Peds 2

Question 1

Describe the events of bilirubin creation and metabolism starting with hemoglobin breakdown

Answer 1

♣ Hemoglobin broken down into heme and globin
♣ Heme then broken down into iron and protoporphyrin
♣ Protoporphyrin converted into unconjugataed bilirubin (water insoluble)
♣ UCB binds to albumin to be brought to the liver
♣ Liver conjugates UCB into CB (water soluble)
• UDP glucuronyl transferase (UGT) is the enzyme in the hepatocytes that conjugates bilirubin
♣ CB dumped into bile canaliculi to be sent to the gallbladder

Question 2

Causes of elevated unconjugated bilirubin (broad categories)

Answer 2

• Increased bilirubin production
• Impaired bilirubin uptake and storage
• Decreased UDP-GT activity

Question 3

Causes of increased bilirubin production

Answer 3

• Hemolytic anemia
• Sickle cell disease
• Hematoma breakdown

Question 4

Causes of impaired bilirubin uptake and storage

Answer 4

• Viral hepatitis

- Drugs

Question 5

Causes of decreased UDP-GT activity

Answer 5

• Gilbert syndrome
• Crigler Najjar syndrome
• Neonatal physiologic jaundice

Question 6

Causes of elevated conjugated bilirubin (general categories)

Answer 6

• Impaired transport of bilirubin
• Biliary epithelial damage
• Intrahepatic biliary obstruction
• Extrahepatic biliary obstruction

Question 7

Causes of impaired transport of bilirubin

Answer 7

• Dubin Johnson syndrome

- Rotor syndrome

Question 8

Causes of biliary epithelial damage

Answer 8

• Hepatitis
• Cirrhosis
• Liver failure

Question 9

Causes of extrahepatic biliary obstruction

Answer 9

• Pancreatic neoplasms
• Pancreatitis
• Cholangiocarcinoma
• Choledocholithiasis

Question 10

Describe physiologic jaundice of the newborn

Answer 10

• Newborn livers have low UGT activity (enzyme that conjugates bili), leading to increased UCB
• Too much UCB can deposit in the brain kernicterus
• Treatment = Phototherapy – makes UCB water soluble

Question 11

Describe physiologic jaundice of the newborn

Answer 11

• Newborn livers have low UGT activity (enzyme that conjugates bili), leading to increased UCB
• Too much UCB can deposit in the brain kernicterus
• Treatment = Phototherapy – makes UCB water soluble

Question 12

Most common hemolytic causes of hyperbilirubinemia

Answer 12

• ABO or Rh incompatibility
• Sepsis
• Membrane disease
• Enzyme defects (G6PD or pyruvate kinase deficiency(
• Hemoglobinopathies (sickle cell, thalassemia)

Question 13

What is breast milk jaundice

Answer 13

Thought to be due to human milk causing increase of intestinal absorption of bilirubin

Question 14

Describe breastfeeding failure jaundice

Answer 14

Decreased intake causes slower bilirubin elimination and increased intrahepatic circulation

Question 15

Describe why high bilirubin is dangerous

Answer 15

UCB can cross the BBB and cause cell death by apoptosis and necrosis

Question 16

Describe major features of kernicterus

Answer 16

• Choreoathetoid cerebral palsy
• Significant hearing loss due to auditory neuropathy
• Gaze abnormalities, especially limitation of upward gaze.
• Dental enamel dysplasia

Question 17

What is acute bilirubin encephalopathy (ABE)

Answer 17

Usually occurs before kernicterus

3 phases:

• Sleepy but arousable with possible hypotonia
• febrile, lethargic, irritable, hypertonia
• apnea, inability to feed, seizures, coma

Question 18

How does G6PD deficiency cause hyperbilirubinemia

Answer 18

♣ Glutathione neutralizes H2O2 but becomes oxidized in the process
♣ NADPH needed to reduce glutathione

In G6PD, no NADPH created in order to reduce glutathione, which is needed to protect RBCs from oxidative damage

Question 19

What is haptoglobin

Answer 19

Protein that carries Hb to the spleen

Will have decreased serum haptoglobin in hemolysis

Question 20

How does pyruvate kinase deficiency cause hyperbilirubinemia

Answer 20

♣ Glycolytic enzyme deficiency = inability to generate ATP

♣ Cannot maintain Na+/K+ ATPase = RBC swelling and lysis

Question 21

Describe neurostorming

Answer 21

Following TBI, caused by increased stress response (corticoids and catecholamines)

Symptoms can include alterations in level of consciousness, increased posturing, dystonia, hypertension, hyperthermia, tachycardia, tachypnea, diaphoresis, and agitation

Question 22

What is refeeding syndrome

Answer 22

he refeeding syndrome is defined as the clinical complications that can occur as a result of fluid and electrolyte shifts during aggressive nutritional rehabilitation of malnourished patients

