How do you manage cardiac arrest due to tricyclic antidepressant overdose?

Management of Cardiac Arrest Due to Tricyclic Antidepressant Overdose

Sodium bicarbonate administration is the cornerstone of treatment for cardiac arrest due to tricyclic antidepressant overdose, along with standard ACLS protocols, and should be administered immediately when TCA toxicity is suspected. 1

Initial Management

• Follow standard BLS and ACLS protocols for cardiac arrest management
• Administer sodium bicarbonate 1-2 mEq/kg IV bolus immediately when TCA overdose is suspected 1
• Repeat sodium bicarbonate as needed, especially with persistent QRS widening (>100 ms) 2, 3
• Maintain arterial pH at 7.45-7.55 through sodium bicarbonate administration and ventilation management 1
• Avoid respiratory acidosis which can worsen TCA toxicity 1

Cardiovascular Management

• Monitor ECG continuously for QRS widening, which predicts serious complications better than serum TCA levels 2
• For hypotension refractory to sodium bicarbonate:
  • Begin with fluid resuscitation
  • If persistent, initiate vasopressors with preference for:
    • Norepinephrine (first-line) 1
    • Epinephrine 1
    • Dopamine or dobutamine as alternatives 1

Antiarrhythmic Considerations

• Avoid Class Ia antiarrhythmics (procainamide, quinidine) and Class Ic antiarrhythmics (flecainide) as they may worsen sodium channel blockade 1
• Evidence for specific antiarrhythmics (lidocaine, magnesium, amiodarone, phenytoin) is limited to negative case reports 1
• Current evidence neither supports nor refutes a role for lidocaine in management 1

Seizure Management

• Administer benzodiazepines (diazepam or lorazepam) for seizure control 4
• If seizures are refractory to benzodiazepines, consider neuromuscular blockade and mechanical ventilation 4

Additional Interventions

• Gastric decontamination with activated charcoal (30-50g) if presenting within 1-2 hours of ingestion and airway is protected 2
• Correct hypoxia, acidosis, and electrolyte abnormalities (especially hypokalemia) aggressively 4
• Consider IV lipid emulsion therapy as rescue therapy in cases refractory to standard treatments, though evidence is limited 5

Post-Resuscitation Care

• Continue sodium bicarbonate therapy in the post-arrest period for patients with persistent QRS widening 1
• Maintain vigilant monitoring for at least 24 hours, as most patients recover within this timeframe 4
• Monitor for delayed complications including persistent arrhythmias and neurological sequelae

Common Pitfalls and Caveats

• Avoid physostigmine despite its theoretical benefit for anticholinergic symptoms, as it has conflicting evidence and potential for dangerous side effects 1, 4
• Do not delay sodium bicarbonate administration while awaiting confirmation of TCA overdose if clinical suspicion exists
• Remember that QRS duration >100 ms is a better predictor of serious complications than serum TCA levels 2, 3
• Avoid respiratory acidosis through careful ventilation management, as it can worsen sodium channel blockade 1

Despite the severity of TCA-induced cardiac arrest, aggressive management with sodium bicarbonate, appropriate vasopressors, and standard resuscitative measures can lead to successful outcomes with normal neurological function, even in cases with multiple cardiac arrests 6.