Birth asphyxia 2

1. Birth Asphyxia
Dr.Anup John Thomas
Assistant Professor
Department of Pediatrics
MGMC&RI

2. 2010 Guidelines for Neonatal Resuscitation

3. Techniques for Achieving Effective Ventilation
(MR. SOPA)

4. NRP Video

5. Neonatal Evaluation and Resuscitation
APGAR Scoring
A Appearance
P Pulse
G Grimace
A Activity
R Respirations
Take the APGAR score at one minute and five minutes.

6. APGAR Score

7. APGAR Score
 7-10 points - The newborn should be active and
vigorous. Provide routine care.
 4-6 points - The newborn is moderately
depressed. Provide stimulation and oxygen.
 0-3 points - The newborn is severely depressed
and requires extensive resuscitation.

8. Apgar Score
• Total Score = 10
score 7-10 normal
score 5-6 mild birth asphyxia
score 3-4 moderate birth asphyxia
score 0-2 severe birth asphyxia

9. Causes of Neonatal Mortality
Infection
32%
Birth Asphyxia
29%
Complications
of Prematurity
24%
Congenital
Anomalies
10%
Other
5%

10. Asphyxia neonatorum is respiratory
failure in the new-born, a condition caused
by the inadequate intake of oxygen before,
during, or just after birth.

11. Definition
Birth asphyxia is defined as a reduction of oxygen
delivery and an accumulation of carbon dioxide
owing to cessation of blood supply to the fetus
around the time of birth.

12. ESSENTIAL CRITERIA FOR PERINATAL ASPHYXIA
AAP and ACOG
• Profound metabolic or mixed acidemia (pH< 7.00) in
umbilical cord blood
• Persistence of low Apgar scores less than 3 for more than 5
minutes
• Signs of neonatal neurologic dysfunction (e.g., seizures,
encephalopathy, tone abnormalities)
• Evidence of multiple organ involvement (such as that of
kidneys, lungs, liver, heart and intestine).

13. Etiology
Pathologically, any factors which interfere with
the circulation between maternal and fetal blood
exchange could result in the happens of
perinatal asphyxia.
These factors can be maternal factor, delivery
factor and fetal factor.

14. Etiology—High Risk Factors
• Maternal factor:
▫ hypoxia
▫ Anemia
▫ Diabetes
▫ Hypertension
▫ Smoking
▫ Nephritis
▫ heart disease
▫ too old or too young
• Delivery condition:
▫ Abruption of placenta
▫ placenta Previa
▫ prolapsed cord
▫ premature rupture of
membranes
• Fetal factor:
▫ Multiple birth
▫ congenital or malformed
fetus

15. Pathophysiology
When fetal asphyxia happens, the body will
show a self-defended mechanism which
redistribute blood flow to different organs
called “inter-organs shunt” in order to
prevent some important organs including
brain, heart and adrenal from hypoxic
damage.

16. PATHOPHYSIOLOGY
Hypoxia
Diving sea reflex
Shunting of
blood to brain
adrenals & heart
Away from
lungs, kidney
gut & skin
NON BRAIN ORGAN INJURY

17. PATHOPHYSIOLOGY
Asphyxia continues
Shunting within the brain
Anterior
Circulation
Suffers
Posterior
Circulation
Maintained
CEREBRAL CORTICAL
LESIONS

18. PATHOPHYSIOLOGY
• Hypoxia – ABRUPT & SEVERE
▫ No time for compensation
THALAMUS & BRAIN STEM INJURY, CORTEX
SPARED

19. Pathophysiology(I)
Hypoxic cellular damages:
a. Reversible damage(early stage):
Hypoxia may decrease the production of ATP,
and result in the cellular functions .
But these change can be reversible if hypoxia is
reversed in short time.

20. b. Irreversible damage:
If hypoxia exist in long time enough, the cellular
damage will become irreversible that means even
if hypoxia disappear but the cellular damages are
not recovers.
In other words, the complications will happen.

