Neonatology CA Flashcards
What is gestational age
Time from the beginning of the womens last menstrual period
What is embryonic age
Time from fertilisation
How do you calaculate genstational age
Embryonic age + 14 days
How many chromosomes does a gamete have
23
What is the process of cleavage during formation of blastocyst
Rapid mitotic cell divisions that create a morula consisting of the blastomeres
Explain the changes in cytoplasmic volume of the zygote during celavage
The cytoplasmic volume doesn’t change during cleavage. Rather, the large volume of the zygote cytoplasm is divided into increasingly smaller cells
What are the three layers of a blastocyst
Inner cell mass (embryoblast) for forms the foetus
Fluid filled hollow (blastocyst cavity)
Outer layer (trophoblast) which forms part of the placenta
What does a blastocyst secrete once fully developed
Immunosuppressant protein called early pregnancy factor
When does implantation occur in foetal development
6 days after fertilization
What is the zona pellucida
This is the extra cellular matrix that surrounds the blastocyst and is maintained through the formation of the morula while it travels to the uterus/endometrium
What does the blastocyst embed itself into in the beginning of implantation
Endometrium in the uterus
What are the two layers that the implanted blastocyte forms into
Outer layer - syncytiotrophoblast - erodes through endometrial tissue via apoptosis enabling the blastocyst to further embed into the endometrium
Inner layer - cytotrophoblast - new cells of the inner layer of the blasyocyst which form villi that project to the syncytiotrophoblast
What releases human chorionic gonadotropin and what is its mode of action
syncytiotrophoblast cells - hCG stimulates the corpus luteum of the ovary to produce progesterone to maintain the preganancy
How does the amniotic cavity form
As implantation progresses, the amniotic cavity forms within the blastocyst on the opposite side of the inner cell mass
What is the fate of the blastocyst cavity as implantation progresses
This forms into the primary umbilical vesicle and ultimately the secondary umbilical vesicle (or yolk sac)W
What is the chorionic cavity in implantation
This surrounds the structure that is imbedded into the endometrium at the final stage of implantation
When does gastrulation occur
Embryonic week 3
What is the bilaminar embryonic disc
This is the double sides layer of cells that separates the blastocyst cavity and amnionic cavity
What are the three layers of the trilaminar embryonic disc
Ectoderm, mesoderm and endoderm
What process occurs to make the third streak in the trilaminar embryonic disc
Invagination
How is the notochord developed in foetal development
Forms cranially from the primitive pit (trilinear embryonic disc) until it reaches the prechordal plate
What is the prechordal plate
small column where the ectoderm and endoderm are fused
What is neurulation
Formation of the neural tube
What does the neural plate then go on to develop into
Central nervous system
How is the neural tube formed
The neural plates begin to move together. Once they merge they make the neural tube that separates from the ectoderm as the folds form a separate enclosed tube and intact surface ectoderm
What forms the neural crest and what does this tissue go on to form in the foetus
Neural crest cells form the neural crest - these become the sensory ganglia of the spinal and cranial nerves
What is the fate of ectoderm cells
epidermis, CNA, PNS, eyes
What is the fate of mesoderm cells
skeletal muscle, blood cells, cardiovascular system
What is the fate of endoderm cells
Endothelial cells
What are electrographic seizures
Seizures that occur in the brain with no clincal symptoms
Why can neonatal EEG be high in amplitude
Due to the lack of bone in the infacts skull
What elelctrodes are used for neonatal EEG
self adhesive hydrogel electrodes
Limited EEG montage
- Ground
- Reference
- EOG electrodes
Ground - Fz
Reference - most accessible mastoid
EOG - placed 1/2 - 1cm from eye. One must be above the eye and the other must be below (opposites)
