Effect of prehospital tourniquets on resuscitation in extremity arterial trauma

Effectiveness and safety of tourniquet utilization for civilian vascular extremity trauma in the pre-hospital settings: a systematic review and meta-analysis

BACKGROUND

Tourniquets (TQ) have been increasingly adopted in pre-hospital settings recently. This study examined the effectiveness and safety of applying TQ in the pre-hospital settings for civilian patients with traumatic vascular injuries to the extremities.

MATERIALS AND METHODS

We systematically searched the Ovid Embase, PubMed, and Cochrane Central Register of Controlled Trials databases from their inception to June 2023. We compared pre-hospital TQ (PH-TQ) use to no PH-TQ, defined as a TQ applied after hospital arrival or no TQ use at all, for civilian vascular extremity trauma patients. The primary outcome was overall mortality rate, and the secondary outcomes were blood product use and hospital stay. We analyzed TQ-related complications as safety outcomes. We tried to include randomized controlled trials (RCTs) and non-randomized studies (including non-RCTs, interrupted time series, controlled before-and-after studies, cohort studies, and case-control studies), if available. Pooled odds ratios (ORs) were calculated and the certainty of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology.

RESULTS

Seven studies involving 4,095 patients were included. In the primary outcome, pre-hospital TQ (PH-TQ) use significantly decrease mortality rate in patients with extremity trauma (odds ratio [OR], 0.48, 95% confidence interval [CI] 0.27-0.86, I2 = 47%). Moreover, the use of PH-TQ showed the decreasing trend of utilization of blood products, such as packed red blood cells (mean difference [MD]: -2.1 [unit], 95% CI: -5.0 to 0.8, I2 = 99%) or fresh frozen plasma (MD: -1.0 [unit], 95% CI: -4.0 to 2.0, I2 = 98%); however, both are not statistically significant. No significant differences were observed in the lengths of hospital and intensive care unit stays. For the safety outcomes, PH-TQ use did not significantly increase risk of amputation (OR: 0.85, 95% CI: 0.43 to 1.68, I2 = 60%) or compartment syndrome (OR: 0.94, 95% CI: 0.37 to 2.35, I2 = 0%). The certainty of the evidence was very low across all outcomes.

CONCLUSION

The current data suggest that, in the pre-hospital settings, PH-TQ use for civilian patients with vascular traumatic injury of the extremities decreased mortality and tended to decrease blood transfusions. This did not increase the risk of amputation or compartment syndrome significantly.

Vascular imaging immediately after tourniquet removal does not increase vasospasm risk

BACKGROUND

Prehospital tourniquet use is now standard in trauma patients with diagnosed or suspected extremity vascular injuries. Tourniquet-related vasospasm is an understudied phenomenon that may confound management by causing erroneous arterial pressure indices (APIs) and abnormalities on computed tomography angiography (CTA) that do not reflect true arterial injuries. We hypothesized that shorter intervals between tourniquet removal and CTA imaging and longer total tourniquet times would be correlated with a higher likelihood of false positive CTA.

MATERIALS AND METHODS

We performed a single-institution retrospective cohort study of patients presenting to a busy, urban Level 1 Trauma Center with prehospital tourniquets from 2019 to 2021. Patients who presented with a tourniquet disengaged upon arrival or who died prior to admission to the Trauma Unit were excluded. Tourniquet duration, time between tourniquet removal and CTA imaging (CTA interval), CTA findings, and management of extremity arterial injuries were extracted. The proportion of false positive injuries on CTA was assessed for correlation with increasing time interval from tourniquet removal to CTA imaging and correlation with increasing total tourniquet time using multivariable logistic regression.

RESULTS

251 patients were identified with prehospital tourniquets. 127 underwent CTA of the affected extremity, 96 patients had an abnormal CTA finding, and 57 (45% of total CTA patients) had false positive arterial injuries on imaging. Using multivariable logistic regression, neither the CTA interval nor the tourniquet duration was associated with false positive CTA injuries. Female sex was associated with false positive injuries on CTA (OR 2.91, 95% CI: 1.01 - 8.39). Vasospasm was cited as a possible explanation by radiologists in 40% of false positive CTA reports.

CONCLUSIONS

Arterial vasospasm is a frequent finding on CTA after tourniquet use for extremity trauma, but concerns regarding tourniquet-related vasospasm should not alter trauma patient management. Neither the duration of tourniquet application nor the time interval since removal is associated with decreased CTA accuracy, and any delay in imaging does not appear to reduce the likelihood of vasospasm. These findings are important for supporting expedited care of trauma patients with severe extremity injuries.

