Lethal injection

Lethal injection is used as a method of capital punishment that involves injecting the condemned with fatal doses of drugs to cause death. It gained popularity in the twentieth century as a "more humane" form of execution meant to supplant methods such as electrocution, hanging, firing squad, gas chamber, or decapitation; the actual humaneness of the technique has been debated in recent decades.

History

The first to suggest injecting a lethal dose of poison as a means for execution was Hitler's personal doctor, Karl Brandt; specifically for euthanizing disabled people. The T-4 Euthanasia Program used lethal injection among other methods. At the Auschwitz concentration camp, SS personnel killed prisoners that were ill or that had been sentenced to death by the injection of phenol and other poisons.

The United States was thus, strictly speaking, the second nation to experiment with lethal injection as a means of execution, using it first on December 7, 1982 when Charles Brooks, Jr. was executed in Texas. [3] [4]

The concept had been proposed in 1888 by J. Mount Bleyer in New York, but was not approved. It was also rejected by the British Royal Commission on Capital Punishment (1949–1953) after pressure from the British Medical Association. In 1977, Oklahoma became the first state to adopt lethal injection after the idea was revived in the U.S. in February 1977 by Dr. Stanley Deutsch. Since then, the majority of US states using capital punishment prefer to use lethal injection.

The practice extended outside the US when it was adopted by the People's Republic of China in 1997, Guatemala in 1998, Philippines in 1999, and Thailand in 2003 . Some other countries have adopted the method in law but not in practice.

Procedure

File:AZgurney.jpg

Gurney for the execution of the sentence of death by lethal injection in Arizona

After the condemned is fastened on the execution table, two intravenous catheters are inserted, one in each arm. Only one is used for the execution, the other is reserved as a backup in case the primary IV fails.

The arm of the condemned is swabbed with alcohol before the needle is inserted. Along with its antiseptic use, the alcohol also causes the blood vessels to rise to the skin's surface, making it easier to insert the needle. [1] The needles and equipment used are also sterilized. One reason for this is because the needles are standard medical products that are sterilized during manufacturing. Also, there is a chance that the prisoner could receive a stay of execution after the needles have been inserted as happened in the case of James Autry in October 1983 (he was executed eventually on 14 March 1984). Finally, it would also be a hazardous for those handling unsterile equipment.

The intravenous injection is usually a mixture of compounds, designed to induce rapid unconsciousness followed by death through paralysis of respiratory muscles and/or by inducing cardiac hyperpolarization.

The execution of the condemned in most states involves three separate injections:

Sodium thiopental: to induce a state of unconsciousness intended to last while the other two injections take effect.
Pancuronium/Tubocurarine: to stop all muscle movement except the heart. This causes involuntary muscle paralysis, collapse of the diaphragm, and eventually death by asphyxiation.
Potassium chloride: to stop the heart from beating, and thus cause death: see cardiac arrest.

The drugs are not mixed externally as that can cause them to precipitate.

The intravenous tubing leads to a room next to the execution chamber, usually separated from the inmate by a curtain or wall. Usually some type of IV technician with certification to insert the IV tube performs that role, while the chemical technician, who is usually a member of the prison staff, orders, prepares, and loads the chemicals into the machine. After the curtain is opened to allow the witnesses to see inside the chamber, the condemned person will then be permitted to make a final statement. Following this, the warden will signal for the execution to commence, and the executioner(s), either prison staff or private citizens depending on the jurisdiction, will then activate the machine which mechanically delivers the three drugs in sequence. Other than visual observation by prison staff and the witnesses, there is no mechanical or scientific monitoring of the inmate during the process. Death usually occurs within seven minutes, although the whole procedure can take up to 45 minutes. According to state law, if participation in the execution is prohibited for physicians, the death ruling is made by the state's Medical Examiner's Office. After confirmation that death has occurred, a coroner signs the executed individual’s death certificate.

Lethal injection drugs

The below three drugs are a representation of a typical lethal injection cocktail.

Sodium Pentothal

Lethal Injection dose: 5 grams

Sodium Pentothal (also known as sodium thiopental) is an ultra-short acting barbiturate, often used for anesthesia induction and for medical induced comas. The typical anesthesia induction dose is 3-5 mg/kg (a person who weighs 200 pounds, or 91 kilograms, would get a dose of about 300 mg). Loss of consciousness is induced within 30-45 seconds at the typical dose, while a five gram dose which is fourteen times the normal dose is likely to induce unconsciousness in 5-10 seconds.

