Optimal Dose of Intrathecal Dexmedetomidine in Lower Abdominal Surgeries in Average Indian Adult.

BACKGROUND: Dexmedetomidine, a selective alpha2 adrenoceptor agonist, has been used as adjuvant to spinal anaesthesia.

AIM: To find out the optimum dose of dexmedetomidine to be used in lower abdomen surgery intrathecally.

MATERIALS AND METHODS: This was a randomized, controlled, double blinded study which included adult ASA I and II patients. They were allocated into five groups (n=20). Patients allergic to drugs to be used in the study and those with co-existing neurological disorders, coagulopathies, cardiac diseases, obesity and hypertension were excluded. Groups were designed as 2.5ml hyperbaric bupivacaine with 0.5ml saline (Control) or 0.5ml dexmedetomidine: 5mcg (D1), 10mcg (D2), 15 mcg (D3) and 20mcg (D4). Data were collected for 10 point VRS for pain, Bromage motor block, Ramsay sedation score, haemodynamics, time of first rescue analgesia (TRA) and any adverse effects and groups were analysed using one way analysis of variance (ANOVA) by SPSS16.0 (p-value <0.05 significant).

RESULTS: The mean duration of analgesia and need of first rescue analgesics are 201.5±29.1 mins in control group but in D1 group 259.1±15.2 mins, D2 310.7±48.1mins, D3 540.3±51.6 mins and D4 702.4±52 mins. p=0.003. The mean highest VRS score along with analgesic requirements were significantly reduced in dexemeditomidine groups, but D3 and D4 had hypotension which needed correction.

CONCLUSION: Weighing the prolongation of anesthesia and analgesia and side effects we conclude that 10 mcg of dexmedetomidine is optimum intrathecal dose.