Question

Following nasal surgery, the nurse suspects a client has developed diabetes insipidus. The nurse knows what laboratory results provide evidence of diabetes insipidus?

Select all that apply
1. White blood cells of 9,500 mm3 (9.5 x 10^9/L)
2. Urine specific gravity of 1.004
3. Serum sodium level of 149 mEq/L (149 mmol/L)
4. Hemoglobin of 20 g/dL (200 g/L)
5. Glucose of 100 mg/dL (5.6 mmol/L)

Answer 1

Laboratory results that indicate diabetes insipidus are a low urine specific gravity, such as 1.004, and a high serum sodium level, such as 149 mEq/L. Other results like white blood cell count, hemoglobin, and glucose levels do not provide direct evidence of this condition. Additionally, unlike diabetes mellitus which results in glucose presence in urine, diabetes insipidus results in very dilute urine with low specific gravity.

Step-by-step explanation:

The nurse suspects that a client has developed diabetes insipidus (DI) following nasal surgery. To confirm this, specific laboratory results are considered. Indicators of diabetes insipidus include low urine specific gravity and high serum sodium levels, among others. In this case, the pertinent lab results that provide evidence of DI are:

• Urine specific gravity of 1.004: This is significantly lower than the normal range, suggesting the kidneys are producing very dilute urine which is typical in DI due to reduced water reabsorption.
• Serum sodium level of 149 mEq/L (149 mmol/L): This indicates hypernatremia, which can occur in DI as a result of excessive loss of free water.

The other laboratory results, such as white blood cell count, hemoglobin, and glucose levels, are not direct indicators of diabetes insipidus.

Additionally, it's important to understand how urine characteristics differ between diabetes mellitus (DM) and DI. While both conditions cause polyuria (excessive urine production), in DM the urine also contains high levels of glucose, leading to increased specific gravity. In contrast, the urine in DI is excessively dilute, reflected by a low specific gravity.