Neonatology Flashcards
when does the foetal heart start to beat and at what period is the heart development most critical?
starts to beat week 4
critical period is day 20-50
what is the oxygen saturation of the foetal circulation?
60-70%
what is the function of the ductus arteriosus?
protects lungs against circulatory overload
allows right ventricle to strengthen
carries low oxygen saturated blood
what does the ductus venosus connect?
connects umbilical vein to the IVC
what carries mostly oxygenated blood…
- ductus arteriosus?
- ductus venosus?
ductus venosus
what carries low oxygen saturated blood..
- ductus arteriosus ?
- ductus venosus ?
ductus arteriosus
what is the normal heart rate of a full term new born?
120-160 bpm
what is the normal blood pressure of a full term newborn…
- 1 hour after birth?
- 1 day after birth?
- 3 days after birth?
1 hour - 70/44
1 day - systolic 70-79, diastolic 42 +/- (12)
3 days - systolic 77 +/- (12), diastolic 49 +/- (10)
what is the normal respiratory rate of a full term new born?
30-60/min
when it is considered bradycardia and tachycardia in a full term newborn?
tachycardia > 160bpm
bradycardia < 100bpm
what is the normal blood gas values of a newborn?
PaC02 5-6 kPa (adult 5-5.5kPa)
Pa02 8-12 kPa (adult 6-13kPa)
how can you measure a babies respiratory system?
blood gas transcutaneous pC02/02 measurement capnography minute ventilation flow-volume loop tidal volume
when does physiological jaundice normally appear and disappear?
normally appears day 2-3 of life
disappears within 7-10s of life (up to 21 days in premature)
what is the main consequence associated with neonatal jaundice?
irreversible changes in the brain - kernicterus
what is the treatment for physiological jaundice in neonates?
blue light
- converts jaundice (lipid soluble) into water soluble form and increases oxidation of bilirubin
what is the treatment for physiological jaundice in a new born?
phototherapy (blue light)
if severe - exchange transfusion
at what levels of bilirubin would you consider an exchange transfusion to treat the jaundice?
> 250 micromol/L
weight loss of up to 10% is normal in a term new born baby. why is this?
loss of fluid due to shift of interstitial fluid to intravascular fluid
diuresis
what is there an increased loss of fluid through the kidney in a pre mature baby?
- decreased GFR
- reduced Na reabsorption
- decreased ability to concentrate or dilute urine
what is the change in a newborns Hg and RBC?
10% of foetal RBC production at day 10
born with 15-20Hg g/L but decreases to 11.4 g/l by week 10
by week 20 it increases to 12 g/L
list causes of being small for dates / IUGR.
maternal;
- pre eclampsia toxaemia
- poor nutrition
- smoking
- diabetes
foetal
- chromosomal i.e. tiresome 18 Edwards syndrome
- infection i.e. CMV
- twin-twin transfusion
placental
- placental abruption
- placental praaevia
what are the common problems associated with being small for dates/ IUGR?
perinatal hypoxia hypoglycaemia hypothermia polycythaemia thrombocyopenia hypoglycaemia gastrointestinal problems i.e. NEC
what are some of the long term problems associated with being small for dates/ IUGR?
hypertension
reduced growth
obesity
ischaemic heart disease
at what birth weight is a baby small for dates (IUGR)?
< 2.5 kg (5.5lb)
at what gestation is preterm and extremely preterm?
< 37 weeks = preterm
< 28 weeks = extremely preterm
name some of the complications associated with prematurity.
respiratory distress syndrome intraventricular haemorrhage periventricular leukomalacia necrotising entero-colitis patent ductus arteriosus broncho-pulmonary dysplasia retinopathy of prematurity post-hemorrhagic hydrocephalus neonatal abstinence syndrome hypoxic ischaemic encephalopathy
how can you prevent respiratory distress syndrome?
antenatal steroids to women who are at risk of preterm labour
what is the treatment for respiratory distress syndrome?
surfactant
non-invasive support (N-CPAP)
minimal ventilation
what is bronchopulmonary dysplasia and what causes it?
overstretched lungs due to volu-baro trauma
(mechanical ventilation and/or long-term oxygen)
lungs try to repair resulting in scarring
what is the treatment for bronchopulmonary dysplasia?
nutrition and growth
steroids
how would you treat a pre mature baby who has apnoea, irregular breathing and/or desaturations?
caffeine
N-CPAP (continued positive airway pressure)
how can you prevent inter-ventricular haemorrhage in a premature baby?
antenatal steroids to a mother who is at risk of a premature birth
what is periventricular leukomalacia?
death of brain tissue surrounding the ventricles
creates holes within the brain
sometimes linked to intraventricular haemorrhage
what problems does a patent ductus arterosus cause and how?
pressure in the aorta is greater than the pulmonary artery therefore blood shunts from the aorta to pulmonary artery (left-right shunt)
results in excess blood in the pulmonary circulation
= over-perfusion of lungs
= lung oedema
also means less blood is in the systemic circulation
= systemic ischaemia
what are the consequences associated with PDA?
worsening of respiratory symptoms
retention of fluids (low renal perfusion)
gastrointestinal problems (ischaemia)
what is necrotising enterocolitis?
ischaemia and inflammation of the intestinal
associated with prematurity
causes necrosis of the bowel
what is the management options for necrotising enterocolitis?
surgery
conservative
- antibiotics
- parenteral nutrition (NG tube)
when is there often a deterioration post-discharge of a premature baby?
between 2nd and 6th years of life
what is the outcome of prematurity?
1/3rd dies
1/3rd have normal or mild disability
1/3rd have severe disability for lifetime
1 in 6 is entirely normal by 6 yrs
a neonate which is otherwise health has minor desaturations and apnoea. how would you manage this patient?
caffeine
N-CPAP
