Trauma Answers 167collisions with another vehicle or with pedestrians are the major causes of
blunt abdominal trauma. The spleenis the organ most often injured, and in
approximately 66% of these cases, it is the only damaged intraperitoneal
organ.
The liver (a)is the second-most commonly injured intra-abdominal
organ, third is the kidney(c), fourth is the small bowel (d), and fifth is the
bladder(e).
152.The answer is e.(Scaletta and Schaider, pp 229-231.) Urethral
injuriesmake up approximately 10% of genitourinary trauma. Anterior ure-
thral injuries are most often attributed to falls with straddle injuries or a blunt
force to the perineum. Approximately 95% of posterior urethral injuries are
secondary to pelvic fractures. Signs and symptoms of urethral injury include
perineal pain, inability to void, gross hematuria, blood at the urethral mea-
tus, perineal or scrotal swelling or ecchymosis, and an absent, high-riding, or
boggy prostate. A retrograde urethrogramis the study of choice when there
is suspicion of a urethral injury. This procedure is performed by inserting an
8F urinary catheter 2 cm into the meatus and inflating the catheter balloon
with 2 cc saline to create a seal. Then, 30 cc of radiopaque contrast is admin-
istered and a radiograph is obtained looking for extravasation of contrast
from the urethra.
(a)A scrotal ultrasound may be necessary later on to evaluate for tes-
ticular injury, but it is not used to evaluate urethral injury.(b)A KUB is not
useful to evaluate the urethra. Prior to CT scanning, it was commonly used
to evaluate for kidney stones. (c)An IV pyelogram is an alternative to CT
scanning for evaluating the kidney and ureter. (d)A retrograde cystogram
is a useful study to evaluate the bladder for injury.
153.The answer is b.(Scaletta and Schaider, pp 110-111.)Orbital floor
fracturestypically occur when a blunt object with a radius of curvature
less than 5 cm (eg, often a fist or ball smaller than a softball) strikes the
orbit. The blunt force causes an increase in intraorbital pressure causing a
fracture along the weakest part of the orbit, usually the inferior or some-
times medial wall. Patients usually complain of pain that is greatest with
upward eye movement. They may have impaired ocular motility or
diplopiaif the inferior rectus muscle becomes entrapped. They may also
present with infraorbital hypoesthesiabecause of compression of the
infraorbital nerve. Generally, the patient has normal visual acuity unless
there is an associated ocular injury. A classic radiographic finding is the