Prematurity Flashcards
Why is neonatology important
First month of life is the period of higher mortality rate
What can go wrong during fetal developmetn
Early stages- formation of organs
Major malformations in first few weeks after conceptions
During fetal maturation and growth more due to viruses and injury
Define full term and prematurity
Full term- 37 to 42 weeks gestation
Premature- Less than 37 weeks gestation
Why do full term babies require neonatal care
Congenital abnormalities/disease, organ malformations, infection, birth trauma, hypoxic ischaemic encephaloptathy
Why do preterm babies require neonatal care
Typically perfectly formed for that gestation but not ready to be born
Initially healthy but made unhealthy by being born
Why does premature birth occur
Maternal illness eg. pregnancy induced hypertension
Placental failure- poor growth or abruption
Preterm labour- mechanical or inflammatory/infection
What are the short term problems of preterm birth
Respiratory, neurological, gastrointestinal, retinal, iatrogenic
What are the long term problems of preterm brith
Neurological, developmental, behavioural, respiratory, growth, programming
What are the stages in management of preterm birth
Antenatal Resuscitation Intensive care High dependence care Special care Transitional care Neonatal follow up
How are premature babies kept warm
Lose 1 degree per minute, large SA compared to body mass
Also lose heat through latent heat of evaporation
Put in plastic bag under radiant heater- water on skin evaporates, becomes humidified, heat not lost
What is respiratory distress syndrome
Lungs not yet ready
Adult lungs have high SA, mostly air with little tissue. Preterm lungs look like solid tissue
Apoptosis to separate capillaries and airways not yet happened
Not enough surfactant
How can respiratory distress syndrome be prevented
Antenatal steroids
Induce differentiation of type 2 pneumocytes which produce surfactants
Also apoptosis within mesenchyme
Produce antioxidants
Describe the stages of lung development
Psuedoglandlar phase- 6 to 16 weeks
Canalicular- 16 to 26 weeks gestation. Vascularity begins, airways develop
Saccular phase- 26 to 32 weeks. Removal of mesenchyme, air sacs with crest formation, surface area increased
Alveolar stage
What can damage the lungs at 22-24 weeks
Oxygen
Overdistension (high pressure ventilation)
Collapse and reinflation of alveoli
Inflammation/infection
Describe the lung compliance curve
If low inflation, takes more effort to inflate
If already inflated, takes less effort to further inflate
If lungs are kept inflated it is easier to breathe
Pressure can damage lungs
