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What Are the Stages of Hypoxic-Ischemic Encephalopathy?

Written by Berkowitz

baby cuddled with mother

Hypoxic-ischemic encephalopathy (HIE) is a catch-all term for brain damage in newborn babies caused by oxygen deprivation and insufficient blood flow. The Sarnat Staging Scale is a diagnostic tool that allows doctors to detect HIE and to classify it as mild, moderate, or severe.

HIE is also commonly referred to as birth asphyxia, perinatal asphyxia, and neonatal encephalopathy. The condition is not particularly uncommon, and about 0.2 to 0.3 percent of children from all full-term births are affected by it. This adds up to thousands of children per year, and malpractice is often the ultimate cause.

How Serious Is HIE?

The seriousness of HIE varies greatly from case to case. In many mild cases of HIE, the infant makes a full recovery. In many severe cases, however, the consequences are serious and even tragic. Although prevention is the best “cure” for HIE, early intervention, especially within a few hours after birth, can make a real difference.

Early Symptoms

An infant suffering from HIE might suffer from the following symptoms immediately after birth:

  • Apparent lethargy, stupor, or coma;
  • Low heart rate;
  • Slow, irregular, or depressed breathing;
  • Acidosis (elevated acidity in the blood);
  • Seizures;
  • Stained amniotic fluid (a well-known symptom of fetal distress);
  • Low muscle tone;
  • Pale or bluish skin; and/or
  • Depressed reflexes or total absence of reflexes altogether.

A victim of HIE may experience some or all of these symptoms.

Early Diagnosis (in Infants)

The diagnosis of HIE in a newborn baby is based on observation and classification on the Sarnat Scale (see below) the use of imaging technology such as EEG, ultrasound, and MRI; and analysis of umbilical cord blood gas levels.

Long-Term Symptoms

HIE in newborns often leads to permanent brain damage and lifelong disability. The following HIE-related conditions are all too common:

  • Cerebral palsy (CP);
  • Epilepsy;
  • Hearing loss;
  • Vision impairments;
  • Stomach and digestive problems;
  • Impaired muscle function;
  • Impaired breathing;
  • Delayed development;
  • Heart damage;
  • Liver damage;
  • Kidney damage; and
  • Various cognitive deficits.

In severe cases of HIE, the infant dies from a lack of oxygen to the brain.

The Sarnat Staging Scale

The Sarnat Staging Scale is the clinical standard used to evaluate HIE cases as normal and healthy/mild HIE, moderate HIE, or severe HIE (Code 1, Code 2, and Code 3, respectively). The evaluation is based on observation of the infant, the duration of any adverse symptoms, the presence or absence of seizures, and other examination findings. The infant’s prognosis is typically based on both the Sarnat Grading Scale and electroencephalogram analysis.

The Sarnat scale analyzes the below-described metrics to reach a single overall conclusion on the seriousness of an infant’s HIE:

Level of Consciousness

  • Code 1: Normal state of waking consciousness; or hyperalertness/irritability.
  • Code 2: Lethargic with delayed response to stimuli.
  • Code 3: Stupor or coma with delayed but incomplete response to stimuli, or no response at all.

Spontaneous Activity

  • Code 1: Active.
  • Code 2: Decreased activity.
  • Code 3: No activity.


  • Code 1: Flexion of hip, knees, and fingers with complete extension.
  • Code 2: Strong distal flexion, complete extension, and complete abduction (frog leg posture)
  • Code 3: Highly unnatural decerebrate posturing, regardless of whether stimulation is applied.

Muscle Tone

  • Code 1: Normal or somewhat increased resistance.
  • Code 2: Focal or general hypotonic, or hypertonic muscle tone.
  • Code 3: Completely flaccid or rigid muscle tone.

Sucking Reflex

  • Code 1: Vigorous sucking of examiner’s finger or ET tube;
  • Code 2: Weakening sucking, or biting
  • Code 3: No sucking at all.

Moro Reflex (response to being startled)

  • Code 1: Extension of limbs, opening of hands and upper limbs in response to a startling stimulus;
  • Code 2: Incomplete response.
  • Code 3: Absent response.

Heart Rate

Code 1: Above 100 beats per minute (normal), or a consistently elevated heart rate above 120 beats per minute.

Code 2: Slow heart rate (under 100 beats per minute) with only occasional increases to above 120 beats per minute.

Code 3: Inconsistent heart rate; varies widely between under 100 beats per minute and over 120 beats per minute.

Pupils (of the eyes)

Code 1: Normal size and reactive to light.

Code 2: Constricted but reactive to light

Code 3: Skew deviation of eyes, asymmetric pupils, dilated pupils, or pupils non-reactive to light.

Respiration (Breathing)

Code 1: Breathing spontaneously or periodically without low blood oxygen.

Code 2: Periodic breathing with low blood oxygen.

Code 3: Apnea or impaired breathing that requires the use of a ventilator.

