In order to understand the effects of lethal doses of pentobarbital on a person with a traumatic brain injury (TBI), one must first know that traumatic brain injuries often produce neurological disorders, including the high risk of developing a seizure disorder. Several factors play into one's risk of developing a seizure disorder after head trauma. (1) It's estimated that between 60-70% of individuals with penetrating traumatic brain injuries will have a seizure.
In 2008, Ernest Johnson had one-fifth of his brain mass removed in an effort to remove a tumor in the frontal lobe of his brain. This massive removal of brain tissue from Mr. Johnson’s brain caused severe scarring, which increased the likelihood and now predisposes him to experiencing seizures, especially in circumstances where he is subject to further trauma to his brain.
In medically ethical circumstances, pentobarbital is given in very low doses to reduce the effects of epilepsy in persons with chronic seizure disorders. However, when given in lethal, unethical doses, pentobarbital is known to produce pulmonary edema, which has been compared to drowning.(2) Other effects of lethal doses of pentobarbital include but are not limited to the rapid slowing and shutting down of the electrical activity of the brain and nerve cells.(3) The rapid slowing of electrical activity and Mr. Johnson’s traumatic brain injury cumulatively increases the likelihood of him experiencing seizures if given a lethal dose of pentobarbital.
In Mr. Johnson's case, and in the case of others who have traumatic brain injuries (TBI), the execution method of lethal injection with one drug, pentobarbital, is unconstitutional under the 8th Amendment, which protects citizens from cruel and unusual punishment.(4)