Is tactical combat casualty care in terrorist attacks suitable for civilian first responders?

INTRODUCTION: Prehospital management of intentional mass casualty incidents is a unique challenge to Emergency Medical Services. Tactical Combat Casualty Care (TCCC) and the use of tourniquets for extremity hemorrhage have already proven to reduce mortality on the battlefield. This literature review aims to determine the place of these military concepts in a civilian high-threat prehospital setting. METHODS: The PubMed database was searched for articles published between January 1, 2000, and December 1, 2019, containing descriptions, discussions, or experiences of the application of tourniquets or other TCCC-based interventions in the civilian prehospital setting. Data extraction focused on identifying important common themes in the articles. RESULTS: Of the 286 identified articles, 30 were selected for inclusion. According to the Oxford Centre for Evidence-based Medicine Levels of Evidence, overall level of evidence was low. Most articles were observational, retrospective cohort studies without a nontourniquet control group. Outcome measures and variables were variably reported. Two articles specifically analyzed tourniquet use during high-threat situations, and three described their application by law enforcement personnel. Overall, tourniquets were found to be effective in stopping major limb bleeding. Reported mortality was low and related complications appeared to be infrequent. Only four articles mentioned the application of other TCCC-based maneuvers, such as airway and respiratory management. CONCLUSION: This literature review shows that tourniquets appear to be safe tools associated with few complications and might be effective in controlling major bleeding in civilian limb trauma. For example, during mass casualty incidents, their use could be justified. Training and equipping ambulance and police services to deal with massive bleeding could likewise improve interoperability and victim survival in a civilian high-threat prehospital setting. More qualitative research is needed to further evaluate the effects of hemorrhage control training for first responders on patient outcomes. Literature describing the application of other TCCC-based principles is limited, which makes it difficult to draw conclusions regarding their use in a civilian setting. LEVEL OF EVIDENCE: Systematic review, level III.

Combat Application Tourniquet fares well in a chemical, biological, radiological or nuclear dress state.

INTRODUCTION: There is a need for a military tourniquet to control catastrophic haemorrhage in a chemical, biological, radiological or nuclear (CBRN) threat environment. No published data exist as to the efficacy of tourniquets while wearing British military CBRN individual protective equipment (IPE). METHODS: 12 volunteers from the counter CBRN instructors' course allowed testing on 24 legs. A Combat Application Tourniquet (C-A-T) was applied to all volunteers at the level of the midthigh. 12 legs were tested while wearing CBRN IPE (both operator and simulated casualty), and the control group of 12 legs was tested while wearing conventional combat dress state (both operator and simulated casualty). The order of leg laterality and dress state were sequenced according to a prerandomised system. Efficacy was measured via use of an ultrasound probe at the popliteal artery. Tourniquets were considered effective if arterial flow was completely occluded on ultrasound imaging. Data were collected on time to successful application, failure of tourniquets and pain scores as rated by the visual analogue scale (1-10). RESULTS: There were no failures of tourniquet application in the CBRN group, and two failures (17%) in the control group. Failures were pain threshold exceeded (n=1) and tourniquet internal strap failure (n=1). The mean application time for the CBRN group was 28.5 s (SD 11.7) and 23.7 s (SD 9.8) for the conventional combat group. There was no statistically significant difference (p=0.27). The median CBRN pain score was 2.0 (IQR 2.0-3.5). The median control pain score was 4.0 (IQR 3-6). This was a statistically significant difference (p=0.002). CONCLUSION: C-A-Ts applied to simulated casualties in CBRN IPE at the midthigh are at least as efficacious as those applied to the midthigh in a conventional combat dress state. The pain experienced was less in CBRN IPE than when in a conventional combat dress state.

Managing junctional haemorrhage in the combat environment.

Tactical combat casualty care and the application of extremity tourniquets have saved lives in combat. In the modern combat environment junctional injuries are common and difficult to treat. Recently, junctional tourniquets have emerged as a potential solution to this problem. Junctional tourniquets can be used as an adjunct to persistent haemorrhage despite application of conventional tourniquets or in the persistently hypotensive casualty. Surgeons must have an approach to receiving patients with junctional tourniquets in place in the operating room. The algorithms presented allow for an evidence-based and command-driven implantation of junctional tourniquets as part of tactical combat casualty care.

