A urinary catheter is a tube which is inserted into the bladder through the urethra. Catheters can be used to drain the bladder if a patient cannot eliminate urine independently and they can also be used to introduce instruments, medications, or tracer dyes into the bladder for various medical procedures. Placement of a catheter can be done by a doctor such as a urologist, an experienced nurse, or even the patient in the case of self catheterization.
One of the main reasons to use a urinary catheter is to provide a patient with drainage because she or he cannot urinate. This may be done to help a patient clear an obstruction, because the urethra is inflamed or infected and urination is painful, to address difficulty urinating due to prostate enlargement, or because a patient is paralyzed and cannot void. In some of these situations, the patient may need to use the urinary catheter for an extended period of time, and special care needs to be taken to avoid infection or damage.
Catheters can also be used in the wake of surgery when a patient may have difficulty urinating or a medical team wants to monitor urine consistency, composition, and output. Another reason to place a catheter is to prepare for an endoscopic procedure in which tools will be introduced to the bladder through the catheter. Such procedures can be used to remove growths and for other reasons such as biopsies of the bladder wall. Introducing tracers through a urinary catheter can be performed for medical imaging studies.
If a catheter is being used to quickly treat urinary retention to empty the bladder, urine is allowed to drain freely through the tube. If the catheter will be left in place, it is attached to a bag which collects the urine. Using a bag helps the patient keep clean and it also allows for easy monitoring of the urine. Patients who want to be active while wearing a urinary catheter can wear a leg bag which is worn strapped to the thigh.
Before a urinary catheter is placed, the external area around the urethra is thoroughly cleaned and draped to reduce the risk of introducing sources of infection. The catheter itself is kept in sterile packaging until it is needed, and the care provider assesses the patient to determine the most appropriate size. The person installing the catheter washes the hands and gloves before placing the catheter, and the patient may be given an anesthetic if the placement will be painful. Anesthetics can also be given for removal if there is a concern that the patient may experience pain.