Control of massive hemorrhage (MH) is a life-saving intervention. The use of tourniquets has been studied in prehospital and battlefield settings but not in aquatic environments.

The aim of this research is to assess the control of MH in an aquatic environment by analyzing the usability of two tourniquet models with different adjustment mechanisms: windlass rod versus ratchet.

A pilot simulation study was conducted using a randomized crossover design to assess the control of MH resulting from an upper extremity arterial perforation in an aquatic setting. A sample of 24 trained lifeguards performed two randomized tests: one using a windlass-based Combat Application Tourniquet 7 Gen (T-CAT) and the other using a ratchet-based OMNA Marine Tourniquet (T-OMNA) specifically designed for aquatic use on a training arm for hemorrhage control. The tests were conducted after swimming an approximate distance of 100 meters and the tourniquets were applied while in the water. The following parameters were recorded: time of rescue (rescue phases and tourniquet application), perceived fatigue, and technical actions related to tourniquet skills.

With the T-OMNA, 46% of the lifeguards successfully stopped the MH compared to 21% with the T-CAT (P = .015). The approach swim time was 135 seconds with the T-OMNA and 131 seconds with the T-CAT (P = .42). The total time (swim time plus tourniquet placement) was 174 seconds with the T-OMNA and 177 seconds with the T-CAT (P = .55). The adjustment time (from securing the Velcro to completing the manipulation of the windlass or ratchet) for the T-OMNA was faster than with the T-CAT (six seconds versus 19 seconds; P < .001; effect size [ES] = 0.83). The perceived fatigue was high, with a score of seven out of ten in both tests (P = .46).

Lifeguards in this study demonstrated the ability to use both tourniquets during aquatic rescues under conditions of fatigue. The tourniquet with the ratcheting-fixation system controlled hemorrhage in less time than the windlass rod-based tourniquet, although achieving complete bleeding control had a low success rate.

The Stop the Bleed campaign provided civilians with tourniquet application training and increased the demand for tourniquets among the general population, which led to the development of new commercially available devices. However, most widely available tourniquets have not undergone testing by regulatory bodies and their efficacy remains unknown.

This study aimed to compare the efficacy and performance of Combat Application Tourniquets (CAT) versus uncertified tourniquets.

This study compared 25 CAT with 50 commercially available “look-alike” tourniquets (LA-TQ) resembling the CAT. The CAT and the LA-TQ were compared for cost, size, and tested during one-hour and six-hour applications on a manikin’s leg. The outcomes were force applied, force variation during the application, and tourniquet rupture rate.

The LA-TQ were cheaper (US$6.07 versus US$27.19), shorter, and had higher inter-device variability than the CAT (90.1 [SE = 0.5] cm versus 94.5 [SE = 0.1] cm; P <.001). The CAT applied a significantly greater force during the initial application when compared to the LA-TQ (65 [SE = 3] N versus 14 [SE = 1] N; P <.001). While the initial application force was maintained for up to six hours in both groups, the CAT group applied an increased force during one-hour applications (group effect: F [1,73] = 105.65; P <.001) and during six-hour applications (group effect: F [1,12] = 9.79; P = .009). The rupture rate differed between the CAT and the LA-TQ (0% versus 4%).

The LA-TQ applied a significantly lower force and had a higher rupture rate compared to the CAT, potentially affecting tourniquet performance in the context of public bleeding control. These findings warrant increased layperson education within the framework of the Stop the Bleed campaign and further investigations on the effectiveness of uncertified devices in real-world applications.

The Stop the Bleed course aims to improve bystander hemorrhage control skills and may be improved with point-of-care aids. We sought to create and examine a variety of cognitive aids to identify an optimal method to augment bystander hemorrhage control skills in an emergency scenario.

Randomized trial of 346 college students. Effects of a visual or visual-audio aid on hemorrhage control skills were assessed through randomization into groups with and without prior training or familiarization with aids compared with controls. Tourniquet placement, wound packing skills, and participant comfortability were assessed during a simulated active shooter scenario.

A total of 325 (94%) participants were included in the final analyses. Participants who had attended training (odds ratio [OR], 12.67; P = 9.3 × 10−11), were provided a visual-audio aid (OR, 1.96; P = 0.04), and were primed on their aid (OR, 2.23; P = 0.01) were superior in tourniquet placement with less errors (P < 0.05). Using an aid did not improve wound packing scores compared with bleeding control training alone (P > 0.05). Aid use improved comfortability and likelihood to intervene emergency hemorrhage scenarios (P < 0.05).

