Epidemiology
- • ~2.2 million poison exposures/year (US - AAPCC)
- • ~90% occur at home
- • Children <6 years: ~44% of all exposures
- • Leading cause: Analgesics, cleaning substances, cosmetics
- • Mortality: ~1,500 deaths/year from acute poisoning
- • Intentional exposures: ~20% (suicidal, abuse)
Classification
- By Intent: Accidental, Suicidal, Homicidal, Iatrogenic, Occupational
- By Route: Oral (most common), Inhalational, Dermal, Parenteral, Ocular, Rectal
- By Agent: Pharmaceutical, Industrial, Agricultural, Biological, Household
- By Timeline: Acute, Chronic, Acute-on-chronic
Key Contacts
- 🇺🇸 US Poison Control: 1-800-222-1222
- 🇬🇧 UK NPIS: 0344-892-0111
- 🇮🇳 India NPIC: 1800-116-117
- 🌐 WHO INTOX: Available globally
- Always contact Poison Control early — they improve outcomes
⚡ Golden Rules of Toxicology
1
Treat the Patient, Not the Poison
Stabilize ABCs first. Resuscitation always takes priority over identification or specific antidotes.
2
History May Be Unreliable
Patients may deny, minimize, or be unable to provide history. Use clinical findings to guide management.
3
Time Is Tissue
Some antidotes (NAC for acetaminophen, fomepizole for toxic alcohols) are time-critical. Don't wait for confirmation.
4
Assume the Worst Case
Always calculate maximum possible dose. Assume co-ingestions until proven otherwise.
5
Decontamination Window Is Narrow
Activated charcoal most effective within 1 hour. Don't delay for imaging or labs.
6
Observation Is Therapeutic
Many poisonings resolve with supportive care. Adequate monitoring may be the best "treatment."
🔬 Top 10 Most Dangerous Ingestions
| Poison | Lethal Dose/Danger | Key Feature | Antidote |
|---|---|---|---|
| Organophosphates | Variable; highly toxic | SLUDGE/DUMBELS + Nicotinic | Atropine + Pralidoxime |
| Paracetamol (APAP) | >150 mg/kg toxic | Delayed hepatotoxicity (24-72h) | N-Acetylcysteine (NAC) |
| Tricyclic Antidepressants | >10 mg/kg toxic | Wide QRS, seizures, hypotension | NaHCO₃ (Sodium Bicarbonate) |
| Calcium Channel Blockers | 1-2 tablets lethal in child | Bradycardia, hypotension, hyperglycemia | High-dose Insulin + Ca²⁺ |
| Beta-Blockers | Variable | Bradycardia, hypotension, hypoglycemia | Glucagon + High-dose Insulin |
| Methanol/Ethylene Glycol | ~1 mL/kg lethal | High AG acidosis + Osmol gap | Fomepizole / Ethanol |
| Cyanide | 1-3 mg/kg lethal | Lactic acidosis, cherry red skin | Hydroxocobalamin / Na thiosulfate |
| Iron | >60 mg/kg toxic | GI hemorrhage → shock → hepatic failure | Deferoxamine |
| Digoxin | >10 mg acute | Hyperkalemia + Dysrhythmias | Digibind (DigiFab) |
| Paraquat | 10-15 mL lethal | Oral burns → Pulmonary fibrosis | No specific antidote (Fuller's earth) |
🩺 Systematic Approach to the Poisoned Patient
Primary Survey: ABCDE
A — Airway
- • Assess patency, secretions, vomitus
- • Protect airway if GCS ≤ 8
- • RSI with caution (avoid succinylcholine in OP poisoning)
- • Consider nasogastric tube placement post-intubation
B — Breathing
- • RR pattern: Kussmaul (acidosis), slow (opioids), rapid (salicylates)
- • SpO₂ unreliable in CO/MetHb poisoning
- • Bronchospasm: OP, chlorine gas
- • ARDS risk: Paraquat, hydrocarbons, opioids
C — Circulation
- • Hypotension: CCBs, BBs, TCAs, iron
- • Hypertension: Sympathomimetics, MAOIs
- • Dysrhythmias: Wide QRS (Na channel), QTc prolongation
- • 2 large-bore IVs, continuous cardiac monitoring
D — Disability
- • GCS assessment + pupils (PEARL)
- • Miosis: Opioids, OPs, clonidine
- • Mydriasis: Anticholinergics, sympathomimetics
- • Seizures: TCAs, isoniazid, tramadol, organochlorines
- • Coma Cocktail: Dextrose + Naloxone + Thiamine
E — Exposure
- • Full body examination — remove all clothing
- • Skin: Chemical burns, needle marks, cyanosis
- • Odor: Garlic (OPs), bitter almonds (cyanide), fruity (DKA/isopropanol)
- • Temperature: Hyper (serotonin, NMS) vs Hypo (opioids, sedatives)
- • Decontaminate skin/eyes if topical exposure
F — Full History
- • 5 W's: What, When, Where, Why, hoW much
- • Co-ingestants? Alcohol?
