Differential Analgesia From Vibratory Stimulation During Local Injection Of Anesthetic: A Randomized Clinical Trial

BACKGROUND Inadequate pain reduction during anesthetic injection is a significant medical and surgical problem. Vibratory distraction reduces this pain; however, there are minimal data identifying those who respond best. OBJECTIVE To quantify analgesia from vibration before anesthetic injection. MATERIALS AND METHODS In this partially blinded, single-institution trial, adult participants were randomized to intervention (vibratory anesthetic device, VAD ON) or placebo (VAD OFF). Pain was assessed using the 11-point numeric rating scale (NRS). Relative reduction in NRS between VAD OFF and ON was used to identify minimum clinically important and substantially clinically important difference in pain. RESULTS One hundred one tested sites from 87 subjects were assessed. Sixty-three percent were men with a median age of 66 years. From univariate analysis, males, subjects aged <60, and head and neck (HN) treated subjects had a significant reduction in NRS (p< .05). Multivariate analysis identified NRS reductions in females <60 (p= .012), males >= 70 (p= .002), females and males treated on HN (p= .048 andp= .035, respectively), and males >= 70 treated on HN (p= .012). Substantially clinically important difference (>= 57% NRS reduction) included subjects <60, females <70, HN treatment aged 60 to 69, males >= 70, and females treated on HN. CONCLUSION Vibratory anesthetic device reduces pain during anesthetic injection, primarily for HN treatments and older male subjects.