Comparative Evaluation of Dexamethasone and Dexmedetomidine as Adjuvants to 0.2% Ropivacaine in Adductor Canal Block for Lower Limb Surgeries

Background: The adductor canal block (ACB) is a commonly used method for postoperative analgesia following lower limb surgeries. Adjuvants added to local anesthetics enhance efficacy and prolong the duration of analgesia, thereby decreasing the postoperative analgesic requirements. The present study aimed to determine the efficacy of dexamethasone and dexmedetomidine as adjuvants to 0.2% ropivacaine in ACB. Material and Methods: This prospective observational study was done on n=60 cases undergoing lower limb surgeries under spinal anesthesia. The selected cases were randomly allotted to two equal groups, viz., Group D received 20 ml of 0.2% ropivacaine with dexamethasone (8 mg). Group DM 20 ml of 0.2% ropivacaine with dexmedetomidine (1 µg/kg). The outcomes analysed were duration of analgesia and Visual Analog Scale (VAS) scores. The other outcomes determined were total analgesic consumption, time for first rescue analgesia, and adverse effects. Results: The results showed that the overall duration of analgesia was significantly longer in Group DM as compared to Group D (16.9 ± 3.5 versus 12.4 ± 2.8 hours), and the p-values were significant. The assessment of VAS scores revealed that group DM had significantly lower VAS scores up to 12 hours postoperatively. The total paracetamol consumption was reduced in Group DM compared to Group D (1.2 g vs 2.4 g and p<0.001). The frequency of requirements for rescue analgesics was higher in Group D as compared to DM (93.3% vs 60.0% and p=0.012). Conclusion: This study found that the efficacy of dexmedetomidine was superior to dexamethasone with 0.2% ropivacaine in Adductor canal block following lower limb surgeries. Dexmedetomidine provides prolonged analgesia, pain control and decrease analgesic requirements compared to dexamethasone and both drugs showed comparable safety profile.

Keywords: Ropivacaine, Dexmedetomidine, Dexamethasone, Postoperative analgesia, Lower Limb Surgeries.