Pentothal reaches the brain within seconds and attains a peak brain concentration of about 60% of the total dose in about 30 seconds. At this level, the patient is unconscious. Within 5 to 20 minutes, the percentage in the brain falls to about 15% of the total dose since the drug redistributes to the rest of the body. At this concentration in the brain, the anesthetic effects wear off and consciousness returns.

The half-life of this drug is about 11.5 hours[2], and the concentration in the brain remains at around about 5-10% of the total dose during that time. When a 'mega-dose' is administered, as in lethal injection, the concentration in the brain during the tail phase of the distribution stays higher than the peak concentration found in the induction dose for anesthesia. This is the reason why an ultra-short acting bartbiturate, such as sodium pentothal, can be used for long-term induction of medical comas.

With a five gram dose, consciousness will probably be regained in about five to six half-lives which occurs in about 57-69 hours. The side effects of such a high dose, however, are respiratory depression (depression of the brainstem respiratory center) and vascular collapse (cardiovascular myodepression), and therefore without medical intervention such as intubation this is in itself a lethal dose.

Barbiturates are the same class of drugs used in medically assisted suicide.

Pancuronium

Lethal Injection dose: 100 milligrams

Pancuronium (Trade name: Pavulon) is a non-depolarizing paralytic that blocks the release of acetylcholine at the neuromuscular junction. Acetylcholine is required for muscles to contract. A depolarizing paralytic such as succinylcholine has a much faster onset of action and is the preferred drug for intubation because of its faster onset. Succinylcholine, however, causes the whole body to contract and fasiculate, which could prove distressing to observers of the execution, even though the subject themselves will be comatose. Non-depolarizing agents do not cause fasiculations.

The typical dose for pancuronium is 0.1 mg/kg (a person who weighs 200 pounds, or 91 kilograms, would get a dose of around 9mg). With a 100 milligram dose, the onset to paralysis occurs in around 15 to 30 seconds, and the duration of paralysis is around 4 to 8 hours. Paralysis of respiratory muscles will lead to death in a considerably shorter time.

Pancuronium is a derivative of curare from the plant Strychnos toxifera.

Potassium

Lethal Injection dose: 100 MEQ (milliequivalents)

Potassium is an electrolyte that is 98% within the cells. The 2% remaining outside of the cell has great implications for cells that generate action potentials. Typically, doctors give patients potassium when they have insufficient potassium in their blood. The potassium can be given orally which is the safest route, or it can be given intravenously in which case there are strict rules and hospital protocols on the rate at which it is given.

The usual intravenous dose is 10-20 MEQ per hour and it is given slowly since it takes time for the electrolyte to equilibrate into the cells. When used in lethal injection, bolus potassium injection affects the electrical conduction of heart muscle. Hyperkalemia (elevated potassium) causes the resting electrical activity of the heart muscle to be lower than normal.

Making the resting potential even lower slows conduction and reduces the ability of the muscle to depolarize and contract. EKG changes include faster repolarization (peaked T-waves), PR interval prolongation, widening of the QRS, and eventual sine-wave formation and asystole. The heart eventually stops in diastole. Cases of patients dying from hyperkalemia (usually secondary to renal failure) are well known in the medical community, where patients have been known to go from a normal state to death within seconds.

Ethics

The American Medical Association believes that a physician's opinion on capital punishment is a personal decision. Since the AMA is founded on preserving life, they argue that doctors "should not be a participant" in executions in any form with the exception of "certifying death, provided that the condemned has been declared dead by another person."[3] Amnesty International distorts the AMA's position, claiming that the AMA "prohibits doctors from participating in executions." [4] The AMA does not have the authority to prohibit doctors from participation in lethal injection, nor has the authority to revoke medical licenses since this is the responsibility of the individual states.

Typically, most states do not require that physicans administer the drugs for lethal injection, but many states do require that physicians be present to pronouce or certify death.

Controversy

Arguments Against

The concern has been raised that execution by lethal injection, as practiced in the United States, is not actually humane. It has been argued that the ultrashort-acting anaesthetic may wear off, leaving the inmate fully conscious, yet rendered paralyzed by the paralytic agent. There are several reasons for the concern.

