Which condition can lead to postrenal failure?

Postrenal failure occurs when there is an obstruction in the urinary tract that prevents urine from being excreted, leading to backup and damage to the kidneys. An enlarged prostate is a common cause of this obstruction, particularly in older men. The prostate can compress the urethra, restricting the flow of urine and ultimately resulting in increased pressure that can harm the renal tissue.

The other conditions listed do not directly lead to postrenal failure. Severe dehydration primarily leads to prerenal failure due to decreased blood flow to the kidneys. Trauma may cause acute kidney injury, but it often does so through direct damage to the kidney rather than an obstruction in the urinary tract. Drug toxicity is also more related to intrinsic renal failure, where the kidney tissue itself is damaged by nephrotoxic agents, rather than causing an obstruction of urine flow as seen in postrenal failure.