2. PRESENTATION OUTLINE
• Birth AsphyxiA?
• WhAt reAlly cAuses it?
• pAthophysiology
• hoW do these pAtients present?
• Any diAgnostic criterion used?
• WhAt’s the therApy?
• prognosis After Birth AsphyxiA
• complicAtions
• resuscitAtion
3. Definition
• Failure to initiate spontaneous, sustained
breathing after birth
• Impaired foetal gas exchange during labour
• This can result in severe hypoxia
• Foetal hypoxia is inadequate oxygenation before
delivery
• This may predispose to birth asphyxia
• Resulting to hypo-ventilation, hyper-capnia,
hypo-perfusion and metabolic acidosis
4. Aetiology/risk factors
• Placental insufficiency
antepartum intrapartum
Maternal age>35 or <16 Traumatic delivery
Maternal infections Prolonged/premature labour
Post term gestation Abnormal presentation
Multiple gestation Analgesics, sedation or drugs
depressing the respiratory
centre
Maternal drug abuse ROM>24hrs
Poly/oligohydramnios Meconium aspiration
5. Pathophysiology
• Severe hypoxia in utero
• Hypoxic insult continues, foetus loses consciousness
• Neural centres cease to function because there is lack of O2
• Then foetus goes into primary apnoea
• Hr remains unchanged, but soon decreases as the myocardium reverts to
anaerobic metabolism
• Lactic acid gets released as a by-product of anaerobic metabolism
• Insult continues, and if the foetus is in utero the foetus will gasp but if the
gasps fail to aerate the lungs, they fade away and the foetus enters a
period of sec Apnoea
• Until this point circulation has been maintained but as terminal apnoea
progresses then cardiac function gets impaired
• The heart eventually fails and if there is no intervention the baby finally
dies
9. Clinical Presen cont...
• Depends upon the aetiology, intensity,
duration of inadequate oxygenation, plasma
CO2 level and acidosis
• Asphyxia livida (stage of cyanosis): primarily
due to respiratory failure with Apgar score of
4-6
• Asphyxia pallidum (stage of shock): due to
combined respiratory and vasomotor failure
with Apgar score of 0-3
10. Diagnostic criteria
• History of foetal distress and or MSL grade 2
• Apgar score <=3 at 1 min or <=6 at 5 min
• Arterial blood lactate >5mmol/L
• Mixed acidosis
– Ph <7.2 on arterial cord blood
– Base excess >-10
– Pa CO2 > 55 mmHg
11. Prognosis
• Depends on associated factors, maturity of
the baby, duration and intensity of hypoxia
and acidosis including initiation of
resuscitative measures in the delivery room
• Subsequent competent care and available
facilities also influence the outcome following
birth asphyxia
12. Prognosis after birth Asphyxia
• Apgar score < 5 at 10 min: nearly 50% death
or disability
• No spontaneous breathing after 20 min: 60%
disability in survivors
• No spontaneous breathing after 30 minutes,
nearly 100% disability in survivors
13. Therapy
• Asphyxia must be anticipated and
precautionary measures introduced
• Supportive measures
14. Complications (HIE)
• Acquired syndrome of acute brain injury characterised by
neonatal encephalopathy in the first 3 days of life and
evidence of intrapartum hypoxia in a term baby
• The immature brain is more resistant to hypoxic-ischemic
events as compared to older children
• NE is characterised by an abnormal LOC, abnormal tone and
primitive reflexes in the first week of life.
• Abnormal breathing and seizures may occur
15. HIE
• An evolving process initiated by the hypoxic-ischemic insult
leading to decreased blood flow to the brain followed by the
restoration of blood flow in an injured brain
• This initiates a cascade of pathways which includes
accumulation of extracellular glutamate
• With excessive activation of glutamate receptors, ca influx
and generation of reactive oxygen and nitrogen species
leading to cell death and brain injuries.
16. Clinical presentation
• Cycling, posturing and myoclonus may
represent seizure activity or lack of
inhibition/control at a brainstem level.
• The Sarmat classification describes 3 clinical
stages of encephalopathy
• ..DocumentsStages of encephalopathy.docx
17. The HIE score
• Maximum score based on the infant’s clinical signs in the
previous 24hrs, is recorded in each categ and totalled for the
day
• Peak score of 10/less in the first 6 days with a score of 0 by
day 7 predicts a N outcome
• Whereas a score above 15 and a score that is still abnormal
on day 7 is predictive of abnormal outcome in 65%.