Assessment of the Efficacy and Safety of a Novel, Low-Cost, Junctional Tourniquet in a Porcine Model of Hemorrhagic Shock.

INTRODUCTION: Commercially available junctional tourniquets (JTQs) have several drawbacks. We developed a low-cost, compact, easy to apply JTQ. The aim of this study was to assess the tourniquets' safety and efficacy in a swine model of controlled hemorrhage. MATERIALS AND METHODS: Five pigs were subjected to controlled bleeding of 35% of their blood volume. Subsequently, the JTQ was applied to the inguinal area for 180 minutes. Afterwards, the tourniquet was removed for additional 60 minutes of follow up. During the study, blood flow to both hind limbs and blood samples for tissue damage markers were repeatedly assessed. Following sacrifice, injury to both inguinal areas was evaluated microscopically and macroscopically. RESULTS: Angiography demonstrated complete occlusion of femoral artery flow, which was restored following removal of the tourniquet. No gross signs of tissue damage were noticed. Histological analysis revealed mild necrosis and infiltration of inflammatory cells. Blood tests showed a mild increase in potassium and lactic acid levels throughout the protocol. CONCLUSIONS: The tourniquet achieved effective arterial occlusion with minimal tissue damage, similar to reports of other JTQs. Subjected to further human trials, the tourniquet might be a suitable candidate for widespread frontline deployment because of its versatility, compactness, and affordable design.

Carpal Tunnel Release without a Tourniquet: A Systematic Review and Meta-Analysis.

BACKGROUND: Open carpal tunnel release is commonly performed with the use of a tourniquet. The combination of local anesthetic and epinephrine with a pneumatic tourniquet helps provide clear visualization during decompression of the median nerve. There has been a rapid expansion of literature challenging the use of tourniquets in open carpal tunnel release. Consequently, the local anesthesia/no tourniquet approach has become increasingly popular. The authors evaluated the outcomes of awake open carpal tunnel release with and without a tourniquet. METHODS: The authors attempted to identify all relevant studies, regardless of language or publication status. A systematic database search for relevant studies was conducted in MEDLINE, EMBASE, EBSCO, and CENTRAL. Included studies compared patients undergoing awake open carpal tunnel release with and without an arm or forearm tourniquet. RESULTS: Eight studies evaluating 765 patients and 866 hands were included. Open carpal tunnel release with the wide awake, local anesthesia, no tourniquet approach resulted in a 2.14 point reduction on the visual analog scale (95% CI, 1.30 to 2.98; p < 0.001). The procedure was 1.82 minutes faster with the use of a tourniquet (95% CI, -3.26 to -0.39; p = 0.01). There were no significant differences between groups in intraoperative blood loss, surgeon perceived difficulty, and complications. CONCLUSION: This systematic review found that tourniquet use causes significantly more pain with no significant clinical benefit as compared with using a wide awake, no tourniquet approach in carpal tunnel decompression.

Effectiveness of the American College of Surgeons Bleeding Control Basic Training Among Laypeople Applying Different Tourniquet Types: A Randomized Clinical Trial.

