Neonates Flashcards
What is the definition of prematurity?
Less than 37 weeks gestation
What is very preterm?
28-32 weeks
What is extremely preterm?
< 28 weeks
What is the typical birth weight of a baby at 24 weeks?
620g females
700g males
What does a preterm infants skin look like and what does this make them prone to?
Red, thin, gelatinous
Prone to evaporative heat loss and easily damaged -> high infection risk
What might you see if you examined a preterm infant?
Adopts extended posture with uncoordinated movements
Eyelids may be fused or partially open - infrequent eye movements in contrast to term infant
Unlikely to breathe w/o resp support
Uncoordinated suckling - most required NG feeding +/- TPN
When does the suckling reflex develop?
34-35 weeks
At what birth weight are babies most at risk of complications?
< 1.5kg
What preterm complications can you get?
Respiratory distress syndrome Infection PDA Necrotising enterocolitis Periventricular-intraventricular haemorrhage Periventricular leukomalacia Retinopathy of prematurity Osteopenia of prematurity
Why do preterm babies develop respiratory distress syndrome?
Lack of pulmonary surfactant production resulting in high surface tension at alveolar surface
Less functional alveoli
Lacking sufficient cartilage to keep airways patent
Which cell produces surfactant in the lungs?
Type II pneumocyte
What antenatal intervention can reduce to rate of RDS?
Steroids
How does RDS present?
Poor APGAR scores at birth Nasal flaring Grunting Recessions Tracheal tug Tachypnoea Poor sats
What might the CXR of a preterm baby with RDS look like?
Diffuse granular opacities (ground glass) bilaterally, low lung volumes, bell-shaped thorax
How do you prevent a baby getting RDS?
Antenatal steroids to induce surfactant production
How can you treat RDS in a newborn?
Surfactant replacement - LISA less invasive surfactant administration
Respiratory support - CPAP, IPPV (mechanical ventilation)
What is the APGAR score?
Appearance Pulse Grimace (reflex irritability) Activity (muscle tone) Respiration
What is a common complication of intubation and ventilation?
Pneumothorax
At 36 weeks corrected gestational age, the baby is still having low sats of 80-90% in room air with some brief apnoeas. What complication has developed?
Bronchopulmonary dysplasia of chronic lung disease AKA chronic lung disease
What is chronic lung disease of the newborn?
Dependence on O2 therapy either at 28 days or 36 weeks gestation - babies undergo oxygen challenge test
- No BPD sats > 90% for 60 mins in room air
- BPD sats < 90% during obs period. Any apnoeas, bradys, or increased O2 requirement means BPD occurred
What is the pathogenesis of chronic lung disease (BPD) of newborn?
Underdeveloped lungs due to prematurity
Initial injury to lungs due to primary disease process eg RDS
Ventilator induced lung injury due to barotrauma (high pressure)
Volutrauma (inappropriately high or low tidal volume delivery when ventilated)
Oxygen toxicity
Inflammatory cascade
Inadequate nutrition
How is chronic lung disease treated?
Supportive
May require O2 treatment at home
What is the prognosis of BPD?
Majority will achieve normal lung function and thrive
Higher risk of death in first year of life
Increased risk of viral infections esp RSV, growth failure, and neurodevelopmental abnormalities
What is the pathology of a PDA?
Left-to-right shunting