My additional recommendation:
In every pediatric patient of any age with abdominal symptoms (pain, decreased appetite, abnormal vital signs, nausea, vomiting, or diarrhea), our job is to always look for and rule out dehydration, sepsis, surgical abdomen*, and serious metabolic problems (for example, diabetic ketoacidosis presenting as GI symptoms) or to begin prompt treatment of the presumed problem (sometimes on spec–i.e. meaning sometimes begin treatment even before you are sure of the diagnosis).
*Don’t ever hesitate to get a pediatric surgery consult, even if your imaging is negative or you are not sure what the appropriate imaging is. The pediatric surgeon can be an invaluable resource for further guidance.
The key to adequate evaluation of any pediatric patient is accurate vital signs. Beware of the temptation to “guestimate” the pediatric vital signs. I recommend purchasing an electronic vital sign monitoring system for infants and children.
This episode will discuss an approach for a child in whom you suspect idiopathic intussusception. Listeners will learn how toa recognize the presenting signs and symptoms of idiopathic intussusception, develop an organized approach to a child with suspected intussusception including differential diagnosis, physical exam and investigations and review the treatment and prognosis of intussusception. This podcast was developed by Kieran Purich a medical student at the University of Alberta, with the help of Dr. Ioana Bratu, a pediatric surgeon and Associate Professor at the University of Alberta.
All that follows is from the script.
You are a fourth year student on a rural emergency medicine elective. A mother arrives in the Emergency Department with her 9-month-old baby boy who has been lethargic for the past couple hours. On history you find that the child has had intermittent, progressive episodes of crying over the past 5 hours, accompanied by vomiting and abdominal distention. The child has no notable comorbidities, yet he was diagnosed with a viral infection four days ago and the mother is worried that the previous physician may have overlooked a more serious infection. What would you consider on your differential diagnoses?
As with many conditions in newborns and toddlers, the differential diagnosis is very broad as the presentation has few distinguishing features. Some diagnoses, which should be considered in this patient, are: gastroenteritis, intussusception, appendicitis, intestinal malrotation, volvulus, testicular or
ovarian torsion, congenital peritoneal bands, Meckel’s diverticulum, or an incarcerated inguinal hernia.
Luckily, intussusception, the focus of our podcast, can be distinguished through imaging with high accuracy. Yet it is important to remember to rule out these other diseases in children with similar
presentations. For a more detailed review of the differential diagnosis, you can listen to our PedsCases podcast on acute abdominal pain.
What is intussusception?
Intussusception is the invagination of a proximal segment of intestine (the intussusceptum) into a distal segment (the intussuscipiens). This can cause obstruction as well as venous and lymphatic congestion in the bowel. If left unresolved it can also lead to intestinal edema, ischemia and potential perforation. Most commonly this invagination occurs at the ileocolic junction with the ileum telescoping into the colon,
and in the antegrade direction, paralleling the direction of peristalsis. This ileocolonic intussusception is typical for idiopathic intussusception.
It is important to stress that idiopathic intussusceptions only occuras an ileo-colonic intussusception where the ileum invaginates into the colon and can travel down from the right colon to the tranverse colon, and even further down to the left colon and sometimes out per rectum!
Intussusception can also occur in other areas of the bowel, such as small bowel to small bowel invagination, or large bowel to large bowel invagination, although this is less common, and would indicate that it is not idiopathic but that it has a pathological lead point.
Idiopathic intussusception occurs primarily in infants from 3 months to 3 years old, peaking between 5-9 months. Risk factors for intussusception include: male sex and co-existing/recent viral illnesses (adenovirus, rotavirus and HHV 6).
Intussusceptions that are not idiopathic have a pathological lead point such as: a Meckel’s diverticulum, duplication cyst, polyps, previous abdominal trauma with hematoma of bowel wall, gastrojejunal tube, lymphoma, metastatic disease, or other less
common lead points.
This being said, over 90% of cases of intussusception in young children are from an idiopathic cause, usually associated with lymphoid hyperplasia in Peyer’s patches within the ileum wall as a normal immune response to a viral illness. Within the older age groups intussusception is rare, and once the patient is older than five years a pathological lead point is much more common and needs to be further worked up.
Imaging is key for the diagnosis of intussusception. Ultrasound is the preferred modality due to its superior safety profile and higher sensitivity and specificity for the diagnoses of intussusception.
In the emergency setting, supine, frontal and left lateral decubitus abdominal radiographs are often used to rule
out other potential conditions such as the presence of free peritoneal air. These radiographs canoccasionally detect intussusception but cannot rule it out.
Sonography is operator dependent; therefore the efficacy for diagnosis depends largely on the examiner.
If sonography is not available, air enema can be used for both diagnosis and therapy. Please note that air enema is only indicated in ileocolonic idiopathic intussusception.
In older patients where you suspect a pathological lead point, other investigations may be needed. To work up a potential pathological lead point for non-idiopathic intussusception, one may need a contrast enema (barium is not preferred in case a perforation occurs), colonoscopy, or CT scan of the abdomen/pelvis.
All patients should have blood drawn for a CBC differential and electrolytes. Hemoccult testing and cultures of the stool may be indicated depending on the presenting symptoms.
When a physician suspects intussusception they should arrange for an urgent surgical consult. All patients may have significant dehydration reduced oral intake and vomiting, and may need fluid resuscitation. The patient should be kept NPO and given IV fluids for rehydration. If the patient is obstructed a nasogastric or NG tube can be placed.
As mentioned previously, pneumatic air enema is the primary treatment for patients with idiopathic intussusception, often completed under fluoroscopy or ultrasound. Air enema is more effective and avoids
the risks associated with liquid or barium enemas. Enema reduction is relatively safe, with under a less than 1% (0.8%) perforation rate and a 10% recurrence rate – which usually occurs within 48 hours of treatment.
Surgical reduction or resection is indicated if air enema reduction is contraindicated, particularly if there is
a bowel perforation.
If the child is critically ill, in shock, has peritonitis or there are signs of sepsis or free air in the peritoneal cavity they should be resuscitated and then managed surgically.
In the rare cases of a suspected intussusception due to a pathological lead point, the treatment is surgical with resection of the lead point if possible, otherwise an ostomy may be needed.
The overall mortality for children with idiopathic intussusception is less than 1%. Most infants do well if
intervention occurs within 24hrs.