Importance: More than 500 000 laypeople in the United States have been trained in hemorrhage control, including tourniquet application, under the Stop the Bleed campaign. However, it is unclear whether after hemorrhage control training participants become proficient in a specific type of tourniquet or can also use other tourniquets effectively. Objective: To assess whether participants completing the American College of Surgeons Bleeding Control Basic (B-Con) training with Combat Application Tourniquets (CATs) can effectively apply bleeding control principles using other tourniquet types (commercial and improvised). Design, Setting, and Participants: This nonblinded, crossover, sequential randomized clinical trial with internal control assessed a volunteer sample of laypeople who attended a B-Con course at Gillette Stadium and the Longwood Medical Area in Boston, Massachusetts, for correct application of each of 5 different tourniquet types immediately after B-Con training from April 4, 2018, to October 9, 2018. The order of application varied for each participant using randomly generated permutated blocks. Interventions: Full B-Con course, including cognitive and skill sessions, that taught bleeding care, wound pressure and packing, and CAT application. Main Outcomes and Measures: Correct tourniquet application (applied pressure of ≥250 mm Hg with a 2-minute time cap) in a simulated scenario for 3 commercial tourniquets (Special Operation Forces Tactical Tourniquet, Stretch-Wrap-and-Tuck Tourniquet, and Rapid Application Tourniquet System) and improvised tourniquet compared with correct CAT application as an internal control using 4 pairwise Bonferroni-corrected comparisons with the McNemar test. Results: A total of 102 participants (50 [49.0%] male; median [interquartile range] age, 37.5 [27.0-53.0] years) were included in the study. Participants correctly applied the CAT at a significantly higher rate (92.2%) than all other commercial tourniquet types (Special Operation Forces Tactical Tourniquet, 68.6%; Stretch-Wrap-and-Tuck Tourniquet, 11.8%; Rapid Application Tourniquet System, 11.8%) and the improvised tourniquet (32.4%) (P < .001 for each pairwise comparison). When comparing tourniquets applied correctly, all tourniquet types had higher estimated blood loss, had longer application time, and applied less pressure than the CAT. Conclusions and Relevance: The B-Con principles for correct CAT application are not fully translatable to other commercial or improvised tourniquet types. This study demonstrates a disconnect between the B-Con course and tourniquet designs available for bystander first aid, potentially stemming from the lack of consensus guidelines. These results suggest that current B-Con trainees may not be prepared to care for bleeding patients as tourniquet design evolves. Trial Registration: ClinicalTrials.gov identifier: NCT03538379.

Health professionals' practices related with tourniquet use during peripheral venipuncture: a scoping review. / Práticas relacionadas ao uso do garrote durante a punção venosa periférica: uma revisão de escopo.

OBJECTIVES: during peripheral venipuncture, health professionals are recommended to use a tourniquet above the puncture site in order to potentiate venous distension. Given its characteristics and use in clinical settings, tourniquets may represent a source of microorganism dissemination. However, the results of scientific studies in this area are scattered in the literature. This scoping review aims to map the available evidence on health professionals' practices related with tourniquet use during peripheral venipuncture and associated microbiological contamination. METHODS: scoping review following the Joanna Briggs Institute methodology. Two independent reviewers analyzed the relevance of the studies, extracted and synthesized data. RESULTS: fifteen studies were included in the review. Overall, tourniquets were reused without being subject to recurring decontamination processes. It has been found that practitioners share these devices among themselves and use them successively for periods between two weeks and seven and half years. CONCLUSION: nursing practices related to tourniquet use during peripheral venipuncture are not standard. Reuse of tourniquets may jeopardize the patient's safety if reprocessing (cleaning and disinfection/sterilization) is not adequate, given the type of tourniquet material and microbiota found. New studies are needed to assess the impact of various types of reprocessing practices on tourniquet decontamination and patient safety.

Adult Tourniquet for Use in School-Age Emergencies.

BACKGROUND: Gunshot injuries are a leading cause of morbidity and mortality in the pediatric population. The Pediatric Trauma Society supports the use of tourniquets for exsanguinating hemorrhage in severe extremity trauma. The Combat Application Tourniquet (CAT) used with success in adults has not been prospectively tested in children. Our objective with this study was to determine if the CAT is successful in arresting extremity arterial blood flow in school-aged children. METHODS: Sixty school-aged volunteers (ages 6-16 years) recruited by age cohort had the CAT applied to an upper arm and thigh while peripheral pulse was monitored by Doppler. The number of windlass turns (maximum allowed: 3 [1080°]) required to arrest arterial pulse was recorded. Success was analyzed by BMI percentile for age and extremity circumference. RESULTS: The CAT was successful in occluding arterial blood flow as detected by Doppler pulse in all 60 (100%) of the upper extremities tested. In the lower extremity, 56 (93%) had successful occlusion. The 3-turn maximum allowed by the protocol was not adequate in some obese, older subjects (BMI >30). In both the upper and lower extremity, the number of turns required to occlude blood flow gradually increased with an increase in arm and thigh circumference. CONCLUSIONS: Prospective testing of a cohort of school-aged children 6 to 16 years revealed the CAT tourniquet to be suitable for use in both the upper and lower extremity.

