Progressive Care Nursing Certification (PCCN) Practice Exam

What is a common consequence of acute tubular necrosis on kidney function?

1. Increased urine output

2. Decreased glomerular filtration rate

3. Accelerated electrolyte excretion

4. Improved acid-base balance

The correct answer is: Decreased glomerular filtration rate

Acute tubular necrosis (ATN) primarily affects the renal tubules and is characterized by damage to the tubular epithelial cells. One of the key consequences of ATN is a decrease in the glomerular filtration rate (GFR). The kidneys' ability to filter blood effectively diminishes due to the injury to the nephrons, specifically the tubules, which play a crucial role in reabsorbing water, electrolytes, and waste products. When the GFR decreases, it leads to an accumulation of waste products in the blood, such as creatinine and urea, which is a hallmark of kidney dysfunction. This reduced filtration capacity is what contributes to the signs and symptoms of acute kidney injury, including oliguria or anuria in severe cases. Therefore, recognizing that decreased GFR is a direct consequence of ATN is essential in understanding the impact of this condition on kidney function. In contrast, conditions such as increased urine output, accelerated electrolyte excretion, or improved acid-base balance are typically not reflective of ATN adversely affecting kidney function. In fact, many of these may occur under different circumstances, such as in a state of kidney recovery or other renal conditions.