When Does a Pressure Dressing Become a Tourniquet: A Prospective Single Centre Study Assessing Variation and Factors Affecting Pressures Exerted by Pressure Bandages

Abstract Introduction Pressure bandages are frequently used for emergency haemostasis in arterial forearm injuries. This study assesses the range of pressures exerted by pressure bandages and the relevant variables, thus evaluating the safety of use. Method We measured pressures under a standard Oleas modular pressure bandage using Flexiforce Prototyping Kit when applied by various members of the hand trauma unit with differing levels of experience. Results 15 measurements of pressure were recorded. The mean applied pressure was 209mmHg (range: 50 – 485mmHg) with 40% measurements exceeding pressure of 250mmHg. Multivariate regression analysis showed the colour of the hand is statistically significantly related to exerted pressures (p<0.005), but not related to clinical experience (p = 0.101), perceived force of application (p = 0.203) or gender (p = 0.289). Pink hands had a mean pressure equal to 79mmHg compared with purple hands; 336mmHg. Conclusions Pressure bandages have large variation in the pressure created, often exceeding safe pressure ranges. Our results suggest if the hand is purple, pressures under the dressing are similar to that of a pneumatic tourniquet. If pressure dressings are required in an emergency setting, these should be removed after 2 hours to prevent the risk of compression injury.