Neonatology

Question 1

What is the definition of Apnea of prematurity

Answer 1

Cessation of breathing for at least 20 minutes or a briefer episode with one of the following:

• Bradycardia
• Cyanosis
• Pallor

Question 2

What is apnea od prematurity related to?

Answer 2

Underdevelopment of the brainstem

Question 3

What other causes must be ruled out before diagnosing with apnea of prematurity?

Answer 3

CNS disorders
Decreased oxygen delivery to brain
Infection
Metabolic disorders
Thermal instability

Question 4

What are the nonpharm tx for apnea of prematurity?

Answer 4

Supplemental O2 (O2 sat b/n 85-95%)
RBC transfusion (increases O2 carry capacity)
Positions (opens upper airways)
Tube removal (Removed airflow impedance)
Environment (maintain temp)
Ventilation (assists O2 delivery and airway maintenance)

Question 5

What are methylxanthines?

Answer 5

Caffeine
Theophylline
Aminophylline

Question 6

What are the hypothesized MOAs of methylxanthines?

Answer 6

Stimulates CNS
Increases CO sensitivity
Enhances diaphragmatic contraction force
Increases CO
Increases HR
Decreases vascular resistance

Question 7

What are the known MOAs of methylxanthines?

Answer 7

Inhibits:
Adenosine which normally depresses central respiratory drive
Phosphodiesterases which normally decrease number of cyclic monophosphates

Question 8

What are the ADRs of Methylxanthines?

Answer 8

Increased UO
Jitteriness
Dose limiting effect of coffeine is tachycardia
Hypotension (less common)

Question 9

What is the half-life of caffeine citrate?

Answer 9

52-96 hours

Question 10

What is the therapeutic concentrations for caffeine citrate?

Answer 10

8-20

Question 11

What is the toxic concentrations for caffeine citrate?

Answer 11

> 50

Question 12

What are the loading doses for caffeine citrate?

Answer 12

20-25 mg/kg/dose

10-12.5 mg/kg/dose (base)

Question 13

What are the maintenance doses for caffeine citrate?

Answer 13

5-15 mg/kg/dose

2-2.5 mg/kg/dose (base)

Question 14

What is the dosing interval for caffeine citrate?

Answer 14

Q24h

Question 15

What is the half-life of theophylline/aminophylline?

Answer 15

17-43 h

Question 16

What is the therapeutic concentrations for theophylline/aminophylline?

Answer 16

6-12

Question 17

What is the toxic concentration for theophylline/aminophylline?

Answer 17

> 15

Question 18

What is the loading dose for theophylline/aminophylline?

Answer 18

5-6 mg/kg/dose

Question 19

What is the maintenance dose of theophylline/aminophylline?

Answer 19

2-6 mg/kg/dose

Question 20

What is the dosing interval of theophylline/aminophylline?

Answer 20

Q8-12h

Question 21

What is the definition of respiratory distress syndrome?

Answer 21

Surfactant deficiency in lungs of premature neonates

Question 22

What is surfactant

Answer 22

Provides surface tension at alveoli level in lungs

“Holds” alveoli open for gas exchange

Question 23

What are the signs of surfactant deficiency?

Answer 23

Delay in normal respirations
Grunting during expirations
Flaring of the nares
Cyanosis in room air
Retraction of intercostal and sternal muscles
Tachypnea
Radiographic findings:
-Reticulograndular, ground-glass pattern
-Air bronchograms

Question 24

What are the treatment outcomes for RDS?

Answer 24

Improved lung compliance
Improved oxygenation
Lower O2 requirement

Question 25

What are the components of surfactant?

Answer 25

Phospholipids | Proteins (A-D)

Question 26

What is protein A?

Answer 26

Hydrophilic protein regulating pulmonary surfactant turnover

Question 27

What is Protein B?

Answer 27

Hydrophobic protein improving surfactant surface activity

Question 28

What is Protein C?

Answer 28

Protein improving surfactant surface activity and fluidity

Question 29

What is Protein D?

