I have been a nurse for about 7 years and I remember in nursing school hearing that when you straight cath or put in a foley you should clamp at 1000 mL and wait a while, to prevent bladder spasms. Another, more experienced, nurse was told in school that it was to prevent hypotension. Some newer nurses had never heard of either. This became a topic of discussion at the nurse's station when an attending sent a resident to find out why 1500 mL had been emptied from her patient at one time. The attending claimed to have seen a patient code in a similar sitiation, but the residents had never heard of this. I spent some time looking at hospital policy and the Potter and Perry book ans found nothing. I also came up empty on article searches. Does anyone know if this is fiction passeddown through generations of nurses or is there evidence to back it up?