Opioid overdose is the most commonly seen toxidrome in prehospital practice in British Columbia, which is, as of 2020, in its fourth year of a public health emergency.  Contamination of the illicit drug supply with powerful, synthetic opioids such as fentanyl is largely responsible for the crisis.  This contamination makes consumption of any illicit drug extremely dangerous. 

In 2018, 1,510 overdose deaths were recorded in the province, which represents more than four times the number of fatalities from motor vehicle accidents.  

• Opioid toxicity should be suspected in any individual with a decreased level of consciousness and depressed respirations or apnea.
• Assisted ventilation is the cornerstone of management.  Paramedics must ensure that proper airway management, including effective ventilations, continue until symptoms have resolved; this must supersede any pharmaceutical interventions.  Consider the use of airway adjuncts to facilitate ventilation.  Monitor oxygenation at all times.
• Assess for and treat hypoglycemia.
• The goal of naloxone administration is the restoration of adequate respirations – a return of full consciousness is not necessary.

• Cardiac arrests related to opioid use are primarily hypoxic.  Naloxone is unlikely to benefit these patients, and its routine use is unsupported by current evidence.  Paramedics must focus instead on effective ventilation, oxygenation, and chest compressions.  In rare cases, patients may present with pulses that are difficult to palpate; if unsure whether a patient has a pulse, begin compressions and ventilations and evaluate the response to these treatments (e.g., oxygen saturation, heart rate, presence of central or peripheral pulses) before considering the use of naloxone. 
• Effective ventilation and oxygenation is the key to successful management of opioid toxicity.  A well-perfused, well-oxygenated brain that receives naloxone will be more likely to recover gracefully.
• Paramedics must differentiate between overdoses of recreational opioids and overdoses of prescribed medication.  In the case of opioid overdose from a patient’s prescribed medication, a careful clinical history of opioid use must be elicited, and naloxone should be administered judiciously to avoid precipitating a pain crisis or significant withdrawals
  • In patients with palliative needs, who are presenting with respiratory depression due to opioids, there is a need to ensure adequate oxygenation while maintaining analgesia and avoiding rapid opioid withdrawal.  In these patients, the administration of naloxone as a bolus, rather than titrating to respiratory effect, may result in refractory reversal of the patients’ opioid analgesia and withdrawal symptoms.  As such it is recommended that the administration of naloxone, at a rate of 0.1 mg IM/IV every two minutes, be titrated to respiratory function, not to the pain or consciousness level.
  • See CPG P00, P01, and P02 for altered mental status in the context of palliative care.  CliniCall consultation is strongly encouraged, and collaboration with the rest of the patient’s care team is required to manage these cases.
    • → P01: Palliative Care: General
    • → P02: Palliative Care: Delirium
    • → P03: Palliative Care: Pain

• Titrate naloxone to effect.  Do not administer subsequent doses of naloxone without allowing the medication time to work, and without assessing ventilation.  Some substances, particularly the fentanyl analogues such as carfentanil, may require significantly larger doses of naloxone to resolve.  Early consultation with CliniCall is recommended in cases where patients do not improve following two doses of naloxone. 
• Consider the possibility of co-intoxication when assessing patients.  Other substances, such as benzodiazepines, gamma hydroxybutyrate, and alcohol can prolong unconsciousness despite resolution of opioid toxicity.  Once adequate spontaneous respirations have been re-established, make preparations to transport the patient. 
• Pulmonary edema is a known, but rare, complication of naloxone use.  If respiratory distress develops following recovery from opioid intoxication, consider the use of CPAP to support oxygenation. 
• Patients who wake up following naloxone administration can be confused and violent.  Calm reassurance is more helpful in these cases than confrontation.  Violence and combativeness can be reduced by ensuring patients are optimally oxygenated prior to receiving naloxone.

A growing body of evidence suggests that allowing patients with an isolated opioid overdose, whose symptoms resolved quickly following naloxone administration, and who do not exhibit signs and symptoms of complications to refuse transport is relatively low-risk.  Paramedics and patients who elect this option must do so in consultation with CliniCall.

The decision to leave a patient at the scene should not be undertaken lightly.  Patients who are discharged at scene must have a safety plan in place (i.e., someone responsible must be able to watch them), must not have taken any other intoxicants, and must not have underlying medical conditions.  The patient must also be free of signs and symptoms of opioid intoxication, including pulmonary edema.

• Beyond a decreased level of consciousness and depressed respiratory drive, as demonstrated by both decreased rate and limited tidal volume, signs and symptoms of an opioid overdose can include:
  • Pinpoint pupils (miosis)
  • Hypotension
  • Hypothermia
  • Tachycardia
• Intranasal drug administration is of limited benefit in opioid overdoses, as the distribution and uptake of the medication requires ongoing respirations.  It may be an acceptable option if parenteral delivery routes are unavailable.
• Patients need not have specifically ingested or otherwise consumed what they believe to be opioids to develop opioid toxicity – many recreational drugs are contaminated with synthetic opioids, and users frequently have no way to establish the safety of their substances.  Black-market prescription medications, cocaine, methamphetamine, and GHB have all been associated with opioid contamination, and users of these substances have died as a result of consumption.  Paramedics should rely on the clinical signs and symptoms of opioid toxicity and manage patients accordingly, regardless of the history available at the scene.
• Drug supply contamination can be caused by multiple agents, of which fentanyl is the most common.  Other fentanyl analogues, of varying potency, have been found in the supply of illicit drugs.  Contaminated supply “outbreaks” occur randomly and can produce waves of overdoses and overdose fatalities. 
• Questioning patients about specific quantities of substances used is unlikely to be helpful.
• Patients should be screened for the risk of additional opioid intoxication, and they (or their friends and family members) educated on the use of naloxone kits.  Distribute kits to patients and families in accordance with BCEHS policy.  Referral pathways for treatment may be available in some regions of British Columbia, and paramedics should make use of these wherever and whenever possible.
• Refer cases of children with opioid toxicity to the Ministry of Children and Family Development in accordance with BCEHS policy.

Overdose-Poisoning