What electrodes are on a limited EEG montage that are not present on a full montage
FP4/FP3 - these are the only frontal electrodes on the EEF just to the underdeveloped frontal lobe and excess artefact
What EEG montage is used for therapeutic hypothermia protocol and seizures, respectifly
Therapeutic hypothermia protocol - Limited
Seziures - Full
What are the values of the high pass filter, low pass filter and sensnitivy in neonatal EEG
Low pass filter - 0.3Hz
High pass filter - 70Hz
Sensiitvity - 7uV/mm
What is the timebase on neonatal EEG
15mm/s
(adult is 30mm/s)
How long is EEG used for during therapeutic hypothermia
Monitor 1hr before then during (84 hours total - 72 cooling + 12 rewarming)
How long is EEG done for suspected seizures
Continuous EEG until paroxysmal episodes are recorded (up to 24 hours)
What is the time base of aEGG
6cm/hr
What channel is aEEG ususally measuring
C3-P3 or C4-P4
What is the voltage classification for normal aEEG
Lower margin - >5uV
Upper margin - >10uV
What is the voltage classification for moderately abnormal aEEG
Lower margin - <5uV
Upper margin - >10uV
What is the voltage classification for severely abnormal aEEG
Lower margin - <5uV
Upper margin - <10uV
When would we expect a discontinuous aEGG
Broad when the baby is in quiet sleep
Narrow when the baby is in active sleep
What does seizure activity look like on an aEEG
Sawtooth pattern (can stick a pencil under it)
How many babies are born with congenital heart disorders
0.8 births per 1000 births
What % of congenital heart diseases are due to malformation
15%
True or false - congenital heart disease are mostly associated with high risk pregnancies
False - 90% of these diseases occur in pregnancy where there is no identifiable risk factors
What % of heart diseases are picked up in antenatal screening
50%
If a baby has pulmonary oedema, what will this present as and what symptoms will the baby have
Present as cardiac failure - reduced feeding, tachypnoea, tachycardia, hepatomegaly, failure to thrive
If a baby has coaction of the aorta, hypoplastic left heart syndrome or critical aortic stenosis, how will this present in the baby
As cardiac shock
What are the 4 pathological changes that occur in the heart of a baby with TOF
- VSD
- Pulmonary Stenosis
- Aortic override (aorta pulls over VSD)
- RVH
What shape is the heart in TOF
Boot shapped
What syndrome is TOF commonly associated with
DiGeorge Syndrome
What will an echo look like of someone with TOF
Turbulent flow through pulmonary artery
What are symptoms of TOF
Cyanosis, SOB, trouble gaining weight, heart murmur
How do you treat TOF tet spells
hold child in knee/chest position, morphine, beta blockers, RVOT shunt
What is the incidence of VSD
25-30% of congenital cardiac defects include a VSD
What is the patholoigcal mechanisms behind the symptoms of VSD
Mixing of oxygenated and deoxygenated blood via the VSD means the baby will increase HR to compensate for decreased oxygen supply to the periphery. Metabolic rate then increases, they are burning more calories and are breathless so they cant feed properly.
At what weight can a baby undergo cardiac catheratization
10kg
Treatment for VSD
high energy formulas, ng feeding
What are the 4 charcteristics of WPW syndrome on ECG
delta wave, wide WRS, short P-R interval and SVT
Sinus tacycardia is normal in children in what state
When the are sick
What QRS width is normal in children (narrow or broad)
Narrow
What rhythm pattern is normal to see in children when they sleep
2:1 Wenchbach
Isolated PACs and PVCs are normal in childrne, true or false
True
What is the first line treatment for ventricular tachycardia in children
Intravenous adenosine
What 4 factors is breathing stimulated by at birth
Chemical, mechanical, thermal and sensory
When during gestation is surfactant produced
end of second semester and third semester
What is the composition of surfactant
90% lipids, 10% proteins
What cells make surfactant
type II pneumocytes
Transient tachypnoea of the newborn (TTN), meconium aspiration syndrome (MAS) and persistant pulmonary hypertention (PPHN) are all pathologies of babies at what gestation?
