Thoughts on bladder management after spinal cord injury.
Dr. William Carter, M.D./MPH
There are many different ways to manage the bladder after a spinal cord injury. Some people use indwelling catheters, suprapubic catheters, condom catheters, intermittent catheterization, or other more advanced diversion techniques performed by Urological surgeons. The optimal amount of fluid is going to depend on the management strategy for your bladder as well as any potential health issues that you may have. To start off, These recommendations are my opinions, which many other SCI physicians share but not all. My recommendations are not applicable for those people who have had issues with fluid overload from kidney failure, heart failure, severe liver disease, and a few other exceptions. With the exception of these conditions which will result in needing to restrict fluids, my general recommendation would be to take in as much fluid as within reason. I will discuss the rationale behind this belief by explaining basic bladder physiology. Things to be discussed will include bladder volume, stones, bladder cancer. I will try to divide this into those using indwelling devices compared to intermittent catheterization and also make some commentary about those who have lower motor neuron bladders ( flaccid) compared to upper motor neuron.
I think of the bladder is a muscular balloon. Similar to a balloon, it can be stretched out of shape at which time it has difficulty shrinking back down. If it is not expanded it will shrink to a very small size. in the setting without medications and without a spinal cord injury the bladder is designed to hold approximately 400 to 500 milliliters at most at which time someone will have a strong urge to urinate.
For those doing intermittent catheterization:
For those of you who use some form of intermittent catheterization, the typical bladder volume all around 500 milliliters is why 400 to 500 milliliters is considered the goal volume for cathing. Initially while an inpatient Rehabilitation you would likely taught to restrict your total daily volume intake to two or two and a half liters per day. The purpose of this was due to the likelihood that you were being catheterized by a nursing staffmember and to try to prevent overdistention of your bladder. And honesty, once you have control over your own intermittent catheterization, you should drink fluids to fit your schedule while trying to maintain bladder volumes less than or around 500 milliliters. For example, I worked with one person who was doing a lot of outdoor activity in the summer so he was drinking forward to 5 liters per day to maintain his hydration thus doing intermittent catheterization more than 10 times per day to keep his bladder volume down. Drinking extra fluid kept him from becoming dehydrated, but having such high fluid intakes also likely helps to flush bacteria and other particles out of his bladder and thus he very rarely had urinary tract infections as well as very rarely had any form of bladder stones. This however, requires that he have very clean technique since he’s doing catheterization so often which, if done improperly can lead to infection. Additionally it requires that he monitor his bladder volume very carefully because there are significant consequences to bladder distention. These consequences include: kickoff- causing bladder accidents, reflux of urine to the kidneys- which can damage them and increase your risk of kidney failure, and increase in the muscle thickness of the bladder wall- which can increase risk of stone formation. Therefore, my recommendation is to drink as much fluid as you can tolerate while maintaining catheterization volumes of 500 or less.
For those with indwelling catheters:
Those with indwelling catheters, your bladder consistently has some small amount of urine left over which could serve as a site for infection as well as stone formation. based on this, unless there’s a contraindication my recommendation would be to drink higher volumes of fluid (water), ideally somewhere around four liters or one gallon per day.
For those with condom catheters:
It is very difficult for me to comment about what is the ideal intervention for those using condom catheters exclusively. Unless your injury is lower motor neuron ( your legs would be flaccid with no spasms), due to the spastic nature of the bladder, there is risk of damage to the kidneys with voiding. I’m not sure how to balance this risk with the risks mentioned above from not drinking enough fluid.
Lower motor neuron injuries:
If you are using intermittent catheterization, I would follow the same guidelines as others while understanding that your risk of leaking is higher with high volumes. If using condom catheter or indwelling catheter, my recommendation would be to drink as much fluid as possible for the reasons mentioned above.
William Carter, MD/MPH is a spinal cord injury medicine trained Assistant Professor of physical medicine and rehabilitation at Virginia Commonwealth University