The safety and efficacy of improvised tourniquets in life-threatening hemorrhage: a systematic review

Arterial Occlusion Effectiveness of Space Blanket‒Improvised Tourniquets for the Remote Setting

INTRODUCTION

Control of severe extremity hemorrhage by tourniquet can save lives. In remote areas or in mass casualty incidents with multiple severely bleeding victims, lack of conventional tourniquets may make it necessary to improvise tourniquets.

METHODS

Occlusion of the radial artery and delayed onset of capillary refill time resulting from windlass-type tourniquets were experimentally investigated by comparing a commercial tourniquet and a space blanket‒improvised tourniquet with a carabiner as a rod. This observational study was conducted on healthy volunteers in optimal application circumstances.

RESULTS

Operator-applied Combat Application Tourniquets were deployed more swiftly (27 s, 95% CI: 25.7-30.2 vs 94 s, 95% CI: 81.7-114.4) and achieved 100% complete radial occlusion compared with improvised tourniquets, as assessed by Doppler sonography (P<0.001). When space blanket‒improvised tourniquets were used, traces of radial perfusion persisted in 48% of the applications. In Combat Application Tourniquets, capillary refill times were significantly delayed (7 s, 95% CI: 6.0-8.2 vs 5 s, 95% CI: 3.9-6.3) compared with those when using improvised tourniquets (P=0.013).

CONCLUSIONS

Improvised tourniquets should be considered only in dire circumstances with uncontrolled extremity hemorrhage and when no commercial tourniquets are available. Complete arterial occlusion was achieved in only half of the applications using a space blanket‒improvised tourniquet when a carabiner was used as a windlass rod. The speed of application was inferior to that for Combat Application Tourniquets. Similar to Combat Action Tourniquets, the correct assembly and application of space blanket‒improvised tourniquets on upper and lower extremities have to be trained.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: BASG No.: 13370800/15451670.

Tourniquet Use in the Prehospital Setting

PURPOSE

Tourniquets are a mainstay of life-saving hemorrhage control. The US military has documented the safety and effectiveness of tourniquet use in combat settings. In civilian settings, events such as the Boston Marathon bombing and mass shootings show that tourniquets are necessary and life-saving entities that must be used correctly and whenever indicated. Much less research has been done on tourniquet use in civilian settings compared to military settings. The purpose of this study is to describe the prehospital use of tourniquets in a regional EMS system served by a single trauma center.

METHODS

All documented cases of prehospital tourniquet use from 2015 to 2020 were identified via a search of EMS, emergency department, and inpatient records, and reviewed by the lead investigator. The primary outcomes were duration of tourniquet placement, success of hemorrhage control, and complications; secondary outcomes included time of day (by EMS arrival time), transport interval, extremity involved, who placed/removed the tourniquet, and mechanism of injury.

RESULTS

Of 182 patients with 185 tourniquets applied, duration of application was available for 52, with a median (IQR) of 43 (56) minutes. Hemorrhage control was achieved in all but two cases (96%). Three cases (5.8%) required more than one tourniquet. Complications included five cases of temporary paresthesia, one case of ecchymosis, two cases of fasciotomy, and two cases of compression nerve injury. The serious complication rate was 7.7% (4/52). Time of day was daytime (08:01-16:00) = 15 (31.9%), evening (16:01-00:00) = 27 (57.4%), and night (00:01- 08:00) = 5 (10.6%). The median transport interval was 22 (IQR 5] minutes. The limbs most often injured were the left and right upper extremities (15 each). EMS clinicians and police officers were most often the tourniquet placers. Common mechanisms of injury included gunshot wounds, motorcycle accidents, and glass injuries.

CONCLUSION

Tourniquets used in the prehospital setting have a high rate of hemorrhage control and a low rate of complications.

Tourniquets, types and techniques in emergency prehospital care: A narrative review

Massive uncontrolled hemorrhage is an important cause of preventable death in trauma. Therefore, applying an arterial tourniquet (TQ) is recommended as a pre-hospital measure to control bleeding after severe traumatic bleeding. Limb TQ applies circumferential compression proximally to the injury site to compress the arteries, resulting in blood flow and consequently hemorrhage interruption. The use of commercial tourniquets (C-TQ), which are designed, tested, and registered to control hemorrhages in pre-hospital care, is a consensus. However, they are still uncommon in many prehospital emergency services and the overall level of evidence in most studies is low. This narrative review aimed to characterize the importance of tourniquets use in prehospital emergency care and its application techniques. Furthermore, it proposes to stimulate the development of new devices, more accessible and easier to use, to suggest new directions of studies and medical education demands, with manikin and simulation development.