Answer 29

Protein involving bacterial opsonization

Question 30

What are the animal derived surfactants?

Answer 30

Beractant (Bovine) Calfactant (Bovine) Poractant (Pork)

Question 31

What are the synthetic surfactants?

Answer 31

Colfosceril (does not contain protein) | Lucinactant

Question 32

How do we prevent RDS?

Answer 32

``` Antenatal steroids (to mother) Early surfactant administration (to baby) ```

Question 33

How do antenatal steroids work in RDS?

Answer 33

Increases rate of fetal lung maturation

Question 34

When do we treat with antenatal steroids in RDS?

Answer 34

24-34 week gestation with risk of delivery within 7 days | Under 32 weeks gestation with premature rupture of membranes

Question 35

When do we prophylax with early surfactant administration?

Answer 35

High risk patients: | Patients less than or equal to 30 week gestation and/or patients that are NOT exposed to antenatal steroids

Question 36

What is PDA?

Answer 36

Patent ductus arteriosus | Ductus arteriosus remaining open after birth

Question 37

What can untreated PDA lead to?

Answer 37

CHF (Edema, hepatomegaly, tachycardia, tachypnea) | Hypoperfusion (Brain, intestines, kidneys)

Question 38

What is used to clinical diagnosis of PDA?

Answer 38

``` Systolic murmur: Bounding palmer pulses Hyperdynamic precordium Increased pulse pressures Pulmonary hemorrhage Refractory hypotension Signs of CHF ```

Question 39

What is a definitive diagnosis for PDA?

Answer 39

Echocardiogram with left-to-right flow

Question 40

What are the causes of PDA?

Answer 40

``` Decreased prostaglandin (from the placenta) metabolism (pre-term) Decreased arterial oxygen concentration (pre-term) ```

Question 41

What are the treatments for PDA?

Answer 41

Medical Surgical (uncommon) Pharmacologic

Question 42

How do we medically treat PDA?

Answer 42

Manage CHF: Fluid restriction Diuretics (Lasix can increase prostaglandin synthesis. If PDA is not closing fast enough, lasix may be the problem)

Question 43

When is surgical treatment of PDA recommended?

Answer 43

Pharmacologic treatment failure | Pharmacologic treatment contraindication

Question 44

What medications are used for treatment of PDA?

Answer 44

Indomethacin | Ibuprofen

Question 45

What are indomethacin/ibuprofens MOA?

Answer 45

Decrease prostaglandin synthesis resulting in vasoconstriction

Question 46

What are indomethacin/ibuprofens ADRs?

Answer 46

Acute kidney damage Bleeding Necrotizing enterocolitis

Question 47

How do NSIADs cause bleeding problems?

Answer 47

NSAIDs cause platelet inhibition

Question 48

How do NSAIDs cause necrotizing enterocolitis?

Answer 48

Vasoconstriction does not allow growing gut to be supplied with nutrients, gut becomes necrotic and becomes colitis

Question 49

How is indomethacin typically dosed?

Answer 49

3 dose course 0.2 mg/kg IV x1 Next dose depends on age Every 12-24 hours

Question 50

What are specific ADRs for indomethacin alone?

Answer 50

Decreased UO | Increased SCr

Question 51

How is ibuprofen typically dosed?

Answer 51

3 dose course 10 mg/kg IV x 1 5 mg/kg IV x 2 Every 24-48 hours

Question 52

Why would we maintain PDAs?

Answer 52

Some congenital heart defects require/need a PDA for patient survival

Question 53

What medication is used for maintaining PDAs?

Answer 53

Prostin VR

Question 54

What is the Loading dose for Prostin VR?

Answer 54

0.05-0.1 mcg/kg/minute continuous infusion

Question 55

What is the maintenance dose for Prostin VR?

Answer 55

Titrate between 0.1-0.4 mcg/kg/minute

Question 56

What are the ADRs for Prostin VR?

Answer 56

Apnea Fever Flushing