JSOM Header

Tourniquet Pressures: Strap Width and Tensioning System Widths

Winter 2014

Wall PL, Coughlin O, Rometti MR, Birkholz S, Gildemaster Y, Grulke L, Sahr SM, Buising CM. 14(4). 19 - 29. (Journal Article)


Background: Pressure distribution over tourniquet width is a determinant of pressure needed for arterial occlusion. Different width tensioning systems could result in arterial occlusion pressure differences among nonelastic strap designs of equal width. Methods: Ratcheting Medical Tourniquets™ (RMTs; m2® inc., http://www.ratcheting buckles.com) with a 1.9cm-wide (Tactical RMT) or 2.3cmwide (Mass Casualty RMT) ladder were directly compared (16 recipients, 16 thighs and 16 upper arms for each tourniquet ® 2). Then, RMTs were retrospectively compared with the windlass Combat Application Tourniquet (C-A-T ["CAT"], http://combattourniquet.com) with a 2.5cm-wide internal tensioning strap. Pressure was measured with an air-filled No. 1 neonatal blood pressure cuff under each 3.8cm-wide tourniquet. Results: RMT circumferential pressure distribution was not uniform. Tactical RMT pressures were not higher, and there were no differences between the RMTs in the effectiveness, ease of use ("97% easy"), or discomfort. However, a difference did occur regarding tooth skipping of the pawl during ratchet advancement: it occurred in 1 of 64 Tactical RMT applications versus 27 of 64 Mass Casualty RMT applications. CAT and RMT occlusion pressures were frequently over 300mmHg. RMT arm occlusion pressures (175-397mmHg), however, were lower than RMT thigh occlusion pressures (197-562mmHg). RMT effectiveness was better with 99% reached occlusion and 1% lost occlusion over 1 minute versus the CAT with 95% reached occlusion and 28% lost occlusion over 1 minute. RMT muscle tension changes (up to 232mmHg) and pressure losses over 1 minute (24 ± 11mmHg arm under strap to 40 ± 12mmHg thigh under ladder) suggest more occlusion losses may have occurred if tourniquet duration was extended. Conclusions: The narrower tensioning system Tactical RMT has better performance characteristics than the Mass Casualty RMT. The 3.8cmwide RMTs have some pressure and effectiveness similarities and differences compared with the CAT. Clinically significant pressure changes occur under nonelastic strap tourniquets with muscle tension changes and over time periods as short as 1 minute. An examination of pressure and occlusion changes beyond 1 minute would be of interest.

Keywords: tourniquet; hemorrhage control; first aid; emergency treatment

PMID: 25399364

Buy Now