Flashcards in Module 8: PEDS: Jaundice, SIDS, Infections, CF,PKU, Gala, Dubin and Rotor Deck (38):
What is the value for neonatal jaundice?
Greater than 5mg/dl bilirubin
What is physiological jaundice?
Increased unconjugated bilirubin during 1st week of life
What is phase I and phase II physiological jaundice?
Phase I: lasts 5 days in term infants and 7 days in preterm infants (Serum bilirubin = 12-15mg/dl)
Phase II: decreased serum bilirubin lasts for 2 weeks (normal adult values are reached)
What is pathological jaundice?
Clinical jaundice appearing in 1st 24 hours, total bilirubin greater than 15mg/dl and conjugated bilirubin greater than 2mg/dl
There are two types of pathological jaundice, Unconjugated hyperbilirubinemia and Conjugated hyperbilirubinemia. First we will discuss Unconjugated hyperbilirubinemia, now there are three different types. The first is fetomaternal blood group incompatibility, what are some features?
Also called hemolytic disease of the newborn
---erythroblastosis fetalis, most common antigens: Rh and ABO blood antigens
--Extent of hemolytic disease varies: death in utero, hydrops fetalis (hepatosplenomegaly and erythroid hyperplasia in the bone marrow) and Kernicterus (increased unconjugated bilirubin due to immature neurons of CNS)
How is the dx made and what is the treatment and prevention of fetomaternal blood group incompatibility?
Dx: high level of bilirubin on aminocentesis and Coombs test positive on fetal cord blood
Tx: exchange transfusion and phototherapy
Prevention: human anti D globulin within 72 hours of delivery
The second type of unconjugated hyperbilirubinemia is crigler-najjar syndrome type I, what are the features?
Complete absence of UDP-glucuronyltransferase activity --- unremitting unconjugated bilirubinemia --- bilirubin encephalopathy
The third type of unconjugated hyperbilirubinemia is crigler-najjar syndrome type II, what are some features?
Partial decreased in UDP-glucuronyltransferase activity so treat with phenobarbital
(enzyme that converts unconjuated to conjugated bilirubin)
Now the next type of pathological jaundice is conjugated hyperbilirubinemia, caused by two different pathologies. each card will go through one. The first is biliary atresia, what are some features?
Complete obstruction of the lumen of the extrahepatic biliary tree within first 3 months of life --- chronic cholestasis, marked bile ductular proliferation and portal tract edema and fibrosis
--most common indication of liver transplant in this age group
--embryonic/fetal type: due to aberrant intrauterine development of extrahepatic biliary tree
--perinatal type: normally developed biliary tree is destroyed by virus after birth (Viral hepatitis)
The second cause of conjugated hyperbilirubinemia in kids is idiopathic neonatal hepatitis, what are some features?
Excluded known associated factors (alpha 1 antitrypsin, extrahepatic biliary atresia and infectious agents)
Next topic is SIDS, sudden infant death syndrome. What is it?
Sudden death of an infant under 1 year which is unexplained after a thorough case investigation which includes a complete autopsy, examination of death scene and thorough review of clinical history
What are the associated risk factors of SIDS?
In 75% of SIDS cases there is NO associated risk factors
What is the pathogenesis for SIDS?
Prolonged spell of apnea, followed by cardiac arrhythmia, in susceptible infant
-multiple petechiae in thymus, pleura and epicardium
--congestion of lungs
--hypoplasia of arcuate nucleus in the brainstem and decrease in brainstem neurons (gliosis of the brainstem)
What are differential diagnosis for SIDS?
Infection: viral myocarditis
Unsuspected congenital anomaly: anomalous origin of coronary artery from pulmonary artery
Genetic/Metabolic defects: long QT syndrome, fatty acid oxidation disorders, histiocytoid cardiomyopathy
What are parental risk factors for SIDS??
Young maternal age
Late or no prenatal care
Black or American Indian
What are infant risk factors for SIDS?
Brain stem abnormality associated with defective arousal/cardiorespiratory control
Prematurity and or low birth weight
Product of multiple birth
SIDS in sibling
Antecedent resp infections
Germline polymorphisms in autonomic nervous system genes
What are environmental risk factors for SIDS?
