Hie 3
Hie 3
Hie 3
Encephalopathy
DR. MAHMOUD MOHAMED OSMAN
MBBCH, MSc (Pedia), MRCPCH (UK), FRCP (Edinburgh)
Consultant Pediatrician & Neonatologist
Al Yammamah Hospital, MOH
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Hypoxic-Ischemic Encephalopathy…………..
LEARNING OBJECTIVES:
Introduction
Definition
Risk factors
Causes
OF HYPOXIC-ISCHEMIC
Pathophysiology
ENCEPHALOPATHY
Clinical features
Diagnosis
Managament
Prognosis
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Hypoxic-Ischemic Encephalopathy…………..
INTRODUCTION:
Anoxia is a term used to indicate the consequences of complete
lack of oxygen as a result of a number of primary causes.
Hypoxemia refers to decreased arterial concentration of oxygen.
Hypoxia refers to a decreased oxygenation to cells or organs.
Ischemia is insufficient blood flow to cells or organs that to
maintain their normal function.
Hypoxic-ischemic encephalopathy Is an abnormal neurobehavioral
state in which the predominant pathogenic mechanism is impaired
cerebral blood flow that may result in neonatal death or be
manifested later as cerebral palsy or developmental delay.
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Hypoxic-Ischemic Encephalopathy…………..
RISK FACTORS
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Pathophysiology
After an episode of hypoxia and ischemia,
anaerobic metabolism occurs and generates
amounts of lactate, inorganic phosphates,
glutamate, free radicals and nitric oxide.
The initial circulatory response of the fetus is
transient maintenance of perfusion of the
brain, heart, and adrenals in preference to
the lungs, liver, kidneys, and intestine.
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Pathophysiology……….
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Pathophysiology……….
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Clinical Manifestations………..
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Multi-organ injuries
as consequences of
hypoxic-ischemic
encephalopathy
Diagnosis
Criteria for diagnosis of HIE:
Profound metabolic or mixed acidemia (pH < 7)
in an umbilical artery blood sample, if obtained.
Persistence of an Apgar score of 0-3 for longer
than 5 minutes.
Neonatal neurologic sequelae.
(seizures, coma, hypotonia)
Multiple organ involvement.
(kidney, lungs, liver, heart, intestines)
Diagnosis………
NEUROIMAGING INCLUDES:
MRI is the preferred imaging modality in neonates with HIE
because of its increased sensitivity and specificity early in the
process and its ability to outline the topography of the lesion.
CT scans are helpful in identifying focal hemorrhagic lesions,
diffuse cortical injury, and damage to the basal ganglia.
Ultrasonography has limited utility in evaluation of hypoxic
injury in the term infant; it is the preferred modality in
evaluation of the preterm infant.
Amplitude-integrated electroencephalography (aEEG); or
EEG.
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MANAGAMENT
1. Hypothermia Therapy
Selective head or whole body hypothermia of a core temperature of
33.5 C applied within 6 hours of birth for 48-72 hours is
neuroprotective.
Possible mechanisms include:
1. Reduced metabolic rate and energy depletion.
2. Decreased excitatory transmitter release.
3. Reduced alterations in ion flux.
4. Reduced apoptosis due to hypoxic-ischemic encephalopathy.
5. Reduced vascular permeability, edema, and disruptions of
blood-brain barrier functions.
Several clinical trials demonstrate that therapeutic hypothermia is a
promising therapy for mild-to-moderate cases of HIE. It reduces
mortality and major neurodevelopmental impairment.
MANAGAMENT……….
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Olympic Cool Cap System
Prognosis:
1. In severe hypoxic-ischemic encephalopathy, the mortality
rate is reported as 25-50%.
2. As many as 80% of infants who survive severe HIE
develop serious complications, 10% develop moderately
serious disabilities, and as many as 10% are healthy.
3. The infants who survive moderately severe HIE 30-50%
may have serious long-term complications, and 10-20%
have minor neurological morbidities.
4. Infants with mild hypoxic-ischemic encephalopathy tend
to be free from serious CNS complications.
Hypoxic-Ischemic Encephalopathy…………..
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Hypoxic-Ischemic Encephalopathy…………..
BEST WISHES 31