Stephen J.LurieMD, PhD, Senior EditorIndividualAuthorJody W.ZylkeMD, Contributing EditorIndividualAuthor
To the Editor: Although typical cooling agents
such as ice packs and ethyl chloride sprays are often used to achieve local
anesthesia, the effect of lowering the temperature of piercing agents has
not been studied.
I studied 77 patients who were receiving bilateral injections of botulinum
toxin (12.5 units per injection) symmetrically into the right and left facial
corrugator muscles using a 30-gauge needle. Each patient received 1 of the
injections with a room-temperature needle and the other with with a needle
that had been frozen overnight at −7°C. An assistant placed the
needles on the syringes, and both patients and physicians were blinded to
the condition. The needles were randomized as to the order in which they were
used. Patients immediately reported the severity of their pain using a pain
scale of 0 to 10. Results were analyzed using the paired t test.
Denkler K. Pain Associated With Injection Using Frozen vs Room-Temperature Needles. JAMA. 2001;286(13):1578. doi:10.1001/jama.286.13.1573