Pediatric emergency medicine trisk 637

Clinical Recognition. The incidence of clinically evident malrotation occurs in
approximately 1 in 6,000 live births. Over half will present in the neonatal period,
and the remainder typically within the first year of life. Consultation with
pediatric general surgery is warranted early in evaluation for any neonate
presenting with bile-stained emesis to help facilitate timely treatment. Early signs
can be falsely reassuring because signs of peritonitis or shock may not be evident
until well after the onset of volvulus and bowel ischemia.
Triage Considerations. Neonates with bilious emesis should be triaged urgently
as volvulus can progress rapidly. Ill-appearing neonates with suspected volvulus
should undergo emergent surgical intervention and exploratory laparotomy.

FIGURE 96.38 Abdominal radiograph showing massively dilated stomach with no distal air,
consistent with proximal intestinal obstruction in a patient with malrotation. (Reprinted with
permission from Fleisher GR, Ludwig S, Baskin MN. Atlas of Pediatric Emergency Medicine .
Philadelphia, PA: Lippincott Williams & Wilkins; 2004.)

Clinical Assessment. The most common presenting sign in the neonate is bilious
emesis. The examination may reveal a distended abdomen; however, signs of
peritonitis or shock are late findings and may not be present. Abdominal
radiograph may reveal obstruction of the stomach with little or no distal air in the
bowel ( Fig. 96.38 ). However, plain radiographs can be nonspecific or even
normal appearing, particularly with intermittent volvulus, or may show a


complete lack of bowel gas. US with Doppler interrogation of the superior
mesenteric vessels may reveal abnormal configuration of the superior mesenteric
vein in relation to the mesenteric artery (normal configuration is where the
superior mesenteric vein lies to the right of the superior mesenteric artery),
however this is inconsistent and normal Doppler evaluation does not exclude
malrotation. Contrast enema may reveal abnormal position of the cecum, but
again, a normal study does not exclude malrotation. Therefore, the diagnostic test

of choice is the upper GI series using fluoroscopy to determine the position of the
ligament of Trietz, its relation to the ileocecal junction, and the position of the
duodenojejunal junction to the left of midline and fixed posteriorly. In volvulus,
the site of the obstruction tapers, similar in appearance to a bird’s beak. In a
partial or intermittent obstruction, the upper GI may reveal a spiral or corkscrew
appearance. Laboratory findings including CBC, BMP, and inflammatory
markers may be normal, particularly early in diagnoses. In more advanced
presentations, these labs may reveal signs of hypovolemia, dehydration, infection,
or shock, particularly in the setting of volvulus or bowel necrosis.
Management. The definitive treatment of malrotation in a symptomatic infant is
emergent surgical repair. In the otherwise healthy infant with an incidental
diagnosis of malrotation, elective surgical repair is still recommended given the
high risk of future volvulus. For infants with congenital diaphragmatic hernia or
abdominal wall defects and known malrotation, the low risk of volvulus allows
for expectant management, as long as the family is well counseled to seek care
should symptoms of obstruction develop. For infants with heterotaxy, there
remains significant debate whether routine surgery should be performed to
prevent complications, or if watchful waiting is sufficient. Current studies are
ongoing to better understand the natural progression of malrotation in this
population. Certainly, if the infant with heterotaxy presents with clinical signs of
obstruction and bilious emesis, immediate consultation with pediatric surgery is
warranted.
In preparation for surgery, the infant should be NPO and started on parenteral
hydration and nutrition. If the infant is dehydrated, initial resuscitation should
include intravenous fluid bolus. The stomach should be decompressed with a
nasoenteric tube. Blood should be drawn for type and cross-match prior to
surgical procedure, an evaluation of the CBC and serum chemistry should be
evaluated and any abnormalities addressed. Serum glucose should be checked as
neonates have fewer glucose stores and can develop hypoglycemia rapidly. Blood
cultures should be sent and the infant started on intravenous antibiotics, as bowel

ischemia can interrupt the gastrointestinal barrier and allow for bacterial
translocation into the blood stream.

Other Causes of Intestinal Obstruction
CLINICAL PEARLS AND PITFALLS
Distal bowel obstructions may present without vomiting.
Intestinal obstruction can lead to bacterial translocation and lifethreatening sepsis in a neonate.
Decompression of obstructed bowel with a nasogastric tube will reduce
hydrostatic pressure and lower the risk of ischemia of the gut.
Abdominal distention can compromise respiratory function in a neonate
by diminishing pulmonary reserve and mechanical impedance from
pressure on the diaphragm.
Small Bowel Atresia and Stenosis
Complete small bowel atresia will often present with emesis and feeding
intolerance immediately after birth, and many are now being diagnosed
prenatally. However, type 1 atresias, with luminal webs or stenosis of the bowel,
may not present until several days later, depending on the degree of obstruction.
Duodenal obstructions are often associated with other congenital anomalies, most
commonly trisomy 21 and CHD. Duodenal stenosis can occur as a result of
extrinsic compression from the hepatobiliary tree or pancreas, as in annular
pancreas malformations. If the obstruction is distal to the ampulla of Vater, the
infant will present with bilious emesis and therefore may be difficult to
distinguish from midgut malrotation. A plain film radiograph may reveal the
classic “double bubble” ( Fig. 96.39 ) with air in the stomach and proximal
portion of the duodenum, and no air in the bowel distal to the obstruction.
Jejunoileal atresias and stenosis can be associated with malrotation, meconium
peritonitis, or ileus, but are not commonly associated with known genetic
syndromes. Infants typically present with bilious emesis, and plain film

radiograph often reveals dilated bowel loops. The more distal the obstruction, the
more bowel loops that are evident. If the level of obstruction is unclear,
malrotation must be urgently ruled out, and can be done with a limited upper GI
series to assess the position of the ligament of Treitz. Small bowel stenosis or
stricture can also result from an acquired condition, particularly in the infant with


a history of necrotizing enterocolitis (NEC). In this population, stricture
formation may not occur until several months after recovery from NEC.

FIGURE 96.39 Abdominal radiograph revealing “double bubble” sign in a patient with
duodenal atresia. Note the air fluid levels in the stomach (open arrow ) and proximal dudoenum
(black arrow ). (Reprinted with permission from Eisenberg RL. An Atlas of Differential
Diagnosis . 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2003.)

Gastrointestinal Duplications
Gastrointestinal duplications can occur along any level of the GI tract. As with
small bowel obstruction, more and more are being diagnosed prenatally. Proximal
obstructions of the stomach or duodenum often present in the neonatal period
with bilious or nonbilious emesis. Upper GI may suggest external compression of
the stomach or small bowel, but US and CT can reveal the duplication mass more
clearly. More distal duplications of the small or large intestine may also present
with obstruction, but can also lead to volvulus or hemorrhage. Treatment requires
surgical resection of the duplication.
Hypertrophic Pyloric Stenosis
Hypertrophic pyloric stenosis is an acquired disease where the muscle of the
pyloric sphincter becomes enlarged and obstructs gastric emptying. It most often
presents between 4 and 6 weeks of age, but can present in neonates as young as 2