“Better get a check up from the NEC up!”

By Christyn Magill MD
CC:   infant vomiting
 
HPI:  2mo term female, born at 38 weeks gestation, SVD, no complications, normal prenatal labs.  Presents with 3 days of projectile vomiting about 10-15 minutes after feeds.  Initially vomitus appeared to be regurgitated food.  Now, vomitus is darker in color, but no bright red blood, non bilious.  Decreased UOP. Normal bowel movements per parents.  Normal energy. Acting hungry.  Parents deny fevers, sick contacts, rashes, diarrhea.  Vomiting seems to bother child and gets fussy, but acts normally in between feeds.  This is a first child for the family.
 
Physical Exam:
VS: T 98.6F rectal, HR 135, BP 114/74, RR 44, O2 98% on RA
GENERAL: Laughs and smiles, very active in the ED, not clinically dehydrated
HEENT: PERRL, EOMI, moist mucous membranes, no icterus, TM's NL, Oral-pharynx NL, nares NL
CHEST: Normal S1 and S2, no murmurs, lungs clear to auscultation
ABD: Tenderness-none, no HSM, bowel sounds NL
Rectal: normal tone, small amt stool in vault, Hemoccult-positive stool
BACK: Non tender, no costovertebral angle tenderness
EXTREMITY: Normal active full ROM throughout all extremities, no tenderness, appearance normal
GU: Normal external female genitalia
SKIN: No pallor/rashes, warm & moist, brisk cap refill
NEURO: Good suck, grasp, makes eye contact, social smile, +Moro reflex, Gross motor normal, gross sensation intact
LYMPH: No lymphadenopathy
 
What is on your differential diagnosis?  What is your highest suspicion?
What studies would you do on this patient in the ED?
 
The following studies were done:
VBG: pH 7.418, PCO2 28.8, PO2 49, Lactate 2.87, HCO3 18.6, Base deficit 5
Urine dip: glu-neg, bili-neg, ketones-large (80), SG-1.030, pH 6.0, prot-1+, urobil-normal, nitrate- neg, leuk-neg
CBC: WBC 13.4K, Hb 10.9, Hct 32%, Plt 430
Chem8: Na 137, K 4.8, Cl 103, CO2 18, BUN 10, Cr <0.2, Glu 90
Hepatic: TProtein 5.4, Albumin 4.0, TBili 1.2, Dbili 0.2, Alk Phos 344, ALT 24, AST 34
CRP <0.5
 
Imaging:

What is your diagnosis based on these studies?  What is your management?
 
 
Diagnosis: Necrotizing Enterocolitis

Clinical Question:  How do I recognize this in the emergency department, and what do I do about it?
Helpful hint:  http://pedemmorsels.com/necrotizing-enterocolitis/
 
 
Discussion:[1, 2]

• Necrotizing Enterocolitis- generally thought of as a “premie problem”
• Up to 10% of cases of NEC are diagnosed in term babies.
• Difficult to recognize and diagnose
  • symptoms can be subtle at first, and present like any other neonatal GI issue. 
  • Initially, looks like reflux or overfeeding
  • Concerns for pyloric stenosis

**One must maintain a high level of suspicion for NEC in order to correctly diagnose it.
 
Pathology

• exact mechanism of NEC is not fully understood
• Related to an immature gut and digestion system, buildup of incompletely digested molecules that instigate an inflammatory process of the bowel mucosa.  [3]
• Bowel inflammation then leads to increased bowel permeability, which allows bacteria to migrate into the peritoneum, causing a peritonitis. 
• At late stages, bowel necrosis and perforation occur.

 
Epidemiology- Often, but not always, the term babies who develop NEC have some sort of underlying abnormality.[4-6]

• congenital heart disease,
• sepsis,
• perinatal hypoxia/asphyxia,
• congenital defects of abdominal wall
• thrombotic conditions
• endocrinopathies
• If you see a term baby with NEC, an underlying cause should be evaluated after the baby is stabilized.

 
Usually presents earlier in term babies- In one retrospective study done by Sharma et al, the extremely premature infants presented with symptoms of NEC an average of 22 days of life, whereas the term babies had symptoms an average of 3 DOL.  But this is not always true, as was the case with our baby above.
 