Preliminary Investigation of Civilian Clinician Perspectives & Just-in-Time Guidance for Tourniquet Use to "Stop the Bleed".

OBJECTIVE: The American College of Surgeons (ACS) encourages clinicians to provide training to laypeople on tourniquet application. It is unclear whether clinicians are confident in their abilities and equipped with adequate knowledge, skills, and resources. This study aimed to determine surgical trainee knowledge and attitudes regarding tourniquet application and compare the effectiveness of instructions. METHODS: Thirty surgical trainees performed a tourniquet application simulation using a Combat Application Tourniquet and one of the three instructions sets developed by ACS, Department of Homeland Security, and the tourniquet manufacturer. Participants reported tourniquet knowledge, attitudes, and confidence and discussed the instructions. One instruction set was updated and compared to the original set with 20 new trainees. RESULTS: Participants with ACS instructions passed the greatest number of steps (p < 0.01) and completed the task significantly faster compared to those with manufacturer instructions (p < 0.01). Participants (80%) reported favorable views toward tourniquets but 30-60% did not align with to ACS tourniquet guidelines. Focus group participants suggested revisions to the ACS instructions. Comparing the original and revised version of these instructions resulted in no significant improvements. CONCLUSIONS: ACS instructions provide guidance; however, improvements to tourniquet instruction are needed for success in controlling exsanguinating hemorrhage.

Sweating the Little Things: Tourniquet Application Efficacy in Two Models of Pediatric Limb Circumference.

BACKGROUND: Current military recommendations include the use of tourniquets (TQ) in appropriate pediatric trauma patients. Although the utility of TQs has been well documented in adult patients, the efficacy of TQ application in pediatric patients is less clear. The current study attempted to identify physical constraints for TQ use in two simulated pediatric limb models. METHODS: Five different TQ (Combat Application Tourniquet (CAT) Generation 6 and Generation 7, SOFTT (SOF Tactical Tourniquet), SOFTT-W (SOF Tactical Tourniquet - Wide), SWAT-T (Stretch Wrap and Tuck - Tourniquet) and a trauma dressing were evaluated in two simulated pediatric limb models. Model one employed four cardiopulmonary resuscitation (CPR) manikins simulating infant (Simulaids SaniBaby), 1 year (Gaumard HAL S3004), and 5 years (Laerdal Resusci Junior, Gaumard HAL S3005). Model two utilized polyvinyl chloride (PVC) piping with circumferences ranging from 4.25" to 16.5". Specific end-points included tightness of the TQ and ability to secure the windlass (where applicable). RESULTS: In both models, the ability to successfully apply and secure the TQ depended upon the simulated limb circumference. In the 1-year-old CPR manikin, all windlass TQs failed to tighten on the upper extremity, while all TQs successfully tightened at the high leg and mid-thigh. With the exception of the CAT7 and the SOFTT-W at the mid-thigh, no windlass TQ was successfully tightened at any extremity location on the infant. The SWAT-T was successfully tightened over all sites of all CPR manikins except the infant. No windlass TQ was able to tighten on PVC pipe 5.75" circumference or smaller (age < 24 months upper extremity). All windlass TQs were tightened and secured on the 13.25" and 15.5" circumference PVC pipes (age 7-12 years lower extremity, age >13 years upper extremity). The SWAT-T was tightened on all PVC pipes. DISCUSSION: The current study suggests that commercial windlass TQs can be applied to upper and lower extremities of children aged 5 years and older at the 50%th percentile for limb circumference. In younger children, windlass TQ efficacy is variable. Further study is required to better understand the limitations of TQs in the youngest children, and to determine actual hemorrhage control efficacy.

