Overdose – Calcium Channel Blocker

Published 13/04/2023

Overdose – Calcium Channel Blocker




18G R ACF, 20G L Hand


0.9% Saline 1L bag running


Self Ventilating, FM 15L NRBM        


Airway trolley


Clinical Setting:

I: You are the ICU trainee called by the EM StR to review a patient in resus

S: Called to see a patient who is hypotensive and bradycardic

B: 59M brought in by ambulance after wife called to found him unresponsive. Paramedics report multiple empty blister packs at scene

A: Bradycardic, hypotensive, reduced GCS

R: Called for help

Potential Clinical Course:

  • Initially A SV, B SpO2 95% on 15L NRBM, quiet bases C HR 40bpm SR, BP 70/50, D E3V4M4 E Gas shows raised glucose, lactic acidosis, reduced PaO2  
  • Initial assessment patient lying on trolley, overdose of antihypertensive – need to ask what the anti-hypertensive was – overdose of67 CCB (verapamil)
  • Examination reveals reduced breath sounds at both lung bases, sinus bradycardia on monitor and hypotension – fluids being prepared by ED nurse
  • Fluid bolus given to support BP + atropine
  • Initial slight improvement - Recognises early need for vasopressor requirement, can give calcium
  • ABG done, metabolic acidosis, raised lactate, reduced pO2, hyperglycaemic  
  • No improvement with other therapies including vasopressors/adrenaline
  • Need to institute external pacing
  • Haemodynamic variables and GCS improve on institution of external pacing

Info Sheet For Faculty

  • Initial settings:
    • SpO2 95% on 15L NRBM
    • RR 24/min
    • Quiet bases R & L
    • HR 40bpm SR
    • BP 70/40
    • Consider reduced GCS (E3V4M5)


  • After a fluid bolus:
    • SpO2 95% on 15L NRBM
    • HR 43bpm SR
    • BP 85/45


  • Progress to:
    • SpO2 92%
    • HR 35bpm SR
    • BP 60/30


  • On Pacing:
    • SpO2 95%
    • HR 60 – pacing spikes seen on monitor
    • BP 90/60
    • GCS improves to E4V5M6

Faculty Roles:

Bedside Nurse 1:

  • You are an ED Nurse
  • You are looking after a 59M who has come in with an overdose
  • The ED StR is now with a major trauma patient so it is just the 2 of you
  • You follow directions well but are not very proactive
  • You point out if the patient worsens or improves to the doctor
  • You offer information when asked (e.g. what drug the overdose was with) otherwise can be very vague
  • You remind the StR that things can take time e.g. setting up infusions and not much help around


Telephone Assistance (Cardiology/Critical Care):

  • You are 30 minutes away and external pacing can’t wait that long
  • If participant inexperienced with external pacing you help talk them through it in real time