Effects of a fixed low-dose ropivacaine with different volume and concentrations on interscalene brachial plexus block: a randomized controlled trial

Table 1 Patient demographic data

	Group 0.75 (n = 33)	Group 0.5 (n = 29)	Group 0.25 (n = 33)	P
Age, yr	45 ± 13	44 ± 16	49 ± 16	0.416
Height, cm	165 ± 9	169 ± 11	168 ± 7	0.211
Weight, kg	67 ± 13	77 ± 13	71 ± 11	0.219
BMI, kg/m²	24.3 ± 3.5	24.8 ± 2.6	25.3 ± 3.3	0.478
Sex (male/female), n	15/18	17/12	24/9	0.079
Surgical type (Bankart repair/Rotator cuff repair), n	8/25	7/22	7/26	0.655
Surgical time, min	101 ± 40	87 ± 32	103 ± 40	0.197
Remifentanil consumption, μg/kg/min	0.07 ± 0.03	0.08 ± 0.03	0.07 ± 0.03	0.619

Continuous variables are presented as the means ± SDs; categorical variables are presented as counts