Minimally invasive preperitoneal balloon tamponade and abdominal aortic junctional tourniquet versus open packing for pelvic fracture-associated hemorrhage: Not all extrinsic compression is equal.

BACKGROUND: Minimally invasive preperitoneal balloon tamponade (PPB) and abdominal aortic junctional tourniquets (AAJT) have been proposed as alternatives to open preperitoneal packing (OP) for the management of pelvic fracture-associated hemorrhage. We hypothesized that the PPB (SpaceMaker Pro) and AAJT would result in similar rates of survival and blood loss versus OP. METHODS: Thirty-two swine underwent creation of a combined open-book pelvic fracture and major iliac vascular injuries. Animals were randomized to no intervention (n = 7), OP (n = 10), PPB (n = 9), or AAJT (n = 6) at a mean arterial pressure <40 mm Hg following initiation of uncontrolled hemorrhage. Survival (up to 60 minutes + 10 minutes after intervention reversal), hemodynamics, extraperitoneal pressures, blood loss, and associated complications were compared between groups. RESULTS: Prior to injury, no difference was measured between groups for weight, hemodynamics, lactate, and hematocrit (all p > 0.05). The injury was uniformly lethal without intervention, with survival time (mean) of 5 minutes, peak preperitoneal pressure (PP) of 14 mm Hg, blood loss of 960 g, and peak lactate of 2.6 mmol/L. Survival time was 44 minutes with OP versus 60 minutes with PPB and AAJT (p < 0.01). Peak PP (mm Hg) was 19 with OP, 23 with PPB, and 23 with AAJT (p > 0.05). Blood loss (g) was 850 with OP, 930 with PPB, and 600 with AAJT (p > 0.05). Peak lactate (mmol/L) was 3.3 with OP, 4.3 with PPB, and 6.3 with AAJT (p < 0.01). Only 33% of AAJT animals survived intervention reversal versus 60% for OP and 67% for PPB (p < 0.01). Necropsy revealed bowel/bladder injury in 50% of AAJT subjects versus 0% in all other arms (p < 0.01). CONCLUSION: Preperitoneal balloon tamponade is a safe and potentially effective alternative to OP for the management of lethal pelvic fracture-associated hemorrhage. Abdominal aortic junctional tourniquet offers a similar survival benefit to PPB but has concerning rates of ischemia-reperfusion and compressive abdominal organ injury.

Study of Tourniquet Use in Simulated First Aid: User Judgment.

BACKGROUND: The purpose of this study was to survey the judgments of tourniquet users in simulation to discern opportunities for further study. METHODS: The study design constituted two parts: questions posed to four tourniquet users and then their tourniquet use was surveyed in simulated first aid, where the users had to decide how to perform among five different cases. The questions addressed judged confidence, blood volumes, a reason bleeding resumes, regret of preventable death, hemorrhage assessment, need for side-by-side use of tourniquets, shock severity, predicting reliability, and difference in blood losses. The mechanical performance was tested on a manikin. Case 1 had no bleeding. Case 2 had limb-wound bleeding that indicated tourniquet use in first aid. Case 3 was like case 2, except the patient was a child. Case 4 was like case 2, except caregiving was under gunfire. Case 5 was like case 4, but two tourniquets were to be used side by side. Each user made tests of the five cases to constitute a block. Each user had three blocks. Case order was randomized within blocks. The study had 60 tests. RESULTS: In answering questions relevant to first-aid use of limb tourniquets, judgments were in line with previous studies of judgment science, and thus were plausibly applicable. Mechanical performance results on the manikin were as follows: 38 satisfactory, 10 unsatisfactory (a loose tourniquet and nine incorrect tourniquet placements), and 12 not applicable (case 1 needed no mechanical intervention). For cases 1 to 5, satisfactory results were: 100%, 83%, 100%, 75%, and 58%, respectively. For blocks 1 to 3, satisfactory results were 50%, 83%, and 83%, respectively. CONCLUSION: For tourniquet use in simulated first aid, the results are plausibly applicable because user judgments were coherent with those in previous studies of judgment science. However, the opportunities for further studies were noted.

Your Metric Matters! Choose Wisely to Assess User Performance With Tourniquets in Simulated First Aid.

