Care of the Newborn Flashcards
Name 6 functions of the placenta
1) Site of 02 transfer
2) Provides nutrition
3) Provides growth hormones
4) Controls fluid and electrolyte balance
5) Undertakes waste removal
6) Allows IgG to pass into the fetus
Name 6 functions of the placenta
1) Site of 02 transfer
2) Provides nutrition
3) Provides growth hormones
4) Controls fluid and electrolyte balance
5) Undertakes waste removal
6) Allows IgG to pass into the fetus
How do 2,3-DPG levels differ in pregnant and non-pregnant women and what effect does this have?
Pregnant women have 30% higher 2,3-DPG levels. 2,3-DPG binds to β-chains of Hb and reduces affinity of Hb for 02 and increases release. This shifts the 02 dissociation curve to the right.
How does 2,3-DPG affect the fetus?
The fetal Hb contains γ chains rather than β chains. γ chains have a much lower affinity for 2, 3-DPG therefore the 02 dissociation curve of the fetus is further left
What three factors allow effective oxygen donation to, and use, by the fetus?
1) Lower PaO2 in umbilical arteries than the maternal circulation creates an O2 gradient
2) The fetal haemoglobin (HbF) has a higher affinity for 02 than maternal haemoglobin (HbA) which facilitates uptake of released O2
3) Higher Hb in fetus allows effective carriage and release of oxygen despite increased affinity
What vessel carries blood from the placenta to the fetus?
The umbilical vein which carries oxygenated blood at low pressure
What vessels carry blood from fetus to placenta?
Umbilical arteries (x2) which carry deoxygenated blood at high pressure
What vessels carry blood from fetus to placenta?
Umbilical arteries (x2) which carry deoxygenated blood at high pressure
What three structures make the fetal circulation different to our own?
1) Foramen ovale
2) Ductus arteriosus
3) Ductus venosus
Describe the location and purpose of the foramen ovale
The foramen ovale is a hole between the right and left atrium, which allows blood to be shunted from the right atrium to the left atrium thus bypassing the lungs.
Describe the location and purpose of the ductus arteriosus
The ductus arteriosus is a small blood vessel connecting the pulmonary artery to the aorta. It allows the remaining blood in the right ventricle to bypass the lungs (RV only pumps 2/3 of cardiac output)
Describe the location and purpose of the ductus arteriosus
The ductus arteriosus is a small blood vessel connecting the pulmonary artery to the aorta. It allows the remaining blood in the right ventricle to bypass the lungs (RV only pumps 2/3 of cardiac output)
Describe the location and purpose of the ductus venosus
The ductus venosus is a small blood vessel connecting the umbilical vein to the fetal IVC. It allows a proportion of the oxygenated blood from the placenta to bypass the liver.
What does the ductus arteriosus become after closure?
Ligamentum arteriosum
What does the ductus venosus become after closure?
Ligamentum venosum
What is ligamentum teres (also known as the round ligament of the liver)?
The remnant of the umbilical vein. The mesentery become the falciform ligament.
Define functional residual capacity
The volume of air present in the lungs at the end of passive expiration
What causes closure of the ductus arteriosus?
The ductus arteriosus is closed by increased partial pressure of oxygen. The effect is mediated by inhibition of prostaglandins.
What happens to the umbilical arteries?
They constrict but some parts remain patent supplying the urinary bladder
What are the nutrient requirements of a neonate?
Water - 150ml/kg/day Calories - 110 kcal/kg/day Protein - 1-2g/kg/day Fat - including essential fatty acids Minerals, vitamins and trace elements
What is the predominant immunoglobulin found in breast milk?
IgA (the colostrum has particularly high levels of IgA)
What is the predominant immunoglobulin found in breast milk?
IgA (the colostrum has particularly high levels of IgA)
What two types of cancer does breast feeding reduce the risk of in the mother?
Breast cancer and ovarian cancer
What two types of cancer does breastfeeding reduce the risk of in the mother?
Breast cancer and ovarian cancer
Define preterm birth
Less than 37 weeks gestation
Define:
1) Low birth weight (LBW)
2) Very low birth weight (VLBW)
3) Extremely low birth weight (ELBW)
1)
Define still birth mortality rate
Fetus born with no signs of life at greater than or equal to 24 weeks old
Define perinatal mortality rate
Stillbirths + deaths within the first 7 days of life per 1000 live births
What is the stage of lung development at 7 weeks?
Pseudoglandular stage
What is the stage of lung development at 18 weeks?
Canalicular stage
What is the stage of lung development at 24 weeks?
Saccular stage, type II pneumocytes
What is the stage of lung development at 32 weeks?
Alveolar stage
Ventilation = ?
Ventilation = tidal volume x respiratory rate
What is perinatal asphyxia? What is the resulting condition called in neonates?
Perinatal asphyxia is when gas exchange, either pulmonary or placental, is compromised or ceases altogether. The resulting neonatal condition is called hypoxic ischemic encephalopathy.
What may cause failure of gas exchange across the placenta?
Excessive or prolonged uterine contractions, placental abruption or a ruptured uterus
What may cause interruption of umbilical blood flow?
Cord compression, including shoulder dystocia; and cord prolapse.
What can cause inadequate maternal placental perfusion?
Maternal hypotension or hypertension - often with IUGR
When do the clinical manifestations of hypoxic-ischaemic encephalopathy start? And how are they graded?
Immediately or up to 48 hours post asphyxia. They are graded as mild, moderate or severe.
Describe mild clinical manifestations of hypoxic ischaemic encephalopathy
The infant is irritable, responds excessively to stimulation, may have staring of the eyes & hyperventilation and has impaired feeding.
Describe moderate clinical manifestations of hypoxic ischaemic encephalopathy
The infant shows marked abnormalities of tone and movement, cannot feed and may have seizures.
Describe severe clinical manifestations of hypoxic-ischaemic encephalopathy
There are no normal spontaneous movements or response to pain; tone in the limbs may fluctuate between hypotonia and hypertonia; seizures are prolonged and often refractory to treatment; multi organ failure is present.
Neuronal damage may be primary from neuronal death or may be delayed from…
Reperfusion injury, causing secondary neuronal death
What treatment may offer neuroprotection from reperfusion injury?
Mild hypothermia (33 to 34 degrees for 72 hours by wrapping in a cooling blanket)
What does aEEG stand for? and what does it monitor?
Amplitude-integrated electroencephalogram. It monitors cerebral function and can detect abnormal background activity to confirm early encephalopathy or identify seizures.
