Hypoxic-Ischemic Encephalopathy (HIE)

Hypoxic-ischemic encephalopathy (HIE) is a type of brain damage caused by insufficient oxygenated blood flow during or near the time of birth. Terms that are sometimes used as synonyms for HIE include birth asphyxia and neonatal encephalopathy, although technically these have distinct meanings.

There are many potential causes of HIE, including high-risk pregnancy conditions, labor and delivery issues, and medical mistakes. Usually, HIE can be prevented through careful fetal monitoring and timely intervention in response to complications. However, medical professionals may miss opportunities to prevent HIE, or perform negligent actions that cause HIE.

If a baby is diagnosed with HIE, it is critical that doctors administer therapeutic hypothermia very shortly after birth/the oxygen-depriving incident. This treatment can minimize the extent of permanent brain damage, and reduces the risk of resultant disabilities such as cerebral palsy.


Hypoxic Ischemic Encephalopathy (HIE)


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What is the incidence of HIE?

(HIE) Hypoxic Ischemic Encephalopathy Definition | Infographic

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Hypoxic-ischemic encephalopathy (HIE) is estimated to occur in about 1.5 per 1,000 live births, although this estimate may be imprecise (1). It accounts for 23% of neonatal deaths worldwide, and babies that survive may develop cerebral palsy (CP), intellectual and developmental disabilities (I/DDs), epilepsy, and many other associated conditions (2).

How serious is HIE?

For babies with HIE, the seriousness of the brain damage (and the likelihood of subsequent disabilities) depends on the following conditions:

  • The severity of the oxygen deprivation
  • The length of time that the baby was deprived of oxygen
  • The condition of the baby prior to the oxygen deprivation
  • The management of the baby by the medical team after the oxygen-depriving event occurred

Breaking down ‘hypoxic-ischemic encephalopathy’: what is a hypoxic-ischemic brain injury?

Hypoxic-ischemic injury occurs when the baby’s brain is deprived of oxygenated blood. “Hypoxic/hypoxia” refers to a lack of oxygen, and “ischemic/ischemia” refers to a lack of blood flow. In older children and adults, HIE may result from anything that causes a lack of oxygen to the brain including a heart attack, stroke, trauma to the head, carbon monoxide poisoning, drug overdose, or near drowning (3, 4). In babies, HIE can be due to problems during pregnancy, labor and delivery, or shortly after birth. See “Causes of birth asphyxia and HIE,” below, for more information.

Frequently asked question: how long can a baby survive without oxygen?

The question of how long an unborn baby can survive without oxygen is a complex one. First, there is the distinction between survival with adverse health effects (such as brain damage) versus survival without adverse health effects. Second, it depends on the severity of the oxygen deprivation. If the baby is receiving no or very little oxygen, they could die or become seriously brain injured in a matter of minutes. Often, the safest and quickest way to save a baby that is being deprived of oxygen is via emergency C-section.

Guidelines from the American College of Obstetricians and Gynecologists (ACOG) state that an emergency C-section must be performed within 30 minutes from the time it is determined to be necessary. However, there are many situations in which this is not fast enough, and it is against standard of care to delay an emergency C-section more than is absolutely necessary. In many cases, the decision-to-delivery interval should only be a few minutes (5).

Frequently asked question: can hypoxia cause seizures?

Yes, HIE can cause neonatal seizures as well as long-term seizure disorders such as epilepsy. When oxygen deprivation occurs, brain cells begin to die, and the complex connections between different parts of the brain are disrupted. This can result in seizures, which are abnormal electrical discharges in the brain.

Visualizing HIE and neonatal brain injury

HIE and diminished blood flow

Hypoxic Ischemic Encephalopathy (HIE), Birth Asphyxia, Neonatal Encephalopathy

Relevant terms and definitions

Understanding HIE - Hypoxic Ischemic Encephalopathy Core Terms - Infographic


Causes of birth asphyxia and HIE

A number of complications and medical mistakes can lead to hypoxic-ischemic encephalopathy (HIE). These include, among others:

For more detailed information about the causes and risk factors for hypoxic-ischemic encephalopathy, please click here.


Signs and symptoms of hypoxic-ischemic encephalopathy

Signs of hypoxic-ischemic encephalopathy (HIE) at birth may include the following:

  • Breathing problems/need for resuscitation of the newborn
  • Low APGAR Scores. An APGAR score assesses the overall health of a newborn over the first few minutes of life. It assigns scores to conditions such as the baby’s skin color and complexion, pulse rate, reflexes, muscle tone, and breathing.
  • Seizures shortly after birth
  • Difficulty feeding, including the inability to latch, suck, or swallow
  • Abnormal neonatal reflexes (e.g. the baby fails to respond to loud sounds or movement, does not grasp onto objects such as a finger, etc.)
  • Profound metabolic or mixed acidemia in an umbilical artery blood sample (the baby’s blood is acidic/has a low ph)
  • Hypotonia (low muscle tone/limpness)
  • Multiple organ problems (e.g., the involvement of the lungs, liver, heart, intestines)
  • Coma/altered consciousness

Important note: HIE can sometimes be recognized while the baby is still in utero by looking for signs of fetal distress. More on this under “Preventing hypoxic-ischemic encephalopathy.”


Diagnosing hypoxic-ischemic encephalopathy

Hypoxic-ischemic encephalopathy is confirmed through tests and neuroimaging studies, including the following:

  • CT scans
  • PET scans
  • MRIs
  • Blood glucose tests
  • Umbilical cord and arterial blood gas tests
  • EEGs
  • Ultrasounds

If delivery was traumatic, oxygen-depriving complications occurred, or signs for HIE are present in the baby, medical professionals should begin the diagnostic process.

