Case 1: A green case of failure to thrive

A 13-month-old boy presented to the emergency department with a three-day history of fever, cough and vomiting. The vomiting was bilious and occurred between one and10 times per day. His bowel movements were normal, and his oral intake and urine output were decreased. There were multiple ill contacts at home. There was no recent travel or animal exposures.

The pregnancy was unremarkable; he was born at term with a birth weight of 2443 g. The patient’s past medical history was significant for failure to thrive and recurrent episodes of nonbilious emesis beginning at six months of age. He was breastfeeding six times per day and ate three meals per day. His developmental history was normal, and his family history was unremarkable.

His initial vital signs were temperature 36.6°C, heart rate 112 beats/min, respiratory rate 22 breaths/min and systolic blood pressure 82 mmHg. His weight was 6.28 kg (well below the fifth percentile), and his head circumference was 43 cm (less than the fifth percentile). His physical examination revealed a cachectic-appearing infant. He was minimally responsive with sunken eyes. After fluid resuscitation with normal saline, he was alert and nontoxic. His abdomen was mildly distended but soft; his genital examination was normal. The remainder of his physical examination was unremarkable.

Initial laboratory data showed sodium level 131 mmol/L(normal range 135 mmol/L to 143 mmol/L), chloride level 82 mmol/L (normal range 99 mmol/L to 111 mmol/L), blood urea nitrogen level 26 mmol/L (normal range 2.9 mmol/L to7.1 mmol/L) and creatinine level 171 μmol/L (normal lower than 53 μmol/L). Results of a venous blood gas were pH 7.42, carbon dioxide 37 mmHg and sodium bicarbonate 25 mEq/L. The patient’s complete blood count was normal. He was admitted for further evaluation and management. Electrolyte levels were corrected with fluid therapy.

A diagnostic test was performed.

CASE 1 DIAGNOSIS: JEJUNAL WEB

To evaluate the bilious vomiting in our patient, an upper gastrointestinal series was performed. Duodenal distension with a filling defect within the bowel lumen was noted, consistent with a web in the proximal jejunum causing partial small bowel obstruction (Figure 1).

Figure 1).

Upper gastrointestinal series showing a markedly dilated duodenum. The ligament of Treitz is in a normal position. A crescentic filling defect representing a web in the proximal jejunum is noted (arrows)

Failure to thrive is defined as inadequate physical growth (1). It may be classified pathophysiologically into inadequate caloric intake, inadequate caloric absorption and excessive metabolic demand. The evaluation should be guided by history and physical examination findings because the majority of children with failure to thrive have no laboratory abnormalities. Initial screening tests may include a complete blood count; electrolyte, urea and creatinine levels; and urinalysis and urine culture. In our patient, the recurrent episodes of vomiting likely resulted in decreased calories available for absorption and utilization.

Vomiting is often divided into two broad categories – nonbilious and bilious. Gastroesophageal reflux is the most common cause of recurrent vomiting in infants. Other etiologies of nonbilious vomiting include neurological, infectious, renal, toxic, metabolic and additional gastrointestinal disorders (2).

Bilious vomiting may result from repeated episodes of vomiting causing pyloric relaxation and reflux of duodenal contents into the stomach (2). However, surgical causes due to obstruction distal to the ampulla of Vater must be considered. The differential diagnosis of bilious vomiting varies by age and includes intestinal atresia or stenosis, malrotation, intestinal duplication, mass lesion, incarcerated inguinal hernia, appendicitis, adhesions, intussusception, ileus and Hirschsprung’s disease. Radiological evaluation begins with plain film studies of the abdomen. Abdominal ultrasound is helpful in assessing for intussusception. An upper gastrointestinal series should be performed urgently when suspicion for malrotation exists because of the potential devastating consequences of midgut volvulus. Because our patient acutely presented with bilious vomiting, he was evaluated with an upper gastrointestinal series to exclude malrotation, which led to the diagnosis of a jejunal web.

Most literature on intestinal atresia, including jejunal webs, involves the neonatal population. In a 25-year retrospective case series (3) of 277 neonates with intestinal atresia or stenosis, the level of obstruction was duodenal in 138 patients (50%), jejunoileal in 128 (46%) and colonic in 21 (8%).

The prevalence of jejunoileal atresia is low. It historically has been categorized into type I (mucosal), type II (atretic fibrous cord), type IIIa (V-shaped mesenteric defect),type IIIb (‘apple peel atresia’) and type IV (multiple atresias) (3). Reported associated anomalies include gastroschisis (16%), cardiac (8%) and renal (4%) (3). A late intrauterine mesenteric vascular insult is believed to be the cause of most cases. Common clinical findings in the neonate include bilious emesis, abdominal distension and failure to pass meconium.

Literature on the incidence and symptoms of intestinal atresia presenting outside the neonatal period is scant, likely due to few patients remaining undiagnosed. It is possible for an infant with type I atresia to survive beyond the neonatal period due to the presence of a pinhole in the web. Symptoms in older infants may include failure to thrive and bilious vomiting; there current episodes of nonbilious vomiting in our patient until the acute presentation seems odd and may have contributed to the delay in diagnosis.

Cystic fibrosis is reported to occur with increased frequency among infants with jejunoileal atresia. One study (4) found that Caucasian infants with isolated jejunoileal atresia had more than 210 times the risk of having cystic fibrosis compared with Caucasian infants in the general population; it has, therefore, been suggested that any infant with jejunoileal atresia should undergo screening for cystic fibrosis.

Diagnosis of jejunal atresia is made with an upper gastrointestinal series showing proximal dilated upper bowel loops ending in a smooth contour at the site of the obstruction. Treatment involves surgery to remove the obstruction. Mortality has steadily declined over the past few decades; increased survival may be due to improvements in neonatal intensive care, nutritional supplementation and surgical techniques. Our patient underwent surgical resection of the jejunal web without complications. A sweat chloride test, performed previously during his evaluation for failure to thrive, was negative. A nutritional consult was obtained and recommendations for maximizing caloric intake were provided.

CLINICAL PEARLS

• Failure to thrive may be due to inadequate caloric intake, inadequate absorption or excessive metabolic demand.

• Although bilious emesis from nonobstructive causes may occur due to relaxation of the pylorus following repeated vomiting, intestinal obstructions distal to the ampulla of Vater must be considered.

• Bilious vomiting may be a presentation of malrotation. A suspicion of malrotation needs urgent evaluation because of the risk of volvulus.

• Intestinal atresia may present beyond the neonatal period. A history of failure to thrive and recurrent vomiting may be signs of an underlying developmental cause of intestinal obstruction.