The nurse determines that a patient is experiencing oliguria based on which amount of urinary output?

Choice A reason: Oliguria is defined as a significantly reduced urine output, typically less than 400-500 ml per day in adults. A urinary output of 350 ml/day falls well below this threshold, indicating a condition of oliguria. This reduced output can be a sign of underlying issues such as dehydration, renal failure, or urinary tract obstructions. It is essential for healthcare providers to identify and address the cause of oliguria to prevent further complications.
Choice B reason: A urinary output of 450 ml/day is also indicative of oliguria but is closer to the higher end of the threshold for this condition. However, the specified definition usually considers less than 400 ml/day as oliguria, making 350 ml/day a more definitive example. While 450 ml/day is still reduced and warrants attention, it is slightly above the typical clinical cutoff for oliguria.
Choice C reason: A urinary output of 550 ml/day is above the typical threshold for oliguria. It indicates reduced urine output but does not meet the clinical definition of oliguria. Such output may still require monitoring, but it does not classify as oliguria, which is generally defined as less than 400-500 ml per day.
Choice D reason: A urinary output of 650 ml/day is well above the threshold for oliguria. This output is closer to normal daily urine output, which typically ranges from 800 to 2000 ml/day, depending on fluid intake and other factors. Therefore, it does not indicate oliguria and would be considered within normal limits or slightly reduced, depending on the clinical context.