- • Medication access (entire household)
- • Psychiatric history & suicidal intent
- • Bring containers, bottles, blister packs
🚨 Toxicology-Specific Resuscitation Priorities
Immediate Actions (0-5 min)
- Stabilize airway — intubate if GCS ≤ 8
- IV access × 2, cardiac monitor, pulse oximetry
- Stat glucose check — treat hypoglycemia
- 12-lead ECG — look for QRS/QTc abnormalities
- If seizures → Benzodiazepines first-line
Early Actions (5-30 min)
- Empiric antidotes if indicated (naloxone, NAC, atropine)
- Consider activated charcoal if within window
- Labs: BMP, LFTs, lactate, ABG, serum levels
- Calculate anion gap & osmol gap
- Contact Poison Control Center
🔍 Physical Exam Clues — "What the Body Tells You"
Vital Sign Patterns
- 🔺 HR + 🔺 BP + 🔺 Temp = Sympathomimetic
- 🔻 HR + 🔻 BP = BB/CCB/Digoxin
- 🔻 HR + 🔻 RR + 🔻 Temp = Opioid/Sedative
- 🔺 RR + Metabolic Acidosis = Salicylates/Toxic alcohols
Skin Findings
- Dry, flushed, hot = Anticholinergic
- Diaphoretic = Cholinergic/Sympathomimetic
- Cherry red = CO poisoning
- Blue/Chocolate = Methemoglobinemia
- Jaundice (delayed) = APAP/Mushrooms
Characteristic Odors
- 🧄 Garlic = Organophosphates, Arsenic
- 🍬 Bitter almonds = Cyanide
- 🍎 Fruity/Acetone = Isopropanol, DKA
- ⛽ Gasoline-like = Hydrocarbons
- 🥚 Rotten eggs = Hydrogen sulfide
🧬 Major Toxidromes
A toxidrome is a constellation of signs and symptoms that suggests a specific class of poisoning. Recognizing toxidromes allows rapid empiric treatment before confirmatory testing.
SLUDGE-M / DUMBELS Mnemonic
SLUDGE-M
- S — Salivation
- L — Lacrimation
- U — Urination
- D — Defecation/Diarrhea
- G — GI cramping
- E — Emesis
- M — Miosis
DUMBELS
- D — Diarrhea
- U — Urination
- M — Miosis
- B — Bradycardia/Bronchospasm
- E — Emesis
- L — Lacrimation
- S — Salivation
Key Clinical Features
- • Muscarinic: SLUDGE + bradycardia + bronchospasm + bronchorrhea
- • Nicotinic: Fasciculations, weakness, tachycardia, hypertension, paralysis
- • CNS: Anxiety, seizures, coma, respiratory depression
- • Intermediate syndrome (24-96h): Proximal muscle weakness
- • OPIDN (2-4 weeks): Delayed neuropathy
Common Causes
Organophosphates, Carbamates, Nerve agents (Sarin, VX), Pilocarpine, Mushrooms (muscarinic type)
Treatment
Atropine: 1-2mg IV doubling every 3-5 min until secretions dry. May need massive doses (100+ mg). Pralidoxime (2-PAM): 1-2g IV over 15-30 min. Most effective within 24-48h before "aging."