Prehospital tourniquet application in extremity vascular trauma: Improved functional outcomes

BACKGROUND

Support for prehospital tourniquet use has increased, with recent data suggesting that tourniquet usage decreases shock without increasing limb complications. We hypothesized that prehospital tourniquet application in extremity vascular trauma, compared with no prehospital tourniquet application, is associated with lower rates of delayed amputation and better functional mobility.

METHODS

We retrospectively studied adult patients with extremity vascular trauma at an urban civilian Level 1 trauma center (June 2016-May 2021). Outcomes of interest included delayed amputation and mobility at hospital discharge, measured by the Activity Measure for Post-Acute Care "6 Clicks" Basic Mobility Score. The "6 Clicks" Basic Mobility Score was documented by physical therapy; higher scores indicate more independent mobility. Injury mechanism, initial lactate, 24-hour transfusions, mortality, and acute kidney injury were also collected. Comparisons were performed using χ2 analysis and Fisher Exact and Wilcoxon rank-sum tests.

RESULTS

Of 232 patients, prehospital tourniquet application was not associated with mortality or lactate level (both P > .05). The prehospital tourniquet application group had more transfusions, lower rates of acute kidney injury, and fewer delayed amputations (all P < .05). Ninety-one patients (45 prehospital tourniquet application and 46 without prehospital tourniquet application) were evaluated for "Moving between Bed and Chair" in the "6 Clicks" Basic Mobility Score, with patients in the prehospital tourniquet application group demonstrating higher levels of independence (P = .034).

CONCLUSION

Prehospital tourniquet application was associated with favorable outcomes, including higher functional mobility and decreased delayed amputation. This suggests that tourniquet use should be encouraged in the civilian setting to improve outcomes and reduce the risk of limb loss.

Impact of time and distance on outcomes following tourniquet use in civilian and military settings: A scoping review

BACKGROUND

The last two decades have seen the reintroduction of tourniquets into guidelines for the management of acute limb trauma requiring hemorrhage control. Evidence supporting tourniquet application has demonstrated low complication rates in modern military settings involving rapid evacuation timeframes. It is unclear how these findings translate to patients who have prolonged transport times from injury in rural settings. This scoping review investigates the relationship between time and distance on metabolic complications, limb salvage and mortality following tourniquet use in civilian and military settings.

METHODS

A systematic search strategy was conducted using PubMed, Embase, and SafetyLit databases. Study characteristics, setting, mechanism of injury, prehospital time, tourniquet time, distance, limb salvage, metabolic response, mortality, and tourniquet removal details were extracted from eligible studies. Descriptive statistics were recorded, and studies were grouped by ischemia time (< 2 h, 2-4 h, or > 4 h).

RESULTS

The search identified 3103 studies, from which 86 studies were included in this scoping review. Of the 86 studies, 55 studies were primarily in civilian environments and 32 were based in military settings. One study included both settings. Blast injury was the most common mechanism of injury sustained by patients in military settings (72.8% [5968/8200]) followed by penetrating injury (23.5% [1926/8200]). In contrast, in civilian settings penetrating injury was the most common mechanism (47.7% [1633/3426]) followed by blunt injury (36.4% [1246/3426]). Tourniquet time was reported in 66/86 studies. Tourniquet time over four hours was associated with reduced limb salvage rates (57.1%) and higher mortality rates (7.1%) compared with a tourniquet time of less than two hours. The overall limb salvage and mortality rates were 69.6% and 6.7% respectively. Metabolic outcomes were reported in 28/86 studies with smaller sample sizes and inconsistencies in which parameters were reported.

CONCLUSION

This scoping review presents literature describing comparatively safe tourniquet application when used for less than two hours duration. However, there is limited research describing prolonged tourniquet application or when used for protracted distances, such that the impact of tourniquet release time on metabolic outcomes and complications remains unclear. Prospective studies utilizing the development of an international database to provide this dataset is required.

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.

Blast Injury Patterns Among Israel Defense Forces Fatalities

INTRODUCTION

The incidence of blast injuries on the battlefield has risen over the last several decades. In order to improve prevention and treatment, it is essential to understand the severity and bodily distribution of these injuries. This study aims to characterize blast injury patterns among IDF fatalities.

