Opioid and sedative poisoning

Management— do this, in order

• Ventilation is the treatment; the antidote is a convenience — protection of the airway and assisted ventilation are the most important treatment measures for any poisoned patient, and they precede the antidote.
• Establish a patent airway by positioning, suction and insertion of a nasopharyngeal or oropharyngeal airway, and nurse the unintubated patient in the lateral (recovery) position with suction available.
• Assist with a bag-valve-mask device or mechanical ventilator: assisted ventilation at 10–12 breaths per minute in an adult is the single highest-value intervention here — support the airway, ventilate, give naloxone and re-decide at three minutes.Not available at your setup — Mechanical ventilator. Use a bag-valve-mask device if a mechanical ventilator is unavailable.
• Intubate if the patient is deeply comatose or airway reflexes are depressed — but these airway interventions may not be necessary if the patient is intoxicated by an opioid and responds to intravenous naloxone.Doctor / NurseNot available at your setup — Endotracheal intubation kit.
• Naloxone, adult, illicit or unknown opioid, apnoeic or barely breathing: 0.4–2 mg intravenously, or the same dose intramuscularly or by endotracheal tube, or 2–4 mg by intranasal spray (other sources quote 1.8 mg, or 4 mg intranasally); repeat every 2–3 minutes, escalating — up to 5–10 mg may be required to reverse potent opioids, and total doses of 10 mg or greater may be needed for fentanyl or buprenorphine.Doctor / Nurse
• Naloxone, adult breathing but inadequately: 0.4 mg intravenously repeated every 2–3 minutes, titrated.Doctor / Nurse
• Naloxone in prescribed-opioid, palliative or post-operative over-sedation or a known chronic user: a tester dose of 0.04 mg intravenously, taken from naloxone 0.4 mg diluted to 10 mL with 0.9% sodium chloride (0.04 mg/mL), repeated every 1–2 minutes and titrated to respiratory rate — this reverses respiratory depression without entirely reversing analgesia.Doctor / Nurse
• Naloxone, child: 0.01 mg/kg intravenously, intramuscularly or intraosseously; if inadequate, 0.1 mg/kg (usual maximum 2 mg per dose), repeated as needed.Doctor / Nurse
• Naloxone maintenance where re-sedation is expected: repeated boluses at the effective dose, or a continuous infusion at approximately two-thirds of the effective bolus dose per hour, titrated hourly against the respiratory rate with continuous monitoring.Doctor / NurseNot available at your setup — Infusion pump.
• The endpoint is a respiratory rate of about 12 or more with adequate depth, a maintained saturation without assistance, and return of airway-protective reflexes — not a fully alert patient; a rousable but drowsy patient who is breathing well and swallowing their own saliva is a success.
• Remove every transdermal opioid patch and wash the skin beneath it — a patch left in place keeps releasing drug for hours after the naloxone has worn off.
• Give 50% dextrose 50–100 mL by intravenous bolus to all obtunded, comatose or convulsing patients unless a rapid point-of-care glucose test rules out hypoglycaemia; in children 10% dextrose 2–5 mL/kg intravenously.Doctor / Nurse
• Thiamine 100 mg intramuscularly before the dextrose, or in the intravenous fluids, in patients with alcohol use disorder or malnourishment who may have marginal thiamine stores.Doctor / Nurse
• Hypotension: repeated 200 mL intravenous boluses of 0.9% sodium chloride or other isotonic crystalloid up to a total of 1–2 litres (paediatric 10–20 mL/kg per bolus); if fluid therapy is unsuccessful after adequate volume replacement, give vasopressors by intravenous infusion — noradrenaline first; and remember hypothermia may itself be the cause of refractory hypotension, so rewarm gradually unless the patient is in cardiac arrest.Doctor / NurseNot available at your setup — Infusion pump.
• Seizures: lorazepam 2–3 mg intravenously, or diazepam 5–10 mg intravenously, or midazolam 5–10 mg intramuscularly if intravenous access is not immediately available; paediatric lorazepam 0.1 mg/kg (maximum 4 mg), diazepam 0.1–0.3 mg/kg (maximum 10 mg), or midazolam 0.1 mg/kg intravenously or 0.2 mg/kg buccally; if convulsions continue, phenobarbital 15–20 mg/kg slowly intravenously over no less than 30 minutes — for drug-induced seizures phenobarbital is the preferred agent.Doctor / Nurse
• A wide QRS from co-ingested sodium-channel blockade: sodium bicarbonate 50–100 mEq by intravenous bolus. Torsades de pointes: magnesium 2 g intravenously over 2 minutes.Doctor / Nurse
• Activated charcoal for small or moderate ingestions: 50–100 g orally or by gastric tube as an aqueous slurry in an adult, 1 g/kg (maximum 50 g) in a child — but not to a comatose or convulsing patient unless the airway is first protected by a cuffed endotracheal tube, and never at the cost of delaying ventilation or naloxone; whole-bowel irrigation with polyethylene glycol (adult 1–2 L/hour, child 25 mL/kg/hour) is indicated for body packers and large modified-release ingestions.Not available at your setup — Endotracheal intubation kit.
• Continuous observation for at least 3–4 hours after the last naloxone dose is mandatory; some authorities specify at least 6 hours, and the longer figure is safer — and features of opioid poisoning can be prolonged for up to 48 hours after methadone or oxycodone, so those agents, with modified-release morphine, transdermal fentanyl and buprenorphine, warrant at least 24 hours of monitored observation.