Poisoning: general principles and initial management

Management— do this, in order

• Treat the patient, not the poison: airway protection and assisted ventilation are the most important treatment measures for any poisoned patient, and most people recover uneventfully on supportive care alone.
• Intubate for loss of the cough or gag reflex, or GCS 8 or less — respiratory failure is the commonest cause of death in the comatose poisoned patient and comes on abruptly; in many severely poisoned patients reflexes are depressed enough to permit intubation without sedatives or relaxants.Doctor / NurseNot available at your setup — Endotracheal intubation kit.
• High-flow oxygen while airway and breathing are assessed, and remember it is a genuine antidote in carbon monoxide, cyanide and hydrogen sulphide poisoning (100% by tight-fitting non-rebreathing mask).
• Intravenous access and cardiac monitoring in any potentially serious ingestion, even if the patient looks well.Doctor / Nurse
• Glucose empirically unless a point-of-care test has excluded hypoglycaemia — adult 50% dextrose 50–100 mL IV, or the same 25 g as 20% dextrose 100 mL or 10% dextrose 250 mL; child 10% dextrose 2 mL/kg IV or IO, and 50% dextrose must never be given to a child; recheck at 10 minutes.Doctor / Nurse
• Thiamine 100 mg intramuscularly or by slow intravenous injection before the dextrose or in the same infusion in alcohol use disorder, malnutrition or chronic illness — but it must never delay treatment of documented hypoglycaemia.Doctor / Nurse
• Naloxone for a respiratory rate below 8/min, cyanosis or unresponsiveness — adult 0.4–2 mg IV repeated every 2–3 minutes, escalating to 5–10 mg for potent synthetics such as fentanyl; without venous access 0.4–2 mg IM or 2–4 mg intranasally; child 0.01 mg/kg IV/IO, and if there is no response 0.1 mg/kg.Doctor / Nurse
• Titrate naloxone to a respiratory rate of about 12, not to full consciousness, and never let it delay intubation if that is what the patient needs.Doctor / Nurse
• Hypotension — isotonic crystalloid in 200 mL boluses to a total of 1–2 L, reassessing after each (child 10–20 mL/kg boluses); much larger volumes may be needed in profound depletion such as the massive diarrhoea of Amanita phalloides poisoning.Doctor / Nurse
• If volume replacement fails, noradrenaline 4–8 micrograms/min intravenously, titrated — more effective than dopamine in tricyclic overdose and with predominantly vasodilating drugs.Doctor / NurseNot available at your setup — Infusion pump.
• Toxin-specific hypotension has specific therapy: sodium-channel blocker, sodium bicarbonate 50–100 mmol IV bolus; beta-blocker, glucagon 5–10 mg IV then 1–5 mg/hour; calcium channel blocker, calcium chloride 1–2 g IV repeated (cumulative doses of 5–10 g and more have been given); either, high-dose insulin euglycaemic therapy 0.5–1 unit/kg/hour IV with glucose supplementation and potassium monitoring.Doctor / NurseNot available at your setup — Infusion pump.
• Seizures — adult lorazepam 2–4 mg IV slowly or diazepam 5–10 mg IV (up to diazepam 10–20 mg or lorazepam 4 mg for persistent fits), or midazolam 5–10 mg IM without venous access, repeated once after 5 minutes; child diazepam 0.1–0.3 mg/kg IV slowly to a maximum of 10 mg per dose, or midazolam 0.1 mg/kg IV.Doctor / Nurse
• Hypotension — 0.9% sodium chloride 500 mL to 1 litre in an adult or 10–20 mL/kg in a child, then reassess; in the wet, bradycardic, hypotensive patient atropine is the pressor, and only if hypotension persists despite adequate volume and full atropinisation should noradrenaline be used.Doctor / Nurse
• Second-line seizure treatment, adult and child: phenobarbital 15–20 mg/kg by slow intravenous infusion at no more than 100 mg/min over not less than 30 minutes — the preferred agent for drug-induced seizures, and it may succeed combined with a benzodiazepine when neither works alone.Doctor / Nurse
• Ventricular arrhythmia of suspected toxicological cause — sodium bicarbonate 50–100 mmol IV by bolus first, and for torsades de pointes with a long QT, magnesium sulphate 2 g IV over 1–2 minutes or overdrive pacing.Doctor / Nurse
• Hypertension — sedate first: lorazepam 2–3 mg IV often suffices; if it persists give phentolamine 2–5 mg IV, glyceryl trinitrate 1–2 mg/hour by infusion to a maximum of 12 mg/hour, or sodium nitroprusside 0.25–8 micrograms/kg/min.Doctor / Nurse
• Hyperthermia above 40–41°C — spray the skin with tepid water and fan at high volume, or immerse in an ice-water bath, sedating with diazepam; if the rectal temperature is not normal within 20–30 minutes, or there is significant rigidity, paralyse with a non-depolarising agent, then intubate, ventilate and sedate.Doctor / NurseNot available at your setup — Mechanical ventilator, Endotracheal intubation kit.
• Decontaminate the skin and eyes — remove all clothing and wash with copious lukewarm water or 0.9% saline including behind the ears, under the nails and in skin folds, using a triple wash (water, soap, water) for pesticides and oily substances; irrigate each eye for at least 15 minutes or until it has received at least 1 litre.
• Activated charcoal only when it is worth it: 50 g orally for an adult, 1 g/kg for a child, ideally within 1 hour of an adsorbable poison, with possible value up to about 6 hours after a sustained-release preparation — and observe asymptomatic or mildly symptomatic patients for at least 4–6 hours from the time of ingestion.