Ischaemia threatening an injured limb gives rise to the syndrome of pain, pallor, paralysis, and pulselessness. It is due to arterial injury by laceration, compression, intra-mural rupture or contusion, or to arterial spasm with or without demonstrable local arterial damage. The differentiation of spasm without local injury from organic obstruction is not possible by clinical methods. The suggested plan of treatment and of management is: 1. General systemic investigation (blood-pressure, blood-count, coagulation time, etc.). 2. Removal of all external pressure. 3. Resuscitation. 4. Direct attempt to relieve the obstruction by operation. 5. Post-operative care. The operative procedure recommended is: 1. Manipulative reduction of the fracture if possible. 2. Proximal control of the artery. 3. Arteriography. 4. Exposure of the occluded artery (unless contra-indicated by time factors and by the anatomy of the collateral circulation), liberation and mobilisation of the vessel, repair by suture where such is necessary and possible, and arterectomy only forirreparable local damage. 5. The provision of sympathetic block by injection or by sympathectomy. The important elements of post-operative care are: 1. To maintain the blood-pressure while cooling the limb and heating the patient.