Question 23

Clinical features of refeeding syndrome

Answer 23

●Hypophosphatemia (*hallmark) - lack of phosphate (ATP) leads to tissue hypoxia, causing myocardial dysfunction and respiratory distress

●Hypokalemia

●Vitamin (eg, thiamine) deficiencies

●Congestive heart failure

●Peripheral edema

●Rhabdomyolysis

●Seizures

●Hemolysis

Question 24

Describe difference between acetylcholinesterase inhibitor toxicity and direct cholinomimetic toxicity

Answer 24

Unlike direct acting cholinomimetics, acetylcholinesterase inhibitors effect nicotinic receptors in addition to muscarinic receptors

Clinically = flaccid paralysis + DUMBBELS

Question 25

Describe DUMBBELS sx of ACh inhibitor toxicity

Answer 25

``` D = diarrhea U = urination M = miosis B = bronchospasm B = bradycardia L = lacrimation S = salivation ```

Question 26

MOA of Pralidoxime

Answer 26

Used to treat PERIPHERAL effects of ACh inhibitor toxicity Regenerates ACh esterase at muscarinic and nicotinic receptors (reverses paralysis as well)

Question 27

MOA of Atropine

Answer 27

Treats both PERIPHERAL and CENTRAL effects of AChI toxicity on MUSCARINIC receptors But does not reverse nicotinic effects, so does not fix paralysis

Question 28

What are the 5 components of apgar score

Answer 28

HR, RR, muscle tone, reflex irritability, color

Question 29

What do you do if meconium is present in a vigorous newborn

Answer 29

Bulb syringe or large-bore suction to clear airway

Question 30

What do you do if meconium is present in a nonvigorous newborn

Answer 30

Intubate and direct suction of trachea before many breaths occur to reduce change of meconium aspiration

Question 31

Diagnose: newborn born with scaphoid abdomen, cyanosis, and respiratory distress

Answer 31

diaphragmatic hernia

Question 32

Tx of newborn with respiratory distress in setting of diaphragmatic hernia

Answer 32

Endotracheal intubation Bag-mask ventilation will also push gas into bowel, which is in the chest cavity, causing further respiratory compromise

Question 33

Next step in neonatal rescusitation if HR remains < 60 beats/min despite positive pressure ventilation

Answer 33

Chest compressions

Question 34

Next step if chest compressions fail

Answer 34

Drug therapy (usually epinephrine)

Question 35

What is choanal atresia and its presentation

Answer 35

Obliteration or blocking of posterior nasal aperture (aka nose is not connected to oropharynx) Presents as baby who can breathe when crying but has respiratory distress when stops. Infants are obligate nose breathers but can breathe through their mouths when crying

Question 36

Tx of choanal atresia

Answer 36

Intubation to bypass obstruction until surgical repair can be completed

Question 37

Describe pathogenesis of infant of a diabetic mother

Answer 37

♣ In response to maternal hyperglycemia, fetal hyperinsulinism begins ♣ Fetal insulin production causes increased glycogen production which is deposited in fetal liver, heart, kidneys, and skeletal muscle ♣ After delivery and removal from high-sugar in utero environment, the infant’s hyperinsulinism can cause hypoglycemia

Question 38

Clinical features of infant of a diabetic mother

Answer 38

♣ Hypoglycemia – seizures, jittery, apnea ♣ Spinal bifida / neural tube defect ♣ Shoulder dystocia, brachial plexus injury (due to large infant being squeezed during delivery) ♣ Hypertrophic cardiomyopathy (due to glycogen deposition) ♣ Hyaline membrane disease, respiratory distress syndrome ♣ Polycythemia ♣ Hyperbilirubinemia, hypocalcemia, hypomagenesia ♣ Renal vein thrombosis ♣ Caudal regression syndrome

Question 39

What causes Respiratory distress syndrome in infant of DM mother

Answer 39

♣ insulin interferes with cortisol’s ability to induce surfactant production

Question 40

What causes hypertrophic cardiomyopathy in infant of DM mother

Answer 40

♣ Fetal insulin production causes increased glycogen production which is deposited in fetal heart

Question 41

What causes polycythemia in infant of DM mother

Answer 41

Due to increased fetal oxygen requirement because of enlarged fetus

Question 42

What causes hyperbilirubinemia in infant of DM mother

Answer 42

due to polycythemia

Question 43

What causes renal vein thormbosis in infant of DM mother

Answer 43

due to polycythemia

Question 44

Tx of newborn of DM mother with glucose < 40 and NO sx of hypoglycemia

Answer 44

♣ If no sx of hypoglycemia, the infant is refed and glucose re-measured 30 min after feeding

Question 45

Tx of newborn of DM mother with glucose < 40 and + sx of hypoglycemia

Answer 45

Requires IV glucose