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Overdose / Poisoning

Category: Medical Sources: raw/protocols/nm-sop-guidelines-treatment-2022.pdf Last updated: 2026-04-03

Overview

Poisoning and overdose involve exposure to substances (inhalation, ingestion, injection, or skin absorption) causing adverse physiologic effects. The spectrum ranges from mild symptoms to cardiovascular collapse and death. Opioid overdose is the most common life-threatening poisoning encountered in prehospital EMS, with naloxone as the reversal agent. Activated charcoal for ingested substances is part of EMT-B scope in some protocols but is declining in use.

Scene safety is the first priority — ensure the hazardous substance no longer poses a risk to providers before approaching the patient. Contact Poison Control early (1-800-222-1222, 24-hour national number).

Key Points

  • Scene safety first — do not enter a potential hazmat environment without appropriate PPE
  • Gather all drug containers and bring them to hospital with the patient
  • Opioid overdose triad: respiratory depression + miosis (pinpoint pupils) + altered LOC
  • Naloxone reverses opioid toxidrome — know EMT-B scope for naloxone in NM
  • Do NOT induce vomiting — outdated practice; inducing emesis worsens corrosive ingestions
  • Activated charcoal: conscious patients only who can swallow; NOT for corrosives, petroleum products, or altered LOC
  • Poison Control Center: 1-800-222-1222 — call early for treatment guidance
  • Carbon monoxide: cannot be detected by standard pulse oximetry; cherry-red skin is a morgue finding, not reliable prehospital

Assessment Relevance

History (history-taking): - What: substance name/type; gather all containers - How much: estimated dose or amount - When: time of exposure/ingestion - Route: oral, inhalation, injection, dermal - Intent: accidental vs. intentional (affects risk assessment and psychiatric evaluation) - Mixed overdose? - Treatment prior to arrival (vomiting, activated charcoal, fluids)? - Underlying illness?

Physical exam (secondary-assessment): - Airway: secretions, vomitus, obstruction - Breathing: respiratory rate and depth (opioids cause respiratory depression); SpO2 - Circulation: HR, BP, skin color and temperature - Neuro: LOC (AVPU), pupils (miosis = opioids; mydriasis = stimulants/anticholinergics) - Skin: track marks (IV drug use), diaphoresis, color - GI: nausea, vomiting, drooling (cholinergic toxidrome)

Toxidromes (recognizable clinical syndromes from specific drug classes): - Opioid: CNS depression, respiratory depression, miosis - Stimulant/sympathomimetic: agitation, tachycardia, hypertension, hyperthermia, mydriasis - Cholinergic (organophosphates): SLUDGE/DUMBELS — salivation, lacrimation, urination, defecation, GI distress, emesis; bradycardia, bronchospasm - Anticholinergic: dry/flushed skin, tachycardia, urinary retention, dilated pupils, AMS ("mad as a hatter, dry as a bone, red as a beet, blind as a bat, hot as a hare") - Sedative/hypnotic: CNS depression, respiratory depression (similar to opioid but no response to naloxone)

Procedures

  1. Scene safety (scene-size-up): BSI/PPE; identify hazardous environment before entry
  2. Primary assessment (primary-assessment): airway (position, suction), breathing (rate and depth — assist if needed), circulation
  3. Gather all drug containers
  4. History from patient, family, bystanders
  5. Contact Poison Control: 1-800-222-1222
  6. Transport immediately; determine level of care needed
  7. If opioid overdose suspected with serious signs (resp depression, altered LOC): administer naloxone per protocol
  8. If ingested toxin (not corrosive, not petroleum, patient conscious and can swallow): activated charcoal per protocol
  9. IV/IO access (ALS scope for most interventions)
  10. Reassessment reassessment — closely monitor airway; naloxone wears off before opioid

NM Protocol Notes

From NM EMS Treatment Guidelines (2022):

EMT-B scope: - Scene safety — ensure safe environment; appropriate BSI/PPE - Primary assessment — airway and breathing management; BVM for respiratory depression - Gather all drug containers for transport with patient - Contact Poison Control early: (800) 222-1222 (national 24-hour, free, confidential) - Transport as soon as possible to appropriate facility - Fluid bolus 20 mL/kg IV/IO if evidence of hypoperfusion

Naloxone (opioid reversal — NM EMT-B scope includes naloxone per state protocols): - Administer if narcotic overdose suspected with serious signs and symptoms (respiratory depression, altered LOC) - Adult: 0.4–2.0 mg IM/SQ (2.0 mg total dose); may repeat at 2–3 minutes if needed; OR 2 mg (1 mg per naris) IN (intranasal) - Pediatric: 0.1 mg/kg IM/SQ, not to exceed 2.0 mg - Neonate: 0.1 mg/kg IM/SQ, not to exceed 2.0 mg - Warning: After naloxone, patient may rapidly awaken, become combative, and vomit — consider this before inserting advanced airway - Note: Higher doses may be needed for propoxyphene, pentazocine, or fentanyl overdoses — contact MCEP for higher doses

Activated charcoal (specific ingestions, conscious patients): - Not a standard first-line treatment; use is declining — verify current NM protocol before administering - Contraindicated: altered mental status, corrosive ingestions, petroleum products, caustics

Specific ingestion protocols: - Caustics (acids/alkalis): Dystonia or extrapyramidal signs → DIPHENHYDRAMINE: Adult 25 mg IV/IO/IM; Pediatric 1 mg/kg IV/IO/IM (max 25 mg single dose) - Carbon monoxide: Remove from environment; 100% O2 via NRB or BVM; cardiac monitor; monitor SpO2 AND ETCO2 (note: standard pulse ox inaccurate in CO poisoning) - Organophosphate/nerve agent (SLUDGE symptoms): ATROPINE 2 mg + PRALIDOXIME (2-PAM) 600 mg IM auto-injector device - Cyanide: HYDROXOCOBALAMIN (Cyanokit): Adult 5 g IV/IO over 30 min; Pediatric 70 mg/kg IV/IO (max 5 g) - TCA (tricyclic antidepressant) or salicylate overdose with serious signs (widening QRS, PVCs, hypotension, seizures): SODIUM BICARBONATE 1 mEq/kg slow IV/IO - Calcium channel blocker overdose: CALCIUM CHLORIDE 10%: Adult 10–20 mL slow IV/IO; Pediatric 0.1–0.2 mL/kg slow IV/IO (do not exceed 2 mL/min)

CO poisoning note: Do NOT look for cherry-red skin as an indicator — this is a morgue finding and not present prehospital. CO oximeter devices may give inaccurate low/normal results in CO poisoning.

NREMT Relevance

High-yield exam topic: - Opioid triad: respiratory depression + pinpoint pupils + altered LOC - Naloxone: reverses opioids; may precipitate combativeness and vomiting upon awakening - Do NOT induce vomiting - Activated charcoal: conscious + can swallow + within 1 hour of ingestion + not corrosive - Carbon monoxide: 100% O2; cherry-red skin is NOT a reliable field sign - Poison Control: 1-800-222-1222 - Scene safety in suspected hazmat/poisoning scenarios - Organophosphate (SLUDGE mnemonic): salivation, lacrimation, urination, defecation, GI, emesis

Sources

  • raw/protocols/nm-sop-guidelines-treatment-2022.pdf — Poisoning/Overdose protocol (p. 40–41)