Hypoxic-Ischemic Encephalopathy (HEI)

8/8/2019 Hypoxic-Ischemic Encephalopathy (HEI)

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-Hypoxic is the lack of oxygen to the brain

-Ischemic is a decrease in the blood supply to a bodily organ

-Encephalopathy is brain and nervous system damage

-HEI is a condition in which there is brain or nervoussystem damage due to the lack of oxygen going to the

brain.



Frequencyy - HIE will affect 1-8/1000 births in the US and most

technologically advanced countries.

y - Internationally birth asphyxia is the cause of 23% of neonatal

deaths.y - one of top 20 leading causes of burden of disease in all age

groups

y - 5th largest cause of death of children under 5 years of age (8%)

y - estimated to account for 920,000 neonatal deaths per year and

associated with another 1.1 million intrapartum stillbirthsy - more than a million children who survive will develop cerebral

palsy, mental retardation, learning disabilities along with otherdisabilities



Causesy - injury or complication during birthy - respiratory failurey - blocked or ruptured blood vessely

- drug overdosey - drowningy - lack of oxygen due to smoke inhalationy - extremely low blood pressurey - strangulationy - cardiac arresty - carbon monoxide poisoningy - high altitudesy - chokingy - compression or injury to the trachea that reduces or stops breathingy - complications from general anesthesia



Risk Factorsy A ny injury or condition that causes the brain to have a

reduction in blood flow or oxygen.



Symptomsy - difficulty concentrating or paying attention

y - poor judgment

y

- poor coordinationy - euphoria

y - extreme lethargy

y - severe oxygen deprivation

y - seizuresy -coma

y - no brain stem reflexes (breathing, responding tolight)



Physical symptoms in Inf antsy Mild hypoxic-ischemic encephalopathy

y - Muscle tone may be slightly increased and deep

tendon reflexes may be brisk during the first few days.y - Transient behavioral abnormalities, such as poor

feeding, irritability, or excessive crying or sleepiness,may be observed.

y - The neurologic examination findings normalize by 3-4 days of life.

y



Conty Moderately severe hypoxic-ischemic encephalopathy y - The infant is lethargic, with significant hypotonia and

diminished deep tendon reflexes.y

- The grasping,Moro, and sucking reflexes may be sluggish orabsent.y - The infant may experience occasional periods of apnea.y - Seizures may occur within the first 24 hours of life.y - Full recovery within 1-2 weeks is possible and is associated with

a better long-term outcome.y - A n initial period of well-being or mild hypoxic-ischemic

encephalopathy may be followed by sudden deterioration,suggesting ongoing brain cell dysfunction, injury, and death;during this period, seizure intensity might increase.

y



Conty Severe hypoxic-ischemic encephalopathy y - Stupor or coma is typical. The infant may not respond to any physical stimulus.y - Breathing may be irregular, and the infant often requires ventilatory support.y - Generalized hypotoniaand depressed deep tendon reflexes are common.y

- Neonatal reflexes (eg, sucking, swallowing, grasping,M

oro) are absent.y - Disturbances of ocular motion, such as a skewed deviation of the eyes, nystagmus,

bobbing, and loss of "doll's eye" (ie, conjugate) movements may be revealed by cranialnerve examination.

y - Pupils may be dilated, fixed, or poorly reactive to light.y - Seizures occur early and often and may be initially resistant to conventional treatments.y - Irregularities of heart rate and blood pressure (BP) are common during the period of

reperfusion injury, as is death from cardiorespiratory failure.y

y Infants who survive severe hypoxic-ischemic encephalopathy y - The level of alertness improves by days 4-5 of life.y - Hypotonia and feeding difficulties persist, requiring tube feeding for weeks to months.



Diagnosisy - CT Scan

y - MR I Scan

y - EKGy - Echocardiogram

y - Blood Tests

y - EEG

y - Ultrasound



Diagnosis in Inf antsy For infants the guidelines from AA P in 1996 all of the

following must be present for the designation of perinatalasphyxia severe enough to result in acute neurological

injury y - profound metabolic or mixed academia (pH < 7) in

an umbilical artery blood sample

y - persistence of an A pgar score of 0-3 for longer than 5minutes

y - neonatal neurologic sequelae ( seizures, coma,hyptonia)

y - multiple organ involvement (kidneys, lungs, liver,heart, intestines)



Treatmenty There is no cure

y - Life-sustaining treatment

y - mechanical ventilationy - treatments for circulatory system

y - seizure control

y - cooling

y - hyperbaric oxygen treatment



The cooling process



Cooling Cap



Two Recent Trials of inf antswith

moderate to severe HEIy 23-27% of infants died prior to dischargey Mortality rate at 18-22 months was 37-38%.y These are the neurodevelopmental outcomes at 18 months

y Mental development index (MDI)y Score of 85 or higher - 40%y Score of 70-84 - 21%y Score less than 70 - 39%

y Psychomotor development index (PDI)y Score of 85 or higher - 55%y

Score of 70-84 - 10%y Score less than 70 - 35-41%

y Disabling cerebral palsy - 30%y Epilepsy - 16%y Blindness - 14-17%y Severe hearing impairment - 6%



Preventiony There is no prevention



Q uick and General Overviewy General Overview



Referencesy http://www.med.nyu.edu/patientcare/library/article.html?ChunkIID=230598

y

y http://emedicine.medscape.com/article/973501-overview

y

y http://www.medterms.com/script/main/art.asp?articlekey=3875

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Hypoxic-Ischemic Encephalopathy (HEI)