The Answer: Intussusception (congrats to @DamonTedford and @AndrewACNP1 on Twitter for getting it right!)
Intussusception is a telescoping of one part of bowel into a distal pat of bowel (the proximal, inner portion of the telescope is referred to as the intussusceptum and the receiving distal portion is called the intussuscipien).
- Most commonly seen between ages 3 months and 5 years. 60% of cases occur in the first year of life, and it peaks between 6 and 12 months
- Most common location: Iliocecal Junction
- Classic presentation and buzzwords include: Intermittent colicky abdominal pain, RUQ (or RLQ) mass, vomiting, current jelly stools
This can be a difficult diagnosis to make as your patients, as noted above, are commonly between 6 and 12 months and unable to provide a great history. There are multiple features that can clue you in, however. When kids present with bilious vomiting, they have an obstructive process until proven otherwise. Children with intussusception will often have colicky pain, with intermittent lethargic periods. They will have periods of fussiness and irritability where they draw their knees up to the chest, followed by periods of peacefulness or even lethargy. In fact, a few cases I have seen have had lethargy as part of the parent’s concern for bringing them in. Remember, the boards always talk about current jelly stools, however this is a late and concerning finding (occurring in less than half of cases).
Ultrasound is a great initial diagnostic modality to use that does not involve radiation, and does not require specialty services (so you can do this at your shop even if you do not have immediate availability of pediatric surgery). Sensitivity and specificity have been reported up to 98-100%. However, remember that it is most useful when the patient is in pain, and this can make it difficult. The colicky pain followed by lethargy may result from telescoping and un-telescoping of bowel, so if performed during lethargic or painless periods or by an inexperienced sonographer it may not yield useful information. Patients with a non-diagnostic US and high clinical suspicion for intussusception need barium or air-contrast enema and pediatric surgery consultation. The board answer is that barium or air-contrast enema is the gold standard as it is both diagnostic and therapeutic.
The classic US finding, as seen in the previous clip and the above images, is the target sign. In this, the hypoechoic intussuscipien surrounds the hyper echoic intussusceptum. This previous video also shows some free fluid around the bowel. This, of course, can be done at the bedside by EM physicians. Common false positives include stool, IBD, and misidentified anatomy. In saggital you can also see a “pseudo kidney” sign, with multiple layers of edematous bowel wall mimicking the appearance of a kidney.
Up to 90% can be reduced non-operatively, and there is a 5-10% recurrence rate (usually in the first 24 hours after reduction). Our patient was transferred to the closest pediatric surgical center. Enema was unsuccessful, and operative intervention was needed. He underwent an uncomplicated operation and post-operative course.
1. Emergency Medicine: A Focused Review of the Core Curriculum. AAEM. p 130-131.
2. Halm, B. Diagnosis of intussusception using point of care ultrasound in the ED: Case report. American J of Emerg Med (2011) 29, 354.
3. Great SAEM resource on pediatric POC US