MATERIALS AND METHODS

This is a descriptive, retrospective study on postmortem reports of military-blast fatalities between the years 1982 and 2021. Body regions injured according to the Abbreviated Injury Scale (AIS) were described. The frequency of body region injury combinations was mapped, and the correlation between injured body regions was calculated using Pearson's coefficient. Analysis of a subgroup with a postmortem computed tomography (CT-PM) or autopsy was performed, describing severe (AIS ≥ 3) injury patterns.

RESULTS

Overall, 222 fatalities suffered from blast injury, with most injuries affecting the upper and lower extremities (63.7% and 66.5%, respectively), followed by the head (57.1%) and the thorax (56.6%). The median number of injured body regions was 4 (interquartile range, 2-5). The most frequent injury combinations were the upper and lower extremities (51%), the upper extremities and the thorax (45%), and the lower extremities and the thorax (41%). In all, 47/222 (21.2%) fatalities had a documented autopsy or CT-PM report. Among the fatalities with CT-PM or autopsy, the head (63.8%) and the thorax (57.4%) were most frequently severely injured (AIS ≥ 3).

CONCLUSIONS

Among blast fatalities in the military setting, the extremities were most commonly injured. However, data suggest that the head and thorax are more likely to sustain severe blast injuries resulting in mortality. Blast injuries in this cohort were characterized by concomitant involvement of several regions. Development of protective gear to minimize the multisystem injuries inflicted by blast injuries is warranted and should be focused on distinct types and anatomical distribution of severe blast injuries as reported in this study.

LEVEL OF EVIDENCE

Level III, Retrospective analysis.

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.

After 800 Mtp Events, Mortality Due to Hemorrhagic Shock Remains High and Unchanged Despite Several In-Hospital Hemorrhage Control Advancements

BACKGROUND

Numerous advancements in hemorrhage control and volume replacement that comprise damage control resuscitation (DCR) have been implemented in the last decade to reduce deaths from bleeding. We sought to determine the impact of DCR interventions on mortality over 12 years in a massive transfusion protocol (MTP) population. We hypothesized that mortality would be decreased in later years, which would have used more DCR interventions.

STUDY DESIGN

This was a retrospective review of all MTP patients treated at a large regional Level I trauma center from 2008 to 2019. Interventions by year of implementation examined included MTP 1:1 ratio (2009), liquid plasma (2010), tranexamic acid (2012), prehospital tourniquets (2013), REBOA/TEG (2017), satellite blood station (2018), and whole blood transfusion (2019). Relative risk and odds of mortality for DCR interventions were examined.

RESULTS

There were 824 MTP patients included. The cohort was primarily male (80.6%) injured by penetrating mechanism (68.1%) with median (interquartile range) age 31 years (23-44) and New Injury Severity Score 25 (16-34). Overall mortality was unchanged [(38.3%-56.6%); P = 0.26]. Tourniquets (P = 0.02) and whole blood (WB) (P = 0.03) were associated with lower unadjusted mortality; only tourniquets remained significant after adjustment (OR: 0.39; 95% CI: 0.17-0.89; P = 0.03).

CONCLUSIONS

Despite lower mortality with use of tourniquets and WB, mortality rates due to hemorrhage have not improved at our high MTP volume institution, suggesting implementation of new in-hospital strategies is insufficient to reduce mortality. Future efforts should be directed toward moving hemorrhage control and effective resuscitation interventions to the injury scene.

Implications of the national Stop the Bleed campaign: The swinging pendulum of prehospital tourniquet application in civilian limb trauma

BACKGROUND

Prehospital tourniquet (PHT) utilization has increased in response to mass casualty events. We aimed to describe the incidence, therapeutic effectiveness, and morbidity associated with tourniquet placement in all patients treated with PHT application.

METHODS

A retrospective observational cohort study was performed to evaluate all adults with a PHT who presented at two Level I trauma centers between January 2015 and December 2019. Medically trained abstractors determined if the PHT was clinically indicated (placed for limb amputation, vascular hard signs, injury requiring hemostasis procedure, or significant documented blood loss). Prehospital tourniquets were further designated as appropriately or inappropriately applied (based on PHT anatomic placement location, occurrence of a venous tourniquet, or ischemic time defined as >2 hours). Statistical analyses were performed to generate primary and secondary results.