"Hot as a Hare, Blind as a Bat, Dry as a Bone, Red as a Beet, Mad as a Hatter, Full as a Flask"
Clinical Features
- • Hyperthermia (Hot as a Hare)
- • Mydriasis (Blind as a Bat)
- • Dry skin & mucous membranes (Dry as a Bone)
- • Flushed skin (Red as a Beet)
- • Agitation, delirium, hallucinations (Mad as a Hatter)
- • Urinary retention (Full as a Flask)
- • Tachycardia, decreased bowel sounds, seizures
Common Causes
Antihistamines (diphenhydramine), TCAs, atropine, scopolamine, Jimson weed (Datura), antipsychotics, cyclobenzaprine
Treatment
- • Supportive care: Cooling, benzodiazepines for agitation
- • Physostigmine 1-2mg slow IV — only for pure anticholinergic toxicity, NOT for TCA
- • Avoid physostigmine if: Wide QRS, seizures, or cardiac conduction delays
Clinical Features
- • Hypertension, tachycardia
- • Hyperthermia, diaphoresis
- • Mydriasis (dilated pupils)
- • Agitation, psychosis, paranoia
- • Seizures, rhabdomyolysis
- • Chest pain (coronary vasospasm)
- • Differentiator from anticholinergic: DIAPHORESIS present
Common Causes
Cocaine, amphetamines, methamphetamine, MDMA, pseudoephedrine, caffeine (massive dose), synthetic cathinones ("bath salts")
Treatment
- • Benzodiazepines — first-line for all symptoms
- • Aggressive cooling for hyperthermia
- • ⛔ Avoid beta-blockers (unopposed alpha stimulation)
- • Cocaine chest pain: Benzos + nitrates, NOT beta-blockers
Classic Triad: CNS Depression + Respiratory Depression + Miosis (Pinpoint Pupils)
Clinical Features
- • Pinpoint pupils (miosis) — absent in meperidine, tramadol
- • Respiratory depression (RR < 12)
- • CNS depression → coma
- • Hypotension, bradycardia
- • Hypothermia
- • Decreased bowel sounds, urinary retention
- • Needle tracks (IV drug use)
Common Causes
Morphine, heroin, fentanyl, methadone, oxycodone, hydrocodone, codeine, tramadol, loperamide (high dose)
Treatment
- • Naloxone (Narcan) 0.04-0.4 mg IV — titrate to respiratory effort, NOT consciousness
- • Start low in known opioid-dependent patients (precipitates withdrawal)
- • May need repeat doses (t½ naloxone 30-90 min vs fentanyl/methadone hours)
- • Consider naloxone infusion: 2/3 of effective bolus dose per hour
- • Intubate if no response to naloxone 10mg total
Clinical Features (similar to opioid but NORMAL pupils)
- • CNS depression, slurred speech, ataxia
- • Normal-sized pupils (distinguishes from opioid)
- • Respiratory depression (less severe than opioids)
- • Hypotension, hypothermia
- • Hyporeflexia
- • Benzodiazepines: rarely fatal alone, dangerous with ethanol
Common Causes
Benzodiazepines, barbiturates, GHB, zolpidem, ethanol, chloral hydrate, baclofen
Treatment
- • Primarily supportive — protect airway
- • Flumazenil 0.2mg IV — ONLY for iatrogenic benzodiazepine oversedation
- • ⛔ Do NOT use flumazenil in chronic benzo users (seizure risk), unknown overdose, or co-ingestion with proconvulsants
Hunter Criteria: Spontaneous clonus, Inducible clonus + agitation, Ocular clonus + agitation, Tremor + hyperreflexia, Hypertonia + Temp >38°C + clonus
Clinical Triad
- • Neuromuscular: Clonus (especially lower limbs), hyperreflexia, rigidity, tremor, myoclonus
- • Autonomic: Hyperthermia, diaphoresis, tachycardia, hypertension, mydriasis, diarrhea
- • Mental Status: Agitation, confusion, hypomania
- • Key differentiator from NMS: Clonus + hyperreflexia + rapid onset (NMS has lead-pipe rigidity + slow onset)
Common Causes
SSRIs + MAOIs, SSRIs + tramadol, SSRIs + linezolid, SSRIs + triptans, MDMA, meperidine + MAOIs, St. John's Wort combinations
Treatment
- • Discontinue all serotonergic agents
- • Cyproheptadine 12mg PO then 2mg q2h (serotonin antagonist)
- • Benzodiazepines for agitation and muscle rigidity
- • Active cooling if temp >41°C
- • ⛔ Avoid: Dantrolene (ineffective), succinylcholine (hyperkalemia risk)
⚡ Quick Toxidrome Comparison
| Feature | Cholinergic | Anticholinergic | Sympathomimetic | Opioid | Sedative |
|---|---|---|---|---|---|
| Pupils | Miosis | Mydriasis | Mydriasis | Miosis | Normal |
| HR | ↓ Brady | ↑ Tachy | ↑ Tachy | ↓ Brady | ↓ or Normal |
| BP | ↓ | Variable | ↑ Hypertension | ↓ | ↓ |
| Temp | Normal | ↑ Hyper | ↑ Hyper | ↓ Hypo | ↓ Hypo |
| Skin | Wet | Dry, Red | Wet | Normal | Normal |
| Bowel | ↑ Active | ↓ Ileus | ↑ Active | ↓ Decreased | ↓ Decreased |
| Mental | Confusion | Delirium | Agitation | Sedation | Sedation |
💊 Specific Poisons — Detailed Protocols
Toxic Doses
- • Acute: >150 mg/kg or >7.5g (whichever is less)
- • Chronic: >4g/day in adults
- • High-risk: Alcoholics, malnourished, CYP2E1 inducers
Phases of Toxicity
Phase I (0-24h): Nausea, vomiting, malaise, normal LFTs — Patients often feel well!
