Straight caths - to clamp or not to clamp?

1 Today, I had a patient retaining urine - over 1500cc out with straight cath. An experienced coworker insists that one must either remove or clamp the straight cath after 1000cc output, lest the patient descend into a hypovolemic state. Based on her statements, I monitored the pt's BP and HR for the rest of the shift - no significant change.

I have been scouring my nursing textbooks and searching online - I can't find any evidence for the need to clamp off and wait after 1000cc out. I have a few basic problems with the idea:

1. Risk of bladder damage, hydroureter, pyelonephritis, etc.
2. The bladder is just plain not part of the circulatory system.
3. Why don't I get hypovolemic letting a liter off at the end of a busy shift?

Thanks, everybody!
I don't know about this whole hypovolemia thing, but I did have a coworker tell me that I needed to clamp after 500 because it could cause spasming of the bladder to have that big of a change in volume, which could make matters worse. I am going to peruse the literature on this one for sure.

Quote from SaraO'HaraToday, I had a patient retaining urine - over 1500cc out with straight cath. An experienced coworker insists that one must either remove or clamp the straight cath after 1000cc output, lest the patient descend into a hypovolemic state. Based on her statements, I monitored the pt's BP and HR for the rest of the shift - no significant change. I have been scouring my nursing textbooks and searching online - I can't find any evidence for the need to clamp off and wait after 1000cc out. I have a few basic problems with the idea: 1. Risk of bladder damage, hydroureter, pyelonephritis, etc. 2. The bladder is just plain not part of the circulatory system. 3. Why don't I get hypovolemic letting a liter off at the end of a busy shift? Thanks, everybody!

I can't imagine how it would make someone hypovolemic, since that fluid isn't in circulation anyways. The bladder spasm explanation makes more sense. I've never heard that, but I have only straight cathed someone once.

Quote from Work in ProgressI don't know about this whole hypovolemia thing, but I did have a coworker tell me that I needed to clamp after 500 because it could cause spasming of the bladder to have that big of a change in volume, which could make matters worse. I am going to peruse the literature on this one for sure.

I know, it doesn't make any sense. I just smiled and nodded at this particular nurse after trying all logical arguments, and she still insisted it was necessary. I think it is one of those "traditions" that don't have any evidence. Anyone a research nurse who wants to take this one on?

Patients with some types of spinal cord injuries can develop autonomic dysreflexia as a result of an overdistended bladder. Draining the bladder too quickly (more than 1000 mL at one time) can cause further complications."Sudden decompression of a large volume of urine would be expected to normalize blood pressure. However, this may cause hypotension if the individual has already been given pharmacological agents to decrease the blood pressure." NGC - NGC Summary

They say 500ml out at most at one time if there is urine retention. Bladder spasms are pretty awful for the patient. I have had this happen to one of my patients before while I was in nursing school.

I will drain up to 1000 ml. I have had patients complain of bladder spasms when I did empty more than that. But hypovolemia? never heard of that one.

I always clamp after about 600-700ml but it because of bladder spasms.

I worked in urology for more than a few years & the physician never clamped the cath after draining any amount of urine. Spasms will likely occur from the cath irritating the bladder, not the volume draining out. I also disagree with the hypovolemia suggestion.

I've never seen it myself but I was taught the 1000cc rule to prevent hypotension. I've probably still got the textbooks to back it up. I never was sure why, though? A vasopressin effect? Does pelvic pressure affect BP just as high PEEP does? Well then I imagine we'd all need pressors after childbirth. I think it's just another nursing "fact" that time and research has passed by. Don't be too hard on the old girl. We spend enough time keeping up with new knowledge that keeping a pet sacred cow can be forgiven. Her way is old. Time consuming. Impractical (I always thought). But not damaging.

This is something that a lot of nurses say but, as the OP points out, isn't based on anything that makes sense. It's been discussed on AN previously, with the same result - there's very little actual data. I've just done a google scholar search using various permutations of: clamp, urine, catheter, volume, danger, risk, spasm, shock, dilate, and hypotension. And the only relevant information that came up had to do with autonomic dysreflexia.However, once I added "myth" to the search I found the following from Abdominal Emergencies by David Cline and Latha G Stead (McGraw-Hill, 2007): Rapid decompression of the obstructed urinary bladder is safe and effective.Hemturia, hypotension, and post obstructive diuresis are rarely clinically significant. The exception is cases of high pressure chronic retention, seen most commonly in BPH. (p. 169)