Table 1.

Basic information.

Group	A(n = 21)	B(n = 24)	C(n = 21)	P value
Gender(Male\Female)	13/18	16/8	14/7	.931
Age $(\overline{x}\pm s)$	62.29 ± 9.05	58.88 ± 11.09	61.29 ± 7.38	.457
ASAII/III	16/5	18/6	15/6	.952
BMI(kg/m2)	22.57 ± 2.09	22.58 ± 2.65	22.53 ± 2.24	.998

Group A (ETT ID 7.0), Group B (ETT ID 7.5), and Group C (ETT ID 8.0).

ASA = American Society of Anaesthesiologists, BMI = body mass index