Effect of clonidine on the cutaneous silent period during spinal anesthesia

Table 2 Cutaneous silent period and latency of cutaneous silent period before, during and after spinal anesthesia (mean ± SD)

	Levobupivacaine group(n = 30)	Levobupivacaine + Clonidine group(n = 30)	P1	P2	P3
CSP latency (ms) preoperative	108.2 ± 11.6	107.2 ± 11.6	0.737
CSP latency (ms) Bromage 0	130.3 ± 10.2	144.7 ± 8.3	< 0.001a	< 0.001e	< 0.001e
CSP latency (ms) 6 h	110.4 ± 10.6	132.3 ± 9.7	< 0.001b	0.459	< 0.001f
CSP latency (ms) 24 h	108.0 ± 10.6	107.5 ± 11.5	0.862	0.933	0.926
CSP (ms) preoperative	62.1 ± 9.5	61.3 ± 6.2	0.691
CSP (ms) Bromage 0	44.8 ± 8.1	40.2 ± 3.8	0.007c	< 0.001g	0.007g
CSP (ms) 6 h	59.6 ± 9.8	44.5 ± 5.0	< 0.001d	0.325	< 0.001h
CSP (ms) 24 h	63.2 ± 9.9	62.9 ± 5.9	0.892	0.681	0.315

¹P values for differences between groups, independent t-test;

²P values for differences compared to preoperative values in Levobupivacaine group, dependent t-test;

³P values for differences compared to preoperative values in Levobupivacaine + Clonidine group, dependent t-test.

^aIndicates significant differences in CSP latency between groups at the time point Bromage 0;

^bIndicates significant differences in CSP latency between groups 6 h after intrathecal administration of the solution;

^cIndicates significant differences in CSP duration between groups at the time point Bromage 0;

^dIndicates significant differences in CSP duration between groups 6 h after intrathecal administration of the solution;

^eIndicates significant differences in CSP latency comparing the preoperative and postoperative values at time point Bromage 0;

^fIndicates significant differences in CSP latency comparing the preoperative and postoperative values 6 h after intrathecal administration of the solution;

^gIndicates significant differences in CSP duration comparing the preoperative and postoperative values at time point Bromage 0;

^hIndicates significant differences in CSP duration comparing the preoperative and postoperative values 6 h after intrathecal administration of the solution. CSP: Cutaneous silent period.