspiration, not helpful, and may delay definitive care)
    6. Adults should also Exercise caution to prevent their Accidental Ingestions
      1. Read medication bottles carefully to confirm the medication they are taking (and proper dose)
      2. Turn on the light when using toiletries (e.g. confirm toothpaste tube)
    7. Keep critical phone numbers by telephone (consider programming into telephone)
      1. Poison Control Center: 1-800-222-1212

XIX. References

  1. (2018) Presc Lett 25(3)
  2. (2014) Presc Lett 21(3)
  3. Fontes (2014) Crit Dec Emerg Med 28(1): 14-24
  4. Thapar, Orantes and Miller (2022) Crit Dec Emerg Med 36(2): 19-24
  5. Chu (2002) Am J Respir Crit Care Med 166(1):9-15 [PubMed]
  6. Erickson (2007) Emerg Med Clin North Am 25(2):249-81 [PubMed]
  7. Frithsen (2010) Am Fam Physician 81(3): 316-23 [PubMed]
  8. Henry (2006) Pediatr Clin North Am 53(2): 293-315 [PubMed]
  9. Mokhlesi (2003) Chest 123(2):577-92 [PubMed]
  10. Nicholson (1983) Med Clin North Am 67(6):1279-93 [PubMed]

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