Symptoms/Stages
 
Modified Bell’s Criteria
From Up To Date:

Workup[2]
CBC plus diff, BMP, LFTs (if more advanced stages), VBG
Thrombocytopenia, metabolic acidosis, hyperglycemia are trended for worsening disease.
Plain films- upright and lateral decubitus to eval for free air, pneumatosis intestinalis, portal venous gas.
RUQ Ultrasound to show portal venous gas. [7]
 
Treatment[8]
Medical- Antibiotics, bowel rest, supportive care, lab and radiologic monitoring.
Antibiotic possible regimens (from UTD):
●Ampicillin, gentamicin (or amikacin), and metronidazole
●Ampicillin, gentamicin (or amikacin), and clindamycin
●Ampicillin, cefotaxime, and metronidazole
●Piperacillin-tazobactam and gentamicin (or amikacin)
●Vancomycin, piperacillin-tazobactam, and gentamicin
●Meropenem
*Vancomycin instead of Ampicillin if in high MRSA area
*Add Fluconazole if worried about fungal infection
Surgical[9, 10]

• Primary peritoneal drainage/drain placement
• Laparotomy/bowel resection with primary vs delayed anastomosis

Indications for surgery:

• Pneumoperitoneum indication perforation
• Clinical deterioration in spite of max medical treatment
• Abd mass with persistent intestical obstruction or sepsis
• Intestinal stricture

 
Complications[6, 11]
Acute- sepsis, meningitis, peritonitis, abscess formation, DIC, hypotension, shock, respiratory failure, hypoglycemia, metabolic acidosis
Late- intestinal stricture, short gut syndrome
*intestinal strictures in 9-36%, not significantly related to medical vs surgical treatment, drain vs laparotomy, gestational age, pneumatosis intestinalis. 
Term infants- 3% risk of NEC, 16% mortality.
 
Updates
Probiotics are now being studied for protective potential. [5]


Back to our patient:

• Consulted Peds Surg to follow
• Admitted to PICU, IV Abx
• Monitored labs and plain films
• Slowly advanced diet after a few days
• Discharged home without complications

 
Clinical Pearls for ED:

• Maintain high suspicion for NEC if ANY baby is acting weird, vomiting. Don’t be afraid to do rectal.
• Low threshold for imaging and labs if you have suspicion.  They can be helpful.
• Consult Peds Surg.  Medical vs Surgical management.
• Antibiotics STAT in ED. NPO. NG tube to intermittent suction.
• Be aware of complications.
   
  Author: Dr. Christyn Magill

 
References:
1.            Sakellaris, G., et al., Gastrointestinal perforations in neonatal period: experience over 10 years. Pediatr Emerg Care, 2012. 28(9): p. 886-8.
2.            Solomkin, J.S., et al., Diagnosis and management of complicated intra-abdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America. Clin Infect Dis, 2010. 50(2): p. 133-64.
3.            Sharma, R., et al., Impact of gestational age on the clinical presentation and surgical outcome of necrotizing enterocolitis. J Perinatol, 2006. 26(6): p. 342-7.
4.            Short, S.S., et al., Late onset of necrotizing enterocolitis in the full-term infant is associated with increased mortality: results from a two-center analysis. J Pediatr Surg, 2014. 49(6): p. 950-3.
5.            Terrin, G., A. Scipione, and M. De Curtis, Update in pathogenesis and prospective in treatment of necrotizing enterocolitis. Biomed Res Int, 2014. 2014: p. 543765.
6.            Lambert, D.K., et al., Necrotizing enterocolitis in term neonates: data from a multihospital health-care system. J Perinatol, 2007. 27(7): p. 437-43.
7.            Buonomo, C., The radiology of necrotizing enterocolitis. Radiol Clin North Am, 1999. 37(6): p. 1187-98, vii.
8.            Barie, P.S., et al., A randomized, double-blind clinical trial comparing cefepime plus metronidazole with imipenem-cilastatin in the treatment of complicated intra-abdominal infections. Cefepime Intra-abdominal Infection Study Group. Arch Surg, 1997. 132(12): p. 1294-302.
9.            Flake, A.W., Necrotizing enterocolitis in preterm infants--is laparotomy necessary? N Engl J Med, 2006. 354(21): p. 2275-6.
10.          Moore, T.C., Successful use of the "patch, drain, and wait" laparotomy approach to perforated necrotizing enterocolitis: is hypoxia-triggered "good angiogenesis" involved? Pediatr Surg Int, 2000. 16(5-6): p. 356-63.
11.          Schwartz, M.Z., et al., Intestinal stenosis following successful medical management of necrotizing enterocolitis. J Pediatr Surg, 1980. 15(6): p. 890-9.