Assessing the Antioxidant Activity of Dexmedetomidine by Measuring the Plasma Antioxidant Enzyme Activity of Catalase, Glutathione Peroxidase, and Superoxide Dismutase During Lumbar Spine Laminectomy

Abstract

Background: Current knowledge on antioxidant properties of anesthetics is inconclusive. Nevertheless, experiments on different anesthesia-related drugs and techniques are growing. Objectives: The aim of this prospective blinded randomized study was to assess the effect of dexmedetomidine (Dex) infusion during anesthesia on oxidative stress resulting from lumbar laminectomy. Methods: The antioxidant activity of Dex compared to placebo (normal saline) was evaluated by measuring the antioxidant enzyme activity of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX). A total of 56 patients who underwent laminectomy surgery were allocated into two groups of intervention and control. Dex group received 0.6 µg.kg-1 dexmedetomidine infusion before induction of anesthesia over 15 minutes, followed by 0.4 µg.kg-1.hr-1 maintenance. Control group received the same volume and sequence of normal saline. Anesthesia protocol was similar in both groups. The antioxidant activity of the previously mentioned enzymes was measured at the beginning of the anesthesia (T1) and after surgery (T2). Propofol consumption, hemodynamic indices, shivering, bleeding volume, and pain numeric rating scale (NRS) were recorded. Results: Although the serum levels of CAT and GPX increased during the procedure, these changes were not significant (P-values 0.579 and 0.762, respectively). Also, the mean SOD level did not change over time in any of the groups, and it was not meaningfully different between the groups at any of the predetermined times (P-value 0.665). Conclusions: As expected, Dex decreased propofol consumption, mean heart rate, mean arterial pressure, and pain intensity allover the perioperative period. It seems that adding Dex to anesthesia regimen during laminectomy had no dominant antioxidant effects.