What is the most likely diagnosis?The mother of a 12-month-old male infant calls you at midnight stating that her son has been crying incessantly for the last 6 hours. His bouts of crying last for about 20 minutes, then completely disappear for 15 minutes at a time. Since early afternoon the child has not been eating much and he has started to vomit the small amounts of juice and milk he had ingested. She decided to call you because the vomitus is now green and the bouts of crying seem to be getting worse.
In the emergency room, you recall that the patient does not have any past medical history, was born at term without complications, and is up-to-date on immunizations. On examination, his temperature is 100°F (37.7°C), his respiration rate is 40 breaths/min, his pulse is 155 beats/min, his blood pressure is 109/60 mm Hg, and his weight is 22 lb. He cries inconsolably for 15 minutes, drawing his legs up to his chest, then becomes quiet. You notice he still produces tears, and his mucosae are moist. Heart and lung examinations are normal; abdominal examination reveals markedly decreased bowel sounds with generalized tenderness to palpation. You feel a sausage-like mass in the right side of the abdomen. His diaper holds some amount of bloody stool mixed with mucus. The rest of the examination is normal.
What is the most likely diagnosis?
What is the next diagnostic step?
What are the possible complications?
Summary: This is a 12-month-old infant who had the sudden onset of intermittent crying with vomiting that later became bilious. As the day progressed, his bouts of pain became more severe, each lasting about 20 minutes. On examination, the infant does not yet reveal signs of hypovolemia, sepsis, or shock. On palpation of the abdomen, there is generalized tenderness and a sausage-like mass on the right side. Even though not mentioned by the parent, there is a small amount of bloody-mucous stool that is best described as “currant jelly.” This patient has an intussusception that has progressed to an obstruction, and is at risk for perforation with ensuing shock and sepsis.
• Most likely diagnosis: Intestinal obstruction caused by intussusception
• Next diagnostic step: Abdominal plain x-rays to rule out perforation
• Possible complications: If perforation occurs, rapid deterioration as a consequence of shock/sepsis
1. Become familiar with the most likely causes of intestinal obstruction in the pediatric population.
2. Learn to differentiate between life-threatening abdominal emergencies and urgent conditions.
3. Have a diagnostic approach to the pediatric patient presenting with abdominal pain and vomiting.
This 12-month-old infant initially presented with vomiting and intermittent abdominal pain. His vomitus was initially the gastric contents of what he had ingested, but later became bilious, which is suggestive of intestinal obstruction. The description of his abdominal pain tends to reveal the pathophysiologic nature of intussusception. The intermittency and “pain-free” intervals correlate with the gradual and slow telescoping of the intussusceptum (proximal or leading part of the intestine) into the intussuscipiens (distal or receiving end of the intestine). As the “telescoping” progresses, the portions of bowel that are trapped within the lumen of the intestine become edematous, which will ultimately lead to obstruction, ischemia, and perforation of the bowel wall. Malrotation with volvulus will also present with a clinical picture of obstruction, and it may be difficult to differentiate among the two solely on clinical findings.
The sausage-shaped mass felt on examination will not be present in all cases. It represents the portions of bowel that are involved and have become edematous. Another common condition that may reveal a palpable mass is that of pyloric stenosis, with an olive-shaped mass sometimes palpable in the right upper quadrant of epigastrium. However, pyloric stenosis presents in younger patients and does not involve bouts of severe pain. “Currant jelly” stools are basically a mixture of blood and mucus that has sloughed from the affected bowel wall. This is not present in all cases.
Before proceeding to diagnostics, the patient should be stabilized with IV fluid hydration and surgery consultation should not be delayed. A nasogastric tube may need to be placed if obstruction is suspected. A plain film of the abdomen is done to rule out perforation. If perforation has occurred, surgical intervention is required. If no perforation is evidenced, an ultrasound of the abdomen may reveal a “coiled spring” lesion, which reflects layers of intestine within the lumen of a different portion of intestine. However, a barium enema will be both diagnostic and therapeutic in the case of intussusception. Although barium is widely used, a water-soluble contrast is preferred if perforation is suspected, because it will not be as irritating to the peritoneum. The therapeutic value of the enema is a result of the constant application of hydrostatic pressure on the intussusceptum, mechanically forcing it to telescope back. Air reduction may also be achieved. This method requires fluoroscopic visualization of bowel-gas patterns until reduction of the intussusceptum is seen. Barium or air reduction is effective in 75% to 90% of cases, after which a 12- to 24-hour observation period is needed until bowel function is adequate and a bowel movement has been produced. The risk of recurrence in this patient with idiopathic intussusception is approximately 10%.
