CATHETERIZATION OF THE MALE AND FEMALE PATIENT
Catheterization of the urinary bladder is the insertion of a hollow tube through the
urethra into the bladder for removing urine. It is an aseptic procedure for which sterile
equipment is required.
PURPOSES OF URINARY CATHETERIZATION
Purposes for urinary catheterization include the following.
a. Relieve Urinary Retention. Urine retained in the bladder for any reason
causes the patient discomfort and increases the likelihood of infection. A catheter may
be inserted to relieve urinary retention when a patient is temporarily unable to void or
has difficulty releasing urine from the bladder due to an obstruction of the urethra or at
b. Obtain a Sterile Urine Specimen from a Female Patient. At one time, this
was considered necessary to obtain a urine specimen entirely free of contamination.
Most physicians now order a collection of a voided, midstream clean-catch specimen.
c. Measure Residual Urine. Catheterization can be done to measure the
amount of residual urine in the bladder when voiding only partly empties it.
d. Empty the Bladder Before, During, or After Surgery. A catheter may be
inserted before or following abdominal surgery, especially if the patient cannot be up
and about. Catheterization to keep the bladder empty of urine during a surgical
procedure permits the surgeon a better view and palpation of internal tissue, and
prevents accidental injury to the bladder. Catheterization may also be used to prevent
urine from touching sutures in the perineum.
URINARY CATHETER SIZES
The French scale (Fr.) is used to denote the size of catheters. Each unit is
roughly equivalent to 0.33 mm in diameter (that is, 18 Fr. indicates a diameter of 6 mm).
The smaller the number, the smaller the catheter. A larger sized catheter is used for a
male because it is stiffer, thus easier to push the distance of the male urethra.
Catheters come in several sizes:
a. Number 8 Fr. and 10 Fr. are used for children.