First, sodium thiopental is an ultrashort-acting barbiturate, used in surgery only in the induction phase of anesthesia, specifically so that the patient may awaken and breathe on his or her own if any complications arise in inserting a breathing tube pre-surgery. It is not used to maintain a patient in a surgical plane of anesthesia because of its short-acting nature.

Second, the second injected chemical, pancuronium bromide, may act to dilute the initial injection of sodium thiopental.

Third, because the personnel involved in administering the injection lack training and expertise in anesthesia, the risk of failing to induce unconsciousness is greatly increased. The dose of sodium thiopental must be measured with precision, and the calculation of the proper amount of the drug depends upon both the concentration of the drug and the size and condition of the subject. Because of the manner in which the drugs are administered (remotely, with no observation of the inmate), the risk of errors in the injection causing insufficient amounts of chemicals to enter the bloodstream is greatly increased.

The effect of dilution or improper administration of sodium thiopental is that the inmate dies an agonizing death through slow suffocation while fully conscious, yet unable to express any pain. While pancuronium bromide paralyzes skeletal muscles, including the diaphragm, it has no effect on consciousness or the perception of pain or suffering. For this reason, the use of paralyzing agents for the euthanasia of animals like cats and dogs has been made illegal — either directly or by reference to the American Veterinary Medical Association's panel on euthanasia, which prohibits the practice generally [5] — in at least 19 states, including Texas, the state that executes the most people by lethal injection. However, the use of these agents for execution continues.

On occasion, there have also been difficulties inserting the delivery needles, sometimes taking over half an hour to find a suitable vein. Some of the previous errors in Texas executions include:

Technicians punctured the inmate repeatedly in both arms and legs for 45 minutes before a vein was located. (Stephen Peter Morin [6], March 13, 1985)
Executioners struggled for 35 minutes to insert the catheter into an inmate's veins. (Elliot Johnson, June 24, 1987)
24 minutes elapsed between the time the initial injection occurred and the time the inmate was pronounced dead; two minutes into the procedure, the syringe came out of the inmate's arm and the chemicals sprayed out towards witnesses. (Raymond Landry [7], December 13, 1988)
After an inmate had a violent physical reaction to the drugs as they were injected, the Texas Attorney General stated the inmate "seemed to have a somewhat stronger reaction," adding "The drugs might have been administered in a heavier dose or more rapidly." (Stephen McCoy [8], May 24, 1989)

In 2005, University of Miami researchers reported in the medical journal The Lancet that they believed in 43 out of the 49 executions they investigated, the level of thiopental in the blood was lower than that required for surgery. This has led them to believe that the prisoners were fully aware of what was happening to them. The authors attributed the rate of likely consciousness among inmates to the lack of training and monitoring in the process, and recommended that states take a look at the American Veterinary Medical Association's recommendations on animal euthanasia, which prohibits the use of paralytic agents in combination with barbiturates and recommends animals like cats and dogs be euthanized by a single injection of a long-acting barbiturate such as sodium pentobarbital. [9]

Opponents of lethal injection as currently practiced argue that the procedure employed is entirely unnecessary and is aimed more towards creating the appearance of serenity and a humane death than an actually humane death. Pancuronium bromide, the paralytic agent employed in lethal injection, is used in surgery to keep patients immobilized during delicate surgical procedures that occur near vital organs. By contrast, its use in lethal injection serves no purpose, since there is no need to keep the inmate completely immobilized and the inmate is physically restrained.

The opponents say that because death can be painlessly accomplished, without risk of consciousness, by the injection of a single large dosage of barbiturate, the use of any other chemicals is entirely superfluous and only serves to unnecessarily increase the risk of torture during the execution. Legal challenges, however, have to date been unsuccessful, and United States federal courts have employed a range of procedural obstacles to avoid reaching the merits of the complaints, likely to avoid the temporary moratorium that would occur while states moved to alter their respective execution protocols.

Proponents of lethal injection as currently practiced counter that that the megadose of sodium pentothal places the condemmed in a medical coma that lasts much longer than the time needed for execution. The administration of potassium chloride may cause a rippling or spasms of the muscles and it is believed that the pancuronium may decrease these effects. Opponents of lethal injection as currently practiced point out, however, that if the inmate is indeed rendered unconscious by the administration of sodium pentothal, as advocates of the status quo assert, it should not matter whether muscles ripple or spasm, because they will not be felt. Critics believe, therefore, that the administration of pancuronium serves no purpose other than to create the appearance of a serene death rather than to actually provide a humane death.

