Gastrointestinal Problems – Neonataology
Echogenic bowel: Increased density of bowel walls seen on antenatal scans for a number of reasons. Commonly seen on antenatal ultrasound. In a structurally normal fetus there are usually no adverse sequelae. If there are genetic abnormalities with IUGR and dilated bowel then the prognosis is poor.
- Swallowed blood
- Cystic fibrosis
- TORCH infections
- GI obstruction
|Condition||Epidemiology/Time course||Mechanism of illness||Typical features||Management|
|Necrotising enterocolitis (NEC)||1 to 3 per 1,000|
Predominantly in prem babies coming on 2 to 3 weeks after delivery
|Ischaemic necrosis of intestinal mucosa (usually terminal ileum and colon, but can involve the whole bowel in severe cases). Unknown exact cause.|
Risk factors: prematurity, artificial feeds, perinatal asphyxia, poor gut perfusion (heart disease, antenatal absent end-diastolic flow, APH), RBC transfusion, polycythaemia, chorioamnionitis/sepsis
Protective factors: breast milk, trophic feeding
|Hx: apnoeas, resp distress, poor feeding, signs of sepsis|
Abdo tender/distended, gastric retention, vomiting+/- bile, diarrhoea, GI bleed, ileus
AXR: dilated bowel loops, intramural gas, perforation, portal venous gas, ascites
Bloods/septic screen - signs of sepsis, inflammation and possible DIC
Bell’s staging criteria
|Nil by mouth + gastric decompression|
Correct DIC or metabolic acidosis as they arise
Antibiotics: penicillin + gentamicin (or cefotaxime) + metronidazole OR Tazocin + gentamicin (+/- vancomycin)
Monitor AXR up to 6 to 12 hourly in acute phase
Indications for surgery: peritonitis, pneumoperitoneum, perforation, unremitting deterioration, abdo mass, ascites, obstruction.
Surgery: resection of necrotic bowel and stoma
|Hirschsprung's disease||1 in 5,000|
M:F = 4:1
Most commonly diagnosed when obstructing in the neonatal period.
Very mild (short segment) cases can present late in childhood as severe constipation.
|Motor disorder of the gut caused by failure of migration of neural crest cells embryologically resulting in an aganglionic section of bowel.|
The aganglionic section fails to relax causing a functional obstruction.
The rectum is always affected and the aganglionic segment extends backwards and can include the whole large bowel in very severe cases.
Associated with a number of syndromes (in 25% cases) including: Downs synd, Bardet-Biedl synd, Congenital central hypoventilation synd, multiple endocrine neoplasia type 2, Smith-Lemli-Opitz sydn
|Hx: Neonatal obstructive presentation (bilious vomiting, abdo distention, failure to pass meconium >48 hrs age), explosive stool after digital rectal exam|
Can have a gastroenteritis/sepsis like presentation
In later childhood: chronic constipation, failure to thrive
Ix: Plain AXR: distal obstruction
AXR with contrast enema: narrow section of bowel with transition zone
Rectal biopsy (gold standard for diagnosis): absence of ganglion cells
|Rare complication: volvulus|
Bowel washout/rectal irrigations to decompress the backed up bowel before surgery
Surgery: resect aganglionic area and attach rest to the rectum (good result in the majority of cases with normal life)