a world of trouble…

The case.

A 3 week old infant is bought into your ED late at night. She is febrile and looks incredibly unwell. Her parents report a 36 hour history of increasing vomiting and poor oral intake. She has not had a wet nappy for 12 hours or so and the parents now report a fever of 39.5*C.

She was born at 39 weeks gestation following an unremarkable pregnancy and delivery. They were only in hospital for 2 days as everything was going so well…..

When you approach this child in resus, you immediately identify that she is in a whole world of trouble. She is flat and listless, tachypnoeic at 70/min (with moderate work of breathing) and tachycardic at 204 bpm. Her capillary return is 5-6 seconds and her skin is mottled. Her abdomen is quite obviously distended.

Amongst the flurry of activity at the bedside the following x-ray is taken….

What’s going on here ?
What are your differentials ??
What are you going to do next ???

Based on the clinical picture above, we were left with a few differentials including;

• Sepsis, sepsis, sepsis…
• Pyloric stenosis
• ‘something nasty in the belly’…
  • obstruction
  • malrotation-volvulus

There are a number of things going on in this xray….

1. a healing left-sided clavicle fracture, with callous formation.
2. small right pneumothorax.
3. intestinal dilatation. nasogastric tube insitu.
4. pneumatosis intestinalis.
5. portal vein gas.

These xray findings were almost diagnostic of necrotising enterocolitis ….

Necrotising Enterocolitis (NEC).

The most common gastrointestinal emergency in neonates and the most common cause of intestinal perforation occurring in the neonatal period. It is a condition of intestinal necrosis in previously well infants and whilst it is predominately a disease of prematurity & most cases occur whilst the child is in the NICU, up to 10% of cases occur in full term infants. As today’s child-delivery practices change (home-births, very early discharges from labour wards – some as early as 4 hours) this is potentially a problem that can make its way into the Emergency Department.

The exact pathophysiologic mechanism behind NEC remains unknown, but appears multifactorial. The primary event may be inflammation or injury to the intestinal wall, which begins in the mucosa and then extends transmurally. The distal ileum and proximal colon are more commonly affected, and the involvement may be continuous or patchy.

Risk factors include;

• Prematurity (90% of cases)
• Aggressive enteral feeding
• Birth-related hypoxic or ischaemic insults (including congenital heart disease)
• Infectious causes

The development of NEC is closely related to gestational age;
          * 24-28 weeks: NEC w/in 2-4 weeks of life.
          * 29-32 weeks: NEC w/in 1-3 weeks of life.
          * Full term infants: NEC in 1st week of life.

Clinically…

The classic symptoms are that of food intolerance (poor feeding) and vomiting (either bilious or non-bilious). Examination may reveal palpable loops of bowel (oedematous & distended with air), as well as erythema & discolouration of the abdominal wall. Other symptoms and signs include; haematemesis, PR bleeding, shock and apnoea.

NEC is commonly divided into three stages:
          1) Early or suspected NEC [food intolerance, vomiting, ileus]
          2) Definite NEC [confirmed on radiograph w/ 
               intestinal dilatation & pneumatosis intestinalis]
          3) Advanced disease [perforation, marked abdo distension,
               metabolic acidosis, DIC & shock]

** an example of pneumatosis intestinalis, courtesy of Wikipedia **