Question

The client with head trauma is admitted following a motor vehicle accident. The nurse notes \(5000 \mathrm{ml}\) of dilute urinary output within 3 hours of admission. Which finding would support a diagnosis of diabetes insipidus? A. Decreased red blood cell count B. Low specific gravity of urine C. Increase blood urea nitrogen D. Increased serum creatinine level

Short answer

Answer: B. Low specific gravity of urine

Step-by-step solution

Understanding Diabetes Insipidus

Diabetes insipidus is a condition characterized by the production of a large amount of dilute urine, which eventually leads to dehydration. It is caused by either inadequate production or an insufficient response to the hormone vasopressin, which regulates the balance of water in the body. Understanding this will help us discern which symptoms are indicative of diabetes insipidus.

Analyzing the options

A. Decreased red blood cell count: A decreased red blood cell count is not directly related to diabetes insipidus and would not support a diagnosis of this condition. B. Low specific gravity of urine: Specific gravity of urine is a measurement of the concentration of solutes in urine. A low specific gravity indicates dilute urine, which is characteristic of diabetes insipidus. Therefore, this option would support a diagnosis of diabetes insipidus. C. Increase blood urea nitrogen: Increased blood urea nitrogen is associated with kidney dysfunction and dehydration, which could also be a result of diabetes insipidus. However, it is a less specific marker than low specific gravity of urine. D. Increased serum creatinine level: Serum creatinine is also a marker of kidney function, but an increase in its levels is not specific for diabetes insipidus.

Selecting the correct option

Based on our analysis, the correct option is B. Low specific gravity of urine, as it directly indicates dilute urine, which is an essential characteristic of diabetes insipidus.

Key concepts

Diabetes Insipidus

Diabetes Insipidus is a medical condition where the kidneys are unable to conserve water, leading to the release of large amounts of dilute urine. This disease is distinct from diabetes mellitus, which involves blood sugar regulation. In diabetes insipidus, the underlying issue is related to the hormone vasopressin, also known as antidiuretic hormone (ADH). Vasopressin is responsible for signaling the kidneys to retain water in the body. When there is a deficiency of vasopressin or a failure in response to it, the kidneys release excess water, causing frequent urination. There are two main types of diabetes insipidus:

• Central Diabetes Insipidus: This results from the pituitary gland not producing enough vasopressin.
• Nephrogenic Diabetes Insipidus: In this type, the kidneys do not respond to vasopressin properly, often due to a genetic condition or complications from certain medications.

Symptoms include excessive thirst, dehydration, and the need to urinate often and in large volumes. Diagnosing includes urine tests to assess concentration levels and blood tests to examine electrolyte imbalances.

Nursing Diagnosis

A nursing diagnosis is a clinical judgement about individual, family, or community responses to actual or potential health problems and life processes. In nursing, diagnoses are used to develop healthcare plans and strategies to improve patient outcomes. When dealing with conditions like diabetes insipidus, nurses perform assessments to gather data on symptoms such as urinary output and dehydration. They also consider the patient’s overall physical condition and any recent incidents, like trauma, that might correlate with the disease. By identifying patterns such as excessive dilute urine, nurses can prioritize problems, plan care, and predict possible complications. Nursing interventions could include:

• Monitoring intake and output to manage dehydration risks.
• administration of vasopressin or synthetic analogs in cases of Central Diabetes Insipidus.
• Educating the patient on fluid replacement strategies to compensate for fluid loss.

Specific Gravity of Urine

Specific gravity of urine is a diagnostic measure used to evaluate the concentration of urine. It compares the density of urine to the density of water, providing insight into the kidney's ability to concentrate or dilute urine. Normal urine specific gravity usually ranges from 1.005 to 1.030. A value lower than 1.005 might suggest dilute urine, which is a key characteristic of diabetes insipidus. During the diagnosis of diabetes insipidus, a persistently low specific gravity could indicate the kidneys' inability to concentrate urine due to the malfunction in vasopressin signaling. Urine tests assessing specific gravity are important in clinical settings because they help to:

• detect conditions like diabetes insipidus early, through identification of dilute urine patterns.
• monitor hydration levels in patients and guide treatment decisions.
• assess renal function in conjunction with other tests to understand systemic health issues.

Understanding the specific gravity of urine aids healthcare providers in crafting optimal strategies for managing diseases that alter fluid regulations, such as diabetes insipidus.