Sixty patients scheduled for orthopedic surgery under spinal anesthesia were allocated into four groups: group 1 (no history of opium use who received intrathecal hyperbaric bupivacaine along with 1 mL saline as placebo); group 2 (no history of opium use who received intrathecal bupivacaine along with 1 mL sufentanil [5 μg]); group 3 (positive history of opium use who received intrathecal bupivacaine along with 1 mL saline as placebo) and group 4 (positive history of opium use who received intrathecal bupivacaine along with 1 mL sufentanil [5 μg]). The onset time and duration of sensory and motor blockade were measured.
The duration of sensory blockade in group 3 was 120 ± 23.1 min which was significantly less than other groups (G1 = 148 ± 28.7, G2 = 144 ± 26.4, G4 = 139 ± 24.7, p = 0.007). The duration of motor blockade in group 3 was 145 ± 30.0 min which was significantly less than other groups (G1 = 164 ± 36.0, G2 = 174 ± 26.8, G4 = 174 ± 24.9, p = 0.03).
Addition of 5 μg intrathecal sufentanil to hyperbaric bupivacaine in chronic opioid users lengthened the sensory and motor duration of blockade to be equivalent to blockade measured in non-addicts.