Exam #3: Diseases of Childhood & Infancy II Flashcards Preview

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Flashcards in Exam #3: Diseases of Childhood & Infancy II Deck (43):

What is an ascending infection?

Infection of the neonate via the uterus


What bacteria cause asecnding infection?

E. coli


What virus causes ascending infection?



What are the diseases/ inflammations caused by ascending infection?

1) Chorioamnionitis= inflammation of the fetal membranes (amnion and chorion)
2) Funisitis= inflammation of the connective tissue of the umbilical cord
3) Placentitis
4) Villitis= inflammation of the chorionic villi


What are the consequences of ascending infection?

- Preterm birth
- Recurrent miscarriage
- Fetal Growth Restriction


Describe the microscopic appearance of villitis in perinatal ascending infection.

Remember that this is an inflammation of the chorionic villi & shows LYMPHOCYTIC infiltration of the chorionic villi


What is the difference between early onset & late onset neonatal sepsis?

Early= < 1 week
Late= 8 days- 3 months


What pathogens typically cause early onset neonatal spesis? What diseases are these pathogens associated with?

GBS: (meningitis)

Gram negatives:
- E. Coli
- Klebsiella

Note that the gram negative organisms cause pneumonia & meningitis


What pathogens are associated with late-onset neonatal sepsis?

- Staphylococci
- H. influenzae
- Listeria
- Chlamydia
- Mycoplasma
- Candidia


What are the major risk factors for early-onset neonatal sepsis (5)?

1) Previous infant with GBS
2) GBS bacteriuria during pregnancy
3) Delivery before 37 weeks (preterm)= diminished immune system
4) Ruptured membranes (amniotic sac) >18 hours
5) Intrapartum temp >38 C/ 100.4 F


Describe the microscopic appearance of neonatal congenital pneumonia.

Many neutrophils infiltrating immature bronchioles


What are the causes of NRDS (Neonatal Respiratory Distress Syndrome)?

1) Prematurity
2) Lack of surfactant
3) Fetal head injury
4) Sedation
5) Aorta abnormalities
6) Umbilical cord coiling
7) Amniotic fluid aspiration


What is the period for surfactant production in the neonate?

26-32 weeks

Type II pneumocytes


What is hyaline membrane disease?

- This is the most common cause of NRDS i.e. most common specific disease process that causes NRDS, which is due to a lack of surfactant production
- Leading cause of mortality & morbidity in infants

****Hyaline Membrane Disease is characterized by a surfactant deficiency, which leads to alveolar collapse and noncompliant lungs


What are the risk factors for Hyaline Membrane Disease?

1) Preterm
2) Maternal DM
3) C-section
4) Male gender


Outline the pathophysiology of Hyaline Membrane Disease.



Describe the microscopic appearance of Hyaline Membrane Disease.

Alternating atelectic alveoli & dilated aleolar ducts lined with pink fibrin rich hyaline & necrotic cells


What is the clinical presentation of Hyaline Membrane Disease?

- Respiratory Distress
- Cyanosis
- Hypoxemia
- Hypercarbia
- Metabolic acidosis (mixed)


What are the complications of Hyaline Membrane Disease?

1) Intraventricular hemorrhage
2) PDA
3) Necrotizing enterocolitis
4) Bronchopulmonary dysplasia
5) Retinopathy of prematurity

*****All are associated with hypoxemia & metabolic acidosis


What is Bronchopulmonary Dysplasia?

- Reduced total numbers of alveoli
- Alveolar wall thickening
- Epithelial hyperplasia
- Squamous metaplasia
- Interstitial fibrosis
- Sponge-like radiology
- Predisposition to respiratory infection

All associated with preterm neonates treated with oxygen therapy > 4weeks & positive pressure ventilation


What is post-mortem exterior cobblestone surface of the lung associated with?

This is pathognemonic for Bronchopulmonary Dysplasia


Describe the microscopic appearance of Bronchopulmonary Dysplasia.