Phase II (24-72h): RUQ pain, rising AST/ALT, rising PT/INR, oliguria
Phase III (72-96h): Peak hepatotoxicity — AST/ALT >10,000, coagulopathy, jaundice, renal failure, encephalopathy, DEATH
Phase IV (4d-2wk): Recovery phase if patient survives
Rumack-Matthew Nomogram
- • Plot serum APAP level at 4h post-ingestion
- • Treatment line: 150 µg/mL at 4h → 4.7 µg/mL at 24h
- • Above line → Treat with NAC
- • If timing unknown or >8h — start NAC immediately, don't wait for levels
NAC Protocol (IV - Preferred)
21-hour IV Protocol:
- 150 mg/kg in 200mL D5W over 1 hour
- 50 mg/kg in 500mL D5W over 4 hours
- 100 mg/kg in 1000mL D5W over 16 hours
Continue NAC if ALT rising, APAP detectable, or INR >2
King's College Criteria (Transplant)
- • pH < 7.3 after resuscitation, OR
- • Grade III/IV encephalopathy + Creatinine >3.4 + INR >6.5
Mechanism
Irreversible inhibition of acetylcholinesterase (AChE) → Excess acetylcholine at muscarinic, nicotinic, and CNS receptors
Common Agents
Malathion, Parathion, Chlorpyrifos, Diazinon, Nerve agents (Sarin, VX, Novichok)
Diagnosis
- • Clinical (SLUDGE-M + Nicotinic + CNS)
- • Serum Cholinesterase (Pseudocholinesterase): Low
- • RBC Cholinesterase: More accurate, slower to return
- • Garlic-like odor on patient/clothes
Treatment Protocol
⚠️ Decontaminate FIRST — remove clothes, wash with soap & water. Protect healthcare workers!
Atropine (Muscarinic Blockade)
- • Adult: 2-5 mg IV bolus
- • Double dose every 3-5 minutes
- • Endpoint: Dry secretions (NOT pupil size or heart rate)
- • May need 100+ mg in severe cases
- • Start infusion: 10-20% of loading dose/hour
Pralidoxime / 2-PAM (AChE Reactivation)
- • Adult: 1-2g IV over 15-30 min
- • Then infusion 500 mg/hr
- • Most effective before "aging" (24-48h for most OPs)
- • NOT needed for carbamate poisoning (spontaneous recovery)
Mechanism — Triple Toxicity
- • Na⁺ Channel Blockade: Wide QRS, R in aVR, Brugada pattern
- • Anticholinergic: Tachycardia, mydriasis, dry skin, urinary retention
- • Alpha-1 Blockade: Hypotension
- • Also: Serotonin/NE reuptake inhibition, GABA antagonism (seizures)
ECG Findings (CRITICAL)
- • QRS > 100ms: Risk of seizures
- • QRS > 160ms: Risk of ventricular dysrhythmias
- • R wave in aVR > 3mm: Highly specific for TCA
- • Terminal R in aVR + S in Lead I
- • Right axis deviation of terminal 40ms of QRS
Treatment
🚨 Sodium Bicarbonate is the ANTIDOTE
- • 1-2 mEq/kg IV bolus for QRS >100ms
- • Repeat until QRS narrows or pH 7.50-7.55
- • Infusion: 150 mEq NaHCO₃ in 1L D5W
- • Monitor QRS continuously
- • Seizures: Benzodiazepines ONLY
- • ⛔ Avoid: Phenytoin, Class IA/IC antiarrhythmics, physostigmine
- • Hypotension: Fluids → NaHCO₃ → Norepinephrine
