Q. I'm a middle-aged woman scheduled to have surgery next week. My doctor said I'll need an indwelling urinary catheter during and for a few days after my surgery. This sounds worse than the surgery. What will it entail?
A. Before describing what it is, I want to explain why it's necessary. When you have general anesthesia, you're unconscious. You can't tell if your bladder is getting full and can't decide to empty it. Even if you have the kind of anesthesia that eliminates pain but leaves you awake, you may not be able to control your bladder. So there needs to be a way to ensure that any urine your kidneys make is eliminated.
The way to do that is to insert a hollow tube (a catheter) into your bladder. Urine will flow from your bladder through the catheter and into a drainage bag outside of your body. The bag is emptied when necessary by the medical team.
The catheter is quite narrow, usually less than one-quarter of an inch in diameter. It can be uncomfortable, but it shouldn't be painful. Usually the catheter is inserted after you've had some relaxing medicine. Not only does the medicine relax you, you also tend to forget you had the procedure done.
When it's time to have the catheter inserted, you'll lie on your back with your knees bent and your legs spread apart. This will allow access to your urethra.
A health care professional (often a nurse) will clean the opening of your urethra with an antiseptic solution. He or she will inject a lubricating jelly into your urethra. This injection will be done with a special syringe that has a smooth plastic tip.
Then the tip of a sterile urinary catheter will be inserted into the urethra's opening. Slowly, the catheter will be advanced up the urethra into your bladder. When the catheter tip reaches the bladder, urine will begin to flow down through the catheter.
At this point, the nurse will advance the catheter a bit further. A small balloon at the tip of the catheter is then inflated. That balloon keeps the catheter from slipping out of your bladder.
The drainage bag will be attached. This bag should remain below the level of your bladder to ensure that urine drains properly, with no backflow.
The area around your urethra will be regularly cleaned and your urine drainage bag will be emptied about once every eight hours. The catheter may be changed periodically, depending on how long it has to stay in.
Even though the catheter is sterile, there is some risk of a urinary tract infection (UTI). Bacteria that live on the skin where the urethra exits the body can get pushed up into the bladder when the catheter is inserted. If an infection occurs, it can be easily treated. These days, techniques for handling urinary catheters have improved, and infections occur less often than they used to.
• Dr. Komaroff is a physician and professor at Harvard Medical School. Go to his website to send questions and get additional information: AskDoctorK.com.