BACKGROUND: Readiness to perform lifesaving interventions during emergencies is based on a person's preparation to proficiently execute the skills required. Graphically plotting the performance of a tourniquet user in simulation has previously aided us in developing our understanding of how the user actually behaves. The purpose of this study was to explore performance assessment and learning curves to better understand how to develop best teaching practices. METHODS: These were retrospective analyses of a convenience sample of data from a prior manikin study of 200 tourniquet uses among 10 users. We sought to generate hypotheses about performance assessments relevant to developing best teaching practices. The focus was on different metrics of user performance. RESULTS: When one metric was chosen over another, failure counts summed cumulatively over 200 uses differed as much as 12-fold. That difference also indicated that the degree of challenge posed to user performance differed by the metric chosen. When we ranked user performance with one metric and then with another, most (90%; nine of 10) users changed rank: five rose and four fell. Substantial differences in performance outcomes resulted from the difference in metric chosen, which, in turn, changed how the outcome was portrayed and thus interpreted. Hypotheses generated included the following: The usefulness of a specific metric may vary by the user's level of skill from novice to expert; demonstration of the step order in skill performance may suffice for initial training of novices; a mechanical metric of effectiveness, like pulse stoppage, may aid in later training of novices; and training users how to practice on their own and self-assess performance may aid their self-development. CONCLUSION: The outcome of the performance assessments varied depending on the choice of metric in this study of simulated use of tourniquets.

Comparison of Two Tourniquets on a Mid-Thigh Model: The Israeli Silicone Stretch and Wrap Tourniquet vs. The Combat Application Tourniquet.

Introduction: Experience from recent conflicts underlines the dramatic impact of effective tourniquet use on combat casualty mortality. Although the Combat Application Tourniquet (CAT) is replacing the silicone band tourniquets (IST; "Israeli Silicone Tourniquet") in the Israeli Defense Forces, no direct comparison was made between them. The purpose of this study is to compare the performance of the two tourniquets on a mid-thigh model. Methods: Participants were Israeli military recruits who previously had the military first aid course. Each participant applied both the CAT and the IST. Applications were assessed by the HapMed Leg Tourniquet Trainer, which measured the applied pressure and the time required to reach it. Results: IST application resulted in higher rates of effective occlusion pressure compared with the CAT (91% vs. 73.1%, p < 0.01), and a higher mean occlusion pressure (41 mmHg, p < 0.01) was recorded using the IST. Among effective attempts, application time did not differ significantly between the tourniquets. Conclusion: The IST was superior to the CAT in producing effective occlusion pressure while not prolonging application time. These results may indicate that the IST remains a valid option for controlling mid-thigh bleeding.

The Platinum 5 min in TCCC: Analysis of Junctional and Extremity Hemorrhage Scenarios with a Mathematical Model.

Introduction: To achieve the aim of zero preventable deaths on the battlefield a deeper understanding of uncontrolled hemorrhage from junctional or proximal extremity sources is mandatory. While tourniquet application to the extremities has drastically reduced morbidity and mortality, there is still room for improvement regarding the timing of tourniquet placement as the available evidence clearly points out a tight correlation between timing of tourniquet application and outcome. To save as many lives as possible the "point of no return" regarding the circulatory breakdown due to hemorrhage, colloquially addressed as platinum 5 min, needs to be determined. As clinical analysis or controlled studies are difficult, if not impossible, and animal experiments cannot be translated to bleeding in humans, we present a mathematical modeling approach. The key assumption of the model is that hemodynamics in the early phase of massive hemorrhage are determined by the cardiac function, the passive physical properties of the vascular system, that is, compliances etc., as humoral compensatory mechanisms kick in at a later point in time, and the baroceptor reflex, which constitutes the immediate response to volume loss. Materials and Methods: A lumped mathematical model based on differential equations describing three distinct arterial and two venous compartments, the heart and the baroceptor mechanism is developed. With this model, different patterns of blood loss (%) and duration of bleeding (s) are simulated: 10%/30 and 60 s, 20%/30 and 60 s, 30%/30, 60 and 120 s, and 35%/30, 120 and 180 s. These bleeding patterns are chosen such that they resemble clinically scenarios following junctional and proximal extremity injuries. Results: Three hemodynamic patterns can be distinguished. The system stabilizes on a lower blood pressure level (10%/30 and 60 s, 20%/30 and 60 s), the system formally stabilizes on a very low level, which is physiologically not reasonable (30%/30, 60 and 120 s), the system irreversibly breaks down with no signs of restabilization (35%/30, 120 and 180 s). Conclusion: Thus the immediacy of intervention in terms of application of a tourniquet is clearly emphasized by the simulation, that is, the window of opportunity for a life-saving intervention, especially in a combat setting, is significantly smaller than the symbolic "platinum five minutes" might suggest. With respect to the 3-min window of opportunity identified in the simulations the effective application of these devices in a TCCC setting appears questionable. Given these observations, further research and development into solutions that allow the timely identification of a junctional bleeding problem and application of compression is necessary.