Using cognitive aids can improve bystander hemorrhage control skills with the strongest effects if they were previously trained and used an aid which combined visual and audio feedback that they were previously introduced to during the course training.

Hemorrhage control prior to shock onset is increasingly recognized as a time-critical intervention. Although tourniquets (TQs) have been demonstrated to save lives, less is known about the physiologic parameters underlying successful TQ application beyond palpation of distal pulses. The current study directly visualized distal arterial occlusion via ultrasonography and measured associated pressure and contact force.

Fifteen tactical officers participated as live models for the study. Arterial occlusion was performed using a standard adult blood pressure (BP) cuff and a Combat Application Tourniquet Generation 7 (CAT7) TQ, applied sequentially to the left mid-bicep. Arterial flow cessation was determined by radial artery palpation and brachial artery pulsed wave doppler ultrasound (US) evaluation. Steady state maximal generated force was measured using a thin-film force sensor.

The mean (95% CI) systolic blood pressure (SBP) required to occlude palpable distal pulse was 112.9mmHg (109-117); contact force was 23.8N [Newton] (22.0-25.6). Arterial flow was visible via US in 100% of subjects despite lack of palpable pulse. The mean (95% CI) SBP and contact force to eliminate US flow were 132mmHg (127-137) and 27.7N (25.1-30.3). The mean (95% CI) number of windlass turns to eliminate a palpable pulse was 1.3 (1.0-1.6) while 1.6 (1.2-1.9) turns were required to eliminate US flow.

Loss of distal radial pulse does not indicate lack of arterial flow distal to upper extremity TQ. On average, an additional one-quarter windlass turn was required to eliminate distal flow. Blood pressure and force measurements derived in this study may provide data to guide future TQ designs and inexpensive, physiologically accurate TQ training models.

Tourniquets are the standard of care for civilian and military prehospital treatment of massive extremity hemorrhages. Over the past 17 years, multiple military studies have demonstrated rare complications related to tourniquet usage. These studies may not translate well to civilian populations due to differences in baseline health. Experimental studies have demonstrated increased rates of post-traumatic acute kidney injuries (AKIs) in rats with obesity and increased oxidative stress, suggesting that comorbidities may affect AKI incidence with tourniquet usage. Two recently published retrospective studies, focused on the safety of tourniquets deployed within civilian sectors, documented increased incidence of AKI in patients with a prehospital tourniquet as compared to previously published military results. This study aimed to provide descriptive data concerning the association between the use of prehospital tourniquets and AKIs amongst civilian patient populations as AKIs increase mortality in hospitalized patients.

This was a single-center, observational, cross-sectional, pilot study involving chart review of participants presenting to a tertiary Level 1 trauma center. Patient data were extracted from prehospital and hospital electronic medical records. For this study, AKI was defined using the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines.

A total of 255 participants were included. Participants with a history of diabetes mellitus had a significantly higher incidence of AKI as compared to those without. Analysis revealed an increased odds of AKI with diabetes in association to the use of a prehospital tourniquet. Participants with diabetes had an increased relative risk of AKI in association to the use of a prehospital tourniquet. The incidence of AKI was statistically higher than what was previous reported in the military population in association with the use of a prehospital tourniquet.

The incidence of AKIs was higher than previously reported. Patients with diabetes had an associated higher risk and incidence of sustaining an AKI after the use of a prehospital tourniquet in association with the use of a prehospital tourniquet. This may be due to the known deleterious effects of diabetes mellitus on renal function. This study provides clinically relevant data that warrant further multi-site investigations to further investigate this study’s associated findings and potential causation. It also stresses the need to assess whether renally-impacting environmental and nutritional stressors affect AKI rates amongst military personnel and others in which prehospital tourniquets are used.

Massive hemorrhage (MH) is a growing pathology in military settings and increasingly in civilian settings; it is now considered a public health problem in the United States with large-scale programs. Tourniquets are the fastest and most effective intervention in MH if direct pressure is not effective.

The Liaison Committee on Resuscitation (ILCOR) recognizes a knowledge gap in optimal education techniques for first aid providers. This review aims to describe training and evaluation methods for teaching tourniquet use to both health care and military professionals.

