Neonatology 4

Question 1

How effective is surfactant therapy?

Answer 1

Preparations are natural, derived from extracts of calf or pig lung- they are instilled directly into the lung via a tracheal tube Shown to reduce mortality from RDS by 40% without increasing the morbidity rate

Question 2

What are the clinical signs of RDS?

Answer 2

At delivery or within 4 hrs
o Tachypnoea >60 breaths/min
o Laboured breathing with chest wall recession and nasal flaring
o Expiratory grunting in order to try to create positive airway pressure during expiration and maintain functional residual capacity
o Cyanosis if severe

Question 3

Why are preterm infants at an increased risk of infection?

Answer 3

IgG is mostly transferred across the placenta in the last trimester and no IgA or IgM is transferred- in addition, infection in or around the cervix is often a reason for preterm labour and may cause infection shortly after birth

Question 4

Which babies are likely to have hypoglycaemia in the first 24hrs of life?

Answer 4

o	IUGR
o	Preterm
o	Born to mothers with diabetes
o	Large for gestational age
o	Hypothermic
o	Polycythaemic
o	Ill for any reason

Question 5

What are the symptoms of hypoglycaemia?

Answer 5

o	Jitteriness
o	Irritability
o	Apnoea
o	Lethargy
o	Drowsiness
o	Seizures
Need >2.6 for good neurodevelopment

Question 6

What is the management for hypoglycaemia?

Answer 6

can be prevented by early and frequent feeding with breast milk and regular monitoring if at risk
If an asymptomatic infant has two levels <2.6 or one <1.6 then IV infusion is given
High IV concentrations should be given centrally to avoid peripheral skin necrosis, glucagon and hydrocortisone may also be given

Question 7

Why are preterm infants particularly vulnerable to hypothermia?

Answer 7

large surface area relative to their mass- so there is a greater heat loss than heat generation
o Their skin is thin and heat permeable- so transepidermal water loss is important in the 1st week of life
o They have little subcutaneous fat for insulation
o They are often nursed naked and cannot conserve heat curling up or generate heat by shivering
Temperature maintained by- incubators or overhead radiant heaters

Question 8

When does bradycardia occur?

Answer 8

• Episodes of apnoea, bradycardia and desaturation are common in very low birthweight infants until they reach abut 32 weeks gestation
when an infant stops breathing for >20-30secs or when breathing continues, but against a closed glottis

Question 9

What are the causes of apnoea?

Answer 9

o	Hypoxia
o	Infection
o	Anaemia
o	Electrolyte disturbance
o	Hypoglycaemia
o	Seizure
o	Heart failure
o	Aspiration due to GORD

Question 10

What is retinopathy of prematurity (ROP)?

Answer 10

Affects developing blood vessels at the junction of the vascular and non- vascularised retina, there is vascular proliferation which may progress to retinal detachment, fibrosis and blindness
Risk is increased by uncontrolled high concentrations fo oxygen
Screened every week by ophthalmologist

Question 11

How does intraventricular haemorrhage present?

Answer 11

very common in very low weight infants (60-70% if 500-750g)
o Apnoea
o Lethargy
o Poor muscle tone
o Sleepiness
o May progression to coma & bulging fontanelle

Question 12

What is the management for an intraventricular haemorrhage?

Answer 12

• Management is supportive with correction of acidosis, anaemia & hypotension- fluid treatment may be needed along with medicine to decrease ICP
• The definitive treatment is a ventriculoperitoneal shunt

Question 13

How is good nutrition delivered to premature babies?

Answer 13

• Infants of 35-36 weeks are mature enough to suck and swallow milk, less mature infants will need to be fed via an oro- or nasogastric tube
even in very preterm infants, enteral feeds (preferably breast milk) are introduced as soon as possible- breast milk needs to be supplemented with phosphate and may need supplementation with protein, calories & calcium

Question 14

How is nutrition delivered in very immature or sick infants?

Answer 14

Parenteral nutrition-central venous catheter inserted peripherally (PICC line). Aseptic technique- risk of septicaemia, thrombosis of major vein
Parenteral nutrition may sometimes be given via a peripheral vein, but extravasation may cause skin damage with scarring

Question 15

How is poor bone mineralisation prevented in premature infants?

Answer 15

Osteopenia of prematurity
phosphate, calcium and vitamin D
Iron is transferred during last trimester
Iron supplements are started at several weeks of age

Question 16

What is bronchopulmonary dysplasia?

Answer 16

Chronic lung disease
Infants who have an oxygen requirement at post-gestational age of 36 weeks
Lung damage comes from pressure and volume trauma
CXR- widespread areas of opacification, sometimes with cystic changes

Question 17

What is the prognosis for severe bronchopulmonary dysplasia?

Answer 17

May die of Intercurrent infection or pulmonary hypertension, subsequent pertussis and RSV infection may cause respiratory failure necessitating intensive care
Pneumothorax- infants ventilated at lowest pressure. Treatment involved CXR and chest drain

Question 18

What are the respiratory changes that occur after birth?

Answer 18

Lung liquid is reabsorbed- chest compression during birth squeezes out a third and the release of adrenaline promotes reabsorption of the rest
• Surfactant is released- triggered by adrenaline and steroids, and synthesis is also begun
• A fall in the capillary pressure of the lungs occurs with expansion of the alveoli and the vasodilatory effect of oxygen- respiratory movements of the chest commence

Question 19

What are the important time frames in the newborn?

Answer 19

Bowels- open within 6hrs or before birth- up to 24hrs
Bladder- open up to 24hrs
Weight- newborns lose around 7-10% of their weight, but should regain it in about 2 weeks