“He won’t wake up.”
At 8:42 p.m., a crew is dispatched to an apartment for an unresponsive adult. A roommate reports that a 34-year-old man became difficult to wake after using a substance he believed was heroin. The roommate gave one 4-mg intranasal naloxone spray about two minutes before EMS arrived. He has the empty device but cannot confirm the substance or whether anything else was taken.
The patient is slumped on a couch. He has a definite radial pulse, shallow respirations with intermittent snoring, and no response to voice. Pupils are small. There is no obvious external trauma, and a bedside glucose is 112 mg/dL. The crew keeps other causes of altered mental status in the differential.
Initial findings: Respirations 4/min and shallow; SpO₂ 78% on room air; pulse 108/min; blood pressure 128/76 mmHg.
The immediate problem is inadequate breathing.
One clinician opens the airway and begins two-person bag-mask ventilation with oxygen as the partner assists with the mask seal, prepares suction, and applies monitoring. Chest rise improves and saturation begins to recover. They do not wait for the bystander’s naloxone dose to work before supporting ventilation.
The 2025 AHA guidance prioritizes breaths or bag-mask ventilation when suspected opioid overdose causes respiratory depression with a definite pulse; naloxone must not delay resuscitation. [1]
One reassuring number is not the whole assessment.
Manes and colleagues reviewed 16 studies involving 12,887 patients. Reported SpO₂ thresholds used to define opioid-induced respiratory depression ranged from 85% to 95%. Hypoventilation and hypercapnia can precede hypoxemia. [4]
Interpret carefully: The review examined heterogeneous definitions and settings; it did not validate a universal EMS intervention or discharge threshold. Its literature search covered 2014–2024 despite its 2026 publication.
Case connection: Interpret saturation alongside respiratory rate, depth, mental status, and the support being provided. Include capnography when available and appropriate; document the trend rather than relying on a single value.
Reassess the response, not just the dose count.
About two minutes into EMS care, spontaneous respirations remain slow and shallow despite improving oxygenation with assisted ventilation. The crew administers additional naloxone under its protocol and continues ventilatory support. Over the next several minutes, the patient develops adequate spontaneous chest rise, a respiratory rate of 14/min, and sustained oxygenation. Assisted breaths are stopped when no longer needed; monitoring continues.
He opens his eyes, answers simple questions, and becomes nauseated. The crew positions him to protect his airway and keeps suction ready. He asks what happened and whether he is in trouble. A clinician explains the breathing problem calmly, without judgment.
The medication endpoint Naloxone is used to reverse opioid-related respiratory depression. Adequate breathing—not forcing an abrupt, fully alert response—is the central pharmacologic goal. Withdrawal remains a possible consequence. [2]
Does the initial route change the response?
Smida and colleagues analyzed 16,550 adults across 1,481 EMS agencies using 2023–2024 data. Initial IM naloxone was associated with lower adjusted odds of additional naloxone administration than initial IN treatment (aOR 0.39; 95% CI 0.35–0.44). The analysis did not find an association between initial route and return to a respiratory rate above 12/min. [3]
Interpret carefully: This was observational, not randomized. Route selection and unmeasured differences may influence results. Treatment for agitation or nausea/vomiting is not a complete measure of withdrawal. These findings do not establish one best route for every patient.
Case connection: Record what was given before arrival and what happened afterward. A dose count alone leaves out route, timing, and response.
The improvement needs a timeline.
The patient agrees to transport after the crew explains why further observation matters. During the 18-minute trip, breathing remains adequate. The crew records serial respiratory findings, mental status, oxygen support, and response to each intervention. The bystander dose is documented as reported; the EMS dose, concentration, volume, route, and time are recorded from the actual administration.
The exact substance and duration of its effects remain unknown. An initial response supports an opioid contribution; it does not resolve every diagnostic question.
What naloxone changes—and what it does not.
