Dexmedetomidine as intrathecal adjuvant to 0.75% isobaric ropivacaine in lower limb orthopaedic surgery

Background and Aim– Adequate post-operative pain relief should be a critical part of management of anaesthesia. Ropivacaine produces a short duration of motor blockade which is useful for early mobilisation of patient and hospital discharge but postoperative analgesia is a crucial concern with Ropivacaine. So, our point of interest is of administering an adjuvant with Isobaric Ropivacaine which provides improved intraoperative hemodynamic parameters along with extended post-operative analgesic effects with the least side effect profile. Thus our aim was to evaluate and compare the efficacy of analgesia following intrathecal administration of isobaric ropivacaine with or without dexmedetomidine in lower limb orthopedic surgeries.
Methods - Study was carried out on 60 patients belonging to American Society of Anaesthesiologists grade I and II, aged between 15 to 60 years, including either gender and they were randomly assigned to one of the two groups: Group RN: 2.5 ml isobaric Ropivacaine 0.75% (18.75 mg) with 0.5 ml normal saline (NS). Group RD: 2.5 ml isobaric Ropivacaine 0.75% (18.75 mg) with 5μg of Dexmeditomidine in 0.5 ml NS. Time to reach peak sensory level, the sensory and motor regression times and duration of sensory and motor blockade were noted. Duration of analgesia, Hemodynamics and side effects were recorded.
Results – Time to onset of sensory block and motor block was early in group RD as compared to group RN. Duration of sensory and motor blockade was prolonged in group RD. The mean regression time to S1 segment was prolonged in group RD and the duration of analgesia was significantly increased in group RD compared to group RN.
Conclusion– The addition of Dexmedetomidine 5μg intrathecally to 0.75 % isobaric ropivacaine seems to be a superior adjuvant with an increased duration of motor and sensory blockade and an increased post-operative analgesia with a negligible side effect profile.