Effectiveness of Pre-Hospital Tourniquet in Emergency Patients with Major Trauma and Uncontrolled Haemorrhage: A Systematic Review and Meta-Analysis

Trauma is one of the leading causes of uncontrolled haemorrhage, death, and disability. Use of a tourniquet can be considered an optimal anti-haemorrhagic resource, in pre-hospital and emergency settings, and its lifesaving effect is clinically contradictory. This review aims to assess the clinical efficacy of the tourniquet in the emergency pre-hospital care setting for the management of haemorrhage. We conducted the systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, the PRISMA statement. We searched the following electronic databases: EMBASE, MEDLINE, and Cochrane-CENTRAL. All studies included were appraised for risk of bias. Prevalent primary outcomes were mortality and use of blood products. Secondary outcomes were related to adverse effects. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach (GRADE). Four studies were involved (1762 trauma patients). The adjusted odds ratio (aOR) of 0.47 (95% confidence Interval (CI) 0.19-1.16; three studies; 377 patients) for overall mortality estimates did not give a clear indication of the benefits of emergency pre-hospital tourniquets (PH-TQ) versus no pre-hospital tourniquet (NO PH-TQ) placement. The adjusted mean difference for blood product use was -3.28 (95% CI -11.22, 4.66) for packed red blood cells (pRBC) and -4.80 (95% CI -5.61, -3.99) for plasma, respectively. The certainty of evidence was downgraded to very low for all outcomes. Our results suggest an unclear effect of emergency pre-hospital tourniquet placement on overall mortality and blood product use. However, this systematic review highlights the availability of only observational studies and the absence of high quality RCTs assessing the efficacy of PH-TQs. Randomized controlled trials are needed.

Tourniquets as a haemorrhage control measure in military and civilian care settings: An integrative review

AIMS AND OBJECTIVES

The aim of review was to describe and synthesise the evidence on the use of tourniquets to control haemorrhages, summarising both civilian and military use.

BACKGROUND

Trauma-related haemorrhage constitutes one of the most preventable deaths among injured patients, particularly in multi-casualty incidents and disasters. In this context, safe instruments such as tourniquets are essential to help healthcare professionals to minimise loss of life and maximise patient recovery.

DESIGN AND METHODS

An integrative review was conducted in Medline, Nursing & Allied Health Premium, and Health & Medical Collection, using published data until March 2021 and following the PRISMA guidelines.

RESULTS

A total of 25 articles were included. Evidence has been synthesised to understand the use of different types of tourniquets, environment of application, indication for their placement and potential complications associated with tourniquet placement.

CONCLUSIONS

Commercial tourniquets such as Combat Application Tourniquet or Emergency Tourniquet models are a valuable and safe instrument for haemorrhage control in both military and civilian out-of-hospital care settings. Nurses, as part of emergency teams, and other professionals should be aware that there is a possibility of adverse complications, but they are directly proportional to the time of tourniquet placement and generally temporary. In addition, national and international guidelines ensure the need for all civilian emergency services to be equipped with these devices, as well as for the training of healthcare professionals and first responders in their use.

RELEVANCE TO CLINICAL PRACTICE

Despite the lack of complications in the use of tourniquets in these cases, their use has been a matter of debate for decades. In this sense, this review yields up-to-date guidelines in the use of tourniquets, their recommendations and their significance among professionals to manage complicated situations.

Tourniquet application by schoolchildren-a randomized crossover study of three commercially available models

BACKGROUND

Life-threatening hemorrhage is a major cause of preventable mortality in trauma. Studies have demonstrated the effectiveness and safety of commercial tourniquets when used by adult civilians. However, there are no data about tourniquet application by children.This study's goal is to determine which of three commercially available tourniquets is most effective when used by children.

METHODS

A randomized crossover study was conducted in four elementary schools in Montreal to compare three commercially available tourniquets. The study population is primary school children aged 10 to 12 years (5th-6th grade). A total of 181 students were invited to participate; 96 obtained parental approval and were recruited. Participants underwent a short 7-minute video training on the use of three commercial tourniquets and were subsequently given a 2-minute practice period. Students were evaluated on their ability to successfully apply the tourniquet and the time to complete application. After applying all three tourniquets, the students selected their favorite model. The primary outcome is the proportion of successful applications per tourniquet model. Secondary outcomes include time to successful application for each tourniquet model and tourniquet model preference.

