NEC

Question 1

Explain the pathophysiology of necrotising enterocolitis

Answer 1

Mucosal damage, bacterial translocation, infection and inflammation of the ascending colon and terminal ileum; causing necrosis, perforation and death.

Question 2

Epidemiology

Answer 2

Commonest cause of death in premature infants - 3 in 10 000

Question 3

Symptoms

Answer 3

Sudden intolerance to feeding
Abdominal distention
Bloody stools
Haemodynamic instability

Question 4

Investigations

Answer 4

Abdominal x ray
Group and save
CRP
Clotting
Stool cultures
Blood gas - lactate and metabolic acidosis

Question 5

What would you see on an abdo x ray?

Answer 5

Small bowel dilatation - (The air loops in the abdomen would be bigger and less neatly divided by linear polygonal borders.)

Pneumatosis intestinalis = mottled appearance from gas in the wall, diagnostic of NEC

Fixed dilated bowel loop across many abdo x rays

Also:

Asymmetrical bowel dilatation
Rigler sign (air on both sides of the bowel, indicating perforation
Pneumotosis intestinalis (intramural gas)
air outlining the falciform ligament (football sign)
Portal venous gas

Question 6

Differentials for NEC

Answer 6

Intestinal obstruction
Sepsis

Question 7

Management of NEC

Answer 7

NBM
IV fluids / TPN
Large bore NG tube on free drainage
Broad spec antibiotics

Feeds are then slowly introduced with caution, as the mucosa of the small bowel has lost absorptive area

Question 8

Staging of NEC

Answer 8

Bell staging
Stage 1 - stable pt
Stage 2 - mild metabolic acidosis, thrombocytopenia, absent bowel sounds
Stage 3 - perforation likely, signs of peritonitis, pneumoperitoneum

Question 9

How does management differ according to staging?

Answer 9

Stage 1 - NBM and ab for 5 days
Stage 2 - may need inotropes, intubation, morphine infusion + serial abdo x rays to watch out for perforation
Stage 3 - requires urgent surgery

Question 10

Explain the two types of surgical procedures if small patch of GI is affected

Answer 10

Resection + anastamosis if small patch of GI tract affected
Or stoma put in to divert proximal bowel to skin

Question 11

What do you call it if the whole GI tract is affected?

Answer 11

NEC totalis

Question 12

Management for NEC totalis

Answer 12

If NEC totalis, bowel is left unresected (bleak prognosis)

Question 13

What happens after a stoma is put into place?

Answer 13

If stoma - continue with NBM and TPN for 14 days at least, then remove after 3 months after laparotomy, once you’ve ruled out stricture in distal bowel with a contrast study

Question 14

Complications

Answer 14

Wound breakdown
Stoma site necrosis
STricture
Short gut / TPN dependence ; TPN related liver cirrhosis, requiring transplants