Local anaesthetic toxicity of haematoma blocks in manipulation of Colles' fractures.

Nine patients undergoing manipulation of Colles' fractures with varying doses of local anaesthetic injected into the fracture haematoma, were investigated by monitoring the arterial levels of lignocaine. Although the procedure was considered satisfactory by all patients, potentially toxic concentrations of lignocaine were found in the arterial circulation, reaching a maximum after manipulation of the fracture. A mean peak level of 2625 micrograms/l was found when 10 ml of 2 per cent lignocaine was used and a mean peak level of 846 micrograms/l in patients receiving 10 ml of 1 per cent lignocaine.