INTUSSECEPTION: A telescoping of the intestine within itself leading to abdominal pain, fever, vomiting, and ultimately bowel necrosis if not resolved
HYPERTROPHIC PYLORIC STENOSIS: Condition of hypertrophy of the pylorus leading to gastric outlet obstruction, commonly manifesting in infants at about 1 month of age
The most important aspect of a diagnostic approach in these cases is to be able to rapidly determine whether or not the condition is an emergency. Although the case presented is that of the most common abdominal emergency among the pediatric
population, it is by no means the most common cause of intestinal obstruction. Among the diagnoses that have to be entertained are hypertrophic pyloric stenosis, malrotation with volvulus/obstruction, foreign-body ingestion, and poisoning.
As described, intussusception will present with intermittent, severe abdominal pain, associated with vomiting that becomes bilious as obstruction sets in. The finding of an elongated mass along the right abdomen is very suggestive of this diagnosis. The location of the mass is because most idiopathic intussusceptions occur at the ileocecal junction. They may be entirely in the jejunum, between the jejunum and ileum, or entirely colonic. Currant jelly stool is most often used to describe the finding in this condition and it correlates with the ongoing bowel ischemia as the intussusception and edema progress.
Hypertrophic pyloric stenosis is the most common cause of GI obstruction in infants. It occurs in approximately 3 in 1000 live births, with a male-to-female ratio of 4:1. The usual presenting age is 3 to 6 weeks old, and is often described as a “hungry baby” with projectile vomiting. Vomiting is nonbilious and occurs immediately after meals. The infant will demand to be refed immediately. On examination, there may be an olive-shaped mass felt in the right upper quadrant, and peristaltic waves may be seen across the upper abdomen moments before emesis occurs. Ultrasonography shows the thickened pyloric muscles that are causing a gastric outlet obstruction. An upper GI contrast study usually reveals an elongated pyloric canal and a “double-track sign,” which is explained by two thin tracts of barium that are created by compressed pyloric mucosa. Once the diagnosis is made, surgical referral is indicated as it is the definitive management. Because of the early age and dramatic nature of the symptoms, parents will usually seek help before the infant becomes severely ill from not eating.
Malrotation occurs in about 1 in 500 live births, but becomes symptomatic in only 1 in 6000 live births. Approximately 60% of patients will be younger than 1 month of age, with approximately 10% presenting after 1 year of age, even into adulthood. Because it is primarily a defect that occurs during embryogenesis, the mesentery that is formed will have an abnormally narrow base, which allows the small bowel to move more freely than normal. This creates a problem when the intestinal attachment to the mesentery twists around itself, creating a volvulus. Once obstruction occurs, the child will present with bilious vomiting and abdominal pain. If diagnosis is delayed, the involved segments of bowel will eventually become necrotic, leading to fluid losses and sepsis. The diagnostic approach in such cases will depend on the stability of the patient. If the patient is hypovolemic, hypotensive, has GI blood loss, or has signs of peritonitis, quick stabilization with surgical intervention is necessary. However, if the patient is hemodynamically stable, imaging can be performed to confirm a diagnosis. If mal-rotation is suspected, an upper GI series is the test of choice. In 75% of patients, the diagnosis will be clearly seen. Diagnostic findings on an upper GI are an obviously misplaced duodenum, or a duodenal obstruction with the classic “beaklike” appearance of the contrast medium caused by a volvulus. Surgery is the only treatment. Although different surgical techniques are applied to prevent a recurrence, a volvulus can repeat itself in as many as 8% of patients. Malrotation can go undiagnosed if a patient never experiences symptoms from it, and older children may present with intermittent vomiting, episodes of abdominal pain, failure to thrive, or syndromes of malabsorption.
