neonatology Flashcards
1
Q
What is RDS caused by
A
surfactant deficiency which leads to lower lung capacity and compliance (by lowering surface tension).
2
Q
What are the risk factors for RDS
A
- prematurity (the more premature, the higher the likelihood of RDS, very common in <28wks and 50% in 28-32wks)
- tends to be more severe in boys than girls
- C-sections
- Hypothermia
- Perinatal asphyxia
- family history of IRDS
- secondary surfactant deficiency may occur due to: Intrapartum asphyxia; pulmonary infection (e.g. group B beta-haemolytic strep pneumonia); pulmonary haemorrhage; meconium aspiration pneumonia; oxygen-toxicity along with pressure or volume trauma to lungs; congenital diaphragmatic hernia/pulmonary hypoplasia
3
Q
when do the signs of infant RDS usually start to present? What are they?
A
Signs usually present within 4 hours of delivery. Babies develop signs of:
- tachypnoea (over 60 breaths/min)
- Laboured breathing with chest wall recession (particularly sternal and subcostal indrawing) + nasal flaring
- Bilateral lung cracks and low oxygen saturation
- expiratory grunting (to try and create a positive airway pressure during expiration and maintain functional residual capacity)
- can be cyanosis if very severe
4
Q
differential diagnoses of RDS?
A
- pulmonary leaks e.g. pneumothorax
- infections (may be causative of RDS)
- pneumonia (GBS)
- aspiration of amniotic fluid/blood/meconium
- TTN (transient tachypnoea of newborn)
- congenital anomalies of the lungs or heart
- metabolic problems e.g. hypothermia or hypoglycaemia
- haematological problems (anaemia, polycythaemia)
5
Q
Investigations for RDS
A
- Blood gases: resp/metabolic acidosis (from poor tissue perfusion + hypoxia
- oxygen sats (should be maintained at 91-95%)
- CXR + monitor FBC/electrolytes/glucose/renal and liver function
- Echo: diagnosis of patent ductus arteriosus, determines direction and degree of shunting, making diagnosis of pulmonary hypertension and excluding structural heart disease
- Cultures to rule out sepsis e
