Local anesthetics are supposed to reduce pain, but the shots themselves can be painful -- sometimes quite painful. But the pain can be reduced substantially by the simple expedient of warming the painkiller before performing the injection, researchers reported Tuesday. The painkillers are normally kept cold to preserve them.
Dr. Anna Taddio of the University of Toronto and her colleagues reviewed 18 studies involving a total of 831 patients. They reported online in the Annals of Emergency Medicine that warming the injections before administering them consistently produced a "clinically meaningful reduction in pain" regardless of how the shot was administered or how large an injection was given.