Question Do patients who catastrophize pain, defined as patients who anticipate higher pain levels on the 11-point Numeric Rating Scale (score >4), receive equal benefit from a vibratory stimulus during local anesthetic injection as patient who do not catastrophize pain (Numeric Rating Scale score ≤4)?
Findings In this randomized clinical trial of 87 patients who experienced 101 unique events, patients who catastrophized pain reported significantly higher Numeric Rating Scale scores during local anesthetic injection than patients who did not. The addition of vibration resulted in a 25.5% reduction of Numeric Rating Scale scores during local anesthetic injection in patients who catastrophized pain and a 79.4% reduction in patients who did not catastrophize pain.
Meaning Patients who catastrophize pain can be identified in the clinical setting with assessment of anticipation of pain levels (Numeric Rating Scale score >4), and these patients benefit from the addition of vibration during local anesthetic injection.
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