Prilocaine leakage during tourniquet inflation in intravenous regional anaesthesia: the influence of fracture manipulation.

Recent evidence has shown that there may be leakage of anaesthetic drugs into the systemic circulation during the tourniquet inflation phase of intravenous regional anaesthesia. This, together with increased pressure in forearm vessels during manipulation of fractures, prompted the measurement of arterial levels of local anaesthetic to assess potential toxicity. Prilocaine levels were measured in nine patients undergoing manipulation of Colles' fractures and six patients undergoing other upper limb procedures. Eleven patients had measurable concentrations of prilocaine in the arterial circulation during the time the tourniquet was inflated, the maximum levels being measured in those patients having fractures manipulated. Considerable vigilance should be ensured during the time of tourniquet inflation in intravenous regional anaesthesia, particularly for fracture manipulation.