- • Intralipid 20% for refractory cardiovascular collapse
- • Observe minimum 6h even if asymptomatic
| Feature | Methanol | Ethylene Glycol | Isopropanol |
|---|---|---|---|
| Source | Windshield fluid, fuel | Antifreeze, coolant | Rubbing alcohol |
| Toxic Metabolite | Formic acid | Glycolic/Oxalic acid | Acetone (less toxic) |
| Key Finding | Visual disturbance/"snowfield" vision | Calcium oxalate crystals in urine, renal failure | Ketosis WITHOUT acidosis |
| AG Acidosis | Severe (↑AG) | Severe (↑AG) | Mild or absent |
| Osmol Gap | ↑ Early | ↑ Early | ↑ Early |
| Antidote | Fomepizole / Ethanol | Fomepizole / Ethanol | Supportive only |
| Dialysis | Yes — if acidosis, visual changes, renal failure | Yes — if acidosis, renal failure | Rarely needed |
Fomepizole Protocol
- • Loading: 15 mg/kg IV
- • Then: 10 mg/kg q12h × 4 doses
- • Then: 15 mg/kg q12h until levels undetectable
- • Mechanism: Inhibits alcohol dehydrogenase → prevents toxic metabolite formation
Acid vs Alkali
Acids (pH < 2)
Coagulation necrosis → Eschar formation (self-limiting). More gastric injury. Examples: HCl, H₂SO₄, acetic acid
Alkalis (pH > 12)
Liquefactive necrosis → Deep penetrating injury (WORSE). More esophageal injury. Examples: NaOH (drain cleaner), bleach, ammonia
Management
- • ⛔ Do NOT induce emesis or give activated charcoal
- • ⛔ Do NOT attempt neutralization (exothermic reaction)
- • Dilution with water/milk within 30 min ONLY if no perforation suspected
- • NPO, IV fluids, pain management
- • Urgent endoscopy within 12-24h (Zargar grading)
- • CT if perforation suspected
- • Long-term: Esophageal stricture risk (alkali)
Classification by Venom Type
Hemotoxic (Viperidae)
Local swelling, ecchymosis, coagulopathy (DIC), hemorrhage, shock. Examples: Russell's Viper, Rattlesnakes
Neurotoxic (Elapidae)
Ptosis, diplopia, respiratory paralysis, minimal local signs. Examples: Cobra, Krait, Mamba
Myotoxic
Rhabdomyolysis, myoglobinuria, renal failure. Examples: Sea snakes, some Elapids
Management
- • Immobilize limb, remove jewelry
- • ⛔ Do NOT: Tourniquet, incision, suction, ice
- • Mark edge of swelling with time
- • 20WBCT (20-minute whole blood clotting test) for coagulopathy
- • Anti-snake venom (ASV) — polyvalent or monovalent
- • Indications for ASV: Coagulopathy, neurotoxicity, severe local envenomation, hemodynamic instability
- • Neostigmine test for neurotoxic envenomation
- • Fasciotomy only for true compartment syndrome (measure pressures)
COHb Levels & Symptoms
10-20%: Headache, nausea, dizziness
20-40%: Confusion, visual changes, syncope, tachycardia
40-60%: Seizures, coma, cardiac ischemia
>60%: Cardiopulmonary failure, death
⚠️ SpO₂ is FALSELY NORMAL — CO absorbs at same wavelength. Use co-oximetry!
