Case vignette
4mo M p/w bilious emesis, poor PO intake, no stool x4d.
HR 190, BP 68/40, RR 35, T 37.
Appears listless with weak cry. Dry mucous membranes with sunken fontanelles, cap refill ~3s. Abdomen is tender with involuntary guarding.
What do you see?
Abd1 US 1: Target sign, with small bowel intussuscepted within small bowel.
Abd1 US 2: telescoping of bowel, long axis view. Anechoic fluids = edema, concerning for inflammation. >2.5cm diameter suggesting ileocolic intussusception
What do you do next?
You suspect intussusception, most likely ileocolic. The case is discussed with surgery who is concerned air enema may be unsuccessful based on patient's peritoneal exam, length of symptoms, and possible obstruction. Air enema is attempted without success. Patient taken to OR where Meckel's diverticulum lead point identified and removed after intussusception reduced.
Teaching points. POCUS can be used both to identify intussusception and help localize it. Mean lesion diameter of intussusception is greater for ileocolic vs ileal-ileal (some sources give ~2.6cm vs ~1.4cm). Ileocolic lesions tend to be more symptomatic, including more vomiting, leukocytosis, and blood in stool. They are right-sided, whereas ileal-ileal (small bowel) lesions are more often periumbilical to left sided.
Sources: https://pubs.rsna.org/doi/full/10.1148/radiol.13122639
Residents/staff: Dr. Laura Waagmeester, Dr. Yvonne Wang
Intussusception