Behind the Execution Curtain: Clayton Lockett Inside Out

Clayton Lockett did not die of a heart attack as has been reported by various media outlets following the botched execution on April 29, 2014.  Lockett died from cardiac arrest, which ultimately is the intended outcome of all executions by lethal injection.

Understanding the difference between a heart attack and cardiac arrest is important for this story because the use of the term  “heart attack” is factually inaccurate.  A heart attack occurs when an occlusion (e.g. blood clot) of an artery in the heart slowly causes tissue to die. This can result in chest pain and discomfort, and requires immediate medical attention to resolve, whereas cardiac arrest is the cessation of normal heart contractions due to the failure of the heart’s electrical system. 

In addition, the drugs used for execution cause cardiac arrest by disrupting the electrolyte balance within the heart, thus affecting the proper electrical activity to sustain life.  It appears that a cataclysmic cascade of events occurred on the day of Lockett’s execution, causing him to suffer a lengthy, torturous death.

Apparently, Lockett had been noncompliant earlier in the day and was tased in order for correctional officers to gain control of him.  Herein lies the first possible contributor to the botched execution.  One of the body’s responses to the electricity produced by a taser is vasoconstriction and hypertension, causing severe stress on the veins and arteries.  This leads one to wonder if the fact that Lockett was tased prior to the execution had caused his blood vessels to constrict, making it difficult for the technician to find a suitable vein in which to insert the IV catheter.  When the use of an artery in his groin was finally utilized, did the stress that had already been placed on Lockett’s vessels as well as the stress of his impending death weaken them, making them more prone to “blowing out"?Should this have been a consideration prior to carrying out the execution?

Another consideration is the mechanism of action of the three drugs used sequentially during Lockett’s execution.  Understanding how these drugs affect the body is imperative for taking a stance for or against lethal injection.

The drugs that were used in the case of Lockett were:

1)    Midazolam: a benzodiazepine which possess sedative, hypnotic, anxiolytic, anticonvulsant, muscle relaxant, and amnesic actions.

2)    Vecuronium Bromide: a muscle relaxant in the category of non-depolaring blocking agents.  It is used as a paralyzing agent, and causes the cessation of respiration by paralysis of the diaphragm.  In depolarizing the musculature, it may trigger a transient release of large amounts of potassium from muscle fibers.  Injections of vecuronium bromide without proper sedation have been known to cause excruciating pain to prisoners.

3)    Potassium Chloride:  potassium is a crucial electrolyte for cardiac depolarization. Most of the potassium is intracellular. If the extracellular potassium increases it can slow the depolarization rate, severe hyperkalemia, can kill reliably. Hyperkalemia results when the concentration of the electrolyte potassium (K+) in the blood is elevated, causing cardiac arrhythmias. In an EKG, it manifests as a reduction of the size of the P wave and development of peaked T waves. Severe hyperkalemia results in a widening of the QRS complex.  This drug is excruciatingly painful if administered without proper anesthesia. When injected into a vein, it inflames the potassium ions in the sensory nerve fibers, literally burning up the veins as it travels to the heart.

The other question that remains is did Lockett’s execution follow proper U.S. protocol? 

For example:

1)    Were two intravenous cannulae ("IVs") inserted, one in each arm?   Only one is necessary to carry out the execution; the other is reserved as a backup in the event the primary line fails.  A line leading from the IV line in an adjacent room is attached to the prisoner's IV, and secured so the line does not snap during the injections.  It has been reported that the only place an IV was inserted in Lockett was in his groin.

2)    Following connection of the lines, were saline drips started in both arms? This, too, is standard medical procedure because it must be ascertained that the IV lines are not blocked, ensuring the chemicals have not precipitated in the IV lines and blocked the needle, preventing the drugs from reaching the subject.

3)    Was a heart monitor attached so prison officials can determine when death has occurred?  The media has reported that Lockett had a faint heartbeat.  Was that determined by auscultation or on an EKG reading?

So, before one can say he or she is for or against lethal injection as a means to execute prisoners in the United States, physiology, accurate use of medical terminology, execution protocol and mechanisms of action of medications must be included in media reports.  This is especially true in the case of Clayton Lockett.