Treatment
- • Remove from source immediately
- • 100% O₂ via NRB mask — reduces COHb t½ from 5h to 90 min
- • Hyperbaric O₂ (HBO) — reduces t½ to 20 min
- • HBO Indications: COHb >25%, loss of consciousness, cardiac ischemia, pregnancy, neurological symptoms
- • Monitor troponin (myocardial injury common)
- • Delayed neuropsychiatric syndrome (2-40 days): Cognitive impairment, personality changes
💉 Essential Antidotes — Quick Reference
| Antidote | Poison | Dose | Notes |
|---|---|---|---|
| N-Acetylcysteine (NAC) | Acetaminophen | 150→50→100 mg/kg IV (21h protocol) | Best within 8h. Continue if ALT rising |
| Atropine | Organophosphates, Carbamates | 2-5mg IV, double q3-5min | Endpoint: dry secretions. No max dose |
| Pralidoxime (2-PAM) | Organophosphates | 1-2g IV over 15-30min | Within 24-48h before "aging" |
| Naloxone (Narcan) | Opioids | 0.04-0.4mg IV, titrate | Titrate to RR, not consciousness |
| Flumazenil | Benzodiazepines | 0.2mg IV q1min (max 3mg) | ⛔ AVOID in chronic benzo use/seizure risk |
| NaHCO₃ | TCAs, Na channel blockers | 1-2 mEq/kg IV bolus | Target pH 7.50-7.55, monitor QRS |
| Fomepizole | Methanol, Ethylene glycol | 15mg/kg load, then 10mg/kg q12h | ADH inhibitor. Start empirically |
| Deferoxamine | Iron | 15 mg/kg/hr IV (max 6g/day) | "Vin rosé" colored urine = working |
| Digibind / DigiFab | Digoxin, Oleander | Based on level or empiric 10 vials | Fab fragments. Monitor K⁺ (drops rapidly) |
| Hydroxocobalamin | Cyanide | 5g IV over 15min | Red discoloration of skin/urine (harmless) |
| Glucagon | Beta-blockers, CCBs | 5-10mg IV bolus → 1-5mg/hr | Bypasses beta receptor. Causes vomiting |
| Calcium (CaCl₂/Gluconate) | CCBs, HF, Hyperkalemia | CaCl₂ 1g IV or Ca Gluc 3g IV | CaCl₂ via central line only (tissue necrosis) |
| High-Dose Insulin (HIET) | CCBs, Beta-blockers | 1 U/kg bolus → 1-10 U/kg/hr | D10W infusion + K⁺ monitoring. Emerging first-line |
| Intralipid 20% | Local anesthetic toxicity, lipophilic drugs | 1.5 mL/kg bolus → 0.25 mL/kg/min | "Lipid sink" — rescue therapy |
| Pyridoxine (B6) | Isoniazid (INH) | Gram-for-gram of INH ingested (max 5g) | First-line for INH seizures (benzo-resistant) |
| Methylene Blue | Methemoglobinemia | 1-2 mg/kg IV over 5 min | ⛔ Avoid in G6PD deficiency. May repeat x1 |
| Cyproheptadine | Serotonin syndrome | 12mg PO then 2mg q2h | Only available PO. Serotonin antagonist |
| Octreotide | Sulfonylurea hypoglycemia | 50-100 µg SC q6-8h | Prevents rebound hypoglycemia after D50 |
🧹 Gastrointestinal Decontamination
⬛
Activated Charcoal (AC)
Dose: 1 g/kg (max 50g) PO/NG
Best within 1 hour of ingestion. May consider up to 2h for large ingestions.
Indications
- • Potentially toxic ingestion within 1-2 hours
- • Protected airway (awake or intubated)
- • Substance binds to charcoal
Contraindications
- • Unprotected airway / decreased consciousness
- • Corrosive ingestion (acids/alkali)
- • GI perforation or obstruction
- • Hydrocarbons with aspiration risk
Does NOT Bind ("PHAILS")
P-esticides (some), H-ydrocarbons, A-cids/Alkali, I-ron, L-ithium, S-olvents/alcohols
Multi-Dose AC (MDAC)
- • 0.5 g/kg q4-6h (without cathartic)
- • Indications: Carbamazepine, dapsone, phenobarbital, quinine, theophylline ("gut dialysis")
🚿
Whole Bowel Irrigation (WBI)
PEG Solution via NG
Adult: 1.5-2 L/hr | Child: 500 mL/hr
Continue until rectal effluent is clear
Indications
- • Iron overdose
- • Lithium overdose
- • Sustained-release/enteric-coated medications
- • Body packers ("drug mules")
- • Lead paint chips ingestion
🫧
Gastric Lavage
⚠️ Rarely Indicated in Modern Practice
- • Only within 1 hour of life-threatening ingestion
- • Large-bore orogastric tube (36-40Fr adult)
