Determining postoperative benefits of intravenous lidocaine and esketamine following thyroidectomy

Dear Editor, By conducting a randomised, double-blind, controlled trial in patients who underwent thyroidectomy, Li et al.[1] showed that the addition of intravenous lidocaine and esketamine to general anaesthesia schemes improved the quality of postoperative recovery as assessed by the quality of recovery-40 (QoR-40) questionnaires and emotional state. In this study, the postoperative analgesic strategy was a single intravenous tramadol. This single opioid-based analgesic plan does not meet the requirements of the standard multimodal analgesic strategy recommended in the current enhanced recovery after surgery practices for thyroid surgery, which contain a combination of non-opioid basic analgesics with different mechanisms.[2,3] As the patients receiving intravenous lidocaine and esketamine had an improved postoperative pain control within 12 h postoperatively, we would like to know if intravenous tramadol dosage was comparable among the three groups. Furthermore, postoperative pain is not only an item of QoR-40, but it can also significantly influence the scoring of other items of QoR-40, such as physical comfort and emotional state.[4] It has been shown that there is a significant negative correlation between the quality of recovery score and postoperative pain intensity.[5] Thus, we are concerned that imbalanced postoperative pain control in the three groups could have biased the results QoR-40 score in favour of patients receiving intravenous lidocaine and esketamine. Finally, anxiety and depression scores of patients on postoperative days 1 and 2 were statistically lower in the patients receiving intravenous lidocaine and esketamine than in the control patients. Li et al.[1] reported that the between-group differences in mean postoperative anxiety and depression scores did not exceed 5 points. We are interested in knowing if the proportion of patients who achieved clinical diagnostic criteria of anxiety and depression symptoms was significantly different among the three groups. Most importantly, this study did not assess the other outcomes of the current enhanced recovery after surgery practices for thyroid surgery, such as the time to gastrointestinal recovery, the time to mobilisation, sleep quality, patient satisfaction and the length of hospital stay.[2,6] In these cases, we question whether the addition of intravenous lidocaine and esketamine to general anaesthesia schemes for thyroidectomy may benefit patients by improving postoperative recovery and clinical outcomes. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.