RESULTS

The mechanical advantage tourniquet (MAT) outperformed the combat application tourniquet (CAT) and the stretch wrap and tuck tourniquet (SWATT) in terms of success rate (MAT, 67%; CAT, 44%; SWATT, 24%; p < 0.0001), time to application (MAT, 57 seconds; CAT, 80 seconds; SWATT, 90 seconds; p < 0.0001), and preference (MAT, 64%; CAT, 30%; SWATT, 6%; p < 0.0001).

CONCLUSION

In this study, the MAT performs better in terms of success rate, time to application, and preference when used by school-aged children. This study can be helpful when facilities are purchasing tourniquets for use by students.

Tourniquet Use in Animal Attacks: An Analysis of News Media Reports

Background

Animal attacks pose a significant public health problem in the United States. Non-venomous animals are the leading cause of mortality in these attacks, and extremity injuries leading to hemorrhage are a common pattern. The Stop the Bleed campaign advocates for public training in bleeding control tactics and public access to bleeding control kits. Controlling life-threatening bleeding, as promoted by the Stop the Bleed campaign, may be a method to reduce preventable death in these attacks.

Methodology

We searched the Nexus Uni database, which compiles international news media articles, to collect newspaper articles in the United States between 2010 and 2019 that referenced animal attacks on humans in which a tourniquet was applied. We screened articles to assess for inclusion criteria and isolated a single report for each attack.

Results

A total of 50 individual attacks met the inclusion criteria and were included for data collection. Overall, 92% (n = 46) of the victims survived the attacks, and the average victim age was 33. California was the most common location of the attacks (n = 12, 24%), sharks caused the most attacks (n = 26, 52%), and victims most often sustained isolated extremity injuries (n = 24, 48% for arm and n = 24, 48% for leg). Laypeople applied the most tourniquets (n = 29, 58%), and appliers most frequently used improvised tourniquets (n = 30, 60%).

Conclusions

While mortality in this series was low, there are hundreds of fatalities from non-venomous animal attacks each year. Equipping and training the at-risk public to stop bleeding may save additional lives. Future Stop the Bleed efforts should improve access to public hemorrhage control equipment and expand educational outreach to people engaged in high-risk activities with animals.

Evaluation of the efficacy of commercial and noncommercial tourniquets for extremity hemorrhage control in a perfused cadaver model

BACKGROUND

Tourniquets are a critical tool in the immediate response to life-threatening extremity hemorrhage; however, the optimal tourniquet type and effectiveness of noncommercial devices remain unclear. Our aim was to evaluate the efficacy of five tourniquets in a perfused-cadaver model.

METHODS

This prospective study used a perfused-cadaver model with standardized superficial femoral artery injury bleeding at 700 mL/min. Five tourniquets were tested: combat application tourniquet; rapid application tourniquet system; Stretch, Wrap, And Tuck Tourniquet; an improvised triangle bandage windlass; and a leather belt. Forty-eight medical students underwent a practical hands-on demonstration of each tourniquet. Using a random number generator, they placed the tourniquets on the bleeding cadaver in random order. Time to hemostasis, time to secure devices, estimated blood loss, and difficulty rating were assessed. A one-way repeated measures analysis of variance was used to compare efficacy between the tourniquets in achieving the outcomes.

RESULTS

The mean ± SD participant age was 25 ± 2.6 years, and 29 (60%) were male. All but one tourniquet was able to stop bleeding, but the rapid application tourniquet system had a 4% failure rate. Time to hemostasis and estimated blood loss did not differ significantly (p > 0.05). Stretch, Wrap, And Tuck Tourniquet required the longest time to be secured (47.8 ± 17.0 seconds), whereas the belt was the fastest (15.2 ± 6.5 seconds; p < 0.001). The improvised windlass was rated easiest to learn and apply, with 22 participants (46%) assigning a score of 1.

CONCLUSION

Four of five tourniquets evaluated, including both noncommercial devices, effectively achieved hemostasis. A standard leather belt was the fastest to place and was able to stop the bleeding. However, it required continuous pressure to maintain hemostasis. The improvised windlass was as effective as the commercial devices and was the easiest to apply. In an emergency setting where commercial devices are not available, improvised tourniquets may be an effective bridge to definitive care.