Final answer:
The distinctive clinical sign indicating diabetic ketoacidosis in a patient with high serum glucose and unresponsiveness is rapid, deep respirations. This type of breathing is a compensatory mechanism for the acidotic state caused by the accumulation of ketone bodies in the blood.
Step-by-step explanation:
The assessment of the patient with a serum glucose level of 824 mg/dL who is unresponsive suggests the possibility of diabetic ketoacidosis (DKA) rather than hyperosmolar hyperglycemic syndrome. The presence of rapid, deep respirations, known as Kussmaul breathing, indicates the body's attempt to correct the metabolic acidosis seen in DKA by expelling more carbon dioxide.
Diabetic ketoacidosis is characterized by the overproduction of ketone bodies due to prolonged hyperglycemia and insulin deficiency. This condition leads to the acidification of the blood and can trigger a series of compensatory mechanisms including Kussmaul breathing. When the kidneys fail to maintain acid-base balance, increased ketone levels may appear in the urine as well.
Patients with diabetic ketoacidosis may also experience polyuria, severe dehydration, but the finding of rapid, deep respirations is a distinctive clinical sign indicating the body's response to the acidotic state. Treatment often includes administration of insulin and intravenous fluids to manage hyperglycemia and correct dehydration and electrolyte imbalances.