The Effect of Spinal and General Anesthesia on Thiol-Disulfide Balance During Ischemia/Reperfusion of the Leg in Patients Undergoing Knee Replacement Surgery

Abstract

Objective: Surgical trauma causes serious neuroendocrine and cytokine activity. In addition, the free oxygen radicals formed because of the ischemia/reperfusion injury resulting from applying and releasing the tourniquet (TQ) cause oxidative stress. Thiol and disulfide are among the new oxidative stress parameters used reliably in recent years. The aim of this study was to compare thiol-disulfide balance in general and spinal anesthesia, which are frequently used in total knee replacement (TKR) surgery. Methods: Fifty six patients aged 60-74 years scheduled to undergo TKR were randomly allocated to the general anesthesia (n=26) and spinal anesthesia (n=30) groups. The tourniquet (TQ) was applied for the TKR procedure after collecting a preanesthetic blood sample (T1). Blood samples were also collected at 5 minutes (T2) and 40 minutes (T3) after TQ release and at postoperative 24 hours (T4) to analyze native thiol, total thiol, disulfide, disulfide/native thiol ratio, disulfide/total thiol ratio, and native thiol/total thiol ratio. All patients had intravenous patient-controlled analgesia during the postoperative period. Mean arterial pressure, TQ times, and Visual Analogue Scale (VAS) scores were recorded. Decrease in thiol and increase in disulfide in the thiol-disulfide balance were recorded as oxidative stress indicators. Results: There was no difference between the groups in terms of VAS and analgesic consumption at the end of 24 hours. The general anesthesia group had higher native thiol, total thiol, and native thiol/total thiol ratio and lower disulfide, disulfide/native thiol ratio, and disulfide/total thiol ratio at all time points compared to the spinal anesthesia group. Conclusion: Assessment in terms of thiol-disulfide balance suggests that general anesthesia had a favorable effect on oxidative stress. Keywords: General anesthesia, oxidative stress, spinal anesthesia, thiol-disulfide, tourniquet time, visual analogue scale