Vibrating device relieves pain at anesthesia injection sites

This randomized trial assessed the efficacy of vibration in reducing injection site pain for patients undergoing cutaneous cancer removal.

Study design

This is a randomized, parallel-group 3-month clinical trial of 87 adults undergoing surgery to remove cutaneous cancer. Prior to anesthetic injection, a vibratory anesthetic device turned on (VAD ON) or off (VAD OFF) was applied to the treatment site. Pain was reported using an 11-point Numeric Rating Scale (NRS; 0 indicates no pain and 11 indicates the worst pain imaginable). The anticipation of a pain score greater than 4 was categorized as the group that catastrophizes pain.

Outcomes

Patients who catastrophized pain reported significantly higher NRS scores during local anesthetic injection than patients who did not. The addition of vibration resulted in a 25.5% reduction of NRS pain scores during local anesthetic injection in patients who catastrophized pain, and a 79.4% reduction in patients who did not catastrophize pain.

Limitations

This was an elective study, so it is possible that the patients who catastrophized pain decided to not participate, representing selection bias. Due to the nature of the vibration device, it was impossible to blind both patient and clinician from the assigned intervention.

Clinical significance

Physicians should consider evaluating NRS scores prior to surgery to identify patients who catastrophize pain (NRS>4) from those who do not (NRS<4). The application of vibration during local anesthetic injection appears to benefit patients in both groups, but seems to work better for patients who do not catastrophize pain than those who do.