A Comparative Study of Intrathecal Clonidine and Intrathecal Buprenorphine as Adjuvant to 0.5% Bupivacaine for Spinal Anaesthesia in Infraumbilical Surgeries

The most widely used local anesthetic for spinal anesthesia are hyperbaric bupivacaine and tetracaine. The most important determinants of level of block are baricity of local anesthetic, position of patient during and immediately after injection and drug dosage. However the duration of anesthetic action of bupivaine is short so adjuvant is required to prolong the effect.Neuroaxially administered opioids and α2 agonists exihibit synergism. They prolong the regression of sensory block, prolong the time to first request of an analgesic and prolong the duration of complete motor block.Total 60 patients were divided by simple randomization technique using computer generated random number list into two groups of 30 each. Patients in group C received 3ml of 0.5% hyperbaric Bupivacaine + 45 µg of clonidine in 0.2 ml normal saline, total volume is 3.5 ml. Patients in group B received 3ml of 0.5% hyperbaric Bupivacaine + 90 µgm of buprenorphine in 0.2 ml normal saline, total volume is 3.5 ml.Intrathecal buprenorphine 90 µg gives adequate analgesia as the mean time required for first rescue analgesia in Group B was 5.87 ± 1.14 min, which is significantly longer than that of intrathecal clonidine 45 µg, i.e., 4.47 ± 0.86 minutes.. Quality of analgesia was acceptable to patients. Administration of buprenorphine and clonidine intrathecally does potentiate the duration of analgesia, sensory and motor block. The study suggests that combination of two or more drugs from different group (e.g., opioid and α2 agonist) can give better analgesia and less chance of side effects.