Chlorprocain is not used because of hypothesized risk of thromboembolism. Bupivacaine is not recommended because of irreversible effects of toxic systemic absorption. This occurs when the tourniquet is deflated and local anesthetic enters the systemic circulation. A full 20 minutes of tourniquet time decreases this risk. Also, the tourniquet can be deflated slowly or intermittently to avoid a large bolus of local anesthetic when the procedure is over to decrease the risk.
Cardiovascular complications can occur, usually in the form of bradycardia.
However, this usually does not produce clinically significant complications. Other signs and symptoms of toxicity are tinnitus, dizziness, blurred vision, seizure activity, and decreased blood pressure. Other complications are inadequate block and thrombophlebitis. Contraindications include the very obese, where the tourniquet can not be applied effectively, and also in diabetic patients with peripheral nerve damage where the tourniquet can further damage nerves. Alexander's care of the patient in surgery.