1.

4组受试者一般资料比较

Demographic and clinical data of the patients in the 4 groups

Chracteristics	Group S	Group M	Group L	Control group	P
Age (years)	74.7±2.6	71.2±3.5	69.8±4.3	73.4±5.1	0.627
Gender (M/F)	17/13	16/14	18/12	17/13	0.819
Weight (kg)	60.3±4.2	61.5±3.7	63.2±5.3	62.4±4.5	0.782
Height (m)	1.67±0.08	1.63±0.11	1.65±0.07	1.69±0.12	0.526
ASA*grade (Ⅰ/Ⅱ/Ⅲ)	2/21/7	4/16/10	5/18/7	4/17/9
Operative time (h)	2.62±0.57	2.42±0.41	2.78±0.29	2.37±0.36	0.263