Postoperative care after a living-donor kidney transplant includes monitoring urinary output; which of the following is true?

• A. It may be large and dilute and should be closely monitored.
• B. It will be zero for the first 24 hours.
• C. It will not be monitored after surgery.
• D. It will always be concentrated.

Answer: (A)

Urinary output after a living-donor kidney transplant is a major clue about graft perfusion and function. In the immediate post-op period, the transplanted kidney often produces a large volume of urine that is dilute, because it hasn’t yet fully regained concentrating ability and there can be osmotic diuresis from previously accumulated solutes. Because this diuresis can be substantial, clinicians vigilantly monitor urine output and fluid/electrolyte balance to ensure adequate perfusion and to prevent dehydration or electrolyte imbalances. A sudden drop in urine output would alert the team to possible problems such as vascular compromise or ureteral obstruction, requiring prompt evaluation. The urine is not expected to be zero in the first day, and it will continue to be monitored after surgery to detect any evolving issues. It is not always concentrated early on; concentration tends to improve as the kidney recovers.