A client arrives at the emergency department exhibiting polyuria, polydipsia, and polyphagia. Assessment findings include orthostatic hypotension, dry warm skin with decreased turgor, and acetone breath. What is the nurse's priority nursing diagnosis?

Rationale: A. There is no evidence of airway obstruction, secretion retention, or respiratory compromise in the assessment findings. Although acetone breath is present, it is a metabolic odor from ketones, not an indication of airway compromise. This diagnosis does not address the most urgent physiologic risk. B. While dry skin and poor turgor are noted, these are symptoms of dehydration, not acute skin breakdown. Skin integrity issues are a secondary concern, not the immediate priority. C. Although acetone breath suggests ketone accumulation, there is no evidence of hypoxia, cyanosis, or respiratory distress. The client may have compensatory Kussmaul respirations (deep, rapid breathing) due to metabolic acidosis, but gas exchange is not the primary threat at this stage. D. The client exhibits classic signs of severe dehydration: Polyuria, polydipsia, polyphagia – signs of uncontrolled hyperglycemia (likely diabetic ketoacidosis), Orthostatic hypotension – indicates decreased intravascular volume, Dry, warm skin with poor turgor – indicates fluid loss from the extracellular compartment Fluid replacement is the highest priority intervention, as hypovolemia can lead to shock, organ hypoperfusion, and death. Immediate IV fluids (typically isotonic saline) are essential before insulin therapy, to restore circulation and correct electrolyte imbalances safely.