Table 1.

Comparison of general data from the two groups (x̅±s, n)

Groups	n	Gender		Average age (years old)	ASA classification		Weight (kg)	Body mass index (kg/m2)	Surgical side
		Male	Female		Grade I	Grade II			Left side	Right side
Observation group	37	20	17	70.82±5.11	16	21	65.39±7.22	23.99±1.06	22	15
Control group	36	21	15	71.03±5.96	16	20	66.02±7.68	24.13±1.15	20	16
χ2/t		0.137		0.162	0.011		0.361	0.541	0.114
P		0.713		0.872	0.918		0.719	0.590	0.736