Naloxone competitively displaces opioid agonists at the μ-opioid receptor. It does not remove the opioid from the body. Route and formulation affect absorption, and the clinical response varies with the exposure and patient. [2]
Intranasal delivery is useful, but it is not pharmacokinetically identical to an IV dose. A 2024 review describes nasal bioavailability of approximately 50%, with considerable variability. That is background pharmacology, not a bedside conversion formula. [2]
Nonopioid sedatives can also contribute to depressed breathing and are not typically reversed by naloxone. Continued impairment calls for ongoing supportive care and reassessment. [1]
Bring the receiving team the trajectory.
The ED team sees an awake patient who is breathing adequately. Your report explains how different that patient looked 25 minutes earlier.
An example of the clinical story “Initially unresponsive with shallow respirations at four per minute and room-air saturation of 78%. His roommate reports one 4-mg nasal dose before we arrived. We assisted ventilation and administered additional naloxone per protocol; the exact EMS dose, route, and times are in the medication record. He is now answering questions, breathing 14 per minute with adequate depth, and has required no further naloxone during the 18-minute transport. He has nausea. Glucose was 112. The reported drug is unconfirmed, and co-exposures are unknown.”
In an actual verbal handoff, state the exact EMS medication details and latest vital signs, including oxygen delivery, rather than relying on the written record alone.
What the patient may experience next
Hospital care includes observation for recurrent respiratory depression. Repeat naloxone or an infusion may be needed if depression returns. Observation duration is individualized; waking up does not establish readiness for discharge. Take-home naloxone and education are recommended at discharge after overdose treatment. [1]
The team may also assess withdrawal and offer linkage to treatment for opioid use disorder. A 2026 NAEMSP position statement supports EMS partnerships for harm reduction, treatment access, and education that reduces stigma. This is a position statement, not a clinical trial. [5]
A calm explanation gives the patient a reason for the next step. Ask about worries, pass those concerns on, and describe observed behavior without labels such as “difficult” or “drug-seeking.”
Understand the medication
behind the response.
Explore receptor agonists and antagonists, medication responses, routes of administration, and medication safety. The course uses naloxone as an antagonist example and includes a structured medication cross-check exercise.
This introductory course covers broader pharmacology principles. The case review and research discussion above are separate educational content.
References
- American Heart Association. Part 10: Adult and Pediatric Special Circumstances of Resuscitation. 2025 Guidelines for CPR and ECC. Section 21.11, Opioid Overdose. Journal publication DOI: 10.1161/CIR.0000000000001380.
- Saari TI, Strang J, Dale O. Clinical Pharmacokinetics and Pharmacodynamics of Naloxone. Clinical Pharmacokinetics. 2024;63:397–422. doi:10.1007/s40262-024-01355-6.
- Smida T, Crowe R, Glenn M, Joiner A, Bardes J. Prehospital Outcomes Associated with an Initial Strategy of Intranasal versus Intramuscular Naloxone Administration by EMS Clinicians: A Nationwide Cohort Study. Prehospital Emergency Care. Published online June 3, 2026. doi:10.1080/10903127.2026.2673361. PMID:42149954.
- Manes A, Sran J, Samra I, Dhaliwal B, Soliman A, Puri N. Oxygen Saturation Thresholds for Opioid-induced Respiratory Depression: A Systematic Review. Western Journal of Emergency Medicine. 2026;27(4):886–894. doi:10.5811/westjem.54000.
- Glenn MJ, Mercer MP, Murrell A, et al. The Role of Emergency Medical Services in Addressing Opioid Use Disorder—A Position Statement and Resource Document of NAEMSP. Prehospital Emergency Care. Published online May 20, 2026. doi:10.1080/10903127.2026.2668009. PMID:42114053.
Evidence note: Sources checked September 21, 2026. Research summaries reflect the indexed abstracts; full-text appraisal is not claimed. The AHA recommendations were reviewed on its official guideline page. No preprints are included. This is a selected educational review, not an exhaustive literature search.
Educational discussion only. This article does not direct clinical practice, replace local protocols or medical direction, or award continuing education credit. It does not prescribe a universal naloxone dose, route, or observation interval.
