Long, but informative:
Procedure
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 ironically needless 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 hazard 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 muscle paralysis, collapse of the diaphragm, and would eventually cause 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 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. During the execution, the inmate's cardiac rhythm is monitored and death is pronounced after cardiac activity stops. 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.
[edit] Lethal injection drugs
The below three drugs are a representation of a typical lethal injection cocktail as practiced in the United States for capital punishment.
[edit] Sodium thiopental
Lethal Injection dosage: 5 grams
Sodium thiopental (US trade name: Pentothal) 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 5 gram dose - 14 times the normal dose - is likely to induce unconsciousness in 10 seconds.
Thiopental 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. This is the typical pharmacokinetics for the induction dose.
The half-life of this drug is about 11.5 hours[2], and the concentration in the brain remains at around 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 barbiturate, such as thiopental, can be used for long-term induction of medical comas.
After a 5 gram dose consciousness will be regained in about 5 to 6 half-lives, which occurs in about 57-69 hours. The effects of such a high dose, however, includes profound respiratory depression (depression of the brainstem respiratory center) and vascular collapse (vasodilatation and myocardial depression), which is in itself lethal.
Thiopental historically has been one of the most commonly used and studied drugs for the induction of comas. Protocols vary with how the medication is given, but the typical doses are anywhere from 500 mg up to 1.5 grams. It is likely that these data were used to develop the initial protocols for lethal injection of giving 1 gram of thiopental to induce the coma. Now, most states use 5 grams to be absolutely certain about its effectiveness.
Barbiturates are the same class of drugs used in medically assisted suicide. In euthanasia protocols, the typical dose of thiopental is 20 mg/kg[3] and a 91 kilogram man would receive 1.82 grams. The lethal injection dose used in capital punishment is therefore about 3 times more than the dose used in euthanasia.
[edit] Pancuronium bromide
Lethal Injection dosage: 100 milligrams
Pancuronium bromide (Trade name: Pavulon) is a non-depolarizing muscle relaxant (a paralytic agent) that blocks the action of acetylcholine at the motor end-plate of the neuromuscular junction. Binding of acetylcholine to receptors on the end-plate causes depolarization and contraction of the muscle fibre; non-depolarizing neuromuscular blocking agents like pancuronium stop this binding from taking place.
The typical dose for pancuronium bromide 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 bromide is a derivative of the alkaloid malouetine from the plant Malouetia bequaertiana. [4]
[edit] Potassium chloride
Lethal Injection dosage: 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 there is insufficient potassium, called hypokalemia, in the 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. Elevated potassium, or hyperkalemia, causes the resting electrical activity of the heart muscle to be higher than normal.
Depolarizing the muscle cell inhibits its ability to fire by reducing the available number of Na channels (they are placed in an inactivated state). 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.
[edit] Euthanasia protocol
Euthanasia can be accomplished either through an oral, intravenous, or intramuscular administration of drugs. In individuals who are incapable of swallowing lethal doses of medication, an intravenous route is preferred. The following is a Dutch protocol for parenteral (intravenous) administration to obtain euthanasia with the old protocol listed first and the new protocol listed second:
First a coma is induced by intravenous administration of 1 g thiopental sodium (Nesdonal), if necessary, 1.5-2 g of the product in case of strong tolerance to barbiturates. Then 45 mg alcuronium dichloride (Alloferin) or 18 mg pancuronium dibromide (Pavulon) is injected. In order to ensure optimal availability, these agents are preferably given intravenously. However, there are substantial indications that they can also be injected intramuscularly. In severe hepatitis or cirrhosis of the liver, alcuronium is the agent of first choice.[5]
Intravenous administration is the most reliable and rapid way to accomplish euthanasia and therefore can be safely recommended. A coma is first induced by intravenous administration of 20 mg/kg thiopental sodium (Nesdonal) in a small volume (10 ml physiological saline). Then a triple intravenous dose of a non-depolarizing neuromuscular muscle relaxant is given, such as 20 mg pancuronium dibromide (Pavulon) or 20 mg vecuronium bromide (Norcuron). The muscle relaxant should preferably be given intravenously, in order to ensure optimal availability. Only for pancuronium dibromide (Pavulon) are there substantial indications that the agent may also be given intramuscularly in a dosage of 40 mg.[6]
[edit] Constitutionality in the United States
The Supreme Court has never ruled that any specific form of execution has violated the Eighth Amendment clause prohibiting cruel and unusual punishment. In Hill v. Crosby, decided June 12, 2006, the Supreme Court ruled that death-row inmates in the United States may challenge protocols used in the lethal injection process as potentially violating the Eighth Amendment's "cruel and unusual" punishment clause outside of a petition for a writ of habeas corpus. Clarence Hill had already exhausted all of his legal appeals through habeas corpus and filed a lawsuit claiming that lethal injection was a civil rights issue. The Supreme Court, in this ruling, did not decide whether lethal injection as currently practiced in the United States constitutes cruel and unusual punishment. [7] [8] [9]
[edit] Ethics of lethal injection
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."[10] Amnesty International argues that the AMA's position effectively "prohibits doctors from participating in executions." [11] The AMA, though, does not have the authority to prohibit doctors from participation in lethal injection, nor does it have the authority to revoke medical licenses, since this is the responsibility of the individual states.
Typically, most states do not require that physicians administer the drugs for lethal injection, but many states do require that physicians be present to pronounce or certify death.
2006-12-07 06:55:05
·
answer #1
·
answered by IU Med 2
·
0⤊
1⤋