The MEDLINE, CINAHL, WEB of Science, and Scopus databases were reviewed (from 2010 through April 2020). The quality of the selected studies was assessed using the Consolidated Standards of Reporting Trials (CONSORT) scale. Studies that met at least 65% of the included items were included. Data were extracted independently by two reviewers.

Ten of the 172 articles found were selected, of which three were randomized clinical trials. Heterogeneity was observed in the design of the studies and in the training and evaluative methods that limit the comparison between studies.

The results suggest that the training strategies studied are effective in improving knowledge, attitudes, and practical skills. There is no universal method, learning is meaningful but research should be directed to find out which ones work best.

Terrorist attacks and civilian mass-casualty events are frequent, and some countries have implemented tourniquet use for uncontrollable extremity bleeding in civilian settings. The aim of this study was to summarize current knowledge on the use of prehospital tourniquets to assess whether their use increases the survival rate in civilian patients with life-threatening hemorrhages from the extremities.

Systematic literature review in Medline (Ovid), Embase (Ovid), Cochrane Library, and Epistemonikos was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guidelines. The search was performed in January 2019.

All types of studies that examined use of tourniquets in a prehospital setting published after January 1, 2000 were included.

The primary outcome was mortality with and without tourniquet, while adverse effects of tourniquet use were secondary outcomes.

Among 3,460 screened records, 55 studies were identified as relevant. The studies were highly heterogeneous with low quality of evidence. Most studies reported increased survival in the tourniquet group, but few had relevant comparators, and the survival benefit was difficult to estimate. Most studies reported a reduced need for blood transfusion, with few and mainly transient adverse effects from tourniquet use.

Despite relatively low evidence, the studies consistently suggested that the use of commercial tourniquets in a civilian setting to control life-threatening extremity hemorrhage seemed to be associated with improved survival, reduced need for blood transfusion, and few and transient adverse effects.

Tourniquets (TQs) save lives. Although military-approved TQs appear more effective than improvised TQs in controlling exsanguinating extremity hemorrhage, their bulk may preclude every day carry (EDC) by civilian lay-providers, limiting availability during emergencies.

The purpose of the current study was to compare the efficacy of three novel commercial TQ designs to a military-approved TQ.

Nine Emergency Medicine residents evaluated four different TQ designs: Gen 7 Combat Application Tourniquet (CAT7; control), Stretch Wrap and Tuck Tourniquet (SWAT-T), Gen 2 Rapid Application Tourniquet System (RATS), and Tourni-Key (TK). Popliteal artery flow cessation was determined using a ZONARE ZS3 ultrasound. Steady state maximal generated force was measured for 30 seconds with a thin-film force sensor.

Success rates for distal arterial flow cessation were 89% CAT7; 67% SWAT-T; 89% RATS; and 78% TK (H 0.89; P = .83). Mean (SD) application times were 10.4 (SD = 1.7) seconds CAT7; 23.1 (SD = 9.0) seconds SWAT-T; 11.1 (SD = 3.8) seconds RATS; and 20.0 (SD = 7.1) seconds TK (F 9.71; P <.001). Steady state maximal forces were 29.9 (SD = 1.2) N CAT7; 23.4 (SD = 0.8) N SWAT-T; 33.0 (SD = 1.3) N RATS; and 41.9 (SD = 1.3) N TK.

All novel TQ systems were non-inferior to the military-approved CAT7. Mean application times were less than 30 seconds for all four designs. The size of these novel TQs may make them more conducive to lay-provider EDC, thereby increasing community resiliency and improving the response to high-threat events.

Acute blood loss represents a leading cause of death in both civilian and battlefield trauma, despite the prioritization of massive hemorrhage control by well-adopted trauma guidelines. Current Tactical Combat Casualty Care (TCCC) and Tactical Emergency Casualty Care (TECC) guidelines recommend the application of a tourniquet to treat life-threatening extremity hemorrhages. While extremely effective at controlling blood loss, the proper application of a tourniquet is associated with severe pain and could lead to transient loss of limb function impeding the ability to self-extricate or effectively employ weapons systems. As a potential alternative, Innovative Trauma Care (San Antonio, Texas USA) has developed an external soft-tissue hemostatic clamp that could potentially provide effective hemorrhage control without the aforementioned complications and loss of limb function. Thus, this study sought to investigate the effectiveness of blood loss control by an external soft-tissue hemostatic clamp versus a compression tourniquet.

