Impact of Anesthetic Cream and Vibration on Injection Pain in Lymphedema.

BACKGROUND

Although lymphaticovenous anastomosis (LVA) is commonly performed under general anesthesia, some centers perform it under awake, local anesthesia. Reducing injection pain is crucial in patients undergoing LVA for lymphedema under local anesthesia. This study examined the effects of a topical anesthetic cream (eutectic mixture of local anesthetics [EMLA]) and vibratory stimulation on injection pain, assessed using a visual analog scale (VAS) in patients with lymphedema. The association between pain and the severity of lymphedema (as classified by the International Society of Lymphology stage) was assessed.

METHODS

We enrolled 47 patients with lymphedema who underwent LVA at our institution. In total, 197 sites (394 injections) were analyzed. For each patient, up to 5 sites were designated by varying EMLA application time and the use of vibratory stimulation. Immediately following the local anesthetic injection, we measured the VAS score at each site and analyzed the data.

RESULTS

Patients with severe lymphedema had low VAS scores (P < 0.001), suggesting a reduced pain sensitivity. Prolonged EMLA application was associated with lower VAS scores (P < 0.05). Vibratory stimulation did not significantly impact the VAS scores (P = 0.59). Age, as well as history of chemotherapy and radiotherapy, did not significantly influence the VAS scores. No adverse events were reported.

CONCLUSIONS

Higher lymphedema severity was associated with lower VAS scores, suggesting reduced pain sensitivity in such patients. EMLA cream application time was associated with a reduction in injection pain in patients with lymphedema. In contrast, the vibratory stimulation device demonstrated no significant benefits, warranting further investigation.