Foreign bodies also need to be considered with abdominal pain and vomiting in a pediatric patient. Only 10% of patients that ingest a foreign body will need an intervention either to relieve an obstruction or to prevent GI complications. Approximately 90% of patients will pass a foreign body spontaneously, and parents need only check the stool within 24 hours to confirm passage. Sometimes, if an object can be seen on plain radiographs, a repeat x-ray within 24 hours can be done. Among objects that require immediate intervention are flat disk, or “button,” batteries in the esophagus. These batteries will conduct electricity when both poles are in contact with the esophageal wall, which may lead to perforation. Sharp objects and multiple magnets also need to be removed. As a general rule, any foreign body in the esophagus needs to be removed in less than 24 hours by upper endoscopy. If a sharp or elongated object (>6 cm) has already passed through the stomach and duodenum, daily x-rays should be done to follow the progress of the object. Those that do not advance within 3 days will require surgical intervention for removal.
Poisoning cannot be overlooked in the evaluation of a child with vomiting and abdominal pain. Among the multiple agents most commonly associated with hospital visits are over-the-counter (OTC) analgesic drugs, cold remedies, insecticides, pesticides, personal care products, and fumes. In a child who presents with vomiting and abdominal pain, a cholinergic syndrome is likely. It is characterized by salivation, lacrimation, diarrhea, vomiting, diaphoresis, intestinal cramps, and seizures. Insecticides and nicotine are among the agents that may induce these symptoms. Antihistamines or tricyclic antidepressants produce dry skin, dry mucosae, urinary retention, and decreased bowel sounds (anticholinergic syndrome). Some medications and substances are radiopaque, such as iron tablets, mercury, lithium, tricyclic antidepressants, Play-Doh, and enteric-coated aspirin. Finding the likely agent of poisoning will mostly depend on the history given. Poison control should be consulted for patients where etiology of ingested toxin is known.
Surgical intervention will almost always be necessary if an anatomical/mechanical defect of the GI tract is present. Intestinal obstruction puts a patient at risk for perforation, which further deteriorates a patient’s condition. A nasogastric tube is recommended in cases where obstruction has set in and the patient is ill. Careful monitoring of the patient’s fluid status is required because of the likelihood of third spacing into ischemic bowel and decreased oral intake.
Match the following etiologies (A-F) to the clinical vignette (31.1-31.6):
A. Malrotation with intermittent volvulus
B. Intussusception
C. Insecticide ingestion
D. Esophageal foreign body
E. Pyloric stenosis
F. Volvulus
31.1 A 6-year-old boy left alone for 10 hours, now with hematemesis and pneumomediastinum on chest x-ray.
31.2 A 3-week-old male infant with 2 days of projectile, nonbilious vomiting and constant feeding.
31.3 A 7-year-old boy with three episodes of severe abdominal pain and vomiting in the last month, previously diagnosed with failure to thrive.
31.4 An 8-month-old girl with bilious vomiting, constant abdominal pain for 12 hours, and upper GI study showing beak-like appearance of contrast.
31.5 An 11-month-old boy with intermittent bouts of crying and nonbilious vomiting, with a history of Meckel diverticulum. A small, elongated mass is felt on right side of his abdomen.
31.6 A 4-year-old girl with profuse vomiting, sweating, lacrimation, and diarrhea, who seizes in the emergency room.
31.1 D. The presence of blood in the vomitus and a pneumomediastinum point to an esophageal perforation, most likely from a foreign body in the esophagus.
31.2 E. The young age and presence of projectile, nonbilious vomiting after feeding are the keys to this diagnosis. The diagnosis of pyloric stenosis is much more common in males than females.
31.3 A. This is the presentation of a malrotation that did not cause enough symptoms at a younger age to lead to a diagnosis.
31.4 F. An infant with bilious vomiting and abdominal pain has a volvulus until proven otherwise. The upper GI study is diagnostic of this condition.
31.5 B. The intermittent nature of the symptoms and the palpable mass are highly suggestive of intussusception.
31.6 C. These symptoms are characteristic of a cholinergic syndrome, possibly caused by insecticide or nicotine poisoning.
Most foreign body ingestions by children will pass spontaneously, but button batteries, sharp objects, and multiple magnets in the esophagus should be removed endoscopically.
The risk of accidental poisoning with common household products and over-the-counter medications should be a routine part of the anticipatory guidance that occurs in a well-child visit.
When a child appears critically ill, do not delay your resuscitative efforts or surgical consultation while you wait for laboratory tests and x-ray results.
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