21. Pathophysiology(II)
Asphyxia development:
a. Primary apnea
 breathing stops but normal muscular tone or
hypertonia, tachycardia (quick heart rate), and
hypertension
 Happens early and shortly, self-defended
mechanism
 No damage to organ functions if corrected quickly

22. b. Secondary apnea
Features of severe asphyxia or unsuccessful
resuscitation, usually result in damage of organs
function.

23. PATHOLOGY
• Target organs of perinatal asphyxia
▫ Kidney 50%
▫ Brain 28%
▫ Heart 25%
▫ Lung 23%
▫ Liver, Bowel, Bone marrow < 5%

24. Clinic manifestations
Fetal asphyxia
fetal heart rate: tachycardia bradycardia
fetal movement: increase decrease
amniotic fluid: meconium-stained

25. Assessment
• Fetal heart rate slows
• Electronic fetal monitoring
• persistent late deceleration of any
magnitude
• persistent severe variable deceleration
• prolonged bradycardia
• decreased or absent beat-to-beat variability
• Thick meconium-stained amniotic fluid
• Fetal scalp blood analysis show pH less than 7.2

26. Effects of Asphyxia
• Central nervous system
▫ intracranial hemorrhage
▫ hypoxic-ischemic
encephalopathy
• Cardiovascular
▫ Bradycardia
▫ Arrhythmia
▫ Hypotension
▫ myocardial ischemia

27. Effects of Asphyxia
• Respiratory system
▫ Apnea
• KUB
▫ acute tubular necrosis
• Gastrointestinal tract
▫ necrotizing enter colitis

28. Effects of Asphyxia
• Hematology
▫ Disseminated intravascular coagulation
• Metabolic
▫ Hypoglycemia
▫ Hyperglycemia
▫ Hypocalcemia
▫ hyponatremia

29. CLASSIFICATION OF HIE (LEVENE)
Mild Moderate
Consciousness
Tone
Seizure
Sucking / Resp.
Irritable
Hypotonia
No
Poor Suck
Lethargy
Marked
Yes
Unable to
suck
Feature Severe
Comatose
Severe
Prolonged
Unable to
sustain
spont. Resp.

30. SPECIFIC MANAGEMENT
PREVENT FURTHER BRAIN DAMAGE
• Maintain temperature, perfusion,
oxygenation & ventilation
• Correct & maintain normal metabolic &
acid base milieu
• Prompt management of complications

31. Management of a neonate with
perinatal asphyxia
• Delivery room care
▫ Obtain arterial cord blood for analysis
• Transfer the infant to NICU if
▫ Apgar score 0-3 at 1 minute
▫ Prolonged bag and mask ventilation (60 seconds
or more )
▫ Chest compression

32. Management of a neonate with
perinatal asphyxia
NICU care
1. Maintain normal temperature
▫ Avoid Hyperthermia
2. Maintain normal oxygenation and ventilation
▫ Maintain saturations between 90% and 95% and avoid
any hypoxia or hyperoxia
▫ Avoid hypocarbia, as this would reduce the cerebral
perfusion
▫ Avoid hypercarbia, which can increase intracranial
pressure and predispose the baby to intracranial bleed.

33. Management of a neonate with perinatal asphyxia
NICU care
3. Maintain normal tissue perfusion
▫ Start intravenous fluid
▫ Administer dobutamine (preferred) or dopamine to maintain
adequate cardiac output, as required.
▫ Do not restrict fluid as this practice may predispose the babies to
hypo perfusion.
▫ Restrict fluid only if there is hyponatremia (Sodium<120 mg%)
secondary to syndrome of inappropriate secretion of ADH
(SIADH) or if there is renal failure.
4. Maintain normal hematocrit and metabolic milieu
▫ maintain blood glucose levels between 75 mg/dL and 100 mg/dl.
▫ Correct Anaemia and maintain haematocrit between 45% and
55%.
▫ Check blood gases to detect metabolic acidosis as needed and
maintain pH above 7.30.
▫ In case of severe asphyxia, provide calcium in a maintenance
dose of 4 mL/kg/day (of 10% calcium gluconate)

