PBL 3 Flashcards
describe the score system for Apgar
appearance
0 pale
1 Body pink, extra blue
2 all pink
pulse
0 absent
1 less than 100
2 over 100
griamce
0 no response
1 grimace
2 cry
activity
0 limp
1 some flexion
2 active motion
respiration effort
0 absent
1 slow cry
2 good cry
what does the response to resuscitation results based on
- Neurological status.
* Effects on other systems.
What is the sarnat score
grading system for hypoxic effects on the brain (usually carried out at 24 hours).
• Can be used as a broad outcome
what grades is the sarnat score made out of
Grade I
Grade II
Grade III
describe the sarnat scoring system
Grade I: hyper alert, tachycardic, jittery, hyper-reflexic, dilate pupils and no fits.
• 100% survive and are usually neurologically normal.
Grade II: lethargic, not comatose, bradycardic, hypotonic, convulsions.
• 5% will die, 20% of survivors will have some neurological deficit.
Grade III: flaccid, stuporose (near-unconscious), poorly reacting pupils, prolonged fits.
• 75% will die, 100% of survivors will have neurological deficit.
what happens in grade III of the sarnat score and what is the prognosis confirmed by
If the baby falls into grade III it a poor prognosis can be expected (with severe neurological deficit).
• Confirmed by MRI shows significant areas of possible infarction
what is the baby at high risk of development of
Baby is at very high risk of going on to develop microcephaly and spastic quadriplegia, difficult to control fits, learning difficulties and feeding difficulties (overall hypoxic-ischaemic encephalopathy).
What is the role of hypothermia in the treatment of hypoxic-ischaemic encephalopathy
o Involves the baby being cooled at a temperature of 33 to 34 degrees for 72 hours followed by a slow rewarming of 0.5 degrees per hour.
o It decreases cerebral metabolism, decreases energy use, decreases accumulation of excitotoxicity amino acids and decrease NO synthase/free radical activity.
• i.e. tries to prevent secondary energy failure.
what specific does hypothermia do to the brain
o It decreases cerebral metabolism, decreases energy use, decreases accumulation of excitotoxicity amino acids and decrease NO synthase/free radical activity.
Ventouse
a cup-shaped suction device applied to the baby’s head in childbirth, to assist the birth
Meconium
dark green substance forming the first faeces of the infant.
Apgar score
measure of physical condition of a newborn infant.
Phenobarbitone
barbiturates (cause prolonged receptor opening of GABAA receptors).
What is the prevelance of birth asphyxia
birth asphyxia accounts for 7-10% of cases of severe neurological handicap
• There is no uniform definition but reported rates of birth asphyxia are 3-9/1000 births.
what is a poor indication of birth asphyxia
At birth a poor Apgar score is most widely used as an indicator of birth asphyxia.
What are the indications of birth asymphixa
• Prolonged time to onset of spontaneous respirations. • Low umbilical vessel blood pH. • Abnormal fetal heart rate patterns. • Abnormal neonatal neurological signs. - poor agar score
what are the fetal rate tracing signs of hypoxia
- Flat trace (loss of beat-to-beat variation
- Tachycardia: >160/mt.
- Bradycardia: <110/m.
What is a type I dip
• Type I dips: decelerations which occur with contractions.
Also, known as early decelerations.
o Immediately recovers when contraction is over
o Due to head compression (normal).
What is a type II dip
• Type II dips: decelerations which persist after contraction.
o Due to uteroplacental insufficiency (UPI).
What is an unprovoked dip
• Unprovoked dips: decelerations not associated with uterine contractions (variable dips).
o Associated with umbilical cord compression.
What are the 3 types of dip
Type I dip
Type II dip
unprovoked dip
what criteria has to be met for a obstetric forceps or venous extractor be used
- Full cervical dilation.
- Engaged fetal cephalic presentation.
- Ruptured membranes.
- Empty bladder.
- No pelvic contracture/obstruction to fetus.
- Adequate analgesia.
- Experienced deliverer.
what happens if you don’t meet the criteria for an obstetric forceps or venous extractor
proceed to Caesarean section
what can inappropriate use of obstetric forceps or a venous extractor lead to
- Pelvic soft tissue injuries.
- Fetal cranial fractures.
- Nerve plexus trauma.
what is meconium
• Contained within the fetal bowel (made up of desquamated bowel cells and bowel secretion).
o It is a green/black colour and is of a thick consistency.
what is meconium made out of
made up of desquamated bowel cells and bowel secretion)
what happens in asphyxia to the meconium
• Asphyxia can cause the fetus to evacuate the bowel allowing meconium to pass into the liquor
o This may prevent onset of normal respiration.
Baby will remain hypoxic and normal process of physiological change from fetal to neonatal circulation will fail to occur.
what are the respiratory changes occurring at birth
- Initial first gaps generate negative intra-thoracic pressure (as low as -60 to 90 cm H20)
- Air fills the lung and much of the fetal lung fluid is expelled.
- Remainder is absorbed into the pulmonary lymphatics/capillaries
what causes the ductus arteriosus to occur
• Oxygen levels (PaO2) increases from 2-3.5 kPa in the fetus to 9-13 kPa in the first few breaths. This hyperoxia causes the ductus arteriosus to close.
o Some babies = have murmur in first day that disappears as ductus closes
what keeps the ductus arteriosus open in utero
• In utero: ductus is kept open under the influence of prostaglandin E1, but the influence declines as term approaches.
o This decline causes the smooth muscle of the ductus to constrict
What is pulmonary vascular resistance
there is a marked fall in pulmonary vascular resistance shortly after birth (so pulmonary blood flow increases
what happens to the foramen ovale
There is also a drop-in pressure on the right side of the heart, so there is no shunting through foramen ovale (is firstly reversed before it closes to allow for oxygenated blood in systemic circulation).
what happens to the ductus venous
decrease in blood flow in inferior vena cave = ductus venosus is closed and becomes the ligamentum teres
what happens to the umbilical vessel
close and fuse within 10 days.
describe the timings of functional and anatomical closure of
- umbilical vessels
- ductus arteriosus
- ductus venous
- foramen ovale
Functional
- Umbilical vessels = 5 minutes
- Ductus arteriosus = 12 hours
- Ductus venous = 1-3 weeks
- foramen ovale = varaible
anatomical
- umbilical vessels = 10 days
- ductus arteriosus =4-7 days
- ductus venous = 1-3 weeks
- foramen ovale = 6 months - never
what is the effects of apraxia on circulation
• Results in poor O2 delivery to vital organs and can lead to multi-organ failure.
o Baby can die from renal failure, hepatic failure or cardiac failure
Most elaborate manifestations: seen in the neurological system.
• Ranges from sings of irritability to fits/coma.
when is the Apgar score tested
• Used to quickly asses the health of an infant one to five minutes after birth using 5 components and scoring these from 0-2.
