A 67-year-old female is brought to the Emergency Department by ambulance following a witnessed cardiac arrest at home. Her husband reports she complained of palpitations and dizziness before collapsing. Paramedics arrived within 8 minutes and found her in cardiac arrest. The initial rhythm is shown below:
After one shock, she achieved return of spontaneous circulation (ROSC).
On arrival to the ED, she is drowsy but maintaining her airway.
Her observations are:
Heart rate: 88 beats per minute, irregular
Respiratory rate: 24 breaths per minute
Blood pressure: 102/68 mmHg
Temperature: 36.2°C
Oxygen saturation: 94% on 15L oxygen via non-rebreathe mask
GCS: E3V4M6 = 13/15
On examination, her chest is clear with no added sounds. Heart sounds are normal with no murmurs. Abdomen is soft and non-tender.
Past medical history includes hypertension, hyperthyroidism, and depression. Current medications include ramipril, carbimazole, and citalopram started 2 weeks ago. She has no known drug allergies.
What is the most appropriate next step in management?
Intravenous amiodarone bolus, followed by infusion
Urgent temporary pacing wire insertion
Administration of intravenous calcium chloride
Initiation of continuous venovenous hemofiltration
Intravenous magnesium sulphate