What urinary output over two hours would most indicate a potential postoperative complication?

For assessing urinary output in a postoperative patient, a key point to understand is that adequate urine production is often considered to be around 30 mL per hour. This benchmark is based on the notion that this level of output indicates sufficient kidney perfusion and function.

A urinary output of 20 mL per hour is lower than the standard acceptable range and could suggest potential issues. If an individual is producing urine at this rate, it may raise concerns about renal perfusion, possible dehydration, or the onset of acute kidney injury, especially in the context of the postoperative period where fluid balance is crucial. Thus, a lower urinary output than 30 mL/hr, particularly as noted in the choice of 20 mL/hr, becomes significant when monitoring for complications such as fluid overload or urinary retention.

Given this context, the other values presented represent a more favorable urinary output, indicating that the kidney may be functioning adequately. Outputs higher than 20 mL/hr are generally reassuring and less likely to be associated with complications. Therefore, the urinary output of 20 mL/hr is most indicative of the potential for postoperative complications and warrants further evaluation or intervention.