29th May 2025

A 65-year-old male with a known history of type 2 diabetes mellitus and obesity presents to the emergency department with complaints of extreme thirst, polyuria, and confusion for the past two days.

A 65-year-old male with a known history of type 2 diabetes mellitus and obesity presents to the emergency department with complaints of extreme thirst, polyuria, and confusion for the past two days. His family reports that he has been feeling unwell with flu-like symptoms. On examination, he is lethargic, has a weak and rapid pulse, and reduced skin turgor. Laboratory investigations reveal a plasma glucose level of 682 mg/dL and a plasma osmolarity of 330 mOsm/L. His ketones are normal and he is not acidotic. What is the most appropriate initial step in the management of this patient?

Select the SINGLE most appropriate option from the list below. Select ONE option only.