RESULTS

A total of 147 patients met study inclusion criteria, of which 70% met the criteria for trauma registry inclusion. Total incidence of PHT utilization increased from 2015 to 2019, with increasing proportions of PHTs placed by nonemergency medical service personnel. Improvised PHTs were frequently used. Prehospital tourniquets were clinically indicated in 51% of patients. Overall, 39 (27%) patients had a PHT that was inappropriately placed, five of which resulted in significant morbidity.

CONCLUSION

In summary, prehospital tourniquet application has become widely adopted in the civilian setting, frequently performed by civilian and nonemergency medical service personnel. Of PHTs placed, nearly half had no clear indication for placement and over a quarter of PHTs were misapplied with notable associated morbidity. Results suggest that the topics of clinical indication and appropriate application of tourniquets may be important areas for continued focus in future tourniquet educational programs, as well as future quality assessment efforts.

LEVEL OF EVIDENCE

Epidemiological, level III; Therapeutic, level IV.

Guidelines for the acute care of severe limb trauma patients

GOAL

To provide healthcare professionals with comprehensive multidisciplinary expert recommendations for the acute care of severe limb trauma patients, both during the prehospital phase and after admission to a Trauma Centre.

DESIGN

A consensus committee of 21 experts was formed. A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independently of any industrial funding (i.e., pharmaceutical, medical devices). The authors were advised to follow the rules of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to guide assessment of the quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasised. Few recommendations remained non-graded.

METHODS

The committee addressed eleven questions relevant to the patient suffering severe limb trauma: 1) What are the key findings derived from medical history and clinical examination which lead to the patient's prompt referral to a Level 1 or Level 2 Trauma Centre? 2) What are the medical devices that must be implemented in the prehospital setting to reduce blood loss? 3) Which are the clinical findings prompting the performance of injected X-ray examinations? 4) What are the ideal timing and modalities for performing fracture fixation? 5) What are the clinical and operative findings which steer the surgical approach in case of vascular compromise and/or major musculoskeletal attrition? 6) How to best prevent infection? 7) How to best prevent thromboembolic complications? 8) What is the best strategy to precociously detect and treat limb compartment syndrome? 9) How to best and precociously detect post-traumatic rhabdomyolysis and prevent rhabdomyolysis-induced acute kidney injury? 10) What is the best strategy to reduce the incidence of fat emboli syndrome and post-traumatic systemic inflammatory response? 11) What is the best therapeutic strategy to treat acute trauma-induced pain? Every question was formulated in a PICO (Patient Intervention Comparison Outcome) format and the evidence profiles were produced. The literature review and recommendations were made according to the GRADE® methodology.

RESULTS

The experts' synthesis work and the application of the GRADE method resulted in 19 recommendations. Among the formalised recommendations, 4 had a high level of evidence (GRADE 1+/-) and 12 had a low level of evidence (GRADE 2+/-). For 3 recommendations, the GRADE method could not be applied, resulting in an expert advice. After two rounds of scoring and one amendment, strong agreement was reached on all the recommendations.

CONCLUSIONS

There was significant agreement among experts on strong recommendations to improve practices for severe limb trauma patients.

An Eastern Association for the Surgery of Trauma multicenter trial examining prehospital procedures in penetrating trauma patients

BACKGROUND

Prehospital procedures (PHP) by emergency medical services (EMS) are performed regularly in penetrating trauma patients despite previous studies demonstrating no benefit. We sought to examine the influence of PHPs on outcomes in penetrating trauma patients in urban locations where transport to trauma center is not prolonged. We hypothesized that patients without PHPs would have better outcomes than those undergoing PHP.

METHODS

This was an Eastern Association for the Surgery of Trauma-sponsored, multicenter, prospective, observational trial of adults (18+ years) with penetrating trauma to the torso and/or proximal extremity presenting at 25 urban trauma centers. The impact of PHPs and transport mechanism on in-hospital mortality were examined.