Arguments in Support

Commonality

The combination of a barbiturate induction agent and a nondepolarizing paralytic agent is used in tens of thousands of surgeries every day. In fact, potassium is given in heart bypass surgery to induce cardioplegia. Therefore, the combination of these three combined drugs is still in use today. It is likely that the designers of the lethal injection protocols intentionally used the same drugs as used in every day surgery to avoid controversy. The only modification is that a massive coma-inducing dose of barbiturates is given.

Anesthesia Awareness

Pentothal and methohexital are ideal drugs for inducing unconsciousness. Both of these drugs cause loss of consciousness upon one circulation through the brain because of their high lipophilicity. Only a few drugs, such as etomidate, have the cabability to induce anesthesia so rapidly. Also since the pentothal is given at such a high dose, a dose that is higher than medical-induced coma protocols, it is impossible for a patient to wake up. Regardless, opponents of the death penalty claim that anesthesia awareness still is a concern.

Anesthesia awareness occurs when there is inadequate inhaled anesthetics given by the anesthesiologist. Barbiturates are only given during the induction phase of anesthesia and these medications rapidly and reliably induce anesthesia. A depolarizing paralytic or a nondepolarizing paralytic, like pancuronium, may then be given to cause paralysis which facilitates intubation. Once intubation has been attained, the anesthesia is converted to the inhaled anesthetics since the barbiturates at the dose given induce unconsciousness for only 5-20 minutes. The anesthesiologist has the responsibility to ensure that the inhaled anesthetics are started soon after intubation to prevent the patient from waking up.

Anesthesia is not maintained with the barbiturate class of drugs since these drugs have extremely long half-lives. The "ultra-short" acting pentothal has a half-life of appoximately 11.5 hours and the long acting phenobarbital has a half-life of approximately 4-5 days. In contrast, the inhaled anesthetics have extremely short half-lives and allow the patient to wake up from surgery. If the barbiturate class of drugs was used for anesthesia, patients would not wake up for days. Patients only regain consciousness if the anesthesiologist fails to give sufficient inhaled anesthetics. Therefore, anesthesia awareness is not a problem when dealing with the barbiturate class of drugs, it only occurs if there is indequate inhaled anesthetics.

The average time to death once a lethal injection protocol has been started is about 7 minutes. Since it only takes about 30 seconds for the pentothal to induce anesthesia, 30-45 seconds for the pancuronium to cause paralysis, and about 30 seconds for the potassium to stop the heart, death can theoretically be attained in as little as 90 seconds. Given that it takes time to administer the drugs through an IV, time for the line to be flushed, time to change the drug being administered, and time to ensure that death has occured, the whole procedure takes about 7 minutes. Procedural aspects in pronouncing death also adds time and, therefore, the condemned is usually pronounced within 10 to 20 minutes of starting the drugs. Supporters of the death penalty say that a megadose of pentothal, which is anywhere from 14-20 times the normal dose and one in which a medical coma is induced for about 60 hours, is unlikely to wear off in 10 to 20 minutes.

Dilution Effect

Pancuronium and pentothal are commonly used together in surgery every day and if there were a dilution effect, it would be a known drug interaction.

Drug interactions are a complex topic, but most drug interactions can be simplistically classified as either synergistic or inhibitory interactions. In addition, drug interactions can occur directly at the site of action, through common pathways or indirectly through metabolism of the drug in the liver or through elimination in the kidney. Given that pancuronium and pentothal have completely different sites of action, one in the brain and one at the neuromuscular junction, it is impossible for a drug interaction to occur acutely. Since the half-life of pentothal is on the order of hours, the metabolism of the drugs it is a nonissue when dealing with the short time frame in lethal injection. The only other plausible interpretation would be a direct one, or one in which the two compounds interact with each other. But even if the 100 mg of pancuronium directly prevented 500 mg of pentothal from working, there would be enough pentothal to induce coma for 50 hours. In addition, if this interaction did occur, then the pancuronium would be incapable of causing paralysis.

