Lonnie King, MD,
Consulting Staff, Department of Emergency
Medicine, Children's Healthcare of Atlanta at Scottish
Rite
Nothing to disclose.
Specialty Editor(s)
Garry Wilkes, MBBS, FACEM,
Director of Emergency Medicine, Bunbury
Hospital, Western Australia; Medical Consultant, St John
Ambulance, WA Ambulance Service; Adjunct Associate Professor,
Edith Cowan University; Clinical Associate Professor, Rural
Clinical School, University of Western
Australia
Nothing to disclose.
Grace M Young, MD,
Associate Professor, Department of
Pediatrics, University of Maryland Medical
Center
Nothing to disclose.
John D Halamka, MD, MS,
Associate Professor of Medicine, Harvard
Medical School, Beth Israel Deaconess Medical Center; Chief
Information Officer, CareGroup Healthcare System and Harvard
Medical School; Attending Physician, Division of Emergency
Medicine, Beth Israel Deaconess Medical
Center
Nothing to disclose.
Mary L Windle, PharmD,
Adjunct Associate Professor, University of
Nebraska Medical Center College of Pharmacy; Pharmacy Editor,
eMedicine
Nothing to disclose.
Chief Editor
Richard G Bachur, MD,
Associate Professor of Pediatrics, Harvard
Medical School; Associate Chief and Fellowship Director,
Attending Physician, Division of Emergency Medicine,
Children's Hospital of Boston
Nothing to disclose.
Background
Intussusception is the telescoping or prolapse of one portion of the bowel into an immediately adjacent segment. Contrast enema can reduce the intussusception in approximately 75% of cases.
Intussusception most commonly occurs at the terminal ileum (ie, ileocolic). The telescoping proximal portion of bowel (ie, intussusceptum) invaginates into the adjacent distal bowel (ie, intussuscipiens).
The mesentery of the intussusceptum is compressed, and the ensuing swelling of the bowel wall quickly leads to obstruction. Venous engorgement and ischemia of the intestinal mucosa cause bleeding and an outpouring of mucous, which results in the classic description of red "currant jelly" stool.
Most cases (90%) are idiopathic, with no identifiable lesion acting as the lead point or pathological apex of the intussusceptum.
Intussusception is the predominate cause of intestinal obstruction in persons aged 3 months to 6 years. The estimated incidence is 1-4 per 1000 live births.
Mortality/Morbidity
Most patients recover if treated within 24 hours. Mortality with treatment is 1-3%. If left untreated, this condition is uniformly fatal in 2-5 days. Recurrence is observed in 3-11% of cases. Most recurrences involve intussusceptions that were reduced with contrast enema.
Sex
Overall, the male-to-female ratio is approximately 3:1. With advancing age, gender difference becomes marked; in patients older than 4 years, the male-to-female ratio is 8:1.
Age
Intussusception is most common in infants aged 3-12 months, with an average age of 7-8 months. Two thirds of the cases occur before the patient's first birthday. Intussusception occurrence is rare in persons younger than 3 months, and it becomes less common in persons older than 36 months.
The typical presentation of intussusception is a previously healthy infant boy aged 6-12 months with sudden onset of colicky abdominal pain with vomiting.
Paroxysms of pain occur 10-20 minutes apart.
Initially, loose or watery stools are present concurrent with vomiting and, within 12-24 hours, blood or mucous is passed rectally.
Early in the course, the patient appears completely well between the episodes of abdominal pain.
Lethargy may dominate the initial presentation. However, lethargy usually occurs later in the process.
The classic triad of colicky abdominal pain, vomiting, and red currant jelly stools occurs in only 21% of cases.
If intussusception is strongly suspected, perform a contrast enema without delay. This is contraindicated in patients with an obvious surgical abdomen (eg, signs of peritonitis or perforation) and in unstable patients. Image obtained during air contrast enema is shown below.
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Intussusception evident during air contrast enema prior to reduction. Courtesy of Dr. Kelly Marshall, Children's Healthcare of Atlanta at Scottish Rit....
Plain abdominal radiographic findings may be normal early in the disease or may show perforation, typical obstructive pattern, or soft tissue mass of the intussusception on the right side. A paucity of gas in the right upper quadrant may be present. Intussusception is shown in the radiograph below.
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Note intussusception in the left upper quadrant on this plain film of an infant with pain vomiting. Courtesy of Dr. Kelly Marshall, Children's Healthc....
Morrison et al evaluated the ability of pediatric emergency physicians to recognize intussusception on abdominal radiographs.[2] In a prospective experimental study, 14 pediatric emergency physicians interpreted radiographs of 50 cases of intussusception and 50 matched controls; these interpretations showed a sensitivity of 48% and a specificity of 21%. In 11% of cases, the abdominal radiographs were incorrectly interpreted as being reassuring. Morrison et al concluded that, when interpreted by pediatric emergency physicians, abdominal radiographs have a low sensitivity and specificity for diagnosing intussusception.
Ultrasonography has been used to diagnose intussusception. A recent study examined the use of ultrasonography as a primary modality to assess ileocolic intussusception.[3] The study reported that the overall sensitivity for detecting intussusception was 97.9% and the specificity was 97.8%. The authors concluded that ultrasonography should be used as a first-line examination for the assessment of possible pediatric intussusception.
Provide rehydration and stabilization as needed in patients with intussusception.
Contrast enema is diagnostic in approximately 95% of intussusception cases. It is therapeutic and curative in most cases with less than 24-hour duration.
Admission is indicated for all patients with intussusception because as many as 10% of those with successful radiologic reduction have a recurrence, usually in the first 24 hours.
Radiologic reduction is best performed with the surgeon on standby because complications may develop and require immediate surgery. This may require transfer to a facility with a pediatric surgeon. The benefit of transfer must be weighed against the delay in reduction.
Intussusception evident during air contrast enema prior to reduction. Courtesy of Dr. Kelly Marshall, Children's Healthcare of Atlanta at Scottish Rite.
Note intussusception in the left upper quadrant on this plain film of an infant with pain vomiting. Courtesy of Dr. Kelly Marshall, Children's Healthcare of Atlanta at Scottish Rite.
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