AST Guidelines for Best Practices for Safe Use of Pneumatic Tourniquets

22 toxic reaction; these are from McEwen (2018), Tourniquet Safety: Mechanisms and Prevention of Injuries . 1) Inadequate pressurization of the cuff prior to injection of the local anesthetic allowing the agent to leak underneath the cuff into the systemic circulation. 2) Inadequate exsanguination of the extremity occurs prior to the injection of the local anesthetic. The veins distal to the cuff that are not adequately exsanguinated will be infiltrated by the local anesthetic increasing the venous pressure to a level that allows the local anesthetic to escape beneath the cuff and into the systemic circulation. 3) An accidental, sudden deflation of the cuff allows the local anesthetic to quickly enter the system circulation. 3. IVRA is usually performed with a dual-bladder cuff, but two single cuffs may be used. A. A higher cuff pressure may be required since the dual-bladder cuffs or two single cuffs are narrower in width; however, the pressure should still be based upon the LOP measurement. 51 B. Since the majority of patients receive monitored anesthesia care during IVRA and will be awake, but sedated, the CST in the assistant circulator role should explain everything to the patient that is occurring including the tourniquet equipment and any tourniquet machine sounds or alarms he/she may hear. C. Each bladder of the dual-bladder cuff must be connected to the tourniquet system by the CST. If a dual-cuff control valve is used between the tourniquet machine and cuffs, the CST should be familiar with the connection and how to operative the valve. 51 The CST should consult the manufacturer’s instruction manual. The CST should be aware that tourniquet systems have two independent channels that control the pressures of both cuffs during a procedure involving IVRA. 51 This is important when one cuff is being inflated, deflated and regulated during the procedure. Since this requires two hose assemblies, the CST should clearly know which cuff is connected to the first and second cuff channels on the tourniquet machine. D. The CST should clearly understand the sequence of cuff inflation and deflation to prevent systemic complications. 10 After the limb is exsanguinated the proximal cuff should be inflated and the anesthesia provider will then inject the local anesthetic; usually, the proximal cuff is inflated first, but the CST should confirm this with the surgeon and anesthesia provider. 6,51 The cuff should not be deflated for at least twenty minutes after the anesthetic has been injected. 6,50 After twenty to thirty minutes, the surgeon and/or anesthesia provider may request the proximal cuff to be deflated and the distal cuff inflated; however, the CST must remember not to deflate the proximal cuff until the distal cuff is fully inflated. 6,51 There are tourniquet systems