In nursing school years ago, I learned never to allow more than 1,000 mL of urine to drain from a urinary catheter immediately after insertion. The rationale was that the rapid loss of so much urine could cause hypotension. So whenever the initial drainage approaches 1,000, I clamp the catheter for 5 minutes, then allow more to drain. A colleague says this practice is outdated. Who's right?-D.E., N.Y.

We asked a nursing professor, who also remembers learning this practice "in the old days." But he agrees with your colleague that it's not supported by research and is no longer considered valid. What hasn't changed is the need to monitor your patient's urinary output, vital signs, and response to treatment.

Bottom line? Don't clamp the catheter.