FAQs: Hypoxic-Ischemic Encephalopathy (HIE)
Hypoxic-ischemic encephalopathy ("HIE") or perinatal encephalopathy, is a catastrophic birth injury involving major damage to the brain. This page will provide answers to some of the most frequently asked questions about HIE.What is HIE?
HIE is an acronym for hypoxic ischemic encephalopathy. The term encephalopathy refers generally to any condition or disease that involves impairment of the brain. Hypoxic-ischemic encephalopathy is an acquired syndrome characterized by clinical and imaging studies that show a brain injury from lack of oxygen.
Hypoxic ischemic encephalopathy or HIE is a particular type of damage to the brain that results when the brain is temporarily deprived of oxygenated blood. HIE often occurs during childbirth because babies are particularly vulnerable to this type of injury during labor. HIE is one of the most severe types of birth injuries. It can cause permanent, debilitating brain injuries and even death. The incidence rate of HIE in the U.S. is between 2-20 cases per 1000.How Does HIE Cause Injury?
The neurological insult from HIE comes from tissue perfusion. This means that the oxygen and nutrients is not being adequately transmitted by blood to the child's tissues. This can lead to injury to all of the vital organs. At greatest risk is the brain.
The extend of the injury to the brain depends on the nature, severity, and time duration of the loss of oxygen. The injury comes in two phases. Following the initial asphyxia injury, the cerebral metabolism recovers only to fall again in the second phase of injury that occurs between 8 and 24 hours after the initial insult.
This new phase of neuronal destruction is a delayed injury that may persist for weeks. One newer development in recent years is cooling as treatment to slow the cellular damage caused by this second phase of brain insult caused by HIE.
What Causes HIE?
The human brain needs a continuous supply of blood in order to maintain itself. The heat pumps blood which is continuously circulated to the brain. The main function of this blood circulation is to deliver oxygen to the brain which is needs at all times. HIE occurs when the brain is deprived of oxygenated blood for an extended time causing cells in the brain to rapidly decay and die. Babies in the womb are particularly vulnerable to HIE because there are a number of complication or adverse events that can occur during pregnancy or childbirth that can interrupt the supply of oxygenated blood to the baby's brain. Events during pregnancy and childbirth that can potentially cause HIE include but are not limited to
- Placental abruption: placental abruption is a dangerous complication during pregnancy in which the placenta (the organ responsible to delivering oxygen and nutrients from mother to baby) becomes fully or partially detached from the wall of the uterus and disrupting the supply of oxygen to the baby.
- Uterine rupture: a uterine rupture is an event that typically occurs during labor where the uterine wall ruptures and tears (often along a scar line from a prior C-section site).
- Pitocin misuse: Pitocin is a synthetic form of the hormone oxytocin which stimulate the muscles of the uterus to start contractions during labor. Pitocin is used by doctors to induce or speed up labor but it sometimes triggers over stimulation causing contraction that are too strong and/or too frequent which can disrupt the supply of oxygen to the baby during delivery.
- Umbilical Cord Prolapse: this complication occurs when the umbilical cord (which connects the baby to the placenta for delivery of oxygen and nutrients) abnormally drops down into the birth canal in front of the baby and gets compressed during delivery. This type of umbilical compression can restrict and even cut off blood and oxygen circulation to the baby.
- Maternal Infection: untreated maternal infections during pregnancy can disrupt the ability of the placenta to delivery oxygen and nutrients to the baby.
- Delayed C-Section: when obstetric emergencies occur during childbirth the appropriate response is often an emergency C-section which is often the only way to avoid harm to the baby. However, doctors frequently fail to recognize the signs of fetal distress or are not prepared to perform an emergency C-section. Failure to intervene and preform a timely C-section is a leading cause of preventable HIE injuries.
Defense lawyers who represent the hospitals, doctors, and nurses in these cases desperately argue that HIE is caused long before childbirth. But there reality is that while hypoxic-ischemic injury certainly can occur during the prenatal period, the incidence rate of antepartum HIE is very low.What are the Possible Consequences of HIE?
Although some cases of HIE can have comparatively mild results, HIE is a usually a very damaging and life threatening injury. HIE is not a very common event, occurring in just 3 out of every 1,000 births in the U.S. Even with this very low occurrence rate HIE still ranks as one of the top causes of infant death during childbirth. Almost a quarter of all babies who suffer HIE during childbirth die within the first week of life. Another 30% of babies born with HIE are eventually diagnosed with major neurologic disabilities such as cerebral palsy.Does HIE Cause Cerebral Palsy?
Yes. Cerebral palsy includes a group of movement disorders caused by neurologic injury during pregnancy or child birth. The neurologic injury that results in CP is most often triggered by asphyxiation or oxygen deprivation during childbirth. Hypoxic ischemic encephalopathy or HIE is the most common types of neurologic oxygen deprivation during labor and delivery. Like all type of oxygen deprivation brain injuries, HIE can potentially result in a diagnosis of cerebral palsy. In fact, approximately 10-15% of cerebral palsy cases are caused by HIE.What Does an MRI Show?
Sadly there really are no effective options for "treating" HIE. Hypoxic ischemic encephalopathy cannot be cured. Once cells in the brain are damaged and die they cannot be medically regenerated or repaired. All brain damage, including HIE, is more or less permanent. Treatment options for HIE are mostly limited to therapy and other techniques that are designed to help manage the condition and improve the child's functionality. Most babies with moderate to severe HIE injuries will require a life time of medical assistance and therapy.What are the Symptoms of HIE?
From a parent's perspective, initial symptoms of HIE can vary significantly from case to case depending on the extent of neurologic damage involved. Symptoms of a moderate level HIE injury can include: significant hypotonia or lack of muscle tone (baby feels like a "rag doll"); unable to suck or grasp; apnea; and seizures. Symptoms of more severe cases of HIE will include major seizures that increase in frequency; coma or total lack of response to external stimulus, abnormal respiration, hypotonia (rag doll feel), abnormal eye movements, and highly abnormal heart rate. A formal diagnosis of HIE will begin with clinical exams with confirmation made by lab and imaging testing.
In litigation, there are a number of things that our medical experts (obstetricians, neonatologists, pediatric neurologists, maternal fetal medicine physicians, etc.) look for when trying to determine whether there is a causal relationship between hypoxia during childbirth and a newborn's brain damage. These factors include Apgar scores, the infant's umbilical artery blood gas values (especially PH and base excess values), and evidence concerning early onset of neonatal encephalopathy. This look back also requires the exclusion of other possible causes for the child's neurological injuries. If there is some genetic disorder, infection, stroke, infection, genetic disorder, stroke, aneurysm, etc., these could all be other reasons for a child's brain injury. So it is important to rule them out.
The fetal heart tracings are also going to be critical in determining whether the fetus was at risk for hypoxic ischemic brain damage. Our experts at trial need to be able to correlate non-reassuring fetal heart rate with the condition of the child during the birthing process to properly preform a medical causation analysis and reach conclusions as the time period within which the HIE injury likely occurred. This is also important in determining whether a doctor was negligent. If the fetal heart monitor tracings show the fetus is at risk for hypoxia and ischemia, the path is clear. a reasonable obstetrician knows that if the fetus is not delivered quickly, the child is at risk for lifelong injuries from brain damage as a result of the oxygen deprivation.Contact M&Z About HIE Malpractice
If you have a child that was born with HIE that may have been the result of medical negligence, contact the birth injury lawyers at Miller & Zois. We can investigate your case and determine whether you have a valid malpractice claim. Call us at 800.553.8082 or submit a request for a free consultation.