Endocrine Abstracts

Pain is one of the few drawbacks of fine-needle aspiration biopsy (FNAB) in patients with nodular thyroid disease (NTD). Lidocaine/prilocaine cream, an eutectic mixture of local anesthetics (EMLA), is a frequently used topical anesthetic. Despite its well-documented efficacy for the relief of pain associated with other cutaneous procedures that involve needle insertion, the analgesic role of EMLA has not been previously reported in patients with NTD who are undergoing FNAB. The aim of this study was to determine the analgesic efficacy of EMLA for FNAB-associated pain in patients with NTD. This double-blind, placebo-controlled clinical trial was conducted at a thyroid outpatient clinic. We studied 99 patients with NTD. Patients with NTD were allocated to receive either 2.5 g of EMLA (n=50) or placebo (n=49) 60 minutes before ultrasonographically guided FNAB. A series of 4 biopsies of each nodule was performed. Patients rated pain associated with the procedure according to a 100-mm visual analog scale (VAS), an 11-point numeric rating scale (NRS), and 4-category verbal rating scale (VRS). When the EMLA group was compared with the placebo group, there were no significant differences with respect to age, sex, thyroid volume, nodule size, or nodule site. Significant differences were noted in the pain ratings of those 2 groups according to all 3 pain scales. When the effectiveness of EMLA was compared with that of placebo, the mean VAS score was 25.0±22.3 mm versus 40.0±30.5 mm (P=.006) and the mean NRS score was 2.9±2.3 points versus 4.0±2.6 points (P=.02). The absolute numbers according to VRS score in each group was also significantly different (P=.01). No adverse events from the use of EMLA were reported. To our knowledge, this is the first study demonstrating that a topical anesthetic, EMLA, provides effective and noninvasive analgesia during the FNAB of NTD.