Background: A number of adjuvants to local anesthetics have been used intrathecally to prolong analgesia. So, the present study was planned to study the effect of intrathecal bupivacaine with neostigmine versus clonidine as an  adjuvants in lower abdominal surgeries.

Material & Methods: 128 patients of ASA physical status grade I and II, aged 30- 50 years, scheduled for lower abdominal surgeries under spinal anesthesia of a tertiary care teaching hospital were randomly selected in two groups of 64 each; Group BN:12.5 mg (2.5 ml) of 0.5% bupivacaine + 25 µg neostigmine with total volume made up to 3.0 ml with normal saline and Group BC:12.5 mg (2.5 ml) of 0.5% bupivacaine + 50 µg clonidine with total volume made up to 3.0 ml with normal saline. Sensory block characteristics, motor block characteristics, time to first rescue analgesic were recorded. Any adverse effects were also noted.

Results: Time to reach T10 sensory level was 2.53±0.58 min in Group BC and 2.33±0.60 min in Group BN which was statistically comparable (p= 0.06). But time to reach peak sensory level was 8.14±0.77 min in Group BC as compared to 6.38±0.79 min in Group BN (p<0.01). The mean duration of sensory block was 321.72±8.32 min in Group BC and 301.72±27.6 min in Group BN (p<0.01). All patients of both groups achieved Bromage score of 3 signifying complete motor block. Duration of motor block was significantly longer in group BC  (223.36±14.39 min) as compared to group BN (204.53±10.64 min) (p<0.01).

Conclusion: Clonidine as adjuvant to bupivacaine results in significant prolongation of duration of sensory blockade and analgesia as compared
to intrathecal neostigmine.