- Interstitial fibrosis
- Epithelial hyperplasia
- Squamous metaplasia
- Alveolar wall thickening


What is the clinical presentation of Necrotizing Enterocolitis?

- Abdominal distension
- Ileus
- Bloody stool

*****Note that this can lead to bowel perforation & stricture


Describe the microscopic appearance of Necrotizing Enterocolitis.

- Hemorrhagic necrosis
- Few nuclei
- Villi destruction
- RBC infiltration of all layers of the GI mucosa

****Note that findings will begin in the mucosa & extend into the muscular wall leading to potential perforation


What are the two forms of edema in the fetus?

Generalized= hydrops fetalis

Localized edema= cystic hygroma

*****Cystic hygroma= congenital multiloculated lymphatic lesion that can arise anywhere, but is classically found in the left posterior triangle of the neck and armpits


What is the difference between immune & nonimmune fetal hydrops?

Immune is caused by blood group incompatibility (erythroblastosis fetalis)

Nonimmune is caused by:
- Infection
- Chromosomal anomalies
- Twin pregnancy
- Cardiovascular defects


Describe the pathogenesis of immune fetal hydrops.

Immune hydrops= erythroblastosis fetalis

- Mom= Rh D- & Dad= Rh D+
- Maternal immune response to fetal Rh- D+ (from Dad)
- Transplacental passage of maternal anti-D IgG & binding to fetal Rh D+ RBCs
- Destruction of RBCs

*****Note that this has been well controlled with "Anti-D antibodies" isolated from Rhesus monkeys i.e. Rhogam


What are the consequences of immune hydrops fetalis?

Hemolytic ANEMIA leading to:
- Heart Failure (caused by ischemia)
- Liver failure (caused by ischemia)
- Hydrops fetalis (edema from reduced plasma oncotic pressure & increased hydrostatic pressure secondary to heart failure)

- Jaundice
- Kernicterus


What is Necrotizing Enterocolitis?

Focal areas of bowel necrosis caused by ischemia, most often in the terminal ileum

*****Note that the etiology is mutlifactorial & contorversial


What are the paternal risk factors for SIDS?

- Young maternal age
- Smoking
- Drug abuse
- Late or no prenatal care
- Short intergestational intervals


What are the risk factors of Necrotizing Enterocolitis?

1) Prematurity
2) Low birth weight

*****Complication of Hyaline Membrane Disease


How does Necrotizing Enterocolitis appear on radiograph?

Gas in bowel wall


What are the potential consequences of Necrotizing Enterocolitis?

- Perforation
- Strictures


What is the difference between capillary hemangioma & cavernous hemangioma?

Capillary= better prognosis & known as "strawberry type"

Cavernous= more likely to be associated with VHL disease, and form in the brain, pancreas, or liver


What are the microscopic differences between capillary & cavernous hemangioma?

- Thin walled capillaries
- Scant stroma

- Large cavernous blood-filled vascular spaces separated by connective tissue stroma


What is Kernicterus?

Staining of brain nuclei with bilirubin in response to hyperbilirubinemia >20 mg/dL


What is SIDS?

Sudden unexplained death under 1 year of age
- 90% < 6 months
- Most < 2-4 months


What are the infant risk factors for SIDS?

- Male
- Premature


What are the environmental risk factors for SIDS?

- PRONE sleeping position
- Sleeping on soft surface
- Sleeping with parents in the first 3 months
- Hyperthermia
- Postnatal passive smoking

****Note that the American Academy of Pediatrics ONLY accepts the SUPINE position as the acceptable sleeping position for infants & has thus generated the "Back to Sleep" Campaign.


What are the developmental vasuclar anomalies of infancy?

Vascular malformations


What is the most common tumor in infants?

- Capillary hemangioma
- Cavernous hemangioma


What are the lymphatic tumors associated with infancy?

- Lymphangioma= hamartoma or neoplasm of lymphatic origin
- Lymphangiectasis= abnormal dilations of prexisting lymphatic channels


How does the derivation of tumors differ between children & adults?

Children= soft-tissue tumors of mesenchymal origin

Adults= epithelial origin