A man with diabetes insipidus has a glomerular filtration of 155 L/day. Which range most likely represents the upper limit for urine flow rate in this individual if he were not receiving treatment but had free access to water?: (A) 1 to 3 L/day, (B) 5 to 10 L/day, (C) 15 to 20 L/day, (D) 30 to 35 L/day
Answer is C. Ans. C. 15 to 20 L/dayUrine flow rate in the absence of antidiuretic hormone (ADH) can approach approximately 10% to 13% of the glomerular filtration therefore, for a glomerular filtration of 155 L/day, urine flow could be as much as 15 to 20 L/ day. To maintain this level of urine flow, the individual must consume an equivalent amount of water per day.