Which of the following is NOT a cause of decreased glomerular filtration rate?

Decreased glomerular filtration rate (GFR) is often associated with various health conditions impacting kidney function. When considering the options, fluid overload is not typically a direct cause of decreased GFR. In fact, fluid overload can sometimes increase intravascular volume and improve GFR temporarily by increasing renal perfusion pressure.

On the other hand, kidney stones can obstruct urinary flow, leading to increased pressure within the renal system and potentially resulting in decreased GFR. Dehydration reduces blood volume and renal perfusion, which directly impacts the kidneys' ability to filter blood, thus lowering GFR. Acute kidney injury refers to a sudden reduction in kidney function, which inherently decreases GFR due to various causes such as ischemia, toxin exposure, or obstruction.

In summary, while the other options directly relate to conditions that can decrease kidney function and GFR, fluid overload typically does not lead to a decrease in filtration rate, making it the correct answer.