Effect of a Vibratory Anesthetic Device on Pain Anticipation and Subsequent Pain Perception Among Patients Undergoing Cutaneous Cancer Removal Surgery: A Randomized Clinical Trial

Importance: Vibration has been shown to decrease injection site pain in patients; however, to date, this effect has not been assessed for patients who catastrophize pain (ie, patients who anticipate a higher pain level). The anticipation of a pain score greater than 4 on the 11-point Numeric Rating Scale (NRS) has been associated with an increase in a patient's perception of procedural pain.

Objective: To assess the efficacy of vibration during cutaneous anesthetic injection for dermatologic surgery for patients who catastrophize pain (NRS score >4) and patients who do not (NRS score ≤4).

Design, Setting, And Participants: Randomized, parallel-group clinical trial from June 19 to September 4, 2018, at a tertiary dermatologic surgery clinic among 87 adults undergoing cutaneous cancer removal surgery. Patients completed a preprocedural questionnaire detailing their baseline pain, anticipated pain, and drug use. Analysis was performed on an intent-to-treat basis.

Interventions: Use of a vibratory anesthetic device (VAD) on the treatment site prior to anesthetic injection in the on (VAD ON) or off (VAD OFF) mode.

Main Outcomes And Measures: Pain was reported using the 11-point NRS (where 0 indicates no pain and 11 indicates the worst pain imaginable). A minimum clinically important difference of 22% or more and a substantial clinically important difference of 57% or more were used to assess the efficacy of vibration in patient-reported NRS score during anesthetic injection (iNRS score).

Results: A total of 87 patients were included, with 101 unique events reported (among the unique events, 37 were reported in women and 64 were reported in men; mean [SD] age, 66.0 [11.3] years). The mean (confidence level [CL]) iNRS score for patients who catastrophized pain was 2.27 (0.66) compared with 1.44 (0.39) for patients who did not (P = .03). A 38.9% decrease in mean (CL) iNRS score was reported with VAD ON compared with VAD OFF in all participants (1.24 [0.38] vs 2.04 [0.54]). Patients who catastrophized pain reported a 25.5% decrease in mean (CL) iNRS score with VAD ON vs VAD OFF (1.91 [0.99] vs 2.57 [0.98]), and patients who did not reported a 79.4% decrease (1.02 [0.40] vs 1.84 [0.66]). VAD ON was the only statistically significant variable to affect iNRS score (F statistic, 2.741; P = .03).

Conclusions And Relevance: This trial demonstrates that those who catastrophize pain prior to a procedure report a higher perceived level of pain. The application of vibration during local anesthetic injection resulted in a minimum clinically important difference in pain level for patients who catastrophize pain and a substantial clinically important difference in pain level for patients who do not.

Level Of Evidence: 2.

Trial Registration: ClinicalTrials.gov identifier: NCT03467685.