A nurse is caring for a patient with type 1 diabetes mellitus who presents to the emergency department. Which assessment finding would be the highest priority for immediate intervention?

A blood glucose level of 450 mg/dL with positive urine ketones indicates diabetic ketoacidosis (DKA), which is a life-threatening emergency requiring immediate intervention to prevent coma and death.

This question assesses the ability to prioritize nursing care for a patient experiencing diabetic ketoacidosis (DKA), one of the most serious acute complications of diabetes. The correct answer focuses on the combination of severe hyperglycemia (blood glucose ≥450 mg/dL) and positive urine ketones, which definitively indicates DKA.

Diabetic ketoacidosis occurs when there is a lack of insulin, which is needed to allow glucose to enter cells for energy metabolism. The body then breaks down fat for energy, producing ketone bodies as a byproduct. This process leads to metabolic acidosis, severe dehydration, and electrolyte imbalances. The three hallmark signs of DKA are hyperglycemia (≥250 mg/dL), ketosis, and metabolic acidosis.

Pathophysiologically, insulin deficiency increases gluconeogenesis and glycogenolysis, causing severe hyperglycemia. At the same time, lipolysis occurs, generating free fatty acids that are converted into ketone bodies in the liver. These ketones cause metabolic acidosis, leading to compensatory hyperventilation (Kussmaul respirations) and the characteristic fruity-smelling breath.

While all assessment findings are concerning and indicate DKA complications, the combination of severe hyperglycemia and positive ketones represents the core pathophysiological process that must be addressed immediately. Without prompt treatment with insulin therapy and fluid resuscitation, the patient will progress to severe acidosis, coma, and potentially death.

The nursing priority is to recognize this as a medical emergency requiring immediate physician notification and preparation for aggressive treatment, including intravenous insulin, fluid replacement, and electrolyte monitoring. Early intervention significantly improves patient outcomes and prevents progression to more severe complications.

Clinical Priority Analysis

The highest priority assessment finding requiring immediate intervention is altered mental status with a Glasgow Coma Scale (GCS) score of 8. In the context of a patient with type 1 diabetes mellitus presenting with confusion and lethargy, a GCS of 8 represents a critical and immediate threat to the airway, breathing, and circulation (ABCs). This score signifies a severe neurological depression where the patient is unable to protect their own airway, placing them at high risk for aspiration, respiratory failure, and hypoxic brain injury.

Pathophysiology and Clinical Correlation

The patient's presentation is highly suggestive of diabetic ketoacidosis (DKA), a severe hyperglycemic crisis. The combination of altered mental status and a low GCS is the most dangerous manifestation of a potential complication of DKA: cerebral edema. While cerebral edema is relatively uncommon, occurring in less than 1% of pediatric DKA cases, its consequences are devastating, representing a significant proportion of DKA-related deaths ^[1]. The systematic review highlights that even among survivors, 25% suffer permanent neurologic deficits ^[1]. The pathophysiology, though not fully elucidated, involves fluid shifts and cellular injury in the brain, leading to increased intracranial pressure. A declining GCS is the primary clinical indicator of this life-threatening process, mandating immediate airway protection and interventions to reduce intracranial pressure, often preceding the full correction of the metabolic abnormalities.

Prioritization Using the ABC Framework

The NCLEX-RN exam tests the ability to prioritize care using the ABC (Airway, Breathing, Circulation) framework and the concept of "acute versus chronic." A GCS of 8 directly indicates an inability to maintain a patent airway, which is the "A" in the ABCs. This takes absolute precedence over the other findings, which represent "C" (circulation) and underlying metabolic causes.

- Option 4 (Correct): A GCS of 8 signifies a comatose state with a non-protected airway. A case report of a severe hyperglycemic crisis describes a patient presenting unresponsive with a GCS of 3 who required immediate intubation for airway protection ^[2]. This illustrates the direct clinical pathway from severe neurological depression to a definitive airway intervention. Without immediate airway management, the patient will deteriorate.

- Option 3: A blood pressure of 90/60 mmHg and heart rate of 110 bpm indicate hypovolemia and compensatory tachycardia, a critical circulation issue in DKA. Fluid resuscitation is a cornerstone of DKA management ^[1]. However, in the hierarchy of ABCs, a non-patent airway will lead to death in minutes, whereas hypotension is a slightly less immediate threat that can be managed concurrently after the airway is secured.

- Option 2: The presence of urine ketones and a fruity breath odor are classic diagnostic clues for DKA, confirming the body's shift to fat metabolism and ketoacid production. While this finding confirms the underlying diagnosis that requires insulin and fluid therapy ^[1], it is a metabolic sign, not an immediate physiological crisis like the loss of an airway.

- Option 1: A blood glucose of 180 mg/dL (10.0 mmol/L) is a marker of hyperglycemia but is not severely elevated in the context of a hyperglycemic crisis. Case reports of severe DKA describe glucose levels exceeding 1,000 mg/dL ^[2]. This value requires treatment but does not represent an immediate, life-threatening emergency compared to a non-patent airway.

The nurse's immediate intervention must be to recognize that a GCS of 8 is a critical threshold for airway compromise, summon the emergency response team, and prepare for definitive airway management, as the risk of cerebral edema and subsequent neurological devastation is the highest priority [1, 2].