Opioid Poisoning: Overview and Management

Opioid poisoning is a critical condition requiring immediate medical intervention.

Assessment and Initial Management

1. Initial Assessment:
   • Airway, Breathing, Circulation (ABC): Always start by assessing and managing the patient’s airway, breathing, and circulation.
   • Level of Consciousness: Use the Glasgow Coma Scale (GCS) to assess the patient’s level of consciousness.
   • Pupil Examination: Look for miosis (pinpoint pupils), a classic sign of opioid poisoning.
2. Call for Emergency Help: If opioid poisoning is suspected, immediately call emergency services.

Management Steps

1. Airway Management:
   • Ensure that the airway is patent. If the patient is unconscious and there is a risk of airway obstruction, consider placing an oropharyngeal or nasopharyngeal airway.
   • If the patient is not breathing adequately, initiate bag-valve-mask (BVM) ventilation with 100% oxygen.
2. Oxygen Therapy:
   • Administer high-flow oxygen via a non-rebreather mask or nasal cannula, depending on the severity of respiratory depression.
   • Oxygen supplementation is crucial, especially if signs of cyanosis (blue tint to the skin) are present.
3. Naloxone Administration:
   • Naloxone is the first-line antidote for opioid poisoning. It works by competitively binding to opioid receptors, thereby reversing the effects of opioids.

Naloxone Dosages:

1. • Adults:
     • IV (Intravenous): 0.4 to 2 mg is the typical starting dose. If there is no response, the dose can be repeated every 2 to 3 minutes.
     • IM (Intramuscular) or Subcutaneous: 0.4 to 2 mg can also be administered via these routes if IV access is not available.
     • Intranasal: 4 mg (one spray) in one nostril. If no response is seen, another dose can be administered after 2-3 minutes.
   • Pediatric:
     • IV/IM/Subcutaneous: 0.1 mg/kg of body weight. The maximum single dose is 2 mg. The dose can be repeated every 2-3 minutes if there is no response.
     • Intranasal: 2 mg (one spray) per nostril; repeat as necessary after 2-3 minutes.

Special Considerations:

1. • Titration: In chronic opioid users, naloxone should be titrated slowly to avoid precipitating acute withdrawal, which can cause agitation, vomiting, or even arrhythmias.
   • Continuous Infusion: If repeated doses of naloxone are required, consider a continuous infusion. The infusion rate can be calculated based on the effective dose that reversed the symptoms. For example, if 2 mg reversed the poisoning, the infusion rate would be approximately 2/3 of that dose per hour (e.g., 1.33 mg/hr).
2. Monitoring:
   • Continuous Vital Signs Monitoring: Include heart rate, respiratory rate, oxygen saturation, and blood pressure.
   • ECG Monitoring: In cases where arrhythmias are suspected, especially with mixed overdoses.
   • Level of Consciousness: Regularly assess the patient’s consciousness level, as opioid effects may reoccur due to naloxone’s shorter half-life compared to many opioids.
3. Activated Charcoal:
   • Indication: Consider activated charcoal (50-100 g) if the patient presents within 1-2 hours of oral opioid ingestion and is conscious and able to protect their airway.
   • Contraindications: Do not use if the patient has a compromised airway or risk of aspiration.
4. Supportive Care:
   • Fluids: Administer IV fluids (e.g., 0.9% saline) to maintain blood pressure and perfusion in hypotensive patients.
   • Temperature Management: Manage hypothermia (e.g., warming blankets) or hyperthermia as necessary.

Post-Reversal Care and Observation

1. Observation Period:
   • Extended Monitoring: After naloxone administration, patients should be observed for at least 4-6 hours due to the risk of re-sedation, especially with long-acting opioids like methadone or extended-release formulations.
   • Continuous Reassessment: Vital signs and level of consciousness should be monitored regularly.
2. Admission Criteria:
   • Consider admitting the patient to a hospital if:
     • They required multiple doses of naloxone.
     • There is ongoing respiratory depression.
     • They have taken a long-acting opioid or mixed drug overdose.
     • They have comorbidities that increase the risk of complications.
3. Addressing Withdrawal:
   • Naloxone may precipitate withdrawal in opioid-dependent individuals. Symptoms can include agitation, tachycardia, hypertension, nausea, vomiting, and diarrhea.
   • Management of Withdrawal:
     • Benzodiazepines can be used to control agitation.
     • Anti-emetics like ondansetron (4-8 mg IV) can be given for nausea and vomiting.