Background: Total knee arthroplasty (TKA) is a highly complex and effective surgery even though its perioperative bleeding may increase the need for blood transfusion and its associated infection risk, cardiovascular overload, increased costs, and mortality. As tourniquet reduces intraoperative bleeding it may be associated with postoperative bleeding, venous thrombosis, and distal ischemia. The reperfusion may trigger a local and systemic inflammatory response. Anesthetic preconditioning (APC) with sevoflurane minimizes ischemia-reperfusion syndrome (I/R). This study evaluated the effects of APC with sevoflurane on perioperative bleeding in TKA.Methods: We allocated 30 patients into two groups: a sevo group (sevoflurane 2% for 15 minutes before the tourniquet) and a control group (propofol infusion). Laboratory tests were collected right before the tourniquet (LAB PRE, in the operating room) and after its release at four moments: LAB POST (immediately after), LAB 2 (two hours after), LAB 12 (12 hours after), and LAB 24 (24 hours after). The volume of the suction drain was measured at one, two, 12, and 24 hours after the end of the surgery. Antifibrinolytics were not administered.Results: There was no statistically significant difference in bleeding-related variables, such as drained volume and hemoglobin and hematocrit measurements. Drainage volume was higher in the first two hours after the procedure, while hematocrit decreased pre- to post-operatively and between two- and 12-hours post-procedure.Conclusion: Sevoflurane as an anesthetic preconditioning did not reduce postoperative bleeding in TKA surgery.Trial Registration: ClinicalTrials.gov – NCT03379103; December 20, 2017.

Background: Total knee arthroplasty (TKA) is a highly complex and effective surgery even though its perioperative bleeding may increase the need for blood transfusion and its associated infection risk, cardiovascular overload, increased costs, and mortality. As the tourniquet reduces intraoperative bleeding, it may be associated with postoperative bleeding, venous thrombosis, and distal ischemia. The reperfusion may trigger a local and systemic inflammatory response. Anesthetic preconditioning (APC) with sevoflurane minimizes ischemia-reperfusion syndrome (IRS). This study evaluated the effects of APC with sevoflurane on perioperative bleeding in TKA. Methods: We allocated 30 patients into two groups: a sevo group (sevoflurane 2% for 15 minutes before the tourniquet) and a control group (propofol infusion). Laboratory tests were collected right before the tourniquet (LAB PRE, in the operating room) and after its release at four moments: LAB POST (immediately after), LAB 2 (two hours after), LAB 12 (12 hours after), and LAB 24 (24 hours after). The volume of the suction drain was measured at one, two, 12, and 24 hours after the end of the surgery. Antifibrinolytics were not administered. Results: There was no statistically significant difference in bleeding-related variables, such as drained volume and hemoglobin and hematocrit measurements. Drainage volume was higher in the first two hours after the procedure, while hematocrit decreased pre-to postoperatively and between two and 12 hours postprocedure. Conclusion: Sevoflurane as an anesthetic preconditioning did not