What is the management approach for acute poison ingestion?

Management of Acute Poison Ingestion

Immediately prioritize airway, breathing, and circulation support following standard BLS/ACLS protocols, as cardiac arrest from poisoning is managed identically to other causes of arrest with few exceptions for toxin-specific interventions during resuscitation. 1

Immediate Life-Threatening Interventions

Resuscitation Priorities

• Implement life-support measures first: cardiopulmonary resuscitation for cardiac arrest, respiratory support for inadequate ventilation, and left lateral head-down positioning with IV glucose for unconscious patients 2, 3
• Call emergency medical services immediately in life-threatening situations and contact poison control center (1-800-222-1222 in US; 1-800-268-9017 in Canada) for expert guidance 1, 2
• Transport via ambulance with continuous monitoring for patients requiring emergency department referral 4, 5, 6

Critical Symptom Management

• Administer benzodiazepines (diazepam or midazolam) for seizures, status epilepticus, or severe agitation (Class I recommendation) 2, 3, 4
• Give atropine for severe bradycardia from organophosphate/carbamate poisoning 2
• Elevate legs for hypotension and administer vasopressors as needed 7
• Administer naloxone 0.2-2 mg IV/IO/IM for opioid-induced respiratory depression, titrating to restore respiratory drive and protective airway reflexes, not full consciousness 1, 2, 3

Gastrointestinal Decontamination

Activated Charcoal

• Administer activated charcoal within 1-2 hours of ingestion if the patient ingested a potentially toxic amount of a substance known to be adsorbed by charcoal 1, 3
• Patient must be fully conscious with intact airway protective reflexes 3, 5
• Do NOT give activated charcoal for caustic substances (acids/alkalis), metals, or hydrocarbons 1
• Do not delay emergency transport to administer charcoal 4, 5, 8, 6

Contraindicated Interventions

• Never induce emesis with ipecac syrup - no clinical benefit and delays definitive care 2, 3, 4, 5, 8, 6
• Gastric lavage only justified in rare life-threatening ingestions of substances not adsorbed by charcoal 3
• Do not give anything by mouth unless specifically directed by poison control (Class III recommendation) 2

Toxin-Specific Antidotes and Management

Acetaminophen Poisoning

• Administer N-acetylcysteine within 24 hours of ingestion for hepatoprotection, ideally within 8-10 hours 9, 3
• Obtain plasma acetaminophen concentration no sooner than 4 hours post-ingestion to assess hepatotoxicity risk using the Rumack-Matthew nomogram 9
• If assay unavailable, assume overdose is potentially toxic and treat empirically 9

Opioid Toxicity

• Naloxone has shorter duration than most opioids, requiring continuous monitoring and repeated dosing 1, 2, 3
• Intranasal naloxone 2-4 mg can be repeated every 2-3 minutes as needed 1
• Naloxone has favorable safety profile and unlikely to cause harm in non-opioid respiratory depression 2

Benzodiazepine Poisoning

• If combined opioid-benzodiazepine poisoning suspected, administer naloxone first (Class 2a recommendation) 1
• Flumazenil can reverse pure benzodiazepine-induced respiratory depression in select patients without contraindications 1, 2
• Flumazenil is contraindicated and causes harm in patients at risk for seizures (chronic benzodiazepine use, seizure disorder, tricyclic antidepressant co-ingestion) 1, 2, 6
• Flumazenil has no role in cardiac arrest from benzodiazepines 1

Calcium Channel Blocker Poisoning

• For asymptomatic patients: observe and consider activated charcoal within 1 hour 1
• For symptomatic/unstable patients: IV calcium bolus, high-dose insulin (1 U/kg bolus, then 1-10 U/kg/h infusion with glucose monitoring), vasopressors 1
• For cardiac arrest: IV calcium, lipid emulsion therapy (1.5 mL/kg bolus of 20% solution, then 0.25 mL/kg/min), and consider VA-ECMO if available 1

Tricyclic Antidepressant Toxicity

• Administer sodium bicarbonate (50-150 mEq bolus) for QRS >100 msec, ventricular arrhythmias, or hypotension to overcome sodium channel blockade 1, 6
• Prepare 150 mEq/L solution and infuse at 1-3 mL/kg/h, monitoring for hypernatremia and alkalemia 1
• Benzodiazepines for seizures; flumazenil is contraindicated 6

Organophosphate/Carbamate Poisoning

• Atropine 1-2 mg IV (pediatric: 0.02 mg/kg) for bronchospasm, bronchorrhea, or severe bradycardia, repeated every 5 minutes and titrated to dry secretions 1, 2
• Pralidoxime 1-2 g IV (pediatric: 20-50 mg/kg) followed by continuous infusion 1
• Early endotracheal intubation for life-threatening poisoning 2

Anticholinergic Toxicity (Datura)

• Benzodiazepines first-line for agitation and delirium 10
• Physostigmine is definitive antidote for severe anticholinergic syndrome with life-threatening symptoms (severe delirium, coma, hyperthermia, refractory seizures) 10

Chemical Exposure Management

Dermal/Ocular Exposure

• Remove all contaminated clothing immediately and irrigate affected skin with copious water for at least 15 minutes (Class I, Level B-NR) 2
• Flush eyes with large amounts of water for at least 15 minutes (Class I, Level C) 2
• Remove chemical powders with gloves before water irrigation 2
• Never apply neutralizing agents to chemical burns 2

Observation and Disposition Criteria

Emergency Department Referral Indications

• All cases of intentional self-harm, suicidal ideation, abuse, or malicious intent 4, 5, 8, 6
• Any patient with more than mild symptoms (altered mental status beyond mild somnolence, cardiovascular instability, respiratory depression) 4, 5, 8, 6
• Ingestion exceeding toxic dose thresholds for specific agents 4, 5, 8, 6
• Patients taking MAO inhibitors with any sympathomimetic ingestion 4, 8

Home Observation Criteria

• Asymptomatic patients with subtoxic ingestions after appropriate observation period (typically 4-6 hours for immediate-release, 12 hours for extended-release formulations) 4, 5, 8, 6
• Poison center-initiated follow-up calls at 2-4 hour intervals to monitor for symptom development 4, 5, 8, 6

Critical Pitfalls to Avoid

• Do not delay supportive care while awaiting toxicology results or poison identification - treatment is based on clinical presentation 7, 10
• Multiple drug exposures are common; maintain broad differential diagnosis 1
• Recognize toxidromes (anticholinergic, cholinergic, sympathomimetic, sedative-hypnotic, opioid) to guide empiric management 1
• Do not wait for acetaminophen assay results to begin N-acetylcysteine if access to emergency care not feasible within 8-10 hours 9, 3
• Consult medical toxicologist or poison center early for potentially life-threatening poisonings to prevent deterioration to cardiac arrest 1