Intravenous regional analgesia. The danger of the congested arm and the value of occlusion pressure

Two cases are described in which congestion of the arm occurred during intravenous regional analgesia. One case exhibited signs of serious local anaesthetic toxicity, while a significant plasma bupivacaine level was demonstrated in the other. In a study in a volunteer, leakage of contrast medium past the cuff was demonstrated radiologically only when congestion of the arm was produced. The Hoyle double cuff apparatus has narrow cuffs producing less tissue compression than a standard blood pressure cuff inflated to the same pressure. It may sometimes not occlude the brachial artery when inflated to a pressure based on the systolic arterial pressure measured with a standard cuff and congestion of the arm may then result. Increases in arterial blood pressure occurring during the procedure can also lead to congestion of the arm. Congestion may increase the risk of local anaesthetic agent leaking past the tourniquet into the systemic circulation. Recommendations are made about the choice of cuff gauge pressure and the prevention of arm congestion occurring during intravenous regional analgesia.