Evaluation of tourniquet application in a simulated tactical environment.

BACKGROUND: Application of a tourniquet in a tactical environment is implemented in two ways: the so-called self-aid, which is the application of a tourniquet by the injured, and the so-called buddy aid, which is the application of a tourniquet by the person provide aid. This study aimed to test the quality of tourniquet use in a simulated situation, close quarter battle. METHODS: The study involved 24 injured operators and 72 operators in the whole simulation, implying 12 sections of six individuals. To validate the application of tourniquets, the recommendations of the Committee of Tactical Combat Care of the Injured were used, and ultrasound with Doppler function was employed to assess the hemodynamic effect of applying tourniquets. RESULTS: Native flow was observed in 15 operators; in three people, a trace flow was noticed, whereas in six people, a full flow was observed. No significant difference was found between the qualities of tourniquet application by the operators themselves compared with those of tourniquet application by another person. The median distance of tourniquet application from the armpit was 9.5 cm for self-aid and buddy aid. In 16 participants the outer arrangement of tourniquets was observed, and in only eight participants tourniquets were correctly located on the internal part of the arm. In 18 participants, tourniquets were not correctly prepared for use in the tactical environment, whereas in only six participants, they were correctly prepared. Most operators with a negative ultrasound flow revealed negative distal observed pulse (DOP). Positive DOP occurred in the majority of operators with full ultrasound flow. CONCLUSION: The application of tourniquets poses a challenge even in case of specialized units; therefore, there is a need to provide regular training for implementing that procedure.

The Tourniquet Gap: A Pilot Study of the Intuitive Placement of Three Tourniquet Types by Laypersons.

BACKGROUND: The "Stop the Bleed" campaign in the United States advocates for nonmedical personnel to be trained in basic hemorrhage control and that "bleeding control kits" be available in high-risk areas. However, it is not clear which tourniquets are most effective in the hands of laypersons. OBJECTIVES: The objective of this pilot study was to determine which tourniquet type was the most intuitive for a layperson to apply correctly. METHODS: This project is a randomized study derived from a "Stop the Bleed" education initiative conducted between September 2016 and March 2017. Novice tourniquet users were randomized to apply one of three commercially available tourniquets (Combat Action Tourniquet [CAT; North American Rescue, LLC, Greer, SC], Ratcheting Medical Tourniquet [RMT; m2 Inc., Winooski, VT], or Stretch Wrap and Tuck Tourniquet [SWAT-T; TEMS Solutions, LLC, Salida, CO]) in a controlled setting. Individuals with formal medical certification, prior military service, or prior training with tourniquets were excluded. The primary outcome of this study was successful tourniquet placement. RESULTS: Of 236 possible participants, 198 met the eligibility criteria. Demographics were similar across groups. The rates of successful tourniquet application for the CAT, RMT, and SWAT-T were 16.9%, 23.4%, and 10.6%, respectively (p = 0.149). The most common causes of application failure were: inadequate tightness (74.1%), improper placement technique (44.4%), and incorrect positioning (16.7%). CONCLUSION: Our pilot study on the intuitive nature of applying commercially available tourniquets found unacceptably high rates of failure. Large-scale community education efforts and manufacturer improvements of tourniquet usability by the lay public must be made before the widespread dissemination of tourniquets will have a significant public health effect.

