How much is too much when you catheterize

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?
The theory is that because the bladder is distended the abdominal aorta cannot expand that much. If the is a sudden removal of a large amount of fluid from the bladder the abdominal aorta can expand and the resistance is reduced causing a drop in BP. Saw it happen 3 weeks ago taking 2 L out of a or stomach who had a SBO. Her WOB decreased because her lungs had more room to expand but the loss of volume in her abdomen reduced resistance for her aorta causing her BP to bottom out

Seems like a reasonable explanation for what is supposed to happen, but if that is really an issue, why is there not more documentation of it? I looked in my nursing school books and didn't find anything and I did a few database searches and came up dry. It is definitely not in my hospital policy and I work at a large hospital that has a policy for everything. As far as I know, it's never happened on my unit. In my 6 years as a nurse and 2 as a CNA, this attending was the first person to mention it outside of nursing school. Is just such a rare occurrence that it doesn't rate any notice?

We have a policy to clamp at 800mL.I did not learn anything about this at school either (Dec 2012 grad) ...but did learn how/why during orientation on my unit.

I learned it in school. No more than 1000 mls. Here's an old thread and it has a good link to another thread:http://allnurses.com/general-nursing...nt-656529.html

That other thread supports what I had been starting to lean towards, that this is one of those old nurses tales that hang around. While there may be some risk, it can't be that great if there is no documentation or research to back it up. It seems that if this were really an issue, there would be more info and greater warnings on the subject.

We have a policy to clamp at 550. I always thought it was fluid shift causing hypotension. But if its just anecdotal, it's pretty amusing that there are still places with policies about it. Good brain teaser for the morning meeting though.

I was taught to not drain more than 900 ml to prevent shock.

I was taught in nursing school to stop at 1000cc due to potential for hypotension. That was in the late 80's.

I can pee 1000mls at a time no problem. Usually in the morning. Never hurt me to pee that much and I never felt close to fainting. In fact I consider myself very normal and that is what my bladder can hold. Never went into shock having my usual morning pee either.

Quote from IsisCI can pee 1000mls at a time no problem. Usually in the morning. Never hurt me to pee that much and I never felt close to fainting. In fact I consider myself very normal and that is what my bladder can hold. Never went into shock having my usual morning pee either.

Never heard of this and there is no policy or practice of clamping where I work.

I had vague memories of hearing this too, that 1000 ml out was the max. But then last year we had a patient who had severe retention, and a urologist finally managed to catheterize him. He drained over 6000 ml!!! I was truly amazed. So, I think it's one of those things that many of us have heard, but which is not followed so much in practice.