Efficacy of intrathecal α2 agonists as adjuvants with low dose of levobupivacaine for lower limb surgeries in elderly patients

Introduction: Elderly orthopedic patients are frequently associated with systemic co morbidities like cardiac, pulmonary or endocrinal disorders. Regional anaesthesia has benefits over general anaesthesia in elderly. But the hypotension caused by regional anaesthesia is a limiting factor which can be overcome by using low dose of local anaesthetics. Low-dose local anaesthetics can limit the block level, but may not provide an adequate ansesthesia level and duration for surgery, requiring more analgesic consumption postoperatively. These shortcomes are overcome by adding intrathecal adjuvants with local anaesthetics. Among them α2 agonists are gaining popularity. Our aim was to compare the characteristics of spinal block, haemodynamic changes following administration of low dose of α2 agonist's intrathecally combined with low-dose levobupivacaine in elderly patients undergoing orthopaedic surgeries. Material and Methods: In this prospective randomized double blind study, 90 patients of more than 65 years of age posted for lower limb surgeries were allotted into three groups. Group-LS received 1.5cc of 0.5% isobaric levobupivacaine with 0.5cc of normal saline, Group –LC received 1.5 cc of 0.5% isobaric levobupivacaine with 30g of clonidine and Group-LD received 1.5 cc of 0.5% isobaric levobupivacaine with 5g of dexmedetomidine. Onset of sensory and motor block, duration of sensory and motor block, haemodynamic parameters, sedation and side effects if any were evaluated. Results: The onset of sensory and motor block were faster in dexmedetomidine group than clonidine or plain levobupivacaine group. Duration of the sensory and motor block were also prolonged in dexmedetomidine group when compared with clonidine or plain levobupivacaine group. Haemodynamic stability was maintained in all the three groups. Conclusion: The addition of dexmedetomidine 5µg to7.5mg 0.5% isobaric levobupivacaine hastens the onset of sensory and motor block and also prolongs the duration of analgesia with good haemodynamic stability in elderly patients.