A study of the blood flow restriction pressure of a tourniquet system to facilitate development of a system that can prevent musculoskeletal complications.

BACKGROUND: After an emergency or disaster, subsequent trauma can cause severe bleeding and this can often prove fatal, so promptly stopping that bleeding is crucial to preventing avoidable trauma deaths. A tourniquet is often used to restrict blood flow to an extremity. In operation and hospital, the tourniquet systems currently in use are pneumatically actuated by an air compressor, so they must have a steady power supply. These devices have several drawbacks: they vibrate and are noisy since they are pneumatically actuated and they are far from portable since they are large and heavy. INTRODUCTION: Presumably, the drawbacks of pneumatic tourniquets could be overcome by developing a small, lightweight, vibration-free, quiet, and battery-powered tourniquet system. The current study built a small, vibration-free electrohydrodynamic (EHD) pump and then used that pump to restrict blood flow to the leg of rats in an experiment. This study explored the optimal conditions for effective restriction of blood flow by assessing biochemical and musculoskeletal complications following the restriction of blood flow, and this study also examined whether or not an EHD pump could be used to actuate a tourniquet system. METHODS: A tourniquet cuff (width 12 mm × length 150 mm, material: polyolefin) was placed on the thigh of Wistar rats and pressure was applied for 2 hours by a device that uses EHD phenomena to generate pressure (an EHD pump). Animals were divided into four groups based on how much compressive pressure was applied with a tourniquet: 40 kPa (300 mm Hg, n = 13), 30 kPa (225 mm Hg, n = 12), 20 kPa (150 mm Hg, n = 15), or 0 kPa (controls, n = 25). Tissue oxygen saturation (regional oxygen saturation, denoted here as rSO2) was measured to assess the restriction of blood flow. To assess behavior once blood flow resumed, animal activity was monitored for third day and the amount of movement was counted with digital counters. Body weight was measured before and after the behavioral experiment, and changes in body weight were determined. Blood was sampled after a behavioral experiment and biochemically assessed and creatine kinase (CK) levels were measured. RESULTS: Tissue oxygen saturation decreased significantly in each group. When a tourniquet was applied at a pressure of 30 kPa or more, tissue oxygen saturation decreased significantly. The amount of movement (the count) over third day decreased more when a tourniquet was applied at a higher pressure. The control group resumed the same amount of movement per day second after blood flow resumed. Animals to which a tourniquet was applied at a pressure of 20 or 30 kPa resumed the same amount of movement third day after blood flow resumed. In contrast, animals to which a tourniquet was applied at a pressure of 40 kPa did not resume the same amount of movement third day after blood flow resumed. After the behavioral experiment, animals to which a tourniquet was applied at a pressure of 40 kPa had a significantly lower body weight in comparison to the control group. After the behavioral experiment, animals to which a tourniquet was applied at a pressure of 40 kPa had significantly elevated CK levels in comparison to the control group. DISCUSSION AND CONCLUSION: A relationship between blood flow restriction pressure and tissue oxygen saturation was noted. rSO2 measurement can be used to assess the restriction of blood flow during surgery. On the basis of the decrease in rSO2, blood flow was effectively restricted at a pressure of 30 kPa or more. When, however, blood flow was restricted at a pressure of 40 kPa, weight loss and decreased movement were noted and CK levels increased after the behavioral experiment. Thus, complications had presumably developed due to damage to muscle tissue. These findings indicate that blood flow was effectively restricted in this experiment and they also indicate the existence of an optimal blood flow restriction pressure that does not cause musculoskeletal complications. The pressure in question was around 30 kPa. The tourniquet system that was developed here is actuated with an EHD pump that is still in the trial stages. That said, its pressure can readily be controlled and this pump could be used in a tourniquet system since it is quiet, vibration-free, and small. The pressure of this pump can be finely adjusted to prevent musculoskeletal complications.