What is HIE?
HIE is a condition that occurs when a baby’s brain does not receive enough oxygen and blood flow. This lack of oxygen can cause brain injury, which can vary in severity. There are many causes of HIE, which include:
- complications during labour and delivery
- problems with the placenta or umbilical cord
- maternal health issues
- difficulties around the time of delivery
- problems with the baby’s heart or lungs at birth
Understanding the underlying cause of HIE helps the health-care team identify the best possible treatment for each baby.
Symptoms of HIE
Newborns with HIE may have:
- sleepiness or irritability
- changes in level of alertness
- poor muscle tone
- seizures
- breathing problems
- weak suck
Symptoms of HIE vary depending on the severity of brain injury.
What type of monitoring and testing do babies with HIE undergo?
To help the health-care team fully understand the extent of the brain injury and to monitor a baby’s progress, each baby undergoes a series of tests. These tests include:
- Blood work: Regular blood tests help monitor a baby’s metabolic balance, check for infections and assess organ function.
- Brain ultrasound: A brain ultrasound shows the structure of the baby’s brain and helps the health-care team detect any major abnormalities.
- Cerebral function monitoring with aEEG: This is a simplified form of brain monitoring that provides a continuous recording of the brain’s electrical activity. It helps detect seizures and monitor brain function over time. This tool is particularly useful in making timely decisions about a baby’s care if they have a seizure. Seizures are abnormal electrical activity of the brain, and most seizures can be detected by cerebral function monitoring.
- Continuous video EEG monitoring: Continuous video EEG monitoring involves recording the brain’s electrical activity alongside synchronized video footage of the baby. This approach allows the team to link any abnormal brain activity with physical movements or behaviours. This gives the team a detailed understanding of your baby’s seizure activity and overall brain function. Babies who are at higher risk of seizures will be monitored this way. This information is useful for tailoring treatments and interventions to a baby’s specific needs.
- Brain MRI: A brain MRI provides more detailed images of the brain and helps the team assess the extent and location of any injury. This information is crucial for planning ongoing care and interventions. The MRI is usually performed after the cooling therapy and gives the team the most accurate picture of a baby’s brain health.
In addition to these tests, the health-care team conducts standardized neurological examinations on a regular basis to monitor each baby.
The importance of brain MRI
A brain MRI allows the health-care team to see the specific areas of the brain that may have been affected by HIE and the extent of the injury. This detailed information helps the team predict potential outcomes and tailor care to meet each baby’s specific needs. The MRI results will also guide in planning for any necessary therapies or interventions that will support a baby’s development. After obtaining the brain MRI, the health-care team will be able to meet with the family and provide them with more information about the nature of the injury and next steps in a baby’s care.
How is HIE treated?
Babies diagnosed with HIE are admitted to the neonatal intensive care unit (NICU) to receive immediate and specialized care. The NICU is equipped with advanced technology and staffed by a multidisciplinary team of experts who are experienced in managing critical conditions such as HIE. The primary goal is to stabilize the baby, minimize any potential brain injury and support their overall recovery and development.
Once a baby is admitted to the NICU, they receive monitoring and treatment. One of the most important treatments for HIE is therapeutic hypothermia, also known as cooling therapy. This treatment involves carefully lowering the baby’s body temperature to protect the brain from further injury. Therapeutic hypothermia is a proven technique that has been shown to improve outcomes for babies with HIE. Cooling the baby’s body to a temperature slightly below normal slows down the brain’s metabolic processes. This helps to reduce inflammation and cell death, giving the brain time to heal. The cooling process typically lasts for 72 hours. During this time, the baby is closely monitored by the health-care team to ensure their safety and comfort. After the cooling period, the baby is gradually rewarmed to their normal body temperature over several hours.
Next steps and long-term follow-up
After a baby is discharged from the NICU, it is very important to return for check-ups in the neonatal neurodevelopmental follow-up clinic. These visits are crucial for keeping track of each baby's growth and development. During each visit, the health-care team will carefully check your baby's progress, including their growth, movements and if they are learning new things. If the health-care team identifies any issues or delays in your baby's development, they can step in early with special therapies or treatments, as early help can make a big difference. The clinic offers support and resources for babies and their families to help navigate this journey.
If needed, some babies will be referred to a neurologist for extra care. Keeping up with these follow-up visits over the long term is very important, as it helps ensure your child gets the best care and support as they continue to grow.
At SickKids
Our dedicated team
At SickKids, every baby is cared for by a large team of dedicated experts from various disciplines. This includes neonatologists, neurologists, nurse practitioners, nurses, respiratory therapists, occupational and physical therapists, social workers and other specialists. Each member of the team plays an important role in each baby’s care, bringing their expertise and compassion to support your family during this challenging time. They work closely together to provide comprehensive, coordinated care that addresses all aspects of every baby’s health and development.