Block performance Characteristics
The mean onset time of sensory block and motor block were 3.8±0.93 and 11.4±2.65min, respectively. The onset time of sensory block and motor block was not significantly different between patients having successful and failed blocks (P = 0.1303, P =0.2633, respectively). The average duration of motor block was 8.6±1.57 h. No difference occurred in duration of motor block between successful and unsuccessful blocks(P =0.7494).