Intussusception

  • See also: Abdominal PainGuideline

    Intussusception is the invagination of a proximal segment of bowel into the distal bowel lumen. The commonest occurrence is a segment of ileum moving into the colon through the ileo-caecal valve. It may occur at any age but commonly occurs in the 2 month to 2 year age group with a peak incidence at 5 to 9 months.

    Assessment

    History

    • The child appears to have intermittent pain which is colicky, severe and may be associated with the child drawing up the legs.
    • Episodes typically occur 2-3 times/hour and may increase over the next 12-24 hours
    • During these episodes of crying the child may look pale.
      (note: many other causes of infant crying are associated with facial redness rather than pallor).
    • Pallor and lethargy may be the predominant presenting signs, may be persistent rather than episodic, and in some the crying episodes may not be very vigorous.
    • Vomiting is usually a prominent feature (but bile stained vomiting is a late sign)
    • Bowel motions
      • blood and/or mucus
      • classic red currant jelly stool is a late sign
    • Diarrhoea is quite common and can lead to a misdiagnosis of gastroenteritis
    • There may be a preceding respiratory or diarrhoeal illness

    Examination

    • Pallor, lethargy - may be intermittent, and may look well in between episodes
    • Abdominal mass - sausage shaped mass RUQ or crossing midline in epigastrium or behind umbilicus, palpable in about two thirds of children.
    • Distended abdomen later in the course
    • Stool
      • Bloody stool/occult blood positive
    • PR unnecessary if good evidence of intussusception; abdominal mass or PR bleeding, but otherwise should be done for signs of PR blood or mass.
    • Signs of an acute bowel obstruction
    • Hypovolaemic shock is a late sign

    Intussusception flowchart
    View flowchart

    Investigations

    See flow chart

    Plain abdominal Xray
    • Performed to exclude perforation or bowel obstruction
    • A normal AXR does not exclude intussusception
    • Signs of intussusception on a plain Xray include:
      1. Target sign - 2 concentric circular radiolucent lines usually in the right upper quadrant
      2. Crescent sign - a crescent shaped lucency usually in the left upper quadrant with a soft tissue mass
    Ultrasound scan
    • Diagnostic investigation of choice (unnecessary if high level of suspicion)
    • Useful if there is a suggestive history but no mass palpable or signs on plain AXR and may identify other pathology
    Air enema
    • This investigation is both diagnostic and therapeutic and is the initial investigation of choice if strong clinical suspicion of intussusception (eg. palpable mass & bowel obstruction)
    • There is a small risk of bowel perforation and bacteraemia during the gas enema (the surgical registrar as well as a suitably trained nurse should attend with appropriate resuscitation equipment)
    Blood tests
    • Blood glucose
    • FBE and U&E's may be useful if child looks unwell
    • Blood group and hold prior to theatre

    Management

    If shocked see resuscitation guidelines

    Involve general surgeons early

    See flow chart

    • Secure IV access for all patients who are suspected to have intussusception
    • Most children will require fluid resuscitation with IV boluses of 20mls/kg normal saline before radiological investigations
    • Give adequate analgesia (usually morphine)
    • Keep nil orally
    • Pass nasogastric tube if bowel obstruction or perforation on AXR
    • Consider IV antibiotics before air enema (discuss with surgeons)