Despite major advances in fetal and neonatal care, hypoxic ischemic encephalopathy (HIE), sometimes called perinatal encephalopathy, continues to cause a significant number of deaths and long-term disabilities in newborns.
The neurologic changes associated with HIE may be brief, lasting only a few minutes to hours, or may be permanent. Generally, the longer an infant goes with low blood flow or low oxygen, the more severe or permanent the injury.
What Causes Hypoxic Ischemic Encephalopathy?
In many cases, the exact cause is not known. In some infants, lack of blood flow or oxygen may occur before, during or shortly after a baby's birth. Some conditions that may result in poor blood or oxygen flow include a ruptured uterus, bleeding from the placenta, early separation of the placenta, trauma, shock or seizures in the mother, or cord accidents.
How Is Hypoxic Ischemic Encephalopathy Treated?
Until recently, the only treatment for HIE was to support the baby's heart, lung and gastrointestinal systems while the body attempted to repair itself. The Neonatal Intensive Care Unit does that by providing all measures of neonatal care, including conventional and high-frequency ventilation, special breathing support measures such as nitric oxide therapy and subspecialty physician support.
Brain cooling is a new therapy designed specifically for HIE and has been shown to improve the outcome of some babies who have experienced birth-associated HIE. Brain cooling (or a similar therapy called "total body cooling") has been shown to be safe and is currently the most effective therapy available.
Ann & Robert H. Lurie Children’s Hospital of Chicago was one of the original study centers for the Cool-Cap® hypothermia system. If your baby's pediatrician or neonatologist diagnoses HIE shortly after birth, he or she will determine if your baby may benefit from head cooling therapy.
Head Cooling & HIE
Although this is an area of continued medical investigation, studies have shown that brain cell injury from HIE occurs in two phases. Shortly after an initial injury, the brain cells stop working correctly, creating chemicals that may further injure the brain. Once blood flow or oxygen returns to normal, these chemicals may further damage the injured cells and the surrounding normal cells.
Research now shows that cooling the infant's head slows the brain's metabolism and allows it to recover over a longer period of time. This protects cells from further chemical damage produced from the original injury. Timing is very important, as the best outcomes are seen when babies receive head cooling treatment as soon as possible after the injury and within six hours after birth.
The newborn is fitted with an FDA-approved cap called a Cool-Cap. A machine circulates water through the cap, carefully controlling the water temperature to ensure moderate cooling of the infant and their brain. After a period of about 72 hours of cooling, the infant is slowly warmed to normal temperature.
Careful and constant monitoring of the baby by specially trained neonatal staff takes place before, during and after the procedure. Continuous monitoring includes:
- Breathing and oxygenation
- Blood pressure and heart function
- Brain wave activity
Upon discharge, newborns receive close follow-up by staff members who specialize in developmental follow-up. An extensive array of Lurie Children's pediatric specialists provides comprehensive care that may include the services of a neonatologist; developmental pediatrician; neurologists; and occupational, physical and speech therapists.