Acute Careniche
A 68-year-old woman having a computed tomography scan develops flushing, wheeze and hypotension eight minutes after the intravenous contrast injection. She takes atenolol, atorvastatin, metformin and alendronate, and has no known allergies. She is given adrenaline 0.5 mg intramuscularly twice five minutes apart, 2 litres of sodium chloride 0.9%, and an adrenaline infusion titrated up to 20 micrograms per minute. Thirty minutes on she is still peripherally shut down and mottled, with a blood pressure of 74/38 mmHg and a heart rate of 52 beats per minute. Which one of the following should be given next?