Comparison of the Analgesic Efficacy of Lidocaine/Prilocaine (EMLA) Cream and Needle-Free Delivery of Lidocaine During Fine-Needle Aspiration Biopsy of Thyroid Nodules - Original Article

Abstract
Objective: Efficacy of eutectic mixture of local anesthetic (EMLA) cream and the needle-free injection of local anesthesia for reducing pain associated with fine-needle aspiration biopsy (FNAB) of thyroid nodules has been previously reported. However, there has not been a direct comparison of the analgesic efficacy of these methods. The aim of this study was to compare the analgesic efficacy of EMLA cream and needle-free injection of lidocaine for FNAB-associated pain.
Materials and Methods: A total of 138 patients having their first ultrasonography-guided thyroid nodule biopsy were randomly assigned to receive either EMLA cream (n=68) or needle-free injection of lidocaine (n=70) before FNAB of thyroid nodules. Four needle passes for biopsy of each nodule were 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).
Results: There were no significant differences between groups in age, sex, thyroid volume, nodule size, or nodule site. Significant differences between groups were noted in ratings of all three pain scales. When the effectiveness of EMLA was compared with that of needle-free injection of lidocaine, the mean VAS score was 23.4±20.5 mm versus 12.7±15.5 mm (p=0.001), and the mean NRS score was 2.8±2.1 points versus 1.6±1.7 points (p<0.001). There was also a significant difference between groups in VRS score (p=0.001).
Conclusions: Needle-free injection of lidocaine provides more effective and faster analgesia than EMLA cream application during the FNAB.