Q. A 32-year-old female patient has presented to the emergency department with a 5-day history of weakness, fatigue, and dizziness. She also reports nausea, vomiting, and diarrhea for the past two days. She has a history of Addison's disease and is on oral hydrocortisone and fludrocortisone. On physical examination, she is hypotensive and has hyperpigmentation of the skin. Laboratory investigations reveal hyponatremia, hyperkalemia, and a low serum cortisol level. What is the most appropriate management for this patient?