Results
PONV, cough
Totally 70 cases were enrolled from October 2020 to June 2021 and all participated in the PSQI questionnaire before surgery, two patients in the lidocaine group were lost in the entire 30 days follow-up period after surgery, eventually sixty-eight cases were analyzed (Fig. 
Consolidated Standards of Reporting Trials (CONSORT) flowchart describing patients progress through the study
Patients’ characteristics for both groups
Types of thyroidectomy and postoperation pathological report of patients in two groupsTypes of thyroidectomy(n, %)lymph node metastasis(n, %)Data are presented as number (percentage)ASA American Society of Anesthesiologists physical status, BMI Body mass index, TT3 Total triiodothyronine, TT4 Total thyroxine, FT3 Free triiodothyronine, FT4 Free thyroxine, TSH Thyroid-stimulating hormone, SD standard deviation. Reference ranges, TT3(0.60–1.81ng/mL), TT4(4.50–10.90 µg/dl), FT3 (2.30–4.20 pg/mL), FT4 (0.89–1.76 ng/dL), TSH (0.550–4.780 µ IU/mL), were used. Data are presented as median (interquartile range), number (percentage) or mean ± SDPSQI scores didn’t change significantly over time (F = 2.799, 
PSQI scores at three time points in the two groups, values are expressed as mean ± SD.
The VAS scores in both groups in the 7th and 30th day after surgeryVAS visual analogue scale, SD standard deviationValues are expressed as mean ± SDThe incidence of PONV within 24 h after surgery was 18.18% in the lidocaine group and 40% in the normal saline group(
(There was no significant difference in the incidence of cough within 5 min after extubation between groups (Table 
The incidence of cough within 5 min after extubation between groupsData are presented as counts (n)
The cough scores between groupsData are presented as counts (n)