19. Assessment tools in HIE
• Neuro-imaging
– MRI: most app technique and is able to show diff
patterns of injury. If available, it can be done at
age 10-14 days
– CT scan: less sensitive than MRI for detecting
changes in the central gray nuclei
– Cranial U/S: not the best in assessing
abnormalities in term infants
– aEEG: has prognostic value and is useful in
diagnosing sub-clinical seizures
20. Management of HIE
• Aim is to treat symptoms and minimize further organ damage
• Correct standard management is more important
than adding neuro-protective therapy such as
hypothermia
21. Systematic management
• CNS
– Perform a daily neurological assessment and on
admission
– Treat recurrent and persistent seizures
– If mod or severe NE is present at birth, induced
hypothermia may improve the outcome if
commenced asap and not after 6hrs post-del
22. Hypothermia MOA
• Reduces cerebral metabolism prevents oedema
• Decreases energy utilisation
• Reduces cytotoxic amino acid accumulation
• Attenuates secondary neuronal damage
• Inhibits cell death
• Reduces extend of brain damage
– Death or severe disability at 18 months has been reduced
significantly
23. Respiratory system
• Monitor oxygen sats
– If oxygen is needed but respiratory effort is good,
nasal CPAP is adeqaute
• Fluid balance and electrolytes
– Intrinsic renal failure and SIADH commonly occurs
– Initially restrict fluids to 40ml/kg/24 hrs with K
free 10% glucose and 0.45 % n saline
– Monitor urine output, electrolytes, blood glucose
24. Parental counselling
• Explain the clinical condition
• Document the parent’s version of events
• Listen to their questions and explain the
management needed and keep them
informed of the prognosis based on the daily
clinical assessment
25. Prognosis and follow up
• Neurological examination and aEEG are only
reliable when abnormalities are severe
• Early infant neuro-developmental assessment
can be predictive of the outcome
• Cerebral palsy and intellectual disabilities are
common in survivors of severe HIE and
multidisciplinary follow-up is required.
26. Question 1
The severity of HIE can be graded as mild, mod
and severe using the Sarnat classification. Of
the ff, the criterion most consistent with Dx of
mild HIE is:
– Absence of seizures
– Low Apgar score
– Need for assisted ventilation
– Proximal muscle weakness
– Decreased LOC
27. Potsisho ya bobedi
Several tests have been proposed to improve
the prediction of long outcome following HIE.
Of the ff, the most useful and practical test for
determining the prognosis of HIE is
– Cranial U/S
– MRI
– EEG
28. Vraag 3
The mother of a baby with HIE enquires about
the possibility of a brain insult in her baby. Of
the ff, the single most useful predictor of brain
insult in her baby is evidence of:
– Abnormal neurological exam findings
– Cerebral oedema on cranial U/S
– Elevated creatinine phosphokinase
– Multisystem organ dysfunction
29. Resuscitation
• Est 5-10% of newborns need the initial steps
of resuscitation
• About 3-6 % require these initial steps as well
as assisted ventilation with bag and mask
• <1% require advanced resuscitation and in
fact < 0.1% require chest compression
• < 0.05% require drugs
30. Dry the baby
• Drying helps keep a baby warm and clean and
also stimulate breathing
• Dry baby with clean cloth and place where
baby will be warm
31. THE GOLDEN MINUTE
• Check if the baby is crying and breathing
• If baby is not crying or breathing well after
delivery, one need to help baby in the first
minute
32. 1. Position head on the side, neck slightly
extended to keep airway open
2. Clear the airway: use a clean device
Clear the mouth first to remove large secretions
before the baby gasps or cries.
When using a suction device with a tube, insert
tube into side of the mouth not >5cm beyond
the lips and not >2cm into nostril
33. 3. Stimulate breathing: gently rub the back once or
twice. Don’t delay or stimulate longer
– Move quickly to evaluate breathing and decide if
ventilation is need
– Evaluate the baby after clearing the airway and
stimulation
– Check if baby is breathing well or crying
Now decide what care the baby needs after
clearing the airway and stimulation
34. Baby not breathing well
• Begin bag and mask ventilation
– Select the correct mask that covers chin, mouth and
nose.
