Oxidative Stress in Controlled Hypotension: Assessment with A Novel Oxidative Stress Marker

Objectives: The aim of this study was to evaluate the effects of oxidative stress on thiol-disulfide homeostasis caused by hypotensive anesthesia in mastoidectomy-tympanoplasty cases undergoing controlled hypotension. Methods: Fifty adult patients scheduled for mastoidectomy and tympanoplasty were included in the study. Anesthesia was induced with lidocaine, propofol, rocuronium, and remifentanil. The maintenance of anesthesia was continued with remifentanil infusion (target mean arterial pressure as 60-65 mmHg) along with 2% sevoflurane/40% O2/air mixture. Blood samples were taken 5 times at the t0 (before induction), t1 (intraoperatively after intubation), t2 (first hour) and t3 (second hour of the operation) and t4 (following recovery). Total thiol (TT) and Native Thiol (NT) levels were measured, and thus, Di-Sulphide (SS), Di-Sulphide/Native Thiol (SSNT), Di-Sulphide/Total Thiol (SSTT), and Native Thiol/Total Thiol (NTTT) values were estimated. Results: During the operation, progressive decrease was observed in thiol levels of patients. There was a significant decrease in t3 thiol values when compared with t0 value. Thiol values were observed to have returned to baseline values after recovery from anesthesia (p>0.05). SS, SSNT and SSTT levels were found as increased in t1 blood samples, but increase in SSNT and SSTT levels was significant. Throughout the operation, values were observed to have dropped and reverted back to initial values. Conclusion: Since the measurement of thiol-disulfide blood values is able to show the instantaneous state of oxidative stress, it can be used in anesthesia practice in which every event occurs very quickly.