Anticholinergic + wide QRS + seizures + hypotension
ABCDE
A-B-C; continuous ECG; sodium bicarbonate for wide QRS; benzodiazepines for seizures.
QRS >100 ms → Sodium bicarbonate IV (narrows QRS, prevents arrhythmia)
Seizures → Benzodiazepines
Intubate when indicated — for ↓GCS, refractory seizures, or hypoventilation; do NOT withhold for fear of arrhythmia; if intubated, hyperventilate mildly (target pH ~7.50)
Order set
- ECG (QRS/QT)
- Continuous monitoring
- VBG
- Sodium bicarbonate if QRS >100
- Benzodiazepines for seizures
Escalate / ICU
- QRS widening / arrhythmia
- Seizures / coma
- Refractory hypotension
Criteria
AdmitAll symptomatic / significant ingestion
ICUQRS widening, arrhythmia, seizures, hypotension
Intubate↓GCS / seizures / airway risk
VasopressorsRefractory hypotension (after bicarbonate/fluids)
DischargeAsymptomatic ≥6 h, normal ECG, normal mental state, psych review
Never
- Give flumazenil — precipitates seizures
Clinical detail — differentials, red flags, pitfalls, disposition
Red flags
- QRS widening
- Arrhythmia
- Seizures
- Hypotension
Differentials
- Other Na-channel blocker OD
- Anticholinergic toxidrome
Common mistakes
- Flumazenil
- Delaying bicarbonate
- Withholding a needed airway for fear of arrhythmia
- Hypertonic saline if QRS widening persists despite bicarbonate; whole-bowel irrigation not recommended — single-dose charcoal only if <1–2 h and airway protected
Disposition & follow-up
Monitored bed/ICU until ECG normal + asymptomatic.
Discharge package
Medications—
Follow-upPsychiatry/crisis assessment before discharge
Warning symptomsReturn if palpitations, drowsiness
💊 Treatment detail — doses & preparation
Sodium bicarbonate 8.4%alkalising agent
DoseTCA: 1–2 mmol/kg IV bolus then infusion to pH 7.50–7.55. Salicylate: urine alkalinisation pH 7.5–8.5
PreparationBolus 50–100 mL of 8.4% (1 mmol/mL); infusion 150 mmol in 1 L D5W + 20–40 mmol KCl
MonitorABG, K⁺ (hypokalaemia blocks alkalinisation), ionised Ca²⁺, volume
Magnesium sulfate IVelectrolyte/antiarrhythmic
DoseTorsades: 2 g over 10–15 min. Asthma: 2 g over 20 min. Eclampsia: 4 g load then 1 g/h
Preparation2 g in 100 mL NS via pump; eclampsia 4 g in 100–200 mL
MonitorReflexes/RR if high doses (toxicity), Mg²⁺ level, renal function
Lipid emulsion (refractory)rescue
Dose20% Intralipid 1.5 mL/kg bolus for life-threatening refractory cardiotoxicity
PreparationPer tox protocol
MonitorConsult poison centre early
📖 AACT / poisons-centre guidanceReviewed July 2026