The external soft-tissue hemostatic clamp would be non-inferior at controlling intravascular fluid loss after damage to the femoral and popliteal arteries in a normotensive, coagulopathic, cadaveric lower-extremity flow model using an inert blood analogue, as compared to a compression tourniquet.

Using a fresh cadaveric model with simulated vascular flow, this study sought to compare the effectiveness of the external soft-tissue hemostatic clamp versus the compression tourniquet to control fluid loss in simulated trauma resulting in femoral and posterior tibial artery lacerations using a coagulopathic, normotensive, cadaveric-extremity flow model. A sample of 16 fresh, un-embalmed, human cadaver lower extremities was used in this randomized, balanced two-treatment, two-period, two-sequence, crossover design. Statistical significance of the treatment comparisons was assessed with paired t-tests. Results were expressed as the mean and standard deviation (SD).

Mean intravascular fluid loss was increased from simulated arterial wounds with the external soft-tissue hemostatic clamp as compared to the compression tourniquet at the lower leg (119.8mL versus 15.9mL; P <.001) and in the thigh (103.1mL versus 5.2mL; P <.001).

In this hemorrhagic, coagulopathic, cadaveric-extremity experimental flow model, the use of the external soft-tissue hemostatic clamp as a hasty hemostatic adjunct was associated with statistically significant greater fluid loss than with the use of the compression tourniquet.

Paquette R, Bierle R, Wampler D, Allen P, Cooley C, Ramos R, Michalek J, Gerhardt RT. External soft-tissue hemostatic clamp compared to a compression tourniquet as primary hemorrhage control device in pilot flow model study. Prehosp Disaster Med. 2019;34(2):175–181

Application of a tourniquet is the cornerstone in management of combat-related extremity hemorrhages. Continuous and appropriate training is required to use tourniquets correctly.

The aim of this study was to analyze the impact of a refresher training session, conducted directly in the theater of military operations, on the performance of tourniquet use.

During their deployment (October 2015-April 2016) in the Central African Republic, a first simulation session evaluated soldiers from two combats platoons for the application of the SOFFT (Special Operation Forces Tactical Tourniquet; Tactical Medical Solutions; Anderson, South California USA) tourniquet. After randomization, a R (+) group underwent a refresher training session, while a R (−) group did not. Two months later, a second simulation session was conducted for both groups: R (+) and R (−). A dedicated score (one to seven points), including delay and effectiveness, evaluated the soldiers’ performance for tourniquet application.

Twenty-six subjects were included in the R (+) group and 24 in the R (−) group. Between the two assessments, the score improved for 61.5% of subjects of the R (+) group and 37.5% subjects of the R (−) group (P=.09). More particularly, the performance score increased from 4.2 (SD=1.4) to 5.5 (SD=0.9; P=.002) in subjects of the R (+) group whose last training for tourniquet application was over six months prior.

A refresher tourniquet training session, conducted directly in a combat zone, is especially effective for soldiers whose last training session was over six months prior. A dedicated score can assess appropriately the performance of tourniquet training.

MartinezT, DuronS, SchaalJV, BaudoinY, BarbierO, DabanJL, BoutonnetM, AussetS, PasquierP. Tourniquet Training Program Assessed by a New Performance Score. Prehosp Disaster Med. 2018;33(5):519–525.

This study evaluated how Tactical Emergency Casualty Care (TECC) training prepared law enforcement officers (LEOs) with the tools necessary to provide immediate, on-scene medical care to successfully stabilize victims of trauma.

This was a retrospective, de-identified study using a seven-item Fairfax County (Virginia USA) TECC After-Action Questionnaire and Arlington County (Virginia USA) police reports.

Forty-six encounters were collected from 2015 through 2016. Eighty-four percent (n=39) of the encounters were from TECC After-Action Questionnaires and 15% (n=7) were from police reports. The main injuries included 13% (n=6) arterial bleeds, 46% (n=21) mild/moderate bleeds, 37% (n=17) large wounds, 20% (n=9) penetrating chest wounds, and 13% (n=6) open abdominal wounds. One-hundred percent of officers reported success in stabilizing victim injuries. Seventy-four percent of officers (n=26) did not encounter problems caring for a patient while 26% (n=9) encountered a problem. Ninety-seven percent (n=37/38) answered Yes, the training was sufficient, and three percent (n=1) indicated it was OK.