RESULTS

Of 2,284 patients included, 1,386 (60.7%) underwent PHP. The patients were primarily Black (n = 1,527, 66.9%) males (n = 1,986, 87.5%) injured by gunshot wound (n = 1,510, 66.0%) with 34.1% (n = 726) having New Injury Severity Score of ≥16. A total of 1,427 patients (62.5%) were transported by Advanced Life Support EMS, 17.2% (n = 392) by private vehicle, 13.7% (n = 312) by police, and 6.7% (n = 153) by Basic Life Support EMS. Of the PHP patients, 69.1% received PHP on scene, 59.9% received PHP in route, and 29.0% received PHP both on scene and in route. Initial scene vitals differed between groups, but initial emergency department vitals did not. Receipt of ≥1 PHP increased mortality odds (odds ratio [OR], 1.36; 95% confidence interval [CI], 1.01-1.83; p = 0.04). Logistic regression showed increased mortality with each PHP, whether on scene or during transport. Subset analysis of specific PHP revealed that intubation (OR, 10.76; 95% CI, 4.02-28.78; p < 0.001), C-spine immobilization (OR, 5.80; 95% CI, 1.85-18.26; p < 0.01), and pleural decompression (OR, 3.70; 95% CI, 1.33-10.28; p = 0.01) had the highest odds of mortality after adjusting for multiple variables.

CONCLUSION

Prehospital procedures in penetrating trauma patients impart no survival advantage and may be harmful in urban settings, even when performed during transport. Therefore, PHP should be forgone in lieu of immediate transport to improve patient outcomes.

LEVEL OF EVIDENCE

Prognostic, level III.

Increased Use of Prehospital Tourniquet and Patient Survival: Los Angeles Countywide Study

BACKGROUND

Recent trends in prehospital tourniquet use remain underreported. In addition, the impact of prehospital tourniquet use on patient survival has not been evaluated in a population-level study. We hypothesized that prehospital tourniquets were used more frequently in Los Angeles County and their use was associated with improved patient survival.

STUDY DESIGN

This is a retrospective cohort study using a database maintained by the Los Angeles County Emergency Medical Services Agency. We included patients who sustained extremity vascular injuries between October 2015 and July 2019. Patients were divided into the following study groups: prehospital tourniquet and no-tourniquet group. Our primary end point was in-hospital mortality. The secondary outcomes included 4- and 24-hour transfusion requirements and delayed amputation.

RESULTS

A total of 944 patients met our inclusion criteria. Of those, 97 patients (10.3%) had prehospital tourniquets placed. The rate of tourniquet use increased linearly throughout our study period (goodness of fit, p = 0.014). In multivariable analysis, prehospital tourniquet use was significantly associated with improved mortality (adjusted odds ratio 0.32; 95% CI, 0.16 to 0.85; p = 0.032). Similarly, transfusion requirements were significantly lower within 4 hours (regression coefficient -547.76; 95% CI, -762.73 to -283.49; p < 0.001) and 24 hours (regression coefficient -1,389.82; 95% CI, -1,824.88 to -920.97; p < 0.001). There was no significant difference in delayed amputation rates (adjusted odds ratio 1.07; 95% CI, 0.21 to 10.88; p < 0.097).

CONCLUSIONS

Prehospital tourniquet use has been on the rise in Los Angeles County. Our results suggest that the use of prehospital tourniquets for extremity vascular injuries is associated with improved patient survival and decreased blood transfusion requirements, without an increase in delayed amputations.

Tourniquet use for civilian extremity hemorrhage: systematic review of the literature

INTRODUCTION

extremity tourniquet (TQ) use has increased in the civilian setting; the beneficial results observed in the military has influenced acceptance by EMS and bystanders. This review aimed to analyze extremity TQ types used in the civilian setting, injury site, indications, and complications.

METHODS

a systematic review was conducted based on original articles published in PubMed, Embase, and Cochrane following PRISMA guidelines from 2010 to 2019. Data extraction focused on extremity TQ use for hemorrhage control in the civilian setting, demographic data, study type and duration, mechanism of injury, indications for use, injury site, TQ type, TQ time, and complications.

RESULTS

of the 1384 articles identified, 14 were selected for review with a total of 3912 civilian victims with extremity hemorrhage and 3522 extremity TQ placements analyzed. The majority of TQs were applied to male (79%) patients, with blunt or penetrating trauma. Among the indications for TQ use were hemorrhagic shock, suspicion of vascular injuries, continued bleeding, and partial or complete traumatic amputations. Upper extremity application was the most common TQ application site (56%), nearly all applied to a single extremity (99%), and only 0,6% required both upper and lower extremity applications. 80% of the applied TQs were commercial devices, and 20% improvised.

CONCLUSIONS

TQ use in the civilian setting is associated with trauma-related injuries. Most are single-site TQs applied for the most part to male adults with upper extremity injury. Commercial TQs are more commonly employed, time in an urban setting is under 1 hour, with few complications described.