Managing Toxicology Emergencies

1. What substance(s) was/were ingested, inhaled, or exposed to? (Name, formulation, amount if known)
2. What was the time of exposure relative to current presentation?
3. Was the exposure intentional (suicide attempt) or unintentional (accidental, pediatric exploratory, therapeutic error)?
4. What are the current vital signs, mental status (GCS), and pupil examination findings?
5. Does the patient have co-ingestants or polypharmacy exposure?
6. What was the route of exposure (oral, inhalation, dermal, IV, ocular)?
7. Has the patient vomited, and has any decontamination been performed in the field?
8. Is the patient pregnant?

Documents to Request

• Pill bottles, medication blister packs, or product containers (photograph and retain)
• Pharmacy fill records (query state PDMP)
• EMS run sheet with field vital signs and treatments
• Prior toxicology encounters and psychiatric history
• Serum and urine drug levels (acetaminophen, salicylate, ethanol, toxic alcohols)
• ECG (QRS width, QTc interval, rhythm)
• Basic metabolic panel with calculated anion gap and osmolar gap
• Arterial blood gas if respiratory/metabolic derangement suspected
• Poison Control Center consultation documentation

Step 1: Toxidrome Identification

Classic Toxidromes

Mnemonic for anticholinergic: "Blind as a bat (mydriasis), mad as a hatter (delirium), red as a beet (flushing), hot as a hare (hyperthermia), dry as a bone (anhidrosis), full as a flask (urinary retention), the heart runs alone (tachycardia)."

Step 2: Universal Toxicology Workup

Order for every intentional ingestion or unknown overdose:

1. Serum acetaminophen level (regardless of reported ingestion—occult co-ingestion found in 5-10%)
2. Serum salicylate level (frequently co-ingested, often missed)
3. Serum ethanol level
4. Basic metabolic panel with anion gap calculation: AG = Na - (Cl + HCO3); normal 8-12
5. Serum osmolality (measured) and osmolar gap calculation: OG = measured osmolality - calculated osmolality; normal <10
6. 12-lead ECG: QRS >100 ms (sodium channel blockade: TCAs, cocaine), QTc >500 ms (risk of torsades)
7. Arterial or venous blood gas
8. Pregnancy test for all women of childbearing age
9. Urinalysis for crystals (calcium oxalate = ethylene glycol)
10. Urine drug screen (qualitative, many false positives/negatives—use for context, not definitive diagnosis)

Anion Gap and Osmolar Gap Differential

Elevated anion gap metabolic acidosis (GOLDMARK): Glycols (ethylene glycol), Oxoproline (acetaminophen chronic), L-lactate, D-lactate, Methanol, Aspirin (salicylates), Renal failure, Ketoacidosis

Elevated osmolar gap: Methanol, Ethylene glycol, Isopropyl alcohol, Ethanol, Propylene glycol, Acetone

Step 3: Decontamination Decisions

Step 4: Specific Antidotes

Step 5: Disposition and Observation

Checkpoint B: Post-Draft Alignment (Mandatory)

1. Was a toxidrome identified or systematically excluded through physical examination findings?
2. Were acetaminophen and salicylate levels obtained regardless of reported ingestion?
3. Was the decontamination decision evidence-based with timing and contraindications documented?
4. Are antidote doses, timing, monitoring parameters, and endpoints documented?
5. Was Poison Control consulted and the case number documented?

Quality Audit

Guidelines

1. Always check acetaminophen and salicylate levels in any intentional ingestion—these are the most common occult co-ingestants and both have specific, time-sensitive antidotes
2. The urine drug screen is a screening tool, not a diagnostic test—false positives (dextromethorphan for PCP, sertraline for benzodiazepines) and false negatives (fentanyl analogs, many synthetic opioids) are common
3. Start low with naloxone (0.04-0.1 mg) in suspected opioid-dependent patients—full reversal with 2 mg causes immediate withdrawal with projectile vomiting (aspiration risk), agitation, and patient elopement
4. Activated charcoal should NOT be given routinely—it is only beneficial within 1-2 hours, the substance must be adsorbable, and the airway must be protected; forced administration increases aspiration risk
5. Sodium bicarbonate for wide-complex tachycardia from sodium channel blockade (TCAs, class IC antiarrhythmics) is a life-saving intervention—do not wait for toxicology confirmation; treat the ECG
6. QTc >500 ms requires continuous monitoring and correction of hypokalemia and hypomagnesemia—avoid additional QT-prolonging medications including ondansetron and haloperidol
7. High-dose insulin therapy for calcium channel blocker and beta-blocker overdose is underutilized—doses of 1-10 units/kg/hr with glucose supplementation are safe and effective when vasopressors fail
8. Fomepizole has replaced ethanol as the preferred antidote for toxic alcohol poisoning—it has a cleaner side effect profile, does not require ICU monitoring for intoxication, and is easier to dose