Medical Archive

C123.1 Meconium Ileus, Peritonitis, and Intestinal Obstruction

Meconium ileus in cystic fibrosis

Meconium ileus? 75%? cystic fibrosis. (10%-20% of CF patients)
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Diagnosis

• Gastrografin enema
  • Both diagnostic and therapeutic for meconium ileus.
  • Visualization of the rectum and bowel to rule out other anatomical causes for bowel obstruction (e.g., intestinal atresia or volvulus) and, in the case of meconium ileus, can reveal the Neuhauser sign, microcolon, or meconium pellets
  • The contrast agent can also induce a laxative effect as the increase of osmolarity within the lumen of the bowel results in breakdown and passage of the meconium obstruction.
• Intraoperative finding
  • Green inspissated mass (dehydrated meconium) in the distal ileum
• For unknown reasons, newborn screens for CF in patients with meconium ileus are often initially negative and require follow up. Infants with meconium ileus should undergo diagnostic testing for CF through a sweat test or, if sufficient amounts of sweat cannot be obtained, through genotyping

	Hirschsprung disease	Meconium ileus
Pathophysiology	Failure of neural crest cell migration	Obstruction by inspissated stool
Level of obstruction	Rectosigmoid	Ileum
Rectal examination	Increased tone Positive squirt sign	Normal tone Negative squirt sign
Meconium consistency	Normal	Inspissated
Imaging	Dilated proximal colon � small bowel Narrow rectosigmoid	Dilated small bowel Microcolon
Associated disorder	Down syndrome	Cystic fibrosis

C123.2 Necrotizing Enterocolitis

Risk factors

• Prematurity (m/i risk factor)
• Very low birth weight <1.5kg
• Enteral feeding (formula riskier than breast milk)
• Asphyxia

Clinical features

• Vital sign instability
  • May be hypothermic (<36.5?) rather than febrile
• Lethargy
• Bilious emesis
• Bloody stools – not be present in early stages.
• Tense, erythematous, distended abdomen
• Erythema on the abdominal skin
• Leukocytosis ? inflammation
• Metabolic acidosis ? intestinal ischemia

X-ray findings

• Pneumatosis intestinalis
• Portal venous gas
• Pneumoperitoneum (perforation d/t severe intestinal necrosis)
• Fixed consistent intestinal loop

Treatment

Bowel rest, parenteral nutrition
Broad-spectrum IV antibiotics
Surgery if perforated or necrotized

C123.3 Jaundice and Hyperbilirubinemia in the Newborn

Etiology

DIAGNOSIS	NATURE OF VAN DEN BERGH REACTION	JAUNDICE		PEAK BILIRUBIN CONCENTRATION		BILIRUBIN RATE OF ACCUMULATION (mg/dL/day)
		Appears	Disappears	mg/dL	Age in Days
“Physiologic jaundice”:	Usually relates to degree of maturity. Due to immature UDP-glucuronosyltransferase.
Full-term	Indirect	2-3 days	4-5 days	10-12	2-3	<5
Premature	Indirect	3-4 days	7-9 days	15	6-8	<5
Hyperbilirubinemia caused by metabolic factors:	Metabolic factors: hypoxia, respiratory distress, lack of carbohydrate
Full-term	Indirect	2-3 days	Variable	>12	1st wk	<5
	Hormonal influences: cretinism, hormones, Gilbert syndrome
Premature	Indirect	3-4 days	Variable	>15	1st wk	<5
	Genetic factors: Crigler- Najjar syndrome, Gilbert syndrome. Drugs: vitamin K, novobiocin
Hemolytic states and hematoma	Indirect	May appear in 1st 24 hr	Variable	Unlimited	Variable	Usually >5
	Erythroblastosis: Rh, ABO, Kell congenital hemolytic states: spherocytic, nonspherocytic Infantile pyknocytosis. Drug: vitamin K Enclosed hemorrhage— hematoma
Mixed hemolytic and hepatotoxic factors	Indirect and direct	May appear in 1st 24 hr	Variable	Unlimited	Variable	Usually >5
	Infection: bacterial sepsis, pyelonephritis, hepatitis, toxoplasmosis, cytomegalic inclusion disease, rubella, syphilis. Drug: vitamin K
Hepatocellular damage	Indirect and direct	Usually 2-3 days; ~2nd wk	Variable	Unlimited	Variable	Variable, can be >5
	Biliary atresia; paucity of bile ducts, familial cholestasis, galactosemia; hepatitis and infection

Clinical manifestations

5mg/dL: ???? ??
12mg/dL: ?? ???? ??
20mg/dL: ????? ??