34. Management of a neonate with
perinatal asphyxia
NICU care
5. Treat seizures
6. Nutrition:
▫ Start oral feeding once baby is hemodynamically
stable
7. Miscellaneous
▫ Administer Vitamin K (1 mg IM) to all infants with
perinatal asphyxia

35. Role of special investigations
• Electroencephalography (EEG):
▫ The prognosis is likely to be poor if
the EEG shows:
 Long periods of inactivity (more
than 10 seconds)
 Brief period of bursts (less than 6
seconds) with small amplitude
bursts
 Interhemispheric asymmetry and
asynchrony
 Isoelectric and low voltage (less than
5 microvolts) 25
• Amplitude-integrated
electroencephalography (aEEG)
▫ simplified form and can be
performed on continuous basis in
NICU.
▫ Following abnormalities would
indicate poor prognosis:
 Wide fluctuations in the amplitude
with the baseline voltages dropping
to near zero
 Peak amplitudes under 5 mV
 Seizure spikes

36. Role of special investigations
• Cranial ultrasound (US):
▫ Cranial US is not good for detecting changes of HIE in the term
babies.
▫ hypoechoic areas can be seen in very severe cases
▫ In preterm babies, periventricular leukomalacia and
intraventricular-periventricular haemorrhage.
• Computed tomography (CT):
▫ CT is more useful after a traumatic delivery and suspected of
having an extra-axial haemorrhage
• Magnetic resonance imaging (MRI):
▫ Abnormalities of thalami and basal ganglia in term
infants
▫ Abnormalities of white and grey matter in preterm infants
▫ Second most common pattern of injury is injury to the
watershed regions.
▫ MRI is preferred over CT as it has no radiation exposure.

37. Newer modes of therapy
1. Therapeutic hypothermia
▫ 330C to 340C
▫ in infants of at least 36 wk.
▫ moderate to severe
encephalopathy
▫ initiated within 4- 6 hr
▫ continued for 72 hr of age
▫ reduce mortality and neuro-
morbidity by 18 months of age.
▫ selectively cooling the head or the
whole body.

38. Newer modes of therapy
2. Prophylactic phenobarbitone
▫ A dose of 40 mg/kg administered prophylactically was
associated with a better neuro-developmental outcome at 3
years of age
3. Drugs under investigation
▫ A large number of drugs are under investigation for neuro-
protection in HIE which need to be used in the early
period.
 blockade of free radical generation (allopurinol, oxypurinol)
 scavenging of oxidants (superoxide dismutase, glutathione, N-
acetyl cysteine and alpha tocopherol)
 calcium channel blockade (flunarizine, nimodipine)
 blockage of NMDA receptors (magnesium, MK801,
dextromethorphan)
 blockage of inflammatory mediators (phospholipase A2,
indomethacin).

39. PREDICTORS OF POOR
NEURO DEVELOPMENTAL OUTCOME
• Failure to establish respiration by 5 minutes
• Apgar 3 or less in 5 mts
• Onset of Seizure in 12 hrs.
• Refractory convulsion
• Stage III HIE
• Inability to establish oral feed by 1 wk.
• Abnormal EEG & failure to normalize by 7 days of life
• Abnormal CT, MRI, MR spectroscopy in neonatal
period

40. HIE OUTCOME (METAANALYSIS)
Severe Moderate
Risk of Death
Risk of Severe
disability
61%
72%
5.6%
20%
Mild
< 1%
< 1%

41. Prognosis
• Apgar score < 5 at 10 minutes : nearly 50 %
death or disability (Leicester)
• No spontaneous respiration after 20 min :60 %
disability in survivors (USA).
• No spontaneous respiration after 30 minutes :
nearly 100 % disability in survivors (Newcastle).