Remote Ischemic Preconditioning in Lower Limb Surgery; the Hemodynamic and Respiratory Effects

Background: Remote Ischemic Preconditioning introduces brief episodes ofischemia and reperfusion, which reduces long term ischemia in orthopedicsurgery. The aim of this study was to evaluate hemodynamic and respiratoryeffects of remote ischemic preconditioning in lower extremity orthopedicsurgeries.Materials and Methods: In this clinical trial, 40 patients scheduled for lowerextremity surgery with pneumatic tourniquet were randomly allocated toremote ischemic preconditioning (RIP) group (n=20) and the control group(n=19). Patients in RIP group received three 5 minutes cycles of ischemia,alternating with 5 minutes of reperfusion before extending the use oftourniquet. Hemodynamic variables prior to inflation of tourniquet, every 30minutes during the surgery and 10 minutes after tourniquet deflation and alsoarterial blood gas sample prior to and after surgery were recorded andcompared between groups.Results: During operation blood pressure dropped in the RIP group andvariations in heart rate, respiratory rate, and pulse oximeter measurementsafter surgical tourniquet release were not significantly different between twogroups. Changes in blood gas parameters were significantly less pronouncedin the RIP group.Conclusion: Remote ischemic preconditioning may not attenuate most of theadverse effects of surgical tourniquet deflation, including variations in heartrate, respiratory rate, and arterial oxygen saturation as well as blood pressuredrops. However, RIP may reduce increases in systolic blood pressure andacidosis following tourniquet application.

Keywords:

Remote Ischemic Preconditioning , Orthopedic , surgery , blood pressure , tourniquet , oxygenation