Term
What is the most common cause of respiratory distress in term newborns
Transient tachypnoea of the newborn (TTN)
What pathology doe transient tachypnoea of the newborn (TTN) cause
Delay in clearance of the lung fluid (low pressure on the thorax and low reabsorbtion of alveolar fluid due to low circulating catecholamines)
At what gestation are babies more at risk of having meconium aspiration syndrome
Postdate newborns (> 42 weeks)
How does nitric oxide support breathing in newborns
Reduces the pressures within the lung blood vessels and helps the heart to pump blood to the lungs = more oxygen in blood = more change of oxygen being absorbed by the alveolar
What is the characteristic appearance on chest x-ray of meconium aspiration syndrome
Patchy changes in the lung tissue (meconium in the alvioli)
What is atelectasis
When the bronchi are blocked so there is no air going to a certain area of the lungs and this area collapses
What is the pathology associated with persistant pulmonary hypertention of the newborn (PPHN)
Due to the increased lung pressure, the heart is beating harder to get blood to the lungs, this increase in pressure continues to keep the shunts open instead of them closing as seen normally in newborns
What is pre–ductus blood saturation
This is the blood saturation of the right hand, as this is supplied by blood above the PDA. If the pre-ductus blood saturation is more than 5% different to the post-ductus saturation (foot) then this tells us the PDA is still open
What is the most common cause of pneumonia in newborns
GBS infection (streptococcus)
What two diseases make up respiratory distress syndrome
Hylaine membrane disease
Surfactant deficient lung disease
When does respiratory distress syndrome onset
Within 4 hours post birth
What is a characteristic sign on chest x-ray of respiratory distress syndrome
‘White out lung’ - there are no boarders of the lung
What is the prevalence of chronic lung disease
20-30% of low birthweight infants
What is the main disease that causes chronic lung disease
Bronchopulmonary dysplasia
What is choanal atresia
Bony obstruction between the nasal cavity and nasophaysynx
What are the relative resistances of the pulmonary vasculature in the fetal circuit and extra uterine circuit?
Fetal circuit - high
Extra uterine - low
How can pulmonary hypertension of the newborn lead to hypoxemia
Elevated pulmonary vascular resistance causes right to left shunt, this means oxygenated blood and deoxygenated blood a mixing, leading to reduced blood flow to the pulmonary circuit and hypoxemia
Failure of what vital transition in birth can lead to pulmonary hypertension of the newborn
In the fetus, pulmonary vascular resistance is higher, pulmonary blood flow is low and gas exchange occurs in the placenta. In a newborn, the pulmonary vascular resistance decreases and pulmonary blood flow increases.
Failure to transition to this decrease in resistance and increase blood flow will cause PPHN
What does right to left shunting in newborns occur via
Foramen ovale and PDA
How is the SPAP measured in predicting persistant pulmonary hypertension of the newborn
Dervived from Bournoulli’s equation
√(2xTR (tricuspid regurgitation))
What value of SPAP is indicative of persistant pulmonary hypertension of the newborn
> 40mmHg
What is TAPSE a measure of in echo
Right ventricular systolic function
What would colour doppler look like in persistant pulmonary hypertesnion of the newborn
Blue/mixture of colours - this means the blood is flowing in multiple directions
What is the equation of the oxygen saturation index (OI)
OI = MAP (mean airway pressure) x FiO2 x 100/PaO2 (arterial pressure)
What is the unit of OI
mmHg or Kpa
How do you convert Kpa to mmHG
Kpa x 75.5 = mmHg
What are the ranges of OI for mild, moderate and severe pulmonary hypertension of the newborn
Mild <15
Moderate >15-25
Severe >25
When measuring the PAATi in echo during pulmonary hypertension assessment, what changes will their be to the curve of the measurement as pressure changes
The higher the pressure the narrower the peak is (steeper the curve of the parabola)
What is PAATi in echocardiograms
pulmonary artery acceleration time
What are the 2 main forms of therapy for treating pulmonary hypertension of newborns
Milrinone and Nitric Oxide
What type of blood absorbs more infrared light then red light
Oxygenated blood abosrbes more infrared light then red light
What is the SpO2 % when the infrared-to-red absorbance is 1
SPO2 = 81%
What is the target SpO2 1 minute after birth
60-65%
