A nurse is caring for a client who has type 2 diabetes mellitus and their glucose levels are rising. Which of the following would indicate the client is in a hyperosmolar hyperglycemic state (HHS)?

Choice A reason: While a glucose level of 500 mg/dL is elevated and common in HHS, it alone is not diagnostic. HHS is characterized by extreme hyperglycemia, hyperosmolarity, and absence of significant ketosis. Choice B reason: Hypertension may be present in many conditions and is not specific to HHS. It does not help differentiate HHS from other hyperglycemic emergencies. Choice C reason: Ketosis is a hallmark of diabetic ketoacidosis (DKA), not HHS. In HHS, insulin levels are sufficient to prevent ketosis but not enough to prevent hyperglycemia. Choice D reason: A plasma osmolarity of 350 mOsm/L is elevated and indicative of HHS. This hyperosmolar state leads to profound dehydration and altered mental status, distinguishing HHS from DKA.