Local Anesthesia: Clinical Observation

To the Editor.—  Most physicians have had personal experience with or are reminded daily by their patients about the pain of local anesthesia. Many of us utilize a very small-gauge needle to lessen the initial pain related to the procedure; however, the major discomfort follows when the anesthetic solution is infiltrated into the dermis.Several years ago while performing a rather prolonged procedure requiring considerable local anesthesia with lidocaine (Xylocaine), the patient, a radiologist, asked me to warm the lidocaine slightly by placing its container in a basin of warm water prior to injection. He had learned (where he could not recall) that such thermal manipulation substantially lessened the discomfort when the solution was infiltrated. By his estimation, the degree of pain was reduced by 75% when compared with lidocaine administered at room temperature. His subjective estimation has been supported by numerous patients.Such warming can be done rapidly