Pediatric ATI Practice Exam 2026 - Free Pediatric Practice Questions and Study Guide

A sodium level of 155 mEq/L indicates hypernatremia, which is a significant sign that a child may be developing diabetes insipidus, especially following a head injury. Diabetes insipidus is characterized by excessive urination and thirst due to the lack of antidiuretic hormone (ADH), which is often a consequence of injury to the hypothalamus or pituitary gland.

In the context of diabetes insipidus, increased urine output leads to the loss of water and results in a higher concentration of sodium in the blood, thus elevating serum sodium levels. A sodium level greater than 145 mEq/L typically signifies hypernatremia.

Other indicators, such as urine specific gravity, blood glucose levels, and urine output, do not specifically point towards the diagnosis of diabetes insipidus in this scenario. For example, a urine specific gravity of 1.045 would usually indicate concentrated urine, not the dilute urine expected in diabetes insipidus. A blood glucose level of 45 mg/dL indicates hypoglycemia, which is not directly related to diabetes insipidus. Lastly, a urine output of 35 mL/hr does not denote the excessive diuresis typically associated with the condition. Therefore,