An Observational Study To Compare Two Different Doses Of Clonidine As An Adjuvant To Intrathecal Bupivacaine In Patients Undergoing Lower Limb Orthopedic Surgeries

Abstract

Introduction: 

In this study, two different doses of intrathecal clonidine were compared for their effectiveness and side effects when used as an adjuvant to hyperbaric bupivacaine for postoperative analgesia during spinal anaesthesia in patients undergoing lower limb orthopedic surgeries.

Methods: 

In patients undergoing elective lower limb orthopedic surgery under spinal anaesthesia, a comparative observational analysis was done. A total of 40 eligible patients were included, with 20 patients divided into each of the two groups: Group BC30 (0.5% hyperbaric Bupivacaine 3.2 ml + Clonidine 30 mcg – Total 3.5 ml) and Group BC45 (0.5% hyperbaric Bupivacaine 3.2 ml + Clonidine 45 mcg – Total 3.5 ml). Sensory and Motor blockade characteristics according to Pin-prick method and Bromage scale respectively were recorded. Visual Analogue Scale (VAS) measurements of the duration of analgesia was done. Vitals were monitored both during and after surgery, and any necessary management of adverse events was done. Results: 

In participants of Group BC30 and Group BC45, the mean time for the onset of sensory and motor block was comparable and not significant (P value > 0.05). When compared to participants who received clonidine 30 mcg with bupivacaine, the mean time for sensory and motor block duration was significantly longer in the group that received clonidine 45 mcg with bupivacaine (P value < 0.05). When compared to the clonidine 30 mcg Group BC30, the mean duration of analgesia was longer in the clonidine 45 mcg Group BC45, which was highly significant (P value < 0.001). After administering spinal anaesthesia, bradycardia and hypotension was observed in a small number of cases in Group BC45. At 150 minutes, the Group BC45 mean heart rate was substantially lower than in Group BC30 (P value < 0.05). Systolic blood pressure in the Group BC45 at 30, 45, 135 and 165 minutes were significantly lower than in the Group BC30 (P value < 0.05). At 165 minutes, diastolic blood pressure in the Group BC45 was significantly lower than in the Group BC30 (P value < 0.05).

Conclusions: 

In conclusion, present study has shown that with relatively stable hemodynamics and little adverse effects which can be managed, intrathecal clonidine added to hyperbaric bupivacaine extends sensory block, motor block, and analgesia duration. Therefore, 45 mcg of clonidine is preferred over 30 mcg of clonidine when prolonging spinal anaesthesia and postoperative analgesia is desired