Resp issues: Apnea of Prematurity, RDS, TTN

Question 1

What body systems can cause non pulmonary respiratory distress?

Answer 1

cardiac, infectious, metabolic, CNS

Question 2

What is considered tachypnea in a newborn?

Answer 2

> 60 breaths/min

Question 3

Things you can do to help differentiate between cardiac/resp causes?

Answer 3

• O2 sat: if still low in room air AND 100% O2, probably intracardiac shunt
• hyperoxia test (ABG on room air and 100% O2): PaO2 levels (if really low = cardiac)
• Echocardiogram

Question 4

Define RDS

Answer 4

• Formerly known as hyaline membrane disease
• Disease of prematurity
• Immature lungs not producing enough surfactant (<10mg/kg compared to 100mg/kg in term)
• Causes increase in surface tension and alveolar collapse/atelectasis
• Leads to increased WOB, decrease FRC, intrapulmonary shunting, VQ mismatch, hypoxia, resp failure

(Collapse -> low FRC -> lung injury -> protein exudation and edema -> acidosis and hypoxia -> resp failure)

Question 5

Risk factors of RDS

Answer 5

1) prematurity ± given antenatal steroids or not
2) male sex
3) GDM
4) perinatal asphyxia
5) hypothermia
6) multiple gestations

Question 6

Resource for RDS

Answer 6

www.macpeds.com/documents/RDSCBLCombined.pdf

Question 7

What is surfactant?

Answer 7

• mixture of phospholipids (phosphatidylcholine) and proteins (SP-A, SP-B, SP-C, SP-D)
• made by Type II pneumocytes
• helps to lower surface tension in alveoli
• prevents alveolar collapse

Question 8

Symptoms of RDS?

Answer 8

Tachypnea, nasal flaring, indrawing, expiratory grunting, central cyanosis, apnea

*Diagnosis involves clinical signs + evidence on CXR

Question 9

What do you look for in prenatal/delivery history for RDS?

Answer 9

GA, maternal illnesses (GDM), antenatal steroid therapy, GBS status, PROM, Maternal fever, Method of delivery, need for resus

Question 10

What investigations would you order for RDS?

Answer 10

• CXR: diffuse atelectasis, ground glass appearance, air bronchograms,
• ABG: hypercarbia, hypoxia, metabolic acidosis

Question 11

Management of RDS antenatally?

Answer 11

• Antenatal steroids (accelerates lung maturation)
• Bethamethasone, dexamethasone
• 2 doses administered 24h apart
• Give before delivery of preterm infants 24-34 weeks GA
• Optimal is up to 7 days before delivery

Question 12

What are the consequences of surfactant deficiency?

Answer 12

1) Decreased lung compliance
2) Unstable alveoli
3) Decreased FRC
4) Hypoxia (from shunting of blood through collapsed areas)
5) Increased WOB
6) Lung edema

Question 13

Describe SRT for RDS

Answer 13

Surfactant therapy (“SRT”)

• BLES (Bovine)
• given via ETT
• 2 or 4 fractional doses, bolus
• can be prophylactic (pre-RDS) after resus, 10-30min of birth, requires intubation
• can be selective/rescue SRT, early (1-2h post birth) or late (>2h)

Question 14

Management of RDS?

Answer 14

1) Antenatal steroids
2) Surfactant therapy
3) Ventilatory management

Question 15

Complications of RDS?

Answer 15

BPD, IVH, sepsis, PTX, PIE, r