HIE Is a Progressive Disease

HIE, because it is caused by lack of blood flow and oxygen to the brain, causes progressive brain cell death. As these cells die, they release toxic substances that damage otherwise healthy cells. This causes a chain reaction, as the otherwise healthy cells die and release toxins of their own to kill even more brain cells. Treatment focuses on either stopping the chain reaction, as in therapeutic hypothermia or mitigating its effects as a variety of treatments do.

Therapeutic Hypothermia

The most effective treatment for HIE is therapeutic hypothermia, also known as hypothermia therapy, brain cooling, cooling therapy, and cooling treatment. Therapeutic hypothermia is the deliberate lowering of body temperature to unnatural levels. This cooling slows down the cell death chain reaction that is characteristic of HIE. It is also used to treat certain conditions in adults such as heart attacks and strokes.

The use of therapeutic hypothermia on a newborn baby involves cooling the body temperature to about 92.3 – 94.1 degrees Fahrenheit for three days, preferably within six hours of the infant’s birth or whatever event triggered the oxygen deprivation. Physicians use a cooling cap to cool the head only or a cooling blanket to cool the infant’s entire body.  The best technique depends on the situation.

The infant is carefully monitored during treatment, and after three days, the infant’s body or brain is gradually warmed to normal temperature over a period of about four hours.

Other Forms of Treatment

Unfortunately, although therapeutic hypothermia needs to be undertaken within a few hours of birth, it is possible for HIE to remain hidden until the child experiences developmental delays later in childhood. The first clear sign of HIE, for example, might not occur until the child has trouble learning how to walk.

Once brain damage has become permanent, typically hours after birth, no cure is possible, because modern medical science cannot bring dead brain cells back to life. Many treatments, however, can reduce the impact and improve functioning in children with HIE, cerebral palsy, and epilepsy. Options include:

  • Physical therapy:
  • Occupational therapy:
  • Speech/language pathology
  • Behavioral and emotional therapy:
  • Sensory integration therapy:
  • Massage therapy:
  • Recreational therapy; and
  • Stem cell therapy.

In addition to these forms of therapy, various medications can improve outcomes for children with HIE and HIE-related conditions.

Malpractice and HIE

Although not all HIE is attributable to malpractice, much of it is. Determining whether or not HIE is attributable to malpractice requires an investigation as well as both medical and legal expertise. A medical expert (typically a physician or former physician in the same specialty) is usually required to establish the standard of care that your physician will be held to.

Malpractice can be caused by a great variety of errors, including:

  • Anesthesia errors;
  • C-section errors;
  • Delay in performing a C-section;
  • Failure to diagnose a fetal infection;
  • Failure to diagnose risk factors such as macrosomia (large infant body size) or cephalopelvic disproportion (the baby’s head is too large to fit through the mother’s pelvis);
  • Failure to provide therapeutic hypothermia within a few hours of birth;
  • Failure to respond to indicators of fetal distress;
  • Mismanagement of a high-risk pregnancy;
  • Mismanagement of shoulder dystocia;
  • Misuse of forceps;
  • Misuse of vacuum extractor;
  • Negligent fetal heart rate monitoring; and
  • Numerous other potential errors.

Birth Injury Lawsuits

HIE is considered to be among the broad class of harms known as birth injuries. If your child is a victim of HIE and you suspect that this condition could have been prevented, you should look into the possibility of filing a birth injury lawsuit, which is a form of a malpractice lawsuit. Your claim might be worth more than you think it is and, since HIE often causes lifelong disability, your child is likely to need it.

Financial Planning

Any lawsuit recovery that you receive can be placed into a special needs trust that is dedicated to meeting your child’s needs throughout their lifetime, even after you are gone. Furthermore, these funds can be invested so that the fund, and the income it generates, can continue to grow. Prudent financial planning can minimize the tax burden on the income generated by the trust.

Even more importantly, a special needs trust can be set up in a manner that will not count distributions from the trust as your child’s taxable income. This setup will allow your child to remain eligible for benefits under Medicare, Medicaid, and certain other government programs, while at the same time, receiving income from the trust to pay for benefits that these programs won’t cover.

Wrongful Death Lawsuits

Tragically, some HIE victims die from their condition, either as children or as adults. When this happens, the idea of filing a lawsuit to obtain the funds necessary for your child’s care becomes irrelevant. Nevertheless, Connecticut still allows the personal representative of your child’s probate estate to file a wrongful death lawsuit for damages, which are paid into your child’s estate and eventually distributed to heirs (close family members).

Damages available under Connecticut wrongful death law include funds to compensate the probate estate for:

  • medical expenses relating to your child’s HIE;
  • funeral and burial expenses;
  • lost earning capacity;
  • pain and suffering endured by your child before death; and
  • damages for loss of capacity to enjoy life’s activities.

We Stand Ready to Assist You

If you believe your child is a victim of HIE, don’t hesitate – contact Berkowitz Hanna for a free consultation, so that we can listen to your story and evaluate your claim. You might think you can’t afford a top-tier personal injury law firm like Berkowitz and Hanna, but such is not the case. We charge precisely $0.00 for our services until we win your claim and the opposing party actually pays it. Telephone us or contact us online to get started today!