Regional anaesthesia is the safe, effective means of providing surgical anaesthesia and postoperative analgesia. Drugs commonly used as neuraxial adjuvants are Opioids (morphine, fentanyl), Adrenergic agonists (epinephrine, clonidine, dexmedetomidine), and miscellaneous drugs like ketorolac, ketamine, neostigmine, butorphanol, magnesium sulphate for adding qualities like sedation, stable haemodynamics and capability to provide smooth and longer post–operative analgesia. Alpha2‑adrenergic agonists such as dexmedetomidine used as an adjuvant to regional anesthesia enhance the effect of local anesthetics agents and prolong the duration of motor as well as sensory blockade and postoperative analgesia.

Objective:

This study was aimed to compare the effectiveness of dexmedetomidine given by epidural versus intravenous route as an adjuvant to epidural anaesthesia with bupivacaine for lower limb and lower abdominal surgery, regarding Onset and duration of sensory blockade, Onset and duration of motor blockade, Haemodynamic changes, Analgesia, Sedation, Side effect if any.

Material and method:

Study was conducted in 54 patients of either sex belonging to ASA Grade I & II between age group of 18 to 60 years. After taking all aseptic precautions and skin infiltration with 2% lignocaine the lumber epidural block was given using 18 gauge Touhy needle in sitting position between L2–L3 or L3–L4 interspace. Epidural space was identified by loss of resistance technique. Epidural space was confirmed to exclude accidental intravascular or subarachnoid injections. Patients were  divided in two groups and received drugs according to their groups. Group I: – 20ml of 0.5% bupivacaine plain + 0.5µg/kg Dexmedetomidine epidurally. Group II:–Inj. Dexmedetomidine 0.5µg/kg intravenously over a period of 10 min prior to epidural block then 20 ml of  0.5% bupivacaine plain epidurally.

Result:

The demographic profile of patients was comparable in both the groups. Onset of sensory analgesia at T10 (9.30±1.17 vs 15.48±1.48min) and establishment of complete motor blockade (21.52±1.90 vs 28.07±2.06 min) was significantly earlier in the group I. Time to two segment dermatomal regression (142.22±9.47 vs 125.19±7.00 min) and Time to regression of motor blockade to bromage scale 1 (256.85±14.35 vs 152.59±7.12 min ) were prolonged significantly in Group Ι as compared to Group ΙΙ. Postoperative analgesia was prolonged significantly in the Group I (410.74±34.07 vs 268.15±20.20min).  92.6% patients in Group II was attained sedation score of 3 intraoperative as compared to 44.4% patients in Group I. Two patients (7.40%) in Group Ι had dry mouth. Nausea was observed in three patient (11.11%) in both Groups.

Conclusion:

We conclude that Epidural Dexmedetomidine with bupivacaine provided better sensory and motor block, adequate surgical anaesthesia and stable cardiorespiratory parameters with prolonged postoperative analgesia as compared to Intravenous Dexmedetomidine