Intussusception — structured clinical encounter

Station 1 — assessment and recognition

Asked for my first impression, I explain that a previously well seven-month-old with rhythmic episodes of screaming, pallor and drawing up the knees, a drowsy interval between them, and vomiting has the classic pattern of intussusception. I would observe him through an episode and palpate during the quiet interval, where the firm sausage-shaped mass in his right upper quadrant makes the diagnosis highly likely. I would grade him as mildly to moderately dehydrated from the vomiting and assess his perfusion. [1] [2]

Station 2 — excluding the mimics

Asked what else I would consider, I state that I would examine the groin hernial orifices for an incarcerated hernia, ask whether the vomit has become bilious to raise malrotation with volvulus, and consider gastroenteritis, appendicitis and colic. The rhythmic, peristalsis-driven pattern with a palpable mass points more strongly to intussusception than these, but I would reach for an ultrasound to confirm rather than settle on a comfortable alternative. The fact that he is drowsy between episodes reinforces rather than reassures me, because lethargy can be the dominant finding. [2] [1]

Station 3 — confirmation and resuscitation

To confirm the diagnosis I would arrange an abdominal ultrasound, which has a sensitivity in the high nineties, and I would expect the target sign on the transverse view and the pseudokidney sign on the longitudinal view. While that is organised I would make him safe: nil by mouth, intravenous access, a nasogastric tube on free drainage, and a ten to twenty millilitre per kilogram isotonic crystalloid bolus reassessed for dehydration, with analgesia and a glucose check. I would have the surgeon and radiologist involved early together. [5] [6]

Station 4 — reduction and the contraindication

For definitive treatment I would offer air enema reduction as first-line therapy, because a meta-analysis found it achieves a higher success rate than liquid or contrast enema, is faster, uses less radiation and makes any perforation easier to manage, succeeding in roughly three-quarters to four-fifths of attempts. I would state clearly that enema reduction is contraindicated if he develops peritonitis, shock or free air, in which case he goes straight to surgery after resuscitation and antibiotics. I would examine him deliberately for tenderness and guarding before the enema. [3] [6]

Station 5 — escalation, observation and the family conversation

Finally I describe how I would observe and counsel the family. After a successful reduction I would observe him briefly to ensure he tolerates feeds and to watch for recurrence, because intussusception recurs in about ten percent of children, usually within days to weeks, and is almost always reducible by a further enema. I would give the family clear safety-netting: return urgently if the same intermittent screaming and drawing up of the knees, vomiting, lethargy or blood in the stool returns. If reduction fails or a lead point is found, he proceeds to surgery, and I would explain the plan honestly while reassuring them that most infants are reduced without an operation and do well. [8] [2]