Pediatric emergency medicine trisk 1461 1461

present with bilious emesis, tenderness to palpation, irritability, and possibly
bloody stools if there has been significant intestinal ischemia. Hirschsprung
enterocolitis may present a history of difficulty passing meconium and with
similar symptoms due to a large bowel obstruction. There may be an explosive
release of stool on digital rectal exam. In all these conditions, fluid requirements
are significantly increased because of bowel wall edema. Plain films including
AP and left lateral decubitus views are indicated to evaluate for obstruction, and
contrast studies (upper GI series for volvulus, contrast enema for intussusception,
and Hirschsprung enterocolitis) may be required to make a definitive diagnosis if
the patient is stable.
Pyloric stenosis causes severe vomiting in the young infant. This is most often
seen in male infants 3 to 6 weeks old. An infant with pyloric stenosis may present
to the ED afebrile, with significant dehydration and lethargy. A careful history
reveals that increasingly projectile, nonbilious vomiting is the predominant
feature of the illness, and there may be a positive family history for pyloric
stenosis. The physical examination reveals the classic abdominal mass, or
“olive,” in less than half of the cases. Rarely, a peristaltic wave is noted to pass
over the epigastric area. Electrolytes typically show hypochloremia, hypokalemia,
and alkalosis. Ultrasound of the upper gastrointestinal tract confirms the
diagnosis.
Necrotizing enterocolitis (NEC) most often occurs in premature infants in the
first few weeks of life, but can also occur in term infants, usually within the first
10 days of life. A history of an anoxic episode at birth or other neonatal stresses
may precede NEC. These infants are quite ill, with lethargy, irritability, anorexia,
distended abdomen, and bloody stools. Radiographs of the abdomen may show
pneumatosis intestinalis caused by gas in the intestinal wall. Neonatal
appendicitis is another rare event, but several cases have been reported to closely
mimic sepsis. Rapid diagnosis is essential as mortality is high, and perforation
worsens the prognosis. The most common presenting signs are nonspecific and
can also be seen with SBO and NEC, including irritability, vomiting, and
abdominal distention. There may also be hypothermia, ashen color, and shock as

the condition progresses, as well as edema of the right abdominal wall and
possible erythema of the skin in that area. The WBC count may be elevated, with
a left shift, and there may be a metabolic acidosis as well as DIC. Ultrasound may
be unreliable in this age, and abdominal radiographs may show a paucity of gas in
the right lower quadrant, evidence of free peritoneal fluid, or a right abdominal
wall thickened by edema.

Neurologic Diseases