How does the sampling rate of oximetry machines vary between in a respiratory sleep lab to those in the ward
The sampling rate in the respiratory lab will be higher so that they are taking more samples per minute and thus gathering more accutate infomation
What occurs to the airway resistance during sleep
Resitnce increases
What occurs to the muscle tone and central respitatory drive during sleep
Decreases
How does the amount of REM sleep of the child compare to that of an adult
Children spend a higher % of their sleep in REM
What pathology accounts for 68% of home oxygen use in infants and children
Bronchopulmonary dysplasia
What is the mean and lowest normal value of oxygen saturation in a 1 month old, 3-4 month old and >2 year old
1 month old: mean =>97%, nadir = >80%
3-4 month old: mean > 97.7%, nadir > 84.7%
2 year old: mean = >97%, nadir >88%
In the oxygen saturation Hb curve, when the curve shifts to the right, what does this mean
Reduced Hb affinity to oxygen
Where are the ideal sensor application sites for capnography on babies
Bony areas - cheek bone, back, sternum
What is the chemical changes that occur and thus are measures during capnography
When CO2 diffuses through the skin it forms carbonic acid - this changes the pH, creating potential different between the elelctrodes
What is the normal AHI for paediatrics and adults respectfully
Peads <1
Adults <5
What is the AHI for paediatrics and adults with mild sleep apnoae, respectfully
Peads 1-5
Adults 5-10
What is the AHI for paediatrics and adults with moderate sleep apnea, respectfully
Peads 5-10
Adults 15-30
What is the AHI for paediatrics and adults with severe sleep apnea, respectfully
Peads >10
Adults >30
What Z score is within the 5th centile
-1.65
Why do we prefer z scores over percentages with diagnostic markers
Z scores are more consistent across age and sex then the predicted %
What three properties of the lungs are assessed in a routine pulmonary function test
Airflow, lung voles and capacities, alceolar capilary gas transfer
What is the positive bronchodilator response in adults and children, respecftully
Adults - increase in FEV1 or FVC by >12%
Children - increase in FEV1 >12% (or PEF of 15%)
What is the average daily diurnal PEF variability in adults and children respectfully
Adults - >10%
Children - >13%
How can DLCO be calculated
DLCO = Va (area) x Kco
What can cause KCo to decrease
Decrease in purfusion, thicked alveolar-capillary membrane, increase in volume relative to surface area
What is the main indication for DLCO testing
Interstitial Lung Disease `
What causes DLCO to increase and decrease respecfully
Increase - high Hb, standing up, obesity and asthma
Decrease 0 age, female, smoking
What 3 things are measured in body plesmography
TLC, FRC, RV
What will be the difference in RV, FRC, VC and TLC in an elderly person
RV and FRC increase
VC decrease
TLC unchanges
What does lung clearance index measure
Ventilation inhomogeneity in the peripheral airways (how much ventilation is required to clear the FRC)
What gas is most commonly used in lung clearance index tests
N2
When are lung clearance tests used
In children with cystic fibrosis when their FEV1 is in the normal range
What are normal and signficantly abnormal results for a lung clearance test in children
Normal <8
Abnormal >10
During nitric oxide measurements, FeNO is increase and decreased in what pathology
Increased - type 2 airway inflammation
Decreased - smokers
What are the values of low Nitric Oxide measurements in children and adults
Adults - <25
Children < 20
Type 2 inflammation unlikely
What are the values of intermediate Nitric Oxide measurements in children and adults
Adults - 25-50
Children - 20-35
Type 2 inflammation possible
What are the values of High Nitric Oxide measurements in children and adults
Adults >50
Children >35
Type 2 inflammation likely
In the umbilical cord, what blood vessels are there and what are their functions
2 umbilical arteries - deoxygenated blood flow from baby to placenta
Umbilical vein - oxygenated blood in placenta returns to foetus
Where in the placenta does gas and nutrient exchange occur
Across placenta membrane between the blood in the maternal sinuses and the foetal blood in the villi
What mechanism moves oxygen from the maternal system to the foeatal system
Simple diffusion
How does foetal Hb levels compare to that of the mother
Hb concentration in foetal blood is 50% higher then maternal blood - Foetal blood can carry 20-50% more oxygen than maternal Hb
How does PCO2 of foetal blood compare to maternal blood
Foetal blood contains 2-3mmHg more CO2 then maternal blood
