Review Question - QID 108910

A 27-year-old woman presents to the emergency department with a migraine headache. She has had several migraines in the past but has never been put on prophylaxis for them. She complains of photophobia, aura, and severe nausea. She reports that she vomited several times at home since the migraine started 2 hours ago. Her past medical history is significant for hypothyroidism and depression. Her home medications include levothyroxine and sertraline. On physical exam, she is lying on the hospital bed with her hand over her eyes and appears to be in moderate distress. She is given an abortive medication as well as several doses of an antiemetic. 1 hour later, the migraine has broken but the patient is complaining of diplopia. Her temperature is 100.3°F (37.9°C), blood pressure is 152/94 mmHg, pulse is 107/min, and respirations are 20/min. On repeat exam, the patient’s neck is extended and her jaw is clenched. Her eyes deviate upwards on convergence testing. Her reflexes are 2+ throughout. Laboratory testing is performed and reveals the following:

Serum:
Na+: 142 mEq/L
K+: 3.4 mEq/L
Cl-: 102 mEq/L
HCO3-: 25 mEq/L
Urea nitrogen: 12 mg/dL
Creatinine: 0.9 mg/dL

An electrocardiogram is performed and can be seen in Figure A. Which of the following is the most appropriate next step in management?