Effect of perithyroidal lignocaine infusion (PLI) to pain experienced during high-intensity focused ultrasound (HIFU) ablation of benign thyroid nodules

Objective To assess whether perithyroidal lignocaine infusion (PLI) could provide additional analgesia in high-intensity focused ultrasound (HIFU) treatment of benign thyroid nodules for patients already receiving their usual intravenous doses of Pethidine and Diazemuls. Methods Two hundred and five patients who underwent HIFU ablation for a benign thyroid nodule were analyzed. Among them, 104 (50.7%) patients received PLI in addition to their boluses of Pethidine and Diazemuls before treatment (group I), while the rest ( n = 101, 49.3%) received intravenous Pethidine and Diazemuls only (group II). After treatment, patients were asked to rate their overall pain experience on a visual analogue scale (VAS) (0–100) (0, no pain; 100, worse possible pain) during treatment. Binary logistic regression was performed to evaluate significant determinants for treatment pain including demographics, doses of medications, and treatment parameters. Results VAS was significantly lower in group I (51.30 vs. 63.79, p = 0.002). In the multivariate analysis, older age at treatment (OR = 1.036, 95%CI = 1.008–1.065, p = 0.011), lower BMI (OR = 1.202, 95%CI = 1.083–1.334, p = 0.001), higher Diazemuls dose (OR = 1.066, 95%CI = 1.018–1.114, p = 0.006), and use of PLI (OR = 2.096, 95%CI = 1.121–3.922, p = 0.020) were independent determinants of less treatment pain. Conclusions PLI can provide additional analgesia in patients already receiving their usual intravenous doses of Pethidine and Diazemuls during HIFU ablation of benign thyroid nodules. Older age, lower body mass index, and greater Diazemuls (i.e., a sedative) dose are significantly associated with less treatment pain. Key Points • PLI provided an additional analgesic effect in HIFU ablation of thyroid nodules. • Older age and lower BMI were significantly associated with less pain. • Higher doses of Diazemuls lessened pain during HIFU ablation.