TCA overdose – beyond bicarbonate

A 38 yr old male presents to your emergency department 2 hours after ingesting an unknown quantity of amitriptyline (TCA) with a GCS of 13, HR 130, BP96/50, Temp 35.6, Sats of 100%. His ECG shows a QRS of 160ms, you give 3 amps of sodium bicarbonate and his QRS is still 160ms. What now?

Dr Emily Austin a toxicologist from Toronto talks us through the case and gives us some additional options.

Summary

Management options for sodium channel blocker overdose:

• Whatever treatment you give, bear in mind the 3 end goals:
  1. Narrowing the QRS to normal for the patient or less than 100ms
  2. Maximum Sodium of 155 mmol/L
  3. pH between 7.5 – 7.55
• Sodium bicarbonate 8.4% boluses (monitor potassium, pH and sodium levels)
• Intubate and hyperventilate to a pH of 7.5 to 7.55
• 3% saline can be given to achieve a sodium of 155 mmol/L if further bicarbonate can not be given.
• Lidocaine 1-1.5mg/kg slow IV push, followed by 20-50 ug/kg/min infusion
• Intralipid
• VA-ECMO

LITFL TCA post for a deeper dive:

• TCA Toxicity overview
• ECG Library – Tricyclic Overdose
• Tox Conundrum 022 – Tricyclic antidepressant toxicity
• Tox Conundrum 050 – Another TCA overdose!