These are performed in doctors' offices and hospitals to administer fluids and medication. Typically a needle-tipped catheter is inserted into a vein, through which medication is given, in single doses or continuously infused.
Vein ruptures — reported to have happened in Oklahoma's execution Tuesday — can occur if an IV needle accidentally pokes all the way through a vein wall, or causes it to burst open, allowing IV fluid or drugs to flow out of the vein and not to the intended target — like a leak in a garden hose. That could happen under any number of circumstances, including if the patient's arm moved during needle insertion, or if a tightened tourniquet creates too much pressure in the vein, causing it to burst like a balloon when the needle pierces it.
In medical settings this is usually fairly inconsequential; nurses attempting to insert the IV typically would notice bruising or swelling and would then insert it in a different vein before administering medication. Experts say it occurs most often in older, sick patients with frail veins, or IV drug users whose veins have scarred, but it is uncommon in healthy younger people.
Sometimes attempts to insert an IV miss the vein entirely, allowing fluid or drugs to flow into surrounding tissue instead of into the bloodstream. That also can cause swelling and pain at the injection site, and can delay action of the medication. While IV saline is typically harmless, many medications can cause serious tissue damage if they spill out of the bloodstream and the breach isn't treated right away.
IV injections are considered extremely safe in skilled hands. It is uncertain how much training was given to the three technicians who each administered one of three drugs used in the Oklahoma execution. According to the state's execution protocol, the warden recruits a "licensed/certified health care specialist in IV insertion." The identity of that person is not disclosed.
The drugs given to Oklahoma inmate Clayton Lockett were midazolam, vecuronium bromide and potassium chloride — all potent drugs with potentially serious side effects. In executions, they are typically injected in that order, at high doses.
Midazolam is a short-acting sedative sold under the brand name Versed, sometimes used to calm patients before medical procedures or before surgery involving general anesthesia. Side effects can include serious breathing problems and cardiac arrest. Vecuronium bromide is a muscle relaxant used during some surgeries. It also can cause breathing difficulties. Potassium chloride is used to treat potassium deficiency but is used in executions to stop the heart.
DOCTORS AND EXECUTIONS
The American Medical Association has a longstanding policy against doctors participating in executions, including selecting injection sites or starting IV lines, given their oath to "do no harm." It also says in most cases it is unethical for doctors to be present at executions, including declaring an inmate dead. That's because a doctor might be put in the position of saying more drugs are needed if the first doses weren't lethal. The association says it is OK for doctors to certify a death if the inmate was declared dead by someone else, or to witness the execution if the inmate has made that request.
Oklahoma protocol calls for a physician to "monitor the condemned offender's level of consciousness." A doctor in the death chamber with Clayton Lockett appeared to do so.
AP Medical Writer Lindsey Tanner can be reached at http://www.twitter.com/LindseyTanner