Necrotising enterocolitis

Question 1

What is necrotising enterocolitis (NEC)?

Answer 1

NEC is the most frequent and lethal gastrointestinal emergency in preterm newborn infants. It is characterized by acute inflammation and variable damage to the intestinal tract, ranging from mucosal injury to full-thickness necrosis and perforation.

Question 2

What is the incidence of NEC in low birth weight infants?

Answer 2

The incidence of NEC is about 6 to 7% in low birth weight infants (less than 1500g).

Question 3

What is the overall mortality rate of NEC?

Answer 3

The overall mortality rate of NEC is 30 to 50% despite advancements in neonatal care.

Question 4

Antenatal risk factors

Answer 4

1. Maternal hypertension.
2. Maternal drug use (cocaine).
3. Maternal infection / chorioamnionitis.
4. Placental abruption.
5. Perinatal hypoxia

Question 5

What do antenatal risk factors lead to

Answer 5

These antenatal factors may lead to circulatory instability, reduced mesenteric blood
flow and bowel ischaemia.

Question 6

Postnatal risk factors

Answer 6

1. Prematurity
2. Non- human milk formula/ enteral feeding
3. Disruption of commensal gut bacteria and presence of pathogenic bacteria
4. Blood transfusion
5. Patent ductus arteriosus

Question 7

How does decreasing gestational age affect the risk of necrotising enterocolitis (NEC)?

Answer 7

Decreasing gestational age is associated with an increased risk of NEC.

Question 8

What factors contribute to the increased risk of NEC in premature infants?

Answer 8

Premature infants have an immature mucosal barrier with increased permeability, reduced concentrations of IgA, mucosal enzymes, and protective factors such as lactoferrin, contributing to the increased risk of NEC.

Question 9

What is the protective effect of human milk compared to formula in relation to NEC?

Answer 9

Human milk compared to formula is more protective against NEC due to the decrease in foreign antigens and the presence of protective factors.

Question 10

Are slow advancement and delayed initiation of feeds associated with a reduced risk of NEC?

Answer 10

No, slow advancement and delayed initiation of feeds are NOT associated with a reduced risk of NEC.

Question 11

Is there a confirmed causal relationship between blood transfusions and necrotising enterocolitis (NEC)?

Answer 11

Transfusion-associated NEC has been described, but a causal relationship is yet to be established.

Question 12

How does a patent ductus arteriosus (PDA) contribute to the risk of necrotising enterocolitis (NEC)?

Answer 12

A patent ductus arteriosus (PDA) results in left-to-right shunting, leading to reduced post-ductal and systemic blood flow, which may contribute to the risk of NEC.

Question 13

systemic signs

Answer 13

Respiratory distress,
apnoea,
lethargy,
irritability,
poor feeding, temperature
instability,
poor perfusion

Question 14

abdominal signs

Answer 14

-Abdominal distension or tenderness,
-abdominal wall erythema or induration,
-localised abdominal -
-mass,
-ascites,
-large gastric aspirates,
-blood or bile-stained
vomitus,
-ileus and bloody stools.

Question 15

Blood studies (not specific for NEC)

Answer 15

• Neutropaenia and thrombocytopaenia on FBC.
• Elevated C-reactive protein / CRP.
• Metabolic acidosis and increased lactate.
• Electrolyte abnormalities.
• Deranged coagulation profile.
• Blood and CSF culture

Question 16

Stools

Answer 16

Stool occult blood.

Question 17

Abdominal X ray

Answer 17

• The radiological hallmark sign for NEC is pneumatosis intestinalis, which appears
  as bubbles of gas in the bowel wall. Other radiological features include, thickened
  bowel walls and abnormal bowel gas pattern, portal or hepatic venous air and
  pneumoperitoneum.

Question 18

Modified Bell’s Staging Criteria: Stage 1

Answer 18

suspected NEC

Question 19

Modified Bell’s Staging Criteria: Stage 2

Answer 19

definite NEC

Question 20

Modified Bell’s Staging Criteria: Stage 3

Answer 20

advanced NEC.

Question 21

What is the initial approach to medical management for newborn infants with Bell’s stage I or II necrotising enterocolitis (NEC)?

Answer 21

The initial approach involves non-operative management, including discontinuation of enteral feeds, decompression of intestinal contents with a nasogastric tube, bowel rest, antibiotic treatment, and correction of electrolyte or coagulation abnormalities.

Question 22

What supportive measures should be provided during bowel rest in NEC management?

Answer 22

During bowel rest, intravenous fluid or parenteral nutrition should be given, and feeds should be reintroduced slowly.

Question 23

What are the indications for surgical management in necrotising enterocolitis (NEC)?

Answer 23

Indications for surgery include pneumoperitoneum with likely bowel perforation, clinical deterioration despite aggressive medical therapy, presence of fixed dilated loop of bowel, and evidence of peritonitis or gangrenous bowel.

Question 24

What are the goals of surgery in NEC management?

Answer 24

The goals of surgery are to resect necrotic bowel, decompress the intestine, free intraperitoneal air, and preserve as much of the bowel length as possible.

Question 25

What are the most common late complications of necrotising enterocolitis (NEC)?

Answer 25

The most common late complications of NEC include stricture formation and short bowel syndrome.

Question 26

What is the most important preventative strategy to reduce the risk of NEC?

Answer 26

Human milk instead of formula is the most important strategy to reduce the risk of NEC.

Question 27

What should be considered if mother’s own milk is unavailable for preterm, low birth weight infants?

Answer 27

If mother’s own milk is unavailable, pasteurized donated human milk should be considered for preterm, low birth weight infants.

Question 28

What has been shown to reduce the risk of NEC and can be used as a prophylactic measure?

Answer 28

Prophylactic probiotic administration has been shown to reduce the risk of NEC.

Question 29

What infection control measures help ensure a lower risk of NEC?

Answer 29

Strict infection control measures, such as handwashing and avoidance of overcrowding within the nursery, help ensure a lower risk of NEC.