some centers utilize prone films or left lateral decubitus radiographs to enhance
air movement into the cecum. In the patient with symptoms longer than 6 to 12
hours, flat and upright films often show signs of intestinal obstruction, including
distended bowel with air–fluid levels ( Fig. 116.5 ). A characteristic “target” sign
may be seen, or more commonly a paucity of gas in the right lower quadrant.
Occasionally, the actual head of the intussusception can be seen on a plain film as
a soft tissue mass ( Fig. 116.8A ).
US can be used diagnostically with reported sensitivity of 98% to 100%,
demonstrating the “target sign” on the transverse view and the “pseudokidney
sign” on the longitudinal view ( Figs. 116.8B and 116.8C ). Whether all patients
should have plain films prior to US is debatable. If signs of intestinal obstruction
or peritonitis, plain films may demonstrate pneumatosis or free air and thereby
expedite operative care. Oftentimes, the radiologist may request a plain film prior
to enema reduction but not necessarily before US. Plain films may be useful in
settings where US is not immediately available, in order to exclude a diagnosis of
intussusception when the pretest suspicion is low.
Hydrostatically controlled contrast enema or air insufflation enema has been a
successful therapy in up to 70% to 95% of cases with higher success rates
reported with air reduction. Strict reduction guidelines must be followed to avoid
perforation. The full reduction of the intussusception is confirmed only when
there has been adequate reflux of barium or air into the ileum. Patients with
peritonitis or free air on plain radiograph should not have an enema study or
reduction attempt. In the seriously ill infant with signs of peritonitis or a frank
small bowel obstruction, the diagnosis of intussusception can be made with
isotonic water-soluble contrast media with no attempt at reduction. The reduction
in such infants should be performed surgically. Perforation rates with enema
reduction have been reported in up to 3%. Risk factors for failed reduction and
perforation include: patient age younger than 3 months or older than 5 years; long
duration of symptoms, especially if greater than 48 hours; hematochezia;
significant dehydration; and evidence of small bowel obstruction on plain
radiograph.

FIGURE 116.8 Ileocolic intussusception. A: Plain radiographs show an abnormal bowel gas
pattern with a soft-tissue mass (asterisk ) in the center of the abdomen. B: In transverse US
images, echogenic serosa of the intussusceptum is seen inside the lumen of intussuscipiens,
giving rise to a “target sign” through the intussusception. Color Doppler blood flow is
demonstrated within the walls of bowel loops. C: Longitudinal image through the
intussusception shows a “pseudokidney sign.” A small amount of free peritoneal fluid is seen.
(Reprinted with permission from Shaffner DH, Nichols DG. Rogers Textbook of Pediatric
Intensive Care . 5th ed. Philadelphia, PA: Wolters Kluwer; 2016.)

Some children with intussusception require emergency surgery, especially if
the intussusception has been of long duration or the child shows evidence of toxic
appearance, significant abdominal distension, or gangrenous bowel that might be
indicated by peritoneal signs, high fever, leukocytosis, and acidosis. If an enema
reduction seems safe and appropriate, the operating room should be placed on
standby and the operating team should be ready to commence immediate surgery
if complications develop during the procedure or if unsuccessful. Preoperative
preparation and resuscitation begins in the ED and continues during the enema. A
general surgeon should be present or immediately available in case of perforation


during the procedure. Air enemas can lead to massive pneumoperitoneum and
cardiopulmonary arrest unless the abdomen is rapidly decompressed (by needle
decompression). Children are not typically sedated for enema reductions,
although there is weak evidence to suggest that sedation may lead to a higher
success rate. Delay in reduction can lead to gangrenous bowel.
Children who have undergone successful air enema reduction, who are
subsequently well-appearing and tolerate oral intake may be candidates for
discharge home from the emergency department with close outpatient

observation. Caregivers must be educated about the risk of recurrence, which
ranges from 3% to 5% in the first 48 hours. When there is a recurrence, a second
attempt at reduction may be done by enema. This is successful in most cases, but
with a third episode of intussusception, an exploratory laparotomy should be
considered. Recurrences are more common in older children and may be caused
by a lead point such as a Meckel diverticulum, an intestinal polyp, or an
intraluminal tumor such as lymphoma. Therefore, it may be wise in an older child
to perform cross-sectional imaging or to operate with the first recurrence.

Incarcerated Inguinal Hernia
Goals of Treatment
The goal of treatment of an incarcerated inguinal hernia is to perform a reduction
before the hernia becomes strangulated. Early surgical consultation is necessary
in cases of incarceration with evidence of bowel obstruction or ischemia.
CLINICAL PEARLS AND PITFALLS
Inguinal mass may represent a torsed ovary or testicle
Blood per rectum with an inguinal hernia may be an indicator of
gangrenous bowel
Bowel obstruction or concerns for ischemic bowel should prompt
emergent surgical consultation
Procedural sedation may be necessary to facilitate reduction of a
hernia
Current Evidence
Incarcerated inguinal hernia is a common cause of intestinal obstruction in the
infant and young child. Approximately 60% of incarcerated hernias occur during
the first year of life. Incarceration occurs more often in girls than in boys, but


usually involves the ovary rather than the intestine. Often, the patient or family
has no previous knowledge of the presence of a congenital hernia. Incarceration

does not necessarily mean that the nonreducible portion of intestine is
compromised or gangrenous. However, strangulation can occur within 24 hours
of a nonreduced incarcerated hernia because of progressive edema of the bowel
caused by venous and lymphatic obstruction. This obstruction then leads to
occlusion of the arterial supply with resulting necrosis of the bowel and perhaps
perforation.
Clinical Considerations
Triage Considerations. Children presenting with an inguinal mass should be
assessed for bowel obstruction or strangulation. If the child is vomiting, has
significant pain, or the hernia is discolored, the patient should be seen
immediately to determine whether emergent surgical consultation is required even
prior to imaging or attempts at reduction.
Initial Assessment. The clinical presentation of a child with an incarcerated
hernia is irritability due to pain, vomiting, and occasionally abdominal distension.
A firm, discrete mass can be palpated at the internal ring that may or may not
extend into the scrotum. Occasionally, the testicle may appear dark blue because
of venous congestion, and in a prolonged incarceration, the testicle may be
infarcted. Intestinal obstruction may develop quickly, and an abdominal
radiograph exhibits signs of small bowel obstruction and possibly gas-filled loops
of intestine in the scrotum. Lack of air in the inguinal region cannot be used to
exclude a hernia because the intestine, especially when incarcerated, is often fluid
filled.
It is often difficult to differentiate a tense hydrocele in the scrotum from an
incarcerated hernia. If the child has had a hydrocele, a sudden increase in fluid in
the tunica vaginalis may produce discomfort and concern for an incarcerated
hernia. However, it is uncommon for a hernia to appear in the presence of a
communicating hydrocele because of the narrowness of the patent processus
vaginalis that is associated with the hydrocele. The acute hydrocele presents only
in the scrotum but may extend superiorly toward the inguinal canal. With a
hydrocele, however, no mass should be palpable up the inguinal canal at the level

of the internal ring.
Management. Unless the child is ill with signs of intestinal obstruction or toxic
from a gangrenous bowel, a manual reduction of the incarcerated hernia should