Common Neonatal Morbidities

Question 1

What risks for bowel injury do preterm neonates face?

Answer 1

Bowel ischemia, immature gut, dysmotility (motility begins around 25 weeks), underdeveloped physical mucosal barrier, poor acid production, abnormal bacterial colonization

Question 2

What is NEC and what causes it?

Answer 2

Intense inflammation and acute intesinal necrosis

• Multifactorial (often prematurity, some level of ischemia, the presence of pathogenic bacteria and a source of food for the bacteria)
• The mucosal barrier is broken down, inflammation of the bowel is noted, ultimately leading to necrosis if not treated

Question 3

What are some GI signs of NEC?

Answer 3

Abdominal distension, feeding intolerance, emesis, bloody stool, occasional diarrhea

Question 4

What are two of the primary ways to prevent NEC?

Answer 4

Implementation of a standardized feeding protocol and exclusive use of human milk

Question 5

Bronchopulmonary Dysplasia (BPD)

Answer 5

The use of positive pressure instead of supplemental oxygen qualifies for a diagnosis of BPD if >36 weeks
- Pro-Inflammatory vs. Anti-Inflammatory Factors (pro-inflammation includes chorioamnionitis, mechanical ventilation, supplemental oxygen, sepsis; anti-inflammation includes steroids, surfactant, good nutrition)

Question 6

What are the 7 P’s of BPD

Answer 6

Prematurity
PPV
Prolonged oxygen exposure
Prolonged airway trauma
Pulmonary edema
Perinatal exposure to infection
Poor nutrition

Question 7

List some ways to reduce the incidence of BPD

Answer 7

Early surfactant administration (within 2 hours of birth), avoidance of intubation and mechanical ventilation, Vitamin A (mediator in lung development), Caffeine (helps treat apnea and support extubation, which reduces BPD), prevent infection

Question 8

What is retinopathy of prematurity (ROP)?

Answer 8

A developmental and vascular retinal disorder with incomplete retinal vascularization

Question 9

What causes initial injury of ROP?

Answer 9

Hypotension, hypoxia, hyperoxia, sepsis

- Abnormal growth of new vessels causes retinal edema, hemorrhage, retinal distortion, and possible detachment

Question 10

Describe what happens in phase 1 of ROP

Answer 10

Normal retinal vessel growth stops with preterm birth

Question 11

Describe what happens in phase 2 of ROP

Answer 11

Phase 2 is retinal neovascularization, which occurs as a result of increased metabolism, periods of hypoxia, and increased growth factors
- By phase 2, the only treatment option is “late treatment” which is usuall laser or Avastin treatment

Question 12

What percentage of ROP cases in ELBW neonates are classified as severe?

Answer 12

0-5% (requiring laser, Avastin, etc.)

Question 13

What is some of the most effective ways to prevent ROP?

Answer 13

Targeted administration of oxygen, avoiding transfusion in the first 14-21 days of life when the retina is most at risk, prevention of sepsis and hypoglycemia, provision of adequate nutrition

Question 14

What is the Hemoglobin Dissociation Curve?

Answer 14

A curve that plots the proportion of hemoglobin in its saturated form against the prevailing oxygen tension

Question 15

Does fetal or adult hemoglobin have a higher affinity for oxygen?

Answer 15

Fetal

Question 16

What percentage of babies born at or less than 28 weeks gestation have apnea of prematurity?

Answer 16

100%

Question 17

What percentage of infants born between 28-31 weeks have apnea of prematurity?

Answer 17

80%

Question 18

What is apnea?

Answer 18

The cessation of breathing for 20+ seconds

or

A shorter cessation of breathing with associated bradycardia (HR <100), pallor, cyanosis, or hypotonia

*A non-breathing interval that an infant cannot tolerate without compensating and having a spell

Question 19

What is periodic breathing?

Answer 19

5-10 second, recurrent pauses in respirations followed by rapid effort and not associated with bradycardia or cyanosis

Question 20

What is central apnea?

Answer 20

The absence of respirstory effort

Question 21

What is obstructive apnea?

Answer 21

The absence of airflow primarily at the pharynx

- May be related to laryngomalacia

Question 22

What is mixed apnea?

Answer 22

A combination of central and obstructive, the most common type

Question 23

What causes apnea of prematurity?

Answer 23

AOP is due to immaturity of the CNS and respiratory drive

• Neural and chemical systems work in tandem to regulate pulmonary function
• Central and peripheral chemoreceptors transmit information to the respiratory center in response to pH, PaCO2, and PaO2 levels; preemies have decreased chemoreceptor sensitivity to CO2

Question 24

How does CPAP help treat AOP?

Answer 24

Provides PPV which increases FRC and end expiratory lung volume, improves static lung compliance, reduces airway resistance and keeps airways open

Question 25

What is the preferred drug for managing apnea in preterm neonates and how does it work?

Answer 25

Caffeine - Has a long half-life and wide therapeutic index (safe) - Diffuses rapidly in the CNS - No need to monitor caffeine levels - Stimulates the CNS, which increases sensitivity to CO2 by increasing sensitivity of peripheral chemoreceptors so the breath is ended

Question 26

What are the recommended loading and maintenance doses of caffeine?

Answer 26

Loading Dose: 20 mg/kg | Maintenance: 5-10 mg/kg/day