Table 1.

Patients demographics and operative characteristics

	Group C	Group R	P
Age (years)	46.54 ± 12.93	49.54 ± 11.99	0.390
Gender:Male/Female	7/19	6/20	0.749
ASA classification (I/II)	7/19	9/17	0.548
Height (cm)	164.31 ± 6.20	165.08 ± 6.37	0.661
Weight (kg)	62.65 ± 10.74	66.38 ± 0.96	0.221
Operation time(min)	88.35 ± 36.46	104.54 ± 46.43	0.168
Anesthesia time (min)	107.42 ± 39.90	122.92 ± 48.52	0.214

Categorical variables were presented as numbers and percentage, quantitative variables were shown as means and standard deviation. ASA American Society of Anesthesiologists. Group R: the patients were recieved 6 ml of 0.75% ropivacaine for throat, glottic area and tracheal mucosa uniform spray; Group C: the patients were recieved with 6 ml of saline for throat, glottic area and tracheal mucosa uniform spray as control