Comparison of effects of 50 μg clonidine and 5 μg dexmedetomidine on characteristics of levobupivacaine spinal block

Abstract

Background: Various adjuvants are being used with local anaesthetics for prolongation of intra- and post-operative analgesia. Methods: We randomly allocated and studied 60 patients, aged between 18 and 60 years into two groups. Group C received 3 mL (15 mg) of 0.5% isobaric levobupivacaine with 0.5 mL (50 μg) clonidine and Group D received 3 mL (15 mg) of 0.5% isobaric levobupivacaine with 0.5 mL (5 μg) dexmedetomidine. Onset and duration of sensory and motor blockade, haemodynamic parameters, and side effects were assessed. Results: Onset of sensory block (seconds) was faster in Group D than in Group C (141.7 ± 84.5 Vs 152.4 ± 77.8; P = 0.48). The mean time (minutes) for regression of sensory block to S1 dermatome was earlier in Group C compared to Group D (372.3 ± 69.3 Vs 395.3 ± 63.8; P = 0.10). The time of onset of motor block was earlier in Group D compared to Group C (3.5 ± 2.1 min Vs 3.3 ± 1.8 P = 0.81). The time required to achieve complete motor block (minutes) was more in Group C compared to Group D (9.7 ± 4.0 Vs 9.1 ± 3.1; P = 0.52). The mean time (minutes) taken for resolution of motor block was longer in Group D compared with Group C (309.5 ± 60.0 Vs 338.2 ± 61.6; P = 0.07). Conclusions: The supplementation of 50 μg clonidine and 5 μg dexmedetomidine to 0.5% isobaric levobupivacaine produced similar characteristics of the spinal block and maintained haemodynamic stability.

Keywords

• clonidine
• dexmedetomidine
• levobupivacaine
• spinal block