It is important to note that a newborn may have sustained a hypoxic-ischemic injury, but not show signs of it until later in childhood, when they exhibit delayed developmental milestones (including problems with motor skills, growth, cognitive function, etc.).

HIE can cause numerous health conditions, including:

Treatments for hypoxic-ischemic encephalopathy

Babies with HIE may require a variety of different treatments. One of the most important is therapeutic hypothermia (brain/body cooling), which has been shown to improve survival rates and minimize the extent of permanent brain damage in babies with HIE. It also reduces the risk of the child developing disabilities such as cerebral palsy. Therapeutic hypothermia consists of lowering a newborn’s temperature to around 92-94 degrees Fahrenheit for a period of about 72 hours. This slows the baby’s metabolic rate, which allows cells time to recover and reduces the spread of damage. It is critical that therapeutic hypothermia begins as soon as possible (it is most effective if begun within the first six hours after injury), as long as the baby meets eligibility criteria (6). Failure to perform therapeutic hypothermia on a newborn baby who is eligible and in need of the treatment is an instance of medical malpractice.

Therapeutic Hypothermia - Body Cooling for Babies with Hypoxic-Ischemic Encephalopathy (HIE)


Preventing hypoxic-ischemic encephalopathy

Prevention of birth asphyxia and HIE boils down to two major components:

  1. Closely monitoring the mother and baby so that fetal distress or impending distress is recognized.
  2. Quickly delivering the baby when fetal distress or impending distress are present.

During pregnancy, the mother and baby should have regular prenatal tests to help ensure fetal health. If the pregnancy is high risk, more frequent prenatal testing is required and the mother should be referred to a maternal-fetal specialist. As soon as the mother is admitted to the labor and delivery unit, a fetal heart monitor should be attached to her body and the baby’s heart rate should be continuously monitored.

The point of a fetal heart monitor is to alert the medical team of fetal distress. If a baby is experiencing a lack of oxygen to the brain, this will result in “nonreassuring heart tracings” on the fetal monitor. When nonreassuring tracings occur, the medical team may try resuscitative maneuvers, which are aimed at increasing blood flow and oxygen to the baby. These maneuvers may include giving the mother IV fluids or oxygen, or changing her position. However, there is no guarantee that resuscitative maneuvers will relieve fetal distress. In fact, distress caused by certain obstetrical conditions, such as complete umbilical cord compression or complete placental abruption may not be affected by in-utero resuscitation; babies experiencing these conditions must be delivered within a matter of minutes.

When fetal distress occurs or is impending (i.e. a pregnancy/delivery complication has been identified), the medical team should make preparations for a possible emergency C-section while doing in-utero resuscitation maneuvers. It is very important to have highly experienced members of the healthcare team involved in labor and delivery. It takes skill to interpret fetal heart tracings, and these tracings are often the only indication that a baby is experiencing birth asphyxia and HIE. The team also must be well-coordinated so that preparations and execution of a C-section delivery are fast. A delay in performing a necessary C-section can cause HIE and permanent brain damage in the baby.


How do you pronounce hypoxic-ischemic encephalopathy?


Video: our Michigan hypoxic-ischemic encephalopathy lawyers discuss HIE

In this video, lawyers Jesse Reiter and Rebecca Walsh discuss the causes of and treatments for HIE.  


Legal help for children with HIE and other birth injuries

Hypoxic-ischemic encephalopathy cases require specific, extensive knowledge of both law and medicine. For the best case outcomes, it’s critical to find an attorney and a law firm that focus specifically on birth injury and HIE cases. At ABC Law Centers, our attorneys have been focusing their careers on this area of law, and they consistently secure multi-million dollar settlements for their clients.

Our office is located near Detroit, Michigan, but we handle cases throughout the United States. Our birth injury team is also equipped to handle cases involving military medical malpractice and federally-funded clinics.

Contact us today to begin your free case review. We will answer your legal questions, determine the negligent party, and inform you of your legal options. Moreover, you pay nothing throughout the entire legal process unless we win or favorably settle your case. Our team is available to speak with you to set up an appointment in any of the following ways:

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Related reading

Legal help: our HIE lawyers and firm

Sources

  1. Kurinczuk, J. J., White-Koning, M., & Badawi, N. (2010). Epidemiology of neonatal encephalopathy and hypoxic–ischaemic encephalopathy. Early human development, 86(6), 329-338.
  2. What is the global prevalence of hypoxic-ischemic encephalopathy (HIE)? (2018, July 26). Retrieved November 15, 2018, from https://www.medscape.com/answers/973501-106461/what-is-the-global-prevalence-of-hypoxic-ischemic-encephalopathy-hie
  3. Heinz, U. E., & Rollnik, J. D. (2015). Outcome and prognosis of hypoxic brain damage patients undergoing neurological early rehabilitation. BMC research notes, 8(1), 243.
  4. (n.d.). Retrieved November 15, 2018, from https://www.uptodate.com/contents/hypoxic-ischemic-brain-injury-in-adults-evaluation-and-prognosis
  5. Reiter, J., P.C. (2008, July). Emergency Cesarean Sections: When 30 Minutes Is Not Fast Enough. BTLG Newsletter.
  6. (n.d.). Retrieved November 15, 2018, from https://www.uptodate.com/contents/clinical-features-diagnosis-and-treatment-of-neonatal-encephalopathy#H16