Prematurity Flashcards
What health problems are associated with prematurity?
- Respiratory distress syndrome
- Apneas
- Necrotising enterocolitis
- Hypoglycaemia
-Increased infection risk
- Difficulty regulating temperature
- Retinopathy of prematurity
- Interventricular haemorrhage
What is necrotising enterocolitis?
Is an infective condition causing necrosis of the bowel.
It is more common in premature babies occurring in the first few weeks of life.
It is thought to result from their immature guts not being able to stop the translocation of gut flora.
How does necrotising enterocolitis present and how is it treated?
Intolerance of feeds Vomiting Abdominal distension Blood in stools Shocked baby
Treatment:
Triple antibiotic therapy and not to feed the child (allows the bowel to rest).
May need op to remove damaged bowel.
20% mortality associated with necrotising enterocolitis.
Why are premature babies more prone to developing infection?
Lack of IgG as it is not transferred until the last trimester.
Why are premature babies more prone to developing hypoglycaemia?
Growth restricted and pre-term infants have poor glycogen stores therefore predisposing them to hypoglycaemia.
Infants of a diabetic mothers are more prone to being born prematurely, they have sufficient glycogen stores but hyperplasia of the islet cells causing high insulin levels which can predispose them to hypoglycaemia.
How does hypoglycaemia present in infants?
- Jitteriness.
- Apnoeas.
- Irritability, lethargy and drowsiness.
- Seizures.
Why are premature infants more predisposed to hypothermia?
Preterm infants are particularly vulnerable as:
• They have large surface area relative to volume
• Their skin in thin and more heat permeable
• They have little subcutaneous fat
• They are often nursed naked and cannot conserve heat by curling up or shivering
To prevent heat loss they are nursed in incubators.
What causes apnoeas of prematurity and how can it be treated?
Episodes of apnoea, bradycardia and desaturation are common in very low birth weight infants until they reach about 32 weeks gestational age.
Bradycardia may occur either when an infant stops breathing for over 20- 30 seconds or when breathing continues but against a closed glottis.
An underlying cause (hypoxia, infection, anaemia, electrolyte disturbance, hypoglycaemia, seizures, heart failure or aspiration) needs to be excluded.
But in many causes it is due to central respiratory control. Breathing will usually start again after gentle physical stimulation and treatment is with caffeine and potentially CPAP.
What is retinopathy of prematurity?
There is vascular proliferation which may progress to retinal detachment, fibrosis and blindness.
It was initially recognised that the risk is increased by uncontrolled use of high concentration oxygen. This occurs in around 35% of very low birth weight infants.
Therefore an ophthalmologist will screen the child’s eyes every week.
Laser therapy is used to any reduce visual impairment.
What is Intraventricular haemorrhage (IVH)?
It is a haemorrhage in the ventricles of the brain which commonly occurs in very underweight infants.
60-70% of those between 500-750g
This is common in very underweight children (60-70% if 500-750g) and presents in the first few days of life with apnoea, lethargy, poor muscle tone and sleepiness. This may progress to a coma and there may also be increased ICP with a bulging fontanelle.
How does intraventricular haemorrhage present?
Presents in the first few days of life with:
- apnoea
- lethargy
- poor muscle tone
This may progress to a coma and there may also be increased ICP with a bulging fontanelle.
How should IVH be managed?
Management is supportive with correction of acidosis, anaemia and hypotension.
Fluid treatment may be needed along with medicine to decrease ICP.
The definitive treatment is a ventriculoperitoneal shunt.
What are the principles and methods of delivering good nutrition to premature neonates?
Preterm infants have a high nutritional requirement because of their rapid growth.
Phosphate, calcium and vitamin D supplementation prevents poor bone mineralisation.
Iron supplements are also given as the majority of iron is usually transferred in the last trimester.
In infants at 35/36 weeks gestation should be able to suck and therefore try to feed orally.
In those younger than 35 weeks give NG feeds and those who are not feeding adequately.
If possible give breast milk to allow transfer of antibodies
What is the impact of prematurity on lung development and what chronic disease can’t it cause?
Prematurity causes respiratory distress syndrome aka lung doesn’t produce surfactant. This condition often requires the child to need long term ventilation and oxygen therapy which can cause chronic lung disease (Bronchopulmoary dysplasia).
When possible the clinician should always aim to step down ventilation to CPAP.
Note:
Ventilation can lead to over distended alveoli and air leakage into the interstitium causing a pneumothorax. To prevent this you should always aim to ventilate at the lowest pressure possible.
What is bronchopulmonary dysplasia?
Chronic lung disease.
The lung damage comes from pressure and volume trauma from artificial ventilation, oxygen toxicity and infection.
The chest x-ray is characteristic and shows widespread areas of opacification, sometimes with cystic changes.