Prone sleep position
Sleeping on a soft surface
Sleeping with the parents the first 3 months
Moving on to intrauterine and perinatal infections, what are the ones ascending from vagina and cervix?
Most bacterial + herpes simplex via inhalation of infected amniotic fluid or passage through birth canal
--fetal infections: chorioamnionitis, funisitis, pneumonia, sepsis and meningitis
What are the hematogenous infections dissemination from the placenta?
TORCH infections, congenital syphilis, parvo B19 and HIV
--TORCH: toxo, others (Syphilis, L. monocytogenes, adenovirus, varicella, enterovirus), Rubella, CMV, Herpes Simplex
-TORCH manifestions: SGA infants, CNS changes, chorioretinitis, pneumonitis, petechiae, hepatosplenomegaly, and osteomyelitis
What are the affects on the infant of Rubella infection in the 1st trimester?
TORCH manifestations + ocular lesions + cardiac lesions
What are other intrauterine and perinatal infections?
maternal to fetal transfusion at delivery (Hep B and HIV)
direct contact at birth
from the environment post partum
accidental introduction in amniocentesis
Moving on to cystic fibrosis, what is this?
AR disorder of exocrine glands characterized by:
-chronic pulmonary disease
--pancreatic insufficiency (chronic pancreatitis)
--inspissaed mucus in small intestine (meconium ileus)
--liver (focal biliary cirrhosis)
---reproductive tract (azoospermia and infertility due to obstruction of the vas deferns and epididymis)
What population does cystic fibrosis affect?
Most common lethal genetic disease that affects White people
What is the pathogenesis for cystic fibrosis?
Absence of CFTR due to loss of phenylalanine residue at amino acid position 508 on chromosome 7 -- defect in phosphorylation of CFTR by PKA
--In sweat gland: increased chloride and sodium concentration in sweat
--in the airway: increased sodium and water reabsorption leads to dehydration of the mucus layer
What is the presentation for CF?
Foul smelling steatorrhea
Failure to thrive
Infections: chronic bronchitis, bronchiectasis and lung absces
How is the diagnosis made for CF?
Pilocarpine sweat test: severe variant : chloride greater than 60mEq/L
What is seen on chest xray for CF?
Cystic spaces and increased bronchial markings
Moving on to PKU (phenylketonuria), what are some features?
Abnormal metabolism of phenylalanine
--AR disorder characterized by progressive mental retardation due to deficiency of phenylalanine hydroxylase -- hyperphenylalaninemia and formation of phenylketones
What is the presentation for a patient with PKU?
Hyperphenylalaninemia: irreversible brain damage (low IQ)
Decreased Melanin: fair skin, blond hair and blue eyes
Phenylketones: mousey odor of urine
What is the tx for PKU?
Restriction of phenylalanine in the diet
Moving on to Galactosemia, what are some features?
AR deficiency of galactose-1-phosphate uridyl transferase (catalyzes galactose --- glucose)
What is the pathogenesis for Galactosemia?
Infants fed formula milk --- hepatosplenomegaly, jaundice, hypoglycemia, cataracts and mental retardation
--extensive fat accumulation in the liver and marked bile ductal proliferation, cholestasis and fibrosis -- can progress to cirrhosis in a few months
What is the treatment for galactosemia?
Moving on to Dubin-Johnson Syndrome, what are some features?
AR recessive disease characterized by chronic or intermittent jaundice + black liver
What is the pathogenesis for Dubin-Johnson Syndrome?
Defective transport of conjugated bilirubin from hepatocytes to canalicular lumen and defect in hepatic excretion of coproporphyrins
-EM: pigment in lysosomes composed of polymers of epinephrine metabolites
What is the presentation for Dubin-Johnson syndrome/
Asymptomatic except mild intermittent jaundice
Finally what is Rotor syndrome?
Familial conjugated hyperbilirubinemia due to defect in excretion of conjugated bilirubin into the biliary canaliculi with the bilirubin being absorbed into the blood
--low grade pigment deposition, dissociation of liver cells, occasional necrotic foci, and fibrin percipitation