ICU Basics

Prehospital and transport

Opioid Overdose Algorithm

Ventilate first, naloxone for breathing, CPR if no pulse

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

Each step lists what to do, then the choices that lead on. In the app the algorithm is tapped through one decision at a time.

1 Check breathing and pulse together

  • Scene safe; gloves. Opioids have minimal vapor pressure and pose no exposure risk unless aerosolized or ingested (NASEMSO V3)
  • Check for no breathing or only gasping and feel for a pulse; spend no more than 10 seconds on the pulse (AHA 2025 BLS)
  • Clues: pinpoint pupils, paraphernalia, patches; normal pupils do not rule out an opioid (NASEMSO V3)

Breathing normally, pulse felt → step 2Not breathing normally, pulse definitely felt → step 3No breathing or only gasping, no pulse → step 4

2 Breathing on their own: monitor

  • Recovery position if mental status is down; oxygen, SpO₂, capnography, glucose
  • Look for other causes: hypoxia (SpO₂ under 94%), hypoglycemia, hypotension, head injury (NASEMSO V3)
  • Remove any opioid patch from the skin (NASEMSO V3)

Breathing slows or stops → step 3

3 Ventilate before naloxone

  • Bag-mask ventilation with oxygen for respiratory depression with a definite pulse (AHA 2025, class 1)
  • 1 breath every 6 seconds (10/min); check the pulse every 2 minutes and start CPR if it is gone (AHA 2025 BLS)
  • Adjust to capnography, aiming for ETCO₂ 35–45 mm Hg (NASEMSO V3)
  • Oral or nasal airway as needed; check glucose

Ventilating: give naloxone → step 5

4 No pulse: CPR with breaths

  • Cycles of 30 compressions and 2 breaths; AED or defibrillator as soon as it arrives (AHA 2025 BLS)
  • Breaths matter: opioid arrest is usually hypoxic
  • Naloxone may be reasonable only if it does not interfere with high-quality CPR with breaths (AHA 2025, 2b); NASEMSO V3 says it has no benefit in arrest
  • Then the ALS cardiac arrest algorithm

Return of spontaneous circulation → step 6

5 Naloxone, titrated to breathing

  • Adult IV, IM or SC: 0.4–2 mg, repeat every 2–3 minutes (naloxone label; NASEMSO V3)
  • Adult intranasal: 4 mg (4 mg/0.1 mL spray), repeat every 2–3 minutes (NASEMSO V3; Narcan label); syringe with atomizer: split the dose, up to 1 mL per nostril
  • Child: 0.1 mg/kg IV, IM or IN, max 2 mg IV/IM and 4 mg IN (NASEMSO V3); the label starting dose is 0.01 mg/kg IV
  • Goal is adequate breathing, not full waking: the smallest dose limits withdrawal and agitation (NASEMSO V3)

Breathing adequately → step 7No response after repeated doses → step 8Pulse lost → step 4

6 Transport and monitor

  • Continuous SpO₂ and capnography; repeat naloxone for recurrent depression
  • Bring naloxone devices used before EMS arrived and any medications found (NASEMSO V3)
  • Methadone can prolong the QT and tramadol can cause seizures (NASEMSO V3): 12-lead and seizure precautions
  • At discharge from a health care setting, patients should receive naloxone and teaching (AHA 2025, class 1)

End of this path.

7 Breathing again: expect it to wear off

  • Naloxone reversal may end within an hour; many opioids last 4 hours or more (NASEMSO V3); label half-life 30–81 minutes
  • Repeat doses for recurrent respiratory depression (AHA 2025, 2a)
  • Responders should be observed in a health care setting until the risk of recurrent respiratory depression is low and consciousness and vital signs are normal (AHA 2025, class 1)

Agitated or combative after naloxone → step 9Wants to refuse transport → step 10Agrees to transport → step 6Breathing slows again → step 3

8 Not responding: rethink

  • Keep ventilating; place an advanced airway if bag-mask ventilation is failing
  • High-potency opioids (fentanyl analogs, carfentanil) may need larger or more frequent doses (NASEMSO V3)
  • No response after 10 mg: question the diagnosis (naloxone label)
  • Other causes: hypoglycemia, hypoxic injury, head trauma, other sedatives, stroke

Pulse lost → step 4Breathing returns → step 7Still unresponsive: transport → step 6

9 Precipitated withdrawal

  • Expect vomiting, agitation and possible violence after naloxone; plan for scene safety in advance (NASEMSO V3)
  • Protect the airway if vomiting; no more naloxone while breathing is adequate
  • Severe agitation: use the Agitated or Violent Patient algorithm

Calmer: transport → step 6

10 Refusal after reversal

  • Assess decision-making capacity once alert; explain that the naloxone may wear off before the opioid does
  • Contact medical direction per your refusal protocol
  • Leave naloxone with teaching if your agency allows: survivors are at high risk of another overdose (AHA 2025)
  • Ask a sober adult to stay and call 9-1-1 again if breathing slows

End of this path.

Drugs in this algorithm

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