Blood Levels

Reasearchers at the University of Miami have published an article in The Lancet claiming that the concentration of pentothal in the blood following execution was not of a sufficient concentration to reach anesthesia. Supporters of lethal injection dispute this claim.

The barbiturate class of drugs is highly lipophilic, meaning that the drugs are absorbed and reach high concentration in fatty tissues. Measurement of the drug by blood testing after administration is difficult to assess since most of the drug will not be in the blood. Blood levels soon after adminstration are the highest for the barbiturate class since the drug has not completely cleared from the blood. This is known as the initial volume of distribution. After a short period of time, the drug then reaches its apparent volume of distribution. Pentothal's initial volume of distribution is 13.8 liters and its apparent volume of distribution is 233 liters.[10] Essentially, any blood level drawn after an execution could be compared to the drug level that one would expect in the intial distribution. Since the apparent volume of distribution is much larger than the initial distribution, and hence its blood concentration much lower, any researcher can incorrectly claim that the level of pentothal was insufficent.

Given that the half-life of pentothal is 11.5 hours, the amount of pentothal required in the brain to induce anesthesia is about 50-75 milligrams, and that the dose of pentothal given is 5 grams, it is not unlikely to expect the inmate will be properly sedated.

In fact, the researchers state that “participation of doctors in protocol design and execution is ethically prohibited.”[11] Therefore, the authors conclude that "a more effective, humane protocol cannot be developed."[12] Supporters of the death penalty state that the bias of the authors and faulty study design invalidates the study's conclusions.

Single Drug

Amnesty International, the Death Penalty Information Center, and other anti-death penalty groups have not proposed a lethal injection protocol which they believe is more humane. Supporters of the death penalty argue that the lack of alternative proposed protocol is testament to the fact that the humaneness of the lethal injection protocol is not the issue. Instead, the issue is the continued existence of the death penalty since if the only issue was the humaneness, then Amnesty International or the DPIC should have already proposed a more humane method.

Regardless of an alternative protocol, some death penalty opponents have claimed that execution can be more humane by the administration of a single lethal dose of barbiturate. Terminally ill patients in Oregon who have requested physican-assisted suicide have received lethal doses of barbiturates. The protocol has been highly effective in attaining a humane death, but the onset to actual death can be a drawn out process. Some patients have taken days to die whereas a few patients have actually survived the process and have regained consciouness up to three days after taking the lethal dose.[13]

Scientifically this is readily explained. Barbiturate overdoses typically cause death by depression of the resipratory center, but the effect is variable. Some patients may have complete cessation of respiratory drive, whereas others may only have depression of respiratory function. In addition, cardiac activity can last for a long time, potentially hours, after cessation of respiration. Since death is pronounced after asystole and given that the expectation is for a rapid death in lethal injection, multiple drugs are required; specifically potassium to stop the heart. In fact, in the case of Clarence Ray Allen a second dose of potassium was required to attain asystole. The position of death penalty supporters is that death should be attained in a reasonable amount of time.

References

Bicknell, Craig (December 1, 1997). "Searching for Humane Execution Machines". {{cite news}}: Check date values in: |date= (help); Unknown parameter |org= ignored (help)
Bean, Matt (June 8, 2001). "Lethal injection—the humane alternative?". {{cite news}}: Check date values in: |date= (help); Unknown parameter |org= ignored (help)
Liptak, Adam (October 7, 2003). "Critics Say Execution Drug May Hide Suffering". {{cite news}}: Check date values in: |date= (help); Unknown parameter |org= ignored (help)
"Prisoners 'aware' in executions". 14 April, 2005. {{cite news}}: Check date values in: |date= (help); Unknown parameter |org= ignored (help)
Kevin Bonsor. http://people.howstuffworks.com/lethal-injection.htm. {{cite web}}: Missing or empty |title= (help); Unknown parameter |Date= ignored (|date= suggested) (help); Unknown parameter |Title= ignored (|title= suggested) (help); Unknown parameter |Work= ignored (|work= suggested) (help); Unknown parameter |Year= ignored (|year= suggested) (help)
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"When someone is executed by lethal injection, do they swab off the arm first?" from The Straight Dope
"Double killer is nation's 1,000th execution". December 1, 2005. {{cite news}}: Check date values in: |date= (help); Unknown parameter |org= ignored (help)