Narrow, non-pneumatic elastic ring tourniquets
Hazards and injuries associated with elastic ring tourniquets
A recent report of a serious injury and a death associated with the use of a non-pneumatic, elastic ring tourniquets provides motivation for reviewing the underlying mechanism of tourniquet-related hazards and injuries, and for establishing tourniquet safety guidelines for minimizing the probability of such injuries. Elastic, non-pneumatic tourniquets have been associated with numerous reports of serious and irreversible injuries to nerves, muscles, blood vessels and soft tissues since the late 1800s (eg [1-8]). The level of pressure applied by elastic non-pneumatic cuffs, and the pressure gradients produced when used as tourniquets or exanguinators, is not known to, or controllable by, clinical users. However, many published reports show that such injuries largely result from the application of unnecessarily high tourniquet pressure levels, well above the minimum pressure needed to stop arterial blood flow (eg [9-12]), and from the application of cuffs producing a high pressure gradient along a patient’s limb (eg [11, 13, 14]). The introduction of pneumatic tourniquets has allowed the tourniquet pressure level to be known, regulated, and maintained (eg [10, 14-16]). Additionally, more recent improvements in the design of certain pneumatic tourniquet cuffs reduce the pressure gradient produced by the cuff on the underlying limb to be reduced, thus reducing another mechanism of injury. (eg [13,17-21]). It is now well established in the clinical literature, and by decreasing reports of the incidence and severity of pneumatic tourniquet injuries, that lower tourniquet pressure levels, and lower tourniquet pressure gradients beneath cuffs, are associated with lower probabilities of tourniquet-related injuries (eg ). Elastic and other non-pneumatic tourniquets which do not provide for the monitoring, control and minimization of tourniquet pressure levels and pressure gradients are hazardous for surgical usage (eg ). In contrast, new personalized tourniquet instruments allow the optimal “limb occlusion pressure” (LOP) to be identified for each patient, surgery, application (etc, from definition ). Optimal tourniquet safety results when LOP is routinely used to establish lowest tourniquet pressures in conjunction with tourniquet cuffs that produce lowest cuff pressure gradients. Published evidence and evolving clinical practice guidelines recognize that employing such low tourniquet pressure levels and cuffs producing low tourniquet pressure gradients lowers the probability of tourniquet-related hazards and injuries.
 McEwen J, Casey V. Measurement of hazardous pressure levels and gradients produced on human limbs by non-pneumatic tourniquets. In: Proceedings of the 32nd Conference of the Canadian Medical and Biological Engineering Society 2009. Calgary, Canada; 2009 May 20-22. p 1-4.
 Graham B, Breault MJ, McEwen JA, McGraw RW. Perineural pressures under the pneumatic tourniquet in the upper extremity. The Journal of Hand Surgery: British & European Volume. 1992 Jun 1;17(3):262-6.
 Pedowitz RA, Gershuni DH, Botte MJ, Kuiper S, Rydevik BL, Hargens AR. The use of lower tourniquet inflation pressures in extremity surgery facilitated by curved and wide tourniquets and an integrated cuff inflation system. Clinical orthopaedics and related research. 1993 Feb 1;287:237-44.
 Graham B, Breault MJ, Mcewen JA, Mcgraw RW. Occlusion of arterial flow in the extremities at subsystolic pressures through the use of wide tourniquet cuffs. Clinical orthopaedics and related research. 1993 Jan 1;286:257-61.
 Younger AS, McEwen JA, Inkpen K. Wide contoured thigh cuffs and automated limb occlusion measurement allow lower tourniquet pressures. Clinical orthopaedics and related research. 2004 Nov 1;428:286-93.