Abdominal distention

Question 1

What are the differentials for abdominal distention?

Answer 1

NEC
DDx: sepsis, intussusception, IEM, CHD, cow-milk protein allergy,
intestinal obstruction

Question 2

What is NEC?

Answer 2

• an acquired neonatal disorder representing an end
  expression of serious intestinal injury after a
  combination of vascular, mucosal and metabolic, etc
  insults to a relatively immature gut
• MC acquired abdominal emergency in PT infants
  requiring IC
• MC life-threatening emergency of GIT in the NB period
• Various degrees of mucosal or transmural necrosis of
  the intestine

Question 3

What is the epidemiology of NEC?

Answer 3

Epid
- Predominant in PT infants
- Incidence: 6-10% in infants <1.5kg
- Incidence increases with decreasing BW and
gestational age
- 70-90% occurs in high-risk, LBW infants
- 10-25% in FT NBs
- 1-5% of NICU admissions
- Risk factors:
o PT – single most impt risk factor
o Asphyxia and acute cardiopulmonary
distress
o Polycythemia and hyperviscosity syndromes
o Enteric pathogenic microorganisms
o Enteric feeding – formula milk
o Aggressive enteral feeding, Feeding
volumes and timing, and rapid
advancement in enteral feedings

Question 4

What is the pathophysiology?

Answer 4

Patho
- At ileocecal area (watershed area)
- The distal part of the ileum and proximal segment of
the colon are involved most frequently
- Triad of: intestinal ischemia (injury), enteral nutrition
(metabolic substrate), and bacterial translocation
(pathogenic organism)
o E.coli, Klebsiella, C.perfringens,
S.epidermidis, astrovirus, rotavirus

Question 5

What are the clinical manifestations of NEC?

Answer 5

CM
- Usually onset at 2nd-3rd WOL
- Age of onset is inversely related to gestational age
1. Lethargy, apnea, RD
2. T instability, poor perfusion, bradycardia, mottling,
hypotension
3. Acidosis, glu instability, DIC
4. Feeding intolerance (regurg/residual), delayed gastric
emptying, vomiting, occult/gross blood in stool, change
in stool pattern/diarrhea
5. Abdominal distention, tenderness, mass, erythema of
abd wall, bilious gastric drainage, emesis, visible bowel
loops
6. Complications: bowel perforation, peritonitis, SIRS,
shock, death
7. Rapid disease progression from mild to severe within
72h

Question 6

What are the diagnostics for NEC?

Answer 6

Dx
1. Plain abd XR, left lateral decubitus, crosstable view –
pneumatosis intestinalis (air in bowel wall) is diagnostic
- Dilated bowl loops
- Portal venous gas: sign of serious disease
- Pneumoperitoneum: perforation
- Serial XR to monitor progression of ds
2. CXR – air trapping
3. Hepatic UTZ – detect portal venous gas
4. BCS – E.coli
5. CBC – low Hgb, elev WBC, low neu, low plt
6. Elev CRP
7. e’s, RBS – e’ abN, hypogly
8. ABG – metabolic acidosis
9. PT,PTT, LFT – to monitor clinical ds and progression.
May show coagulopathy.

Question 7

Modified Bell’s Staging Criteria

Question 8

Management of NEC

Answer 8

Mgt
1. Supportive care – cessation of feeding to allow bowel
rest, NGT decompression, IV fluids, parenteral nutrition
2. Ventilation assisted
3. Blood transfusions, correction of hema, metabolic and
electrolyte abnormalities
4. Abx – broad spectrum vs aerobic and anaerobic
bacteria ASAP, combination x 7-14d
- 1st line: Ampicillin + Gentamicin/Amikacin +
Metronidazole/Clindamycin
Ampicillin 100-200 mkd IV q6
Gentamicin 4 mkdose IV OD
Amikacin 15mkd OD IV
Clindamycin 5 mkdose q6 IV
Metronidazole 30 mkd IV q12
- 2nd line: Ampicillin-Sulbactam/Piperacillin-Tazobactam
+ Gentamicin/Amikacin/Ceftriaxone/Cefotaxime +
Metronidazole/Clindamycin
5. Refer to Pedia Surg. Indications for surgery:
exploratory laparotomy and bowel resection
- Pneumoperitoneum
- positive result of abdominal paracentesis
- relative: failure of medical mgt, single fixed bowel loop
(XR), abd wall erythema, palpable mass
- stage II is a surgical emergency
6. if unstable with perforated NEC – peritoneal drainage
through explore lap

Question 9

Complications of NEC

Answer 9

Complications
1. sepsis
2. meningitis
3. abdominal abscess, intestinal stricture
4. coagulopathy and bleeding
5. respi, CV insufficiency, metabolic complications
6. neurodev injury

Question 10

Prevention of NEC

Answer 10

Prevention
1. EBF – primary modality in ds prevention
2. Probiotics (?)
3. Judicious use of PPIs and abx – inc risk of NEC
4. Term deliveries, avoid elective CS
5. Feeding guidelines: initiate early minimal enteral feeds
of <20 ml/kg/d enteral nutrition and advanced daily
based on feeding tolerance