Abstract

Background: Adductor canal block (ACB) has recently been considered as a promising method for providing analgesia after knee surgeries with sensory blockade. ACB blocks the sensory innervation of the knee via the saphenous nerve ^[1]. ACB preserves quadriceps muscle strength better than Femoral Nerve Block, minimizing weakness during knee extension and thus functional recovery is improved within the first 24 hrs post‑operative period and the risk of developing Deep Vein Thrombosis is reduced ^[1]. Addition of Dexamethasone to local anaesthetics improves the quality and duration of peripheral nerve block ^[2]. We evaluated the effect of adding dexamethasone to levobupivacaine on the duration of postoperative analgesia in patients undergoing knee surgery using ultrasound-guided adductor canal block.
Methods: The study was a prospective double blinded randomized comparative study. Sixty patients scheduled for knee surgery were randomly allocated into two groups to receive adductor canal block. The control group L received 15 mL levobupivacaine 0.25% + 2 mL normal saline, and the dexamethasone group D received 15 mL levobupivacaine 0.25% + 2 mL dexamethasone (8 mg). Measurements included duration of sensory blockade, hemodynamic stability, visual analog score, time to first analgesic requirement and analgesic consumption.
Results: Postoperative analgesia was better in Group D patients. The mean VAS score increased with time and the magnitude of increase was more in the Group L than in group D. Duration of analgesia was significantly prolonged in Group D (14 ± 2.25 hours) when compared to Group L (10.57 ± 1.65 hours) with significant P value (<0.05). There was no significant difference between two groups in terms of age, sex, ASA grading and type of surgery. Both the groups maintained hemodynamic stability, which was statistically insignificant (P value >0.05).