A nurse is assessing a client who has fluid volume deficit. The nurse should expect which of the following findings?
A.
Increased urine ketones.
B.
Decreased Hgb.
C.
Decreased urine specific gravity.
D.
Increased BUN.
The Correct Answer and Explanation is:
The correct answer is D. Increased BUN.
Explanation:
Fluid volume deficit, or hypovolemia, occurs when there is a reduction in the body’s total fluid volume. This condition can result from various causes, including excessive fluid loss through vomiting, diarrhea, sweating, or bleeding, or insufficient fluid intake. The body’s response to fluid volume deficit includes a range of physiological and laboratory changes.
One of the key laboratory findings associated with fluid volume deficit is an increased blood urea nitrogen (BUN) level. BUN is a waste product formed in the liver from the breakdown of proteins and is excreted by the kidneys. When there is a reduction in blood volume, the kidneys receive less blood flow and become less efficient at excreting waste products. This leads to an accumulation of urea in the blood, causing an increase in BUN levels. Typically, BUN levels rise disproportionately compared to creatinine levels in hypovolemia.
Here’s a breakdown of why the other options are less likely to be associated with fluid volume deficit:
- A. Increased urine ketones: Urine ketones are often associated with conditions like diabetic ketoacidosis or prolonged fasting, rather than fluid volume deficit alone. In fluid volume deficit, urine ketone levels are not a primary diagnostic indicator.
- B. Decreased Hgb: Hemoglobin levels (Hgb) are generally not directly affected by fluid volume deficit. While dehydration can lead to hemoconcentration and potentially higher hemoglobin levels due to reduced plasma volume, a decrease in hemoglobin is more commonly associated with anemia or blood loss rather than fluid volume deficit.
- C. Decreased urine specific gravity: Fluid volume deficit typically results in increased urine specific gravity because the urine becomes more concentrated due to the body’s attempt to conserve water. Decreased urine specific gravity is more associated with conditions where there is excessive fluid intake or kidney dysfunction leading to diluted urine.
In summary, increased BUN is a characteristic finding in fluid volume deficit due to the reduced renal perfusion and decreased clearance of urea. This helps clinicians diagnose and manage fluid balance effectively in patients presenting with hypovolemia.