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Redheads Harder To Knock Out For Surgery

Study: Red-Haired Women Require More Anesthesia

The genetic quirk that makes red hair red may also make carrot-tops harder to knock out in the operating room.

A new study conducted by anesthesiologists at Outcomes Research Institute at the University of Louisville suggests people with naturally red hair need about 20 percent more anesthesia than patients with other hair colors.

The findings will be presented this week at the annual meeting of the American Society of Anesthesiologists in Orlando, Fla.

It's a small study that will need confirmation. But lead researcher Dr. Edwin Liem said it's the first time scientists linked a visible genetic trait to anesthesia doses.

"The art and science of anesthesiology is choosing the right dose," Liem said. "There is very little difference between the effective dose and the toxic dose of most anesthetics. Patients can awaken during surgery if they are given insufficient anesthesia or suffer cardiac and pulmonary complications when they are given too much."

Researchers tested 10 redheads and 10 darker-haired women. Each got an anesthetic and gradually increasing electric shocks. The redheads required a 20 percent higher dose of anesthetic.

The exact reason for the distinction is uncertain. But Liem theorizes that the same cell characteristics that determine redheads' coloring also release an extra amount of a hormone that stimulates the brain to feel pain.

"In a nutshell, redheads are likely to experience more pain from a given stimulus and therefore require more anesthesia to alleviate that pain," Liem said.

-- Anonymous, October 15, 2002