Definition
Key History
Key Physical Exam
Risk Factors for Intussusception
Differential Diagnosis
Diagnostic Testing
Clinical Risk and Safety Pearls
Treatment
Complications

Definition

Intussusception is the invagination of part of the intestine into itself. It is the most common abdominal emergency in early childhood. Intussusception is the most common cause of intestinal obstruction in children between 6 and 36 months of age. 60% are younger than one year old and 80% are younger than two years old.

There is now an increasing body of evidence that suggests that viral triggers may play a role in some cases. The incidence of intussusception has a seasonal variation; approximately 30% of patients experience viral illness before the onset; and there appears to be a strong association with adenovirus infection.

Key History

Key Physical Exam

• Sausage-shaped abdominal mass in RUQ
• If event witnessed, infant drawing leg up to abdomen, and in obvious severe pain.

Risk Factors for Intussusception

Differential Diagnosis

Diagnostic Testing

1. Imaging:
   • Ultrasound – should be the first study when the diagnosis is ambiguous; accuracy of ultrasound for intussusception approaches 100%.
   • CT – can identify intussusception, but is time consuming and best used for patients for whom the other imaging modalities are unrevealing.
   • Air contrast enema study – is the standard procedure for diagnosis and treatment for children with high suspicion of intussusception.
   • Plain abdominal films – are not highly useful except if needed to rule out perforation, which would contraindicate air contrast enema.
2. Labs:
   • CBC
   • Urinalysis
   • Electrolytes
   • Stool guaiac

Clinical Risk and Safety Pearls

• Maintain a high index of suspicion for intussusception in this age group.
• The initial presenting sign may be lethargy or altered consciousness alone. Thus intussusception is often confused with sepsis.
• Intussusception should be considered in the evaluation of lethargy or altered consciousness, especially in infants.
• Prior to the air contrast enema study the patient should be stabilized and prepped for surgery in the event surgery becomes necessary. The surgical team should be notified before the enema is performed.
• The lead point is the leading edge of the intussusception and is usually seen in older children and may be due to an anatomic anomaly such as Meckel’s diverticulum, polyp or lymphoma.
• Classic triad – currant-jelly stool, sausage abdominal mass in RUQ and pain seen in less than 15% of patients
• Approximately 33% of patients do not pass blood or mucus or develop an abdominal mass.

Treatment

1. ABCs
2. Notify surgical consultant prior to enema.
3. The standard procedure for diagnosis and treatment of intussusception is a contrast enema.
4. NG tube for gastric decompression
5. Air or carbon dioxide reduction techniques are also being used successfully and have the advantage of less radiation and cost. When perforation is noted with air reduction the colonic wall tears are smaller compared with hydrostatic contrast techniques.
6. Surgery is indicated when nonsurgical attempts at reduction are incomplete or unsuccessful.
7. Enema reduction is contraindicated if there is free air, air fluid levels, peritonitis, perforation, hypovolemic shock, or currant-jelly stools for more than 24 hours.

Complications

• Perforation of bowel – risk is higher the longer the intussusception has been present
• Recurrence after successful nonoperative reduction is about 10%. Recurrence is not necessarily an indication for surgery. Each recurrence should be handled as if it were the first episode.