Avoiding tourniquet-induced neuropathy through cuff design

Pneumatic tourniquets are routinely used in limb surgery to provide a bloodless operating field, but they are known to cause nerve injuries. Simulation results based on the hypothesis that axial compression of nerves is responsible for a certain class of these mechanically induced injuries are in substantial accord with clinical observations. A model of the limb and tourniquet that treats the tissue as a linearly elastic solid is presented and is used to predict the induced axial strains. The smallest axial strains are induced by a tourniquet design for which the applied pressure distribution rolls off as gradually as possible; according to the axial-strain hypothesis, such a design will markedly decrease a tourniquet's inherent potential for injury. Use of a wider cuff in and of itself will not reduce axial strain, so if the hypothesis is correct, a wider cuff would not be intrinsically safer than a regular cuff, a result that is contrary to current opinion.