Urethral catheterization is the most frequent retrograde manipulation
of the urinary tract. It is routinely performed for diagnostic and
therapeutic reasons in both urologic and nonurologic diseases.1–5 Although
this is one of the more routinely performed procedures in the Emergency
Department, great care must be taken to avoid lower urinary tract
injury, reduce the introduction of infection, and minimize patient
discomfort. It is important to respect the patient’s need
for modesty and privacy as much as possible.
The genitourinary system is frequently divided into upper and
lower urinary tracts. The former refers to the kidneys and ureters
or those structures above the bony pelvis. The lower urinary tract includes
the bladder and urethra or those structures contained within or
below the bony pelvis. Although the entire urinary tract may be
catheterized, it is the lower tract, namely the urethra, which will
be the focus of this chapter.
Averaging 4 cm in length, the female urethra is rarely a focus
of difficulty. Most of the confusion related to urethral catheterization
in the female results from poor anatomic knowledge of the external
genitalia (Figure 121-1). The clitoris is often mistaken for the
urethral meatus. This can result in catheter-related trauma,
bleeding, patient discomfort, and frustration. After lateral retraction
of the labia minora and exposure of the vaginal vault, the cephalad-most
structure is the clitoris. Traveling in a caudal direction, the
orifices encountered are the urethra, followed by the vagina, and
External anatomy of the female genitourinary tract.
The male urethra is most often the site of catheter-associated
difficulty.3 In contrast to the female, the male urethra
may extend upwards of 20 cm in length and follows a tortuous course.
The urethra is named based on the anatomic structure it traverses
or travels with. The distal-most portion of the male urethra is
the meatus, followed by the penile, bulbar, membranous, and prostatic
portions (Figure 121-2). Resistance to the advancement of a catheter
may occur at any point along the course of the urethra as a result
of meatal stenosis, urethral strictures, urethral valves, false
urethral passages, enlarged prostates, inflammatory processes, malignant processes,
bladder neck contractors, urethral disruptions, and bladder neck
disruptions. A careful clinical history and thorough physical examination
will, in most cases, uncover these causes. The two most common sites
that may be difficult for the catheter to pass are the junction
between the bulbar and membranous urethra and the bladder neck.
Anatomy of the male genitourinary tract.
Urinary catheterization can be performed for diagnostic and/or
therapeutic reasons.2,5 Urethral catheterization is often
performed in females to collect urine for culture and avoid contamination
from skin and vaginal flora. This is ...