What is the placental membranes permeability to oxygen and CO2 respectfully
Extremely permeable to CO2
What mechanisms is glucose transported across the placental membrane
Facilitated diffusion via carrier molecular in the trophoblast cell
What are the glucose levels of foetal blood compared to maternal blood in early pregnancy
Foetal blood contains 20-30% less glucose then maternal blood
How does urea and creatine, respectfully, get expelled from the foetal system
Urea - diffuses with ease
Creatine - requires a high foetal creatine level to allow diffusion
On what day gestation does the primative heart begin to beat
22 days
What structures ultimately form the heart and at what age
Days 18-19: 2 tubes from the ventral mesoderm fuse together to form the primitive heart
What process occurs to form the hearts 4 chambers
Cardiac looping during the 4th week
What pathway is the ductus venosus apart of in the foetal circulation
Blood travelling through the ductus venosus bypasses the metabolically active developing liver. It empties directly to the IVC where it mixes with deoxygenated blood returning from the foetal body
What is the role of the spincter in the ductus venosus
Prevents damage to the foetal heart in the event of high umbilical vein pressure such as during uterine contractions
For the blood that doesnt go through the ductus venosus, where does it go
It flows through the umbilical bein into the sinusoids of the liver and enters the IVC via the hepatic vein
Blood flow through the foramen ovale is unidirectional, true or false
True - this is maintained by a valve
What is the relative pressure differences between the right and left side of the foetal heart, and what causes this
Right side pressure is higher due to the increase pulmonary resistance in the deevloping lungs
What occurs to the blood once it is pumped through the foramen ovale
It mixes with the relatively small amount of deoxygenated blood returning from the lungs and is pumped into the ascending aorta
What major blood vessels does the PDA connect
Pulmonary arteries to the descending aorta
What part of the aorta in foetal circulation has the most oxygenated blood
Ascending aorta due to it not having blood from the foramen ovale
What parts of the foetal body receive the highest oxygenated blood
Upper limbs, neck and head - this is due to these parts being supplied by the ascending aorta which doesn’t contain blood mixed with low oxygen blood from the lungs (PDA)
Where does the blood in the descending aorta in foetal circulation go?
65% goes to umbilical cord and is oxygenated in the placenta
35% supplies the inferior foetus and rejoins the oxygenated blood from the umbilical vein in the ICV
What three changes to the circulation occur in the baby immediately after termination of the placenta
Immediate decrease in blood pressure
Increase in systemic vascular resistance
Decrease in pulmonary vascular resistance
What occurs to the heart pressures immediately after birth
The pressure differences switch - the left side has higher pressure causing the foramen ovale and PDA
What occurs the ductus venosus after birth
The spinchter closes, removing the bypass to the liver
By what age is the foramen ovale fully closed
3 months post birth
What does the PDA then turn into after birth
Ligamentum arteriosum
What does the ductus venosus turn into after birth
Ligamentum cenoss
What is the pressure required for the baby to produce its first breath
Minimum of 25mmHg to inflate the lungs for the first time
Most newborns produce 60mmHg pressure on first inhale
What percentage of time during a sleep study is the oxygen saturation allowed to drop below 92% in:
1 month old
3-4 month old
>2 year old
1 month - <82%
3-4 month old - <25%
2 year old - <15%
During a sleep study, clusters of oxygen desaturation are frequent or not frequent in:
1 month old
3-4 month old
>2 year old
1 month old - frequent
3-4 month old - frequent
>2 year old - <2
What stage in gestation does mylination of nerves begin
second semester
By what age is 90% of a brain formed
5 years old
Perinatal asphyxia occurs in what % of live births
2%
What is the incidence of HIE
3 per 1000 births
What are the two most common outcomes for babies with HIE
Cerebral palsy and learning deficits
What percentage of enchephalopathy cases are mild, and what is the incidence of abnormal outcome for these individuals
40% of enchephalopathies are mild.
20-35% will have an abnormal outcome
What percentage of enchephalopathy cases are moderate, and what is the incidence of abnormal outcome for these individuals
40% of encephalopathies are moderate.
