Thirty-Six Hours of Intussusception in a Lethargic Five-Year-Old
A 5-year-old boy has 36 hours of episodic crampy abdominal pain with vomiting and one episode of blood-tinged stool. He is now drowsy and difficult to rouse, with dry mucous membranes and capillary refill of 3 seconds. He is afebrile. Ultrasound shows a 3.2 cm target-like bowel-within-bowel mass in the right upper to mid abdomen, no free fluid, preserved mural vascularity on color Doppler, and no identifiable lead point. The appendix is not visualized. Serum sodium is 133 mmol/L, bicarbonate 15 mmol/L, and lactate 3.1 mmol/L. A pediatric surgeon is in the room and asks whether the duration of symptoms and the lethargy are contraindications to enema reduction.
1. Is this idiopathic ileocolic intussusception? Does the 36-hour duration and the lethargy change your approach?
Read the worked answer
Diagnosis. The ultrasound description is classic for ileocolic intussusception. No lead point is seen, and idiopathic lymphoid hyperplasia remains the most common cause even at age 5, though the probability of a pathologic lead point (Meckel diverticulum, duplication cyst, polyp, lymphoma) rises above age 2 and warrants a lower threshold for later workup if there is recurrence.
Duration. Greater than 24–48 hours is a relative, not absolute, contraindication. Success rates fall and perforation risk rises, but most children in this window still reduce. The absolute contraindications are peritonitis, free perforation, and shock - none of which are present.
Lethargy. Obtundation occurs in a substantial minority of children with intussusception and is a well-recognized presentation, not evidence of an irreducible bowel or a surgical abdomen. It should not by itself divert the child from enema reduction.
The real issue is resuscitation. Dry mucosa, delayed capillary refill, bicarbonate 15, and lactate 3.1 indicate dehydration and hypoperfusion. Give isotonic fluid boluses first; reduced mesenteric perfusion is both a reason the bowel may not reduce and a reason a perforation would be poorly tolerated. After resuscitation, proceed with pneumatic reduction under fluoroscopy or ultrasound with surgical standby. The surgeon should be told the plan, not asked to veto it.
2. Describe your pneumatic reduction technique and pressure limits, and state what you do if the first attempt fails.
Read the worked answer
Technique.
- Confirm the diagnosis and exclude perforation and peritonitis; place a large-bore rectal catheter with the balloon inflated in the rectum and the buttocks taped.
- Use fluoroscopic or ultrasound guidance with a manometer and an occlusion device in the room. Fluoroscopy gives better leak detection; ultrasound avoids ionizing radiation and is increasingly preferred where expertise exists.
- Pressure. A maximum of 120 mmHg is conventionally accepted (many centers use 80–120 mmHg titrated to the child). Exceeding 120 mmHg adds risk without improving success.
- Attempts. Up to three attempts of about 3 minutes each, with complete decompression between attempts.
- Success. Complete reflux of gas into the terminal ileum with resolution of the mass and clinical improvement. Success is roughly 80–90% when symptoms are under 48 hours.
If the first attempt fails: decompress, reassess the child, allow a short interval (30–60 minutes) with continued resuscitation, and consider a second attempt if the child remains stable and there is no sign of perforation. Persistent failure, perforation, or clinical deterioration mandates operative reduction. After successful reduction, observe for early recurrence (5–10%) and instruct the family to return for recurrence. Do not perform a delayed repeat enema in an unstable child.
3. Reduction is successful. Six months later the child returns with a second episode, again reduced successfully. What workup do you recommend, and how would a Meckel scan fit in?
Read the worked answer
Recurrent intussusception in a child over 2 years raises the probability of a pathologic lead point and warrants evaluation.
- First-line evaluation. Repeat high-quality ultrasound by an experienced sonographer, and consider contrast or cross-sectional evaluation of the small bowel (CT or MR enterography) to look for a duplication cyst, polyp, or mass. Endoscopy can identify Peutz-Jeghers polyps or lymphoma.
- Meckel diverticulum. A Meckel diverticulum can act as a lead point or invert and cause intussusception. A pertechnetate (Meckel) scan is most useful when there is painless lower gastrointestinal bleeding; sensitivity is improved by pretreating with an H2 blocker or proton pump inhibitor for several days, and by imaging dynamically with a bladder catheter in place. In a child whose presentation is intussusception without bleeding, the pre-test probability is lower and the scan is a secondary, not first-line, test.
- Radiation reasoning. A Meckel scan delivers roughly 1–3 mSv, comparable to a low-dose CT abdomen; choose based on the question being asked, not on the assumption that nuclear medicine is always lower dose.
- Key point. For a single idiopathic episode at age 5 with no lead point on ultrasound, no workup is indicated. Recurrence changes that calculus.