- • Patient must be intubated for airway protection
- • 200-300 mL aliquots of NS, repeated until clear
- • ⛔ Contraindicated: Corrosives, hydrocarbons, sharp objects, unprotected airway
🔄
Enhanced Elimination
Urinary Alkalinization
- • NaHCO₃ infusion → target urine pH 7.5-8.5
- • Indications: Salicylates, methotrexate, phenobarbital
- • Monitor K⁺ (hypokalemia prevents alkalinization)
Hemodialysis (EXTRIP Criteria)
- • Methanol, Ethylene glycol
- • Salicylates (level >100 mg/dL or renal failure)
- • Lithium (level >4 mEq/L or symptomatic)
- • Theophylline, Valproic acid, Metformin
- • Ideal for: Small molecular weight, low protein binding, small Vd, water soluble
🔬 Laboratory Workup & Diagnostic Approach
📋 Standard Tox Workup
Order for ALL suspected poisonings:
- ✅ BMP (Chem-7): Na⁺, K⁺, Cl⁻, HCO₃⁻, BUN, Cr, Glucose
- ✅ ABG/VBG with lactate
- ✅ Serum osmolality (measured)
- ✅ 12-lead ECG
- ✅ Acetaminophen level (always — often co-ingested)
- ✅ Salicylate level
- ✅ Ethanol level
- ✅ CBC, LFTs, Coagulation studies (PT/INR)
- ✅ Urinalysis (crystals, myoglobin)
- ✅ Pregnancy test (all women of childbearing age)
🧮 Anion Gap Calculation
AG = Na⁺ − (Cl⁻ + HCO₃⁻)
Normal: 8-12 mEq/L (or 10-14 with K⁺)
↑ AG Metabolic Acidosis — "MUDPILES" / "CAT MUDPILES"
Methanol | Uremia | DKA | Propylene glycol | Isoniazid/Iron | Lactic acidosis | Ethylene glycol | Salicylates
+Cyanide Acetaminophen Toluene
Osmol Gap
OG = Measured Osm − Calculated Osm
Calc Osm = 2(Na⁺) + Glucose/18 + BUN/2.8 + EtOH/4.6
OG > 10: Think toxic alcohols (methanol, ethylene glycol, isopropanol)
Key concept: Early = ↑OG, normal AG → Late = normal OG, ↑AG (as parent alcohol converted to acid metabolites)
❤️ ECG in Toxicology — Critical Patterns
Wide QRS (>120ms)
- • TCAs (Na⁺ channel block)
- • Class IA/IC antiarrhythmics
- • Cocaine, diphenhydramine
- • Hyperkalemia
- → Treat with NaHCO₃
Prolonged QTc (>500ms)
- • Antipsychotics (haloperidol, quetiapine)
- • Antiarrhythmics (sotalol, amiodarone)
- • Fluoroquinolones, macrolides
- • Methadone, SSRI overdose
- → Risk of Torsades → IV Magnesium
Bradycardia + Hypotension
- • Beta-blockers
- • Calcium channel blockers
- • Digoxin
- • Clonidine, organophosphates
- → Glucagon, Ca²⁺, HIET, pacing
👶 Pediatric Toxicology
☠️ "One Pill Can Kill" — Fatal in a Toddler
These medications can be lethal to a 10kg toddler with just 1-2 tablets/doses:
Calcium Channel Blockers
Single sustained-release tablet (verapamil, nifedipine)
Sulfonylureas
Glipizide, glyburide → Prolonged hypoglycemia
Opioids
Methadone, fentanyl patches, oxycodone
TCAs
Amitriptyline, desipramine — most dangerous TCA
Camphor
5 mL of 20% solution → seizures
Clonidine / Imidazolines
CNS depression, bradycardia, hypotension
Antimalarials
Chloroquine, quinine — cardiotoxic
Methyl Salicylate
Oil of wintergreen: 1 tsp = 7g aspirin
Theophylline
Seizures, dysrhythmias at low doses
📏 Pediatric Dosing Differences
- • Activated Charcoal: 1 g/kg (can mix with cola/juice)
- • NAC: Same weight-based protocol as adults
- • Naloxone: 0.1 mg/kg IV (max 2mg/dose) — can start with 0.01 mg/kg in neonates
- • Atropine: 0.02 mg/kg IV (min 0.1mg)
- • Dextrose: D10W 5 mL/kg (neonates), D25W 2 mL/kg (children)
- • Weight-based calculations are critical — use Broselow tape in emergencies
🏥 When to Admit Pediatric Patients
- • ANY intentional ingestion (psychiatric evaluation required)
- • Ingestion of "one pill can kill" medications
- • Symptomatic patient (GI, CNS, cardiac)
- • Sustained-release or delayed-toxicity agents
- • Unknown ingestion with concerning exam
- • Social concerns (neglect, abuse, unsafe environment)
- • Minimum observation: 6h for immediate-release, 12-24h for sustained-release formulations