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PERINATAL
ASPHYXIA
Fred N WereDepartment of Paediatrics
University of Nairobi
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DEFINITION
A range of disorders that occur
subsequent to oxygen deprivation of a
fetus/newborn during the two weekssurrounding delivery
The main syndrome usually involves the
brain but many other organs can beinvolved
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Pathophysiology-Gross
Reduction of oxygen supply to the body
organs (HYPOXIA)
Progressive reduction of systemic bloodflow (ISCHEMIA)
Eventual decrease of cerebral & coronary
blood flow (LOSS OF AUTOREGULATION)
Hypoxic/Ischaemic cell death
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Pathophysiology-Molecular
Accumulation of intracellular calcium
Increase of excitatory amino acids in thedamaged cells
Elaboration and increased liberation of
reactive oxygen species (free radicals)
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Etiology
PrenatalPlacental insufficiency syndromes
Labor/Deliveryprolonged/obstructed laborcord accidents/ Ante partum hemorrhage
Post Natalineffective resuscitation at birthsevere respiratory diseases
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Clinical Diagnosis
APGAR SCORING
This signifies presence of Central
Nervous system depression
PRESENCE OF ENCEPHALOPATHYSuggesting actual neuronal damage
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APGAR SCORING
0 1 2
Appearance Pale/blue peripheral cyanosis pink
PULSE 0 100
Grimace None Weak Strong
Activity None Weak Strong
Respiration None Shallow LustyPerformed at 1&5 minutes. If abnormal repeated at 10 &
20 minutes
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APGAR Interpretation
1 minute score identifies those needing
resuscitation
5 minute score defines asphyxia as:
Mild 6&7
Moderate 4&5
Severe 0-3
Extended scores estimate or predict later
outcomes
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Hypoxic Ischaemic Encephalopathy
Grade 1; MILD
Hyperactive and jittery, no convulsions
Grade 2; MODERATE
dull and lethargic but awake or arousable
convulsions frequent
Grade 3; SEVEREStuporous/comatose with intractable fits
Other organ involvement, decorticate or decerebrate
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Laboratory Evaluation
Cerebral Ultrasound
Electro Encephalography
CT Scans
MRI
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Principals of Management
Effective resuscitation at birth
Active maintenance of normal homeostasis
during the acute phase
Appropriate management of convulsions and
other complications
Some experimental methods
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Principals of Management
Effective resuscitation at birth
Active maintenance of normal homeostasis
during the acute phase
Appropriate management of convulsions and
other complications
Some experimental methods
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Objectives Of Resuscitation
To correctly identify the need for
resuscitation at birth
To understand the ABC sequence of
resuscitation as applied to the newborn
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Evaluation of the Newborn
Dry and warm the newborn
The need for life support interventions willbe indicated by the simultaneous
evaluation of:
Respiration
Colour
Heart rate
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Respiration
Good spontaneous respiratory activity may manifest as
vigorous crying or adequate breaths
Dry warm and leave infant alone
If apnoea or gasping persist after a few seconds of tactile
stimulation:
ABC of resuscitation must commence
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Heart Rate
Observe HR at praecodium or base of umbilicus
If HR
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Colour
Central
cyanosis/palor
with adequatebreathing:
Deliver free flow
oxygen
No breathing:
ABC of resusc
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AIRWAY: Clearing
Position infant and
remove secretions
Neutral / slightlyextended position by
towel placement
Secretions clearedfirst from the mouth,
then from the nose
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BREATHING and Stimulation
Routine drying and
suctioning
Rubbing the back
Flicking the soles of thefeet
If no response to tactile
stimulation occurs within
few seconds:Then bag, valve and mask
ventilation with 21-100%
oxygen
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Positive Pressure Ventilation
Adequate expansion of the lung is the most important
measure needed for successful resuscitation
Indicationsfor IPPV:
Apnoea / gasping
breath
HR < 100 bpm
Persistent central
cyanosis
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Positive Pressure Ventilation
Most newborns who require positivepressure ventilation can be adequately
ventilated with a bag valve and mask
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Key Point:
The most important and effective
action in neonatal
resuscitation is:
Ventilation with Air or Oxygen
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Tracheal Intubation
Indications for tracheal intubation during neonatal
Resuscitation include: Tracheal suctioning
Ineffective / prolonged BVM
Chest compression required
Tracheal drugs
Congenital diaphragmatic
hernia
Extreme prematurity
Transport
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If the heart rate is < 60 bpm despiteeffective positive pressure ventilation with100%oxygen then give CC at ratio of 3 to 1
i e 90 cc for 30 breaths
Chest Compressions
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Emergency Drugs
Very rarely required
If HR < 60 bpm after 30 seconds of adequateventilationand chest compressions:
Adrenaline (10-30mcg/kg)
IV (peripheral/umbilical), Tracheal, Osseous
Newborn Life Support
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CCD
Newborn Life Support
Airway&
BreathingAB
CD
coverDry &
RC (UK)
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Principals of Management
Effective resuscitation at birth
Active maintenance of normal homeostasis
during the acute phase
Appropriate management of convulsions and
other complications
Some experimental methods
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Maintenance of Homeostasis Monitor and maintain oxygenation
Monitor and correct serum electrolytes;
Sodium, Calcium, Magnesium
Monitor and correct Blood glucose (especiallyavoiding hypoglycemia)
Monitor and maintain acid base balance within
the normal range
Monitor and maintain normal blood circulation
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Principals of Management
Effective resuscitation at birth
Active maintenance of normal
homeostasis during the acute phase
Appropriate management of convulsions
and other complications
Some experimental methods
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Treatment of Convulsions Ensure normal homeostasis
Phenobarbitone at 20mg/kg bolus is the 1stline drug; if 2 doses 1 hr apart fail then
Phenytoin at 20mg/kg bolus is used. Thiscan also be used as 1stline especially when respiratorydepression is an important consideration
Refractory convulsions; Phenytoin andPhenobarb at maintenance dose plus either clonazepamor paraldehyde.
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Major Complications
Pulmonary (PPH, Mec Asp Synd)Hyperventilation, pulmonary vasodilators
Renal (Acute Tubular Necrosis; ARF)Fluid restriction, peritoneal dialysis, ultrafiltration
Cardiac (Myocardial Ischemia; Pump Failure)Ionotropic drugs
Gastrointestinal (Necrotizing Enterocolitis)
Antibiotics, GUT resting, surgery Haematological (DIC, Jaundice)
Blood platelate and clotting factor replacement
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Principals of Management
Effective resuscitation at birth
Active maintenance of normal homeostasis
during the acute phase
Appropriate management of convulsions and
other complications
Some experimental methods
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Experimental Methods
Oxygen free radical scavengers
Calcium channel blockers
Inhibitors of glutamic activity
These are presumed to work reducing the secondary celldamage following the initial hypoxic injury. None in
clinical use yet
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Clinical Prognostic Indicators
Low extended APGAR score
Severity of neurological syndrome
Additional organ complications
especially cardiac and renal
Poor socioeconomic status
particularly predicts later neuro developmental delays
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Summary
Perinatal asphyxia is an important cause of both
neonatal morbidity and mortality
It accounts for probably one quarter of allneonatal deaths in many countries
The mainstay of care is anticipation and effective
resuscitation at birth (BVM).
Supportive care seldom useful in severe cases