40% will have a disability
What percentage of enchephalopathy cases are severe, and what is the incidence of abnormal outcome for these individuals
20% of encephalopathies are severe.
50% will die, 40% will have severe cerebral pausy
What causes cerebral calsy
Injury to the motor pathways in the brain (thalamus)
An EEG with continuous activity, amplitude of 25-100uV and sleep cycling is what type of EEG
Normal
Severe enchephalopathy is characterised by what EEG characteristic
Isoelectric baseline
What is a common prognostic tool used in EEG to measure prognosis of babies with encephalopathy
Inter-burst intervals of discontinuous activity
Shorter the IBI = better prognosis
What scale is used to grade the severeity of cerebral palsy? What grades will never walk
Growth motor function classification
Level 3 and 4 will never walk
Burst suppression is normal in an EEG of what age baby
27 weeks
Grade IV intraventricular haemorrhage can cause what in babies
Cerebral palsy due to haemorhage damaging the motor tracks
What is periverntricular leukomalacia
Damage to the while matter
What is the requirements for a neonatal seizure
Require repetative and evolving pattern with a minimum 2uV peak-to-peak voltage and duration of at least 10 seconds
What are the 3 possible outcomes for neonatal stroke
Adverse outcome
Cerebral palsy
Postnatal epilepsy
If stoke occurs in the middle main artery what are the chances of them developing cerebral palsy and cognitive deficits
100% will have cerebral palsy
57% will have cognitive deficits
What changes do we expect in SAT’s in neonatal EEG throughout maturation
the amount of SAT’s will be high in preterm babies, but show be absent in a term baby
What occurs to the IBI in babies preterm compared to those term
IBI intervals should decrease as the baby gets more to term
In a term baby, when should continuous EEG activity be present
Awake and REM/active sleep
What is the major hallmarke of preterm baby on EEG
Delta Brush
Explain the syncronous nature of the EEG of a preterm compared to a term baby
Not unusual for preterm baby to have asynchrous activity - as they reach term the EEG should be fully synchronous during wake
In regards to reactivity, explain an EEG of a beby 24-28 week GA
EEG doesnt correlate to behavoural changes (can’t tell if the baby is awake, asleep, ect from the EEG alone)
What continuity is present on a EEG of a 24-28 week GA baby
Background EEG very discontinuous with large IBI
Over what areas of the brain is delta brush expected in the EEG of a 24-28 week GA baby
Temproal, central and occipital lobes
At what age GA does the EEG begin to represent behavoural changes
28-31 weeks
At what age GA does sleep stages begin to be easier to distinguish on EEG
32-24 weeks
What frequency is delta waves in 32-24 week GA baby
2 Hz
What EEG pattern is expected in a term baby during quiet sleep
Trace alternant
What are is delta brush localised to in a term baby EEG
Occipital lobe
What is the maximum duration an IBI should last in a preterm infant to not be deemed irregaulr
cannot be more then 60seconds
The amplitude of neonatal EEG is generally higher then adults, true or false
True
Loss of faster frequencies in neonatal EEG is the earliest sign of what pathology
Cortical dysfunction
Complete absence of poly frequency in neonatal EEG suggests what pathology
Severe brain insult (HIE, toxic metabolic enchephalopathies, cerebral heamorhage)
Non-reactive and unchanged suppression burst activity suggests what pathology
Epileptic encephalopathies
Positive Rolandic sharp waves that are constantly on the central regions are associated with what pathology
Periventricular white matter injury, meningitis, HIE, ect
What are the 3 major abnormalities seen in NICU EEG
Abnormalities in background
Abnormalities of maturation
Seizure and ictal patterns
How does the amount of REM sleep progress throughout the evening
The amount of time we spend in each REM cycle gets longer each cycle we have
If sleep is very fragmented what 2 pathologies could this indicate
Insomnia or narcolepsy
What is the recommended amount of sleep in children and infants, respectfully
Children - 9-10 hours
Infants 12-16 hours
What age should children no longer be taking naps
5 Years