– Make a tight seal on the face to aerate the lungs
• Position the head slightly extended
• Position the mask on the face
• Make a firm seal between the mask and face
while squeezing the bag to produce a gentle
movement of the chest
• Give 40 breaths per minute.
35. Evaluate the baby during ventilation
• Remember a baby who is breathing well will
be crying or breathing quietly
• While the one who isn’t breathing well will be
gasping or showing other signs of resp distress
• If the baby is grunting, cyanoses and having
chest indrawing commence O2 and refer to
neonatal unit
• Baby still not breathing, continue ventilation
and call for help
37. Advanced resuscitation
• Hr normal but baby still doesn’t breath: wheck
whether mother was never given pethidine or
opioids.
• Baby not breathing or cyanosed, check O2 sats
and if necessary give supplemental oxygen.
• Aim for sats resembling a healthy term baby
38. Heart rate <60
• Despite good ventilation
• Start chest compressions
• To move O2 blood from lungs back to the heart.
• Allow enough time during the relaxation phase of
each compression cycle for the heart to refill with
blood
• Compress for 30 sec then check Hr
• Hr >60 stop compressions
39. Stubborn HR
• Administer Adrenaline within 1 minute of
adequate ventilation and chest compressions
• Give 0,01-0,03 mg/kg(equates to 0,1-0,3ml/kg of
1 in 10 000)
• Mix 1 ml of 1000 adrenaline with 9 ml of Saline to
get 1 in 10000
• Repeat every few minutes, if Hr remains <60
despite effective ventilation and cardiac
compressions
• Don’t ever forget Glucose
40. When to stop
• No Hr and breathing after ventilation for 10
minutes.
• No breathing after 20 minutes
• Only gasping after 30 minutes
Hypoxia during labour in term babies is the most common cause of neonatal brain damage and is the leading cause of CP
The whole process takes about 20 minutes in a term baby. In the phase of asphyxia, the baby can maintain an effective circulation throughout the period of primary apnoea, through the gasping phase, and even for a while after terminal apnoea.
Thus the most urgent requirement for any asphyxiated baby is to aerate the lungs effectively. If the baby’s circulation is sufficient, oxygenated blood will then be conveyed from the lungs to heart. The Hr increases and brain gets perfused with oxygenated blood.
Then the neural centres will function once again and normal breathing kicks in.
Vasomotor centre is a group of sympathetic nerve cells contained in the Medulla Oblangata. The centre is responsible for vital vegatative functioning of the human body i.e BP, Breathing and heart rate
Other studies are brain sonography, aEEG and MRI being the study of choice (expensive)
This is a serious brain injury due to birth asphyxia. Most deaths occur in the first week due to multiple organ failure or withdrawal of care due to prospect of severe neurological impairments. Moreover children who survive birth asphyxia develop problems such as CP, MR, Learning difficulties, etc.
Clinical signs vary with time. Moderately or severely affected babies typically develop obvious or severe signs during the first 48-72 hours.
Induced hypothermia: aim to get core temperature at 33-35 for 72 hrs.
Infants must be 35 weeks or more
Infants must have: Apgar of &lt;=5 at 10 minutes, mechanical vent or resuscitation at 10 min, cord arterial Ph of &lt;7 within 1 hr post del.
Cooling must be started within 6 hrs of birth,
There is no proven benefit that sodium bicarbonate can be used to treat lactic acidosis
Remember to prepare an area for ventilation and check equipment before delivery.
There is no need to slap the baby, drying is enough for stimulation
Drying, clearing airway and stimulating breathing should take less than a minute.
A baby who is not breathing well will have signs of respiratory distress.
Delay in ventilation may result in preventable death or brain damage. Ventilation with bag and mask helps carry air into the lungs and starts the changes that are needed so the baby can breath. Ventilation opens the lungs with air.
Take steps to improve ventilation if chest isn’t moving.
If baby is still not breathing at this stage, one has to start advanced resuscitation.
Evaluate the heart rate
1,2,3, bag…..
Compress the chest to a depth of 1/3 the AP diameter.
Establishing adequate ventilation is the most imortant step to improving Hr&lt; but if Hr remains &lt; 60 adrenaline should nopw be given
