Analgesic Characteristics of Ultrasound-guided Great Auricular Nerve Block in Middle Ear Surgery: A Prospective Randomized Controlled Preliminary Trial.

Abstract

Purpose: To explore the analgesic characteristics of ultrasound-guided great auricular nerve (GAN) block to further improve pain management.

Design: Single-center, prospective, randomized, controlled, and double-blind preliminary clinical trial.

Methods: Thirty-seven patients who underwent middle ear surgery were included in this study: 15 in the GAN block group (the large ear nerve block [NB] group) and 22 in the traditional anesthesia group (control [CON] group). After induction of anesthesia, the NB group was given an ultrasound-guided GAN block (0.25 % Ropivacaine 2 mL), while the CON group was exempt from the GAN block. The patient's basic information, perioperative information, the region, and numeric rating scale of postoperative pain (at 1 hour, 6 hours, 12 hours, and 24 hours), and adverse reactions were recorded. Repeated measurement analysis, t test, and Fisher exact probability method were used for statistical analysis.

Findings: Compared with the CON group, the numeric rating scale in the NB group was lower after surgery (1 hour: 1.18 ± 0.35 vs 0.27 ± 0.20, P = .023; 6 hours: 1.82 ± 0.37 vs 1.13 ± 0.39, P = .203; 12 hours: 1.05 ± 0.19 vs 0.20 ± 0.10, P < .001; 24 hours: 0.55 ± 0.17 vs 0.13 ± 0.09, P = .029). In the NB group, the region of pain was merely concentrated in the ear canal. In the CON group, the pain extended to areas outside the ear canal, such as tragus and mastoid (at 12 hours, P = .006). There was no significant difference in the risk of postoperative adverse reactions between the two groups.

Conclusions: Ultrasound-guided GAN block can relieve patients' pain after middle ear surgery, especially in the area outside the ear canal.