What stage of sleep do infants and children enter immediately upon onset of sleep, respectfully
Infants - REM
Children - NREM
How does the REM-NREM cycle differ between infants and children
Infants have a much shorter cycle whereas children alternative between the two stages every 90-100 minutes
What % of a childs sleep is spent in NREM
75%
What age is considered an infant, child and adult, respectfully
Infant - 0-2 months
Children - >2 months
Adults - >18
What is the sleep stages seen in adults
wakefulness, N1, N2, N3, REM
What are the sleep stages seen in chilldren
wkaefulness, N1, N2, N3, NREM, REM
What are the sleep stages seen in infants
Wakefullness, NREM, REM, transitional
What is the distance between chin EMG elelctrodes on children
1cm
What is the distance the EOG electrodes are from the eye in children
o.5cm
How are the electrodes used on EEG different in adult/children sleep scoring then infant sleep scoring
In adult/children sleep scoring they only use the reccomended elelctrodes, whereas in infants they use reccomended and back up
What is the common montage used for infant sleep scoring
F4-M1, C4-M11, O2-M1
What are the characterisitcs of sleep spindles in those under the age of 2
Asynchronous and more prominent in the midline
What is the AASM criteria for awake infants (behaviour, EMG, respiration, EEG)
Eyes open, vocaliation, REMS or scanning eyes, sustained chin EMG with bursts of muscle activity, irregular respiration, EEG low voltage irregular or mixed
What is the AASM criteria for NREM infant (behaviour, EMG, respiration, EEG)
eyes closed with no eye movements, chin EMG tone present, regular respiration, trace alternate/high voltage or sleep spindles present, reduced movement compared to wake
What is the AASM criteria for REM infant (behaviour, EMG, respiration, EEG)
low chin EMG, eyes closed with at least 1 REM, irregular respiration, mouthing/sucking/switches or brief movements, EEG has continuous pattern without sleep spindles
What is the AASM criteria for transitional sleep infant (behaviour, EMG, respiration, EEG)
When 3NREM and 2REM or 2NREM and 3REM characteristics are present
Is trace alternat continuous or discontinuous EEG
discontinuous
When is trace alternant generally only seen on EEG
NREM in full term infants
What is trace alternat on an EEG defined by
At least 3 alternating runs of bilaterally symmetrical synchronous high voltage burst of delta activity lasting 5-6 seconds
Low voltage irregular EEG
- Continuous or discontinuous
- What type of waves does it invovle
- What stages is it seen in
Continuous
Mixed frequency activity with delta and prodominantly theta
Seen in REM and wakefullness
high voltage slow EEG
- Continuous or discontinuous
- What type of waves does it invovle
- What stages is it seen in
Continuous
high voltage delta activity
REM
What stage of sleep are sleep spindles seen and what frequency are they
NREM
12-14Hz
What is the most reliable characteristic of determining the presence of REM or NREM sleep
Regularity of respiration
When should you score an arousal on a sleep score
If there is an abrupt shift in EEG frequency (but not sleep spindles) that lasts at least 3 seconds
How is HIE graded
Clinical Examination - takes into account consciousness, activity, tone/posture, autonomic function and reflexes
What is the incidence of HIE
1-5 per 1000 births
Explain the primary energy failure phase in HIE
During an ischemic insult the tissue switches to anaerobic metabolism - this causes ROS production and ATP deficit. Na+/K+ pump stops, Na+ entering cells, causes cells to swell = necrotic cell death
What is the latant period in HIE
This follows the primary energy failure phase where the blood flow and oxygen is restored to the tissues.
Occurs 6 hours after insult
What causes the secondary energy failure phase in HIE
Apoptosis cell death
What is the mechanism of therapeutic hypothermia
Aims to reduce cell death during the latant phase and secondary energy failure phase
What is the process of thereputic hypothermia
Baby cooled to 33.5 celcius for 72 hours then rewarmed
What severity of HIE is eligible for therapeutic hypothermia
Moderate - Severe HIE
What are three adverse side effects of therapeutic hypothermia
Reduced blood clotting ability
Pulmonary hypertension
Subcutaneous fat necrosis
