Resp issues: Apnea of Prematurity, RDS, TTN Flashcards
What body systems can cause non pulmonary respiratory distress?
cardiac, infectious, metabolic, CNS
What is considered tachypnea in a newborn?
> 60 breaths/min
Things you can do to help differentiate between cardiac/resp causes?
- 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
Define RDS
- 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)
Risk factors of RDS
1) prematurity ± given antenatal steroids or not
2) male sex
3) GDM
4) perinatal asphyxia
5) hypothermia
6) multiple gestations
Resource for RDS
www.macpeds.com/documents/RDSCBLCombined.pdf
What is surfactant?
- 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
Symptoms of RDS?
Tachypnea, nasal flaring, indrawing, expiratory grunting, central cyanosis, apnea
*Diagnosis involves clinical signs + evidence on CXR
What do you look for in prenatal/delivery history for RDS?
GA, maternal illnesses (GDM), antenatal steroid therapy, GBS status, PROM, Maternal fever, Method of delivery, need for resus
What investigations would you order for RDS?
- CXR: diffuse atelectasis, ground glass appearance, air bronchograms,
- ABG: hypercarbia, hypoxia, metabolic acidosis
Management of RDS antenatally?
- 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
What are the consequences of surfactant deficiency?
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
Describe SRT for RDS
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)
Management of RDS?
1) Antenatal steroids
2) Surfactant therapy
3) Ventilatory management
Complications of RDS?
BPD, IVH, sepsis, PTX, PIE, r