Final answer:
The statement regarding urine output between 50ml and 400ml/day in a patient with acute renal failure is true. Oliguria, indicating a urine output of less than 400 ml per day, is a characteristic of ARF. Monitoring urine output is crucial in these patients for effectively removing metabolic wastes.
Step-by-step explanation:
The statement 'Classically, the client in ARF shows a decrease in urine output to between 50ml and 400ml/day within 1 to 2 days.' refers to the diagnostic criteria for acute renal failure (ARF), specifically the feature of oliguria. Acute renal failure is characterized by a rapid decline in kidney function, which includes a reduced urine output.
Oliguria is defined as having a urine output of less than 400 ml per day in adults, which is consistent with one of the manifestations of ARF. Additionally, anuria, which is the virtual absence of urine production and is defined as a urine output below 10 ml per day, can also occur in conditions such as acute renal failure. It is critical that urine output is monitored in patients with ARF due to the role of the kidneys in excreting metabolic wastes and maintaining fluid balance. In the specific context of the question, the given statement is True.