Tourniquet Training Effectiveness Study

Hemorrhage control by rapid application of commercial tourniquets has significantly improved the survival of military personnel injured on the battlefield.7,8 The U.S. civilian population has seen a spike in battlefield like injuries in the recent years, a prime example being the Boston Marathon bombing.9,10 To address this issue, the American College of Surgeons (ACS) formed a committee comprised of individuals from the fields of healthcare, law-enforcement, fire department, pre-hospital care and the military. This committee came up with a set of recommendation regarding first response and capacity building for hemorrhage control, known as the Harford Consensus.11 These recommendations include educational programs for lay-people in hemorrhage control with an emphasis on rapid and early tourniquet application. There is level 4 evidence that after adjustment for covariates, emergency medical providers' application of tourniquets in civilian trauma decreases mortality, though not to the same dramatic degree seen in the military setting.12-14 Researchers are working to show the effect of training of laypersons in hemorrhage control in the real world but no data beyond the simulation setting is currently presented in the literature.15 Various groups have developed training programs for hemorrhage control training, the most notable of which is the ACS "Stop the Bleed" Bleeding Control Basic (B-Con) training.16 B-Con has trained over 100,000 individuals in the US since its implementation.5 Goralnick et. al. have shown that there is moderate retention for the retention of B-Con specifically for application of the Combat Application Tourniquet (CAT), which is also the type of tourniquet with the best evidence for its use as it is the type used by the US military.17 However, the Hartford consensus and the "Stop the Bleed" campaign state that "(1) commercial windlass-type tourniquets should be used in the prehospital setting for the control of significant extremity hemorrhage when direct pressure is ineffective or impractical, (2) improvised tourniquets should be used only if no commercial device is available."5,18 This advocacy for types of commercial tourniquets beyond the CAT and, more significantly, for improvised tourniquets has not been studied in either a simulated or real setting.

There are multiple different tourniquet types available for which, while the principle is the same for all, the actual mechanism and steps for application vary. B-Con in its current iteration informs participants the principle is the same for both other commercial tourniquets and improvised tourniquets, which is to be tight enough to occlude arterial bleeding. Other courses which have been widely disseminated have taught how to use tourniquets other than the CAT, such as the Stretch-Wrap-And-Tuck tourniquet (SWAT-T).19 Currently, the courses being offered typically only teach how to use one, and sometimes two, different types of tourniquets. Furthermore, as there is not broad consensus statement about which tourniquet type to use and teach, different groups distribute different types of tourniquets in publicly available bleeding control kits, and professional first responders carry different types of commercial tourniquets. A randomized trial has shown that among some of the available commercial tourniquets, the CAT, ratcheting medical tourniquet (RMT), and SWAT-T, the proportion of application for those without training ranges from 10.6-23.4%.

The B-Con course presumption that participants understand tourniquet principles rather than a single technique, which would enable them to apply devices they have not seen before, has not been evaluated. In this context, the investigators would evaluate participants, immediately after completing the full B-Con course, on their ability to apply different commercial tourniquets than what they were trained on and their ability to apply a commercial tourniquet.

