Effects of Systemic Lidocaine Versus Dexmedetomidine on the Recovery Quality and Analgesia After Thyroid Cancer Surgery: A Randomized Controlled Trial

INTRODUCTION: Surgical management is commonly used for thyroid cancer. We evaluated the effects of systemic lidocaine versus dexmedetomidine on the recovery quality and analgesia after thyroid cancer surgery. METHODS: A total of 120 patients with thyroid cancer were randomly allocated to group L (received lidocaine 1.5 mg/kg loading, continuously infused 1.5 mg/kg per hour), group D (received dexmedetomidine 0.5 µg/kg loading, continuously infused 0.5 µg/kg per hour) and group C (received normal saline), with 40 cases in each group. Anaesthesia induction and maintenance were performed using target-controlled infusions (TCIs) of propofol and remifentanil. The primary outcome of the quality of recovery-15 (QoR-15) score was recorded on the day before surgery and postoperative day 1 (POD1). Secondary outcomes included the consumption of remifentanil during surgery, time to first required rescue analgesia, number of patients requiring rescue analgesia, postoperative cumulative consumption of tramadol, visual analogue scale (VAS) pain score, incidence of postoperative nausea or vomiting (PONV) and side effects. RESULTS: The total score of the QoR-15 at POD1 (median, IQR) was higher in group L (128.0, 122.0-132.8) and group D (127.5, 122.5-132.5) compared to group C (118.5, 113.0-123.5) (P = 0.000). Compared to group C, systemic lidocaine and dexmedetomidine reduced cumulative consumption of remifentanil and VAS pain score (P = 0.000). The time to first required rescue analgesia (mean, SD) was longer in group L (8.1 h, 1.2 h) and group D (8.5 h, 1.9 h) than group C (5.9 h, 0.9 h) (P = 0.000). The number of patients requiring rescue analgesia was lower in group L (8/40, 20%) and group D (6/40, 15%) than group C (16/40, 40%) (P = 0.029), and cumulative consumption of tramadol (mean, SD) was lower in group L (44.0 mg, 17.1 mg) and group D (51.7 mg, 14.1 mg) than group C (73.9 mg, 18.4 mg) (P = 0.000). The incidence of PONV in group L (7/40, 17.5%) and group D (9/40, 22.5%) was lower than group C (18/40, 45.0%) (P = 0.016). Bradycardia (heart rate less than 50 beats/min or lower) was noted in 25 patients (25/40, 62.5%), which was reversed by intravenous administration of atropine 0.5 mg. CONCLUSION: Systemic lidocaine and dexmedetomidine had similar effects on enhancing the quality of recovery, alleviating the intensity of pain and reducing the incidence of PONV after thyroid cancer surgery. However, dexmedetomidine may result in bradycardia. Therefore, lidocaine was superior to dexmedetomidine. TRIAL REGISTRATION: ChiCTR.org.cn (ChiCTR2000038442). Registered on September 22, 2020.