Warm anesthetic eases infiltration

Toronto - An analysis of multiple related studies suggests that warming local anesthetics to body temperature before injection can help ease the pain associated with infiltration of the drug, MedPage Today reports.

A University of Toronto research team analyzed 18 studies that included 831 patients. They found that the mean difference in pain scores with local injection of a warmed anesthetic was -11 mm on a 100-point scale.

In addition, a subgroup analysis of eight studies found that warming buffered local anesthetics also reduced the injection pain, with a mean difference of -7 mm.

Participants in all but one study were adolescents or adults. Eight studies included only healthy volunteers, while the remainder used patients. Most studies used lidocaine, while a few used other anesthetics such as bupivacaine, and the warming methods used in the various studies were incubators, warming trays and thermostatically controlled water baths.

Oral injection for dental procedures in children was the only scenario in which warming the local anesthetic produced no benefit. The authors write that future research should include extensive study of warming anesthetic for use with children, for dental procedures and with different injection techniques and speeds.