1. Study design:
2. Prospective open-label trial
3. Consent:
4. Verbal consent
5. Protocol:
6. All participants will receive the ACS stop the Bleed training from qualified instructors. This training is 45 to 60 minutes long, consisting of an audio-visual presentation with tourniquet application instructions followed by hands-on training under the supervision of an instructor. The training takes place in groups of 20 to 50 at a time. The audio-visual part of the training takes place in groups of 20, which are then divided in to subgroups of 4-8 for hands-on training with an instructor. There is no compensation for the study participants.
7. The evaluation of hemorrhage control competence will take place individually. A mannequin, the Hapmed tourniquet trainer, with a traumatic amputation of the leg just above the knee will be present. A reviewer will provide instructions, including that the lights on the leg represent continued bleeding and they will have a maximum of 2 minutes to apply the tourniquet. The participant will be provided a tourniquet and told to stop the simulated bleeding. Participants will be tested in all 5 types of tourniquets sequentially using the same method but with the order of testing varying according to the randomization. The reviewer will start timing after telling the participant to begin. This will then be repeated for the other type of tourniquet the individual will need to apply. No feedback will be given to the participant throughout the testing process.
8. Supplies for the improvised tourniquet will include a T-shirt, long stretch of gauze, a stick to act as a windlass, and a leather belt c) Parameters measured: i) The participants will be timed until they feel that they have stopped the bleeding or they tell the instructor they are done. The maximum amount of time provided to apply the tourniquet will be 2 minutes based on the results of the investigators prior studies in which the 90th percentile for time to correct application was 117 seconds. ii) Appropriateness of hemorrhage control will be determined by correct placements of tourniquet as defined by at least 2 inches proximal to the amputation site iii) Adequate pressure to stop the bleeding which will be set at 250 mmHg. For unsuccessful hemorrhage control, the reason for failure will be recorded. iv) Correct tourniquet application defined by: (1) Time to application < 120 seconds (2) Placement of tourniquet a minimum of 2 inches proximal to amputation (3) Tourniquet application pressure > 250 mmHg d) All the reviewers would be physicians, nurses and EMTs, trained in hemorrhage-control. The complete test for each individual will not take more than 15 mins.
9. Randomization for the order of tourniquet application:
10. Permutated block randomization will be used to vary the order for application of the 5 different types of tourniquets (CAT, RAT, SWAT-T, Sof-T, and improvised tourniquet)
11. Pre-trial questionnaire:
12. Study subjects will be given a pre-trial questionnaire to gather information regarding age, gender, and level of education. The questionnaire will also include questions to assess their knowledge regarding hemorrhage control and to determine their willingness and self-reported comfort level in acting as a first-responder in a mass causality scenario. Answers will be presented on a Likert-type scale or dichotomous yes-no.
13. Post-trial questionnaire:
14. After the hemorrhage control training, all participants will be given a questionnaire to evaluate comfort level, self-efficacy, and other questions relating to hemorrhage control response.
15. Sample size calculation:
16. Sample Size calculation was done for paired comparisons with 80% power and Bonferroni corrected for 4 pairwise comparisons for an alpha level of 0.0125 and correlation of 0.1. The largest difference was then taken as the sample size for each arm.
17. The expected corrected proportions for the different tourniquets are:
18. CAT: 80-90% (Control)
19. RAT: 10-30%
20. SWAT-T: 10-30%
21. Sof-T: 20-40%
22. Improvised: < 10% ii) The smallest presumed difference in correct application for the CAT (control) at 80% is to the Sof-T at 40%. To attain 80% power with alpha of 0.0125 the required minimum sample size is 34.
23. All sample size calculations performed using Stata v14.1.
24. Statistical Analysis:
25. Paired statistical tests using McNemars test will be used for the univariate analysis of the primary outcome of correct tourniquet application comparing the CAT tourniquet as a control (CAT being type of tourniquet taught in the B-Con course) to each of the other tourniquet types (RAT, SWAT-T, Sof-T, Improvised) for 4 total pairwise comparisons.
26. Descriptive statistical analysis (ANOVA, Kruskal-wallis, Mann Whitney U test, Student T-test) will be used to assess the secondary outcomes of time to tourniquet application, estimated blood loss prior to tourniquet application, and pressure applied by the tourniquet.
27. Multiple Logistic regression will be used to assess for predictors of correct tourniquet application for each of the different tourniquet types. The model will include age, gender, education level, any prior hemorrhage control training, and success in application for each of the other tourniquet types.
28. Descriptive statistics will also be used to assess participants responses on the questionnaires. Non-parametric statistical tests (Wilcoxon signed rank test and generalized estimating equations) will be used to assess 5-point Likert scale questions.
29. P-value for significance will be set at 0.05 after Bonferroni correction.