Differential diagnosis

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?? 24hr ??	Erythroblastosis (ABO/Rh ???)
?? 2-3?	??? ??
3?-1?	???, ??(TORCH)
1? ??	?? ??, ??, ?? ??
1?? ??	??, ?? ??, ?? ??

Physiologic jaundice (icterus neonatorum)

Pathophysiology

• At birth, fetal RBCs are increased (Hct 50%-60%) with a shortened life span (90 days), resulting in high RBC turnover and increased bilirubin production
• Hepatic bilirubin clearance is decreased b/c UGT activity does not reach adult levels until age 2 weeks.
• Enterohepatic recycling is increased b/c the low bacterial load in the newborn gut results in slower conversion of bilirubin to urobilinogen for fecal excretion.

Clinical features

Indirect bilirubinemia on days 2-4 of life.
Peaks at 5-6mg/dL, resolve within 7-14 days.

• Signs indicate pathologic jaundice
  • ?? 24-36?? ??? ??? ???? ??
  • Bilirubin? 24?? ?? 5mg/dL ?? ???? ??
  • ??? bilirubin >12mg/dL, ??? >10~14mg/dL
  • ??? ?? 10-14? ?? ??
  • Direct bilirubin >2mg/dL

Pathologic hyperbilirubinemia

Jaundice associated with breastfeeding

Breast-feeding jaundice

• ?????? 13%, ???.
• Decreased bilirubin elimination & increased enterogepatic circulation d/t insufficient intake of breast milk
• Clinical features
  • Suboptimal breastfeeding
  • Signs of dehydration – tachycardia, decreased urine output, cool or clammy skin
• Management
  • Newborns should feed for >10-20 minutes per breast every 2-3 hours (8-12 times a day)
    • Feeding frequency should be increased and he/she should be reevaluated within 1-2 days.
    • If bilirubin continues to rise despite efforts to optimize lactation, formula supplementation may be necessary.

Breast-milk jaundice

• ?????? 2%, 3-5? ? ??~2? ? peak
• High levels of ?-glucuronidase in breast milk deconjugate intestinal bilirubin & increase enterohepatic circulation
• Clinical features
  • Adequate breastfeeding
  • Normal examination
• Diagnosis
  • Identify the concerning signs of dehydration & anemia

Neonatal cholestasis

See C383.1

Congenital atresia of the bile ducts

See C383.1

Direct bilirubin? 2.5mg/dL ?? ??? ?? DISIDA scan? ?? ?? ?????? ??? ??? ??? ???? ????.

C123.4 Kernicterus

??? ????(???)? ??? ?? BG? ???? ???? ???.
??? bilirubin >25mg/dL, ??? bilirubin >20mg/dL ?? ?? ??.

Clinical manifestations

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???? ??? ???? ?? ?? ?? (75% ??, ??? 80%??? ?????? CP)

Incidence and prognosis

Prevention

• Goal: ??? ??? ?? ?? ???? ??? ???? ???? ??
• Phototherapy (biliirubin >15mg/dL)
  • Complications: ??? ??, ??, ??, ?? ??, ??? ???(?? ???? ??)
• Plasmapheresis (bilirubin >20mg/dL)
  • ???? ???? ?? ??? ???? ??? ???? ??
  • ???? ?? ? ??? ?? ???? ??
  • ??? bilirubin ???? 5mg/dL ???? ??.

Treatment of hyperbilirubinemia

Phototherapy

Full-term, healthy: T.bil > 20mg/dL

Intravenous immune globulin

Metalloporphyrins

Exchange transfusion

Full-term, healthy: T.bil > 25mg/dL