This is the most comprehensive study of TECC use among LEOs to date that supports the importance of TECC training for all LEOs in prehospital trauma care. Results of this study showed TECC training prepared LEOs with the operational tools necessary to provide immediate, on-scene medical care to successfully stabilize victims of trauma. Continuing to train increasing numbers of LEOs in TECC is key to saving the lives of victims of trauma in the future.

RothschildHR, MathiesonK.Effects of Tactical Emergency Casualty Care Training for Law Enforcement Officers. Prehosp Disaster Med.2018;33(5):495–500.

Based upon military experience, law enforcement has developed guidelines for medical care during high-threat conditions. The purpose of the current study was to provide a descriptive analysis of reported outcomes of law enforcement medical interventions.

This was a descriptive analysis of a convenience sample of cases submitted to the Wisconsin Tactical Medicine Initiative (Wisconsin USA), after the provision of successful patient care, between January 2010 and December 2015. The study was reviewed by the Mayo Foundation Institutional Review Board (Rochester, Minnesota USA) and deemed exempt.

Nineteen agencies submitted information during the study period. Of the 56 episodes of care reported, four (7.1%) cases involved care provided to injured officers while 52 (92.9%) involved care to injured civilians, including suspects. In at least two cases, on-going threats existed during the provision of medical care to an injured civilian. Law enforcement rendered care prior to Emergency Medical Services (EMS) arrival in all but two cases.

The current case series demonstrates the life-saving potential for law enforcement personnel trained and equipped under current Tactical Combat Casualty Care (TCCC)/ Committee on Tactical Emergency Casualty Care (C-TECC) tactical casualty care guidelines. Although originally developed to save the lives of wounded combat personnel, in the civilian sector, the training appears more likely to save victims rather than law enforcement personnel.

StilesCM, CookC, SztajnkrycerMD. A Descriptive Analysis of Tactical Casualty Care Interventions Performed by Law Enforcement Personnel in the State of Wisconsin, 2010-2015. Prehosp Disaster Med. 2017;32(3):284–288.

To aid in preparation of military medic trainers for a possible new curriculum in teaching junctional tourniquet use, the investigators studied the time to control hemorrhage and blood volume lost in order to provide evidence for ease of use.

Models of junctional tourniquet could perform differentially by blood loss, time to hemostasis, and user preference.

In a laboratory experiment, 30 users controlled simulated hemorrhage from a manikin (Combat Ready Clamp [CRoC] Trainer) with three iterations each of three junctional tourniquets. There were 270 tests which included hemorrhage control (yes/no), time to hemostasis, and blood volume lost. Users also subjectively ranked tourniquet performance. Models included CRoC, Junctional Emergency Treatment Tool (JETT), and SAM Junctional Tourniquet (SJT). Time to hemostasis and total blood loss were log-transformed and analyzed using a mixed model analysis of variance (ANOVA) with the users represented as random effects and the tourniquet model used as the treatment effect. Preference scores were analyzed with ANOVA, and Tukey’s honest significant difference test was used for all post-hoc pairwise comparisons.

All tourniquet uses were 100% effective for hemorrhage control. For blood loss, CRoC and SJT performed best with least blood loss and were significantly better than JETT; in pairwise comparison, CRoC-JETT (P < .0001) and SJT-JETT (P = .0085) were statistically significant in their mean difference, while CRoC-SJT (P = .35) was not. For time to hemostasis in pairwise comparison, the CRoC had a significantly shorter time compared to JETT and SJT (P < .0001, both comparisons); SJT-JETT was also significant (P = .0087). In responding to the directive, “Rank the performance of the models from best to worst,” users did not prefer junctional tourniquet models differently (P > .5, all models).

The CRoC and SJT performed best in having least blood loss, CRoC performed best in having least time to hemostasis, and users did not differ in preference of model. Models of junctional tourniquet performed differentially by blood loss and time to hemostasis.

KraghJFJr , LunatiMP , KharodCU , CunninghamCW , BaileyJA , StockingerZT , CapAP , ChenJ , AdenJK3d , CancioLC . Assessment of Groin Application of Junctional Tourniquets in a Manikin Model. Prehosp Disaster Med. 2016;31(4):358–363.