A client was recently admitted with a diagnosis of diabetes mellitus. The nurse notices that the client has polyphagia, polydipsia, and oliguria. He also complains of a headache, malaise, and has a fingerstick glucose of 1000. Assessment reveals poor skin turgor and other signs and symptoms of dehydration. Labs reveal hypokalemia, negative ketones, and elevated BUN. Which diagnosis could be made?

Choice A rationale: Hyperosmolar hyperglycemic nonketotic syndrome (HHNS) is a serious complication of diabetes characterized by extremely high blood glucose levels, often over 600 mg/dL, and severe dehydration. The absence of ketones and acidosis, along with the presence of severe dehydration, hypokalemia, and elevated BUN, are hallmark signs. A fingerstick glucose of 1000 mg/dL is a key indicator of HHNS. Choice B rationale: Diabetic ketoacidosis (DKA) is a life-threatening complication of diabetes characterized by hyperglycemia, ketosis, and metabolic acidosis. While the client has hyperglycemia, the absence of ketones and a normal pH rules out DKA. Ketones are a byproduct of fat metabolism, which occurs when the body lacks sufficient insulin to utilize glucose for energy. Choice C rationale: Diabetic neuropathy is a long-term complication of diabetes resulting from nerve damage due to prolonged hyperglycemia. It can manifest as numbness, tingling, or pain, particularly in the extremities. The client's acute symptoms of dehydration, polyphagia, and extremely high blood glucose are indicative of an acute metabolic crisis, not a chronic neurological condition. Choice D rationale: Hypoglycemia is a condition characterized by abnormally low blood glucose levels, typically below 70 mg/dL. The client’s fingerstick glucose of 1000 mg/dL is a sign of severe hyperglycemia, the opposite of hypoglycemia. Symptoms of hypoglycemia include shakiness, dizziness, and confusion, but not severe dehydration or polyphagia.