Nonselective versus Selective Angioembolization for Trauma Patients with Pelvic Injuries Accompanied by Hemorrhage: A Meta-Analysis
Medicina (Kaunas, Lithuania). 2023;59(8)
Background and Objectives: Angioembolization has emerged as an effective therapeutic approach for pelvic hemorrhages; however, its exact effect size concerning the level of embolized artery remains uncertain. Therefore, we conducted this systematic review and meta-analysis to investigate the effect size of embolization-related pelvic complications after nonselective angioembolization compared to that after selective angioembolization in patients with pelvic injury accompanying hemorrhage. Materials and Methods: Relevant articles were collected by searching the PubMed, EMBASE, and Cochrane databases until 24 June 2023. Meta-analyses were conducted using odds ratios (ORs) for binary outcomes. Quality assessment was conducted using the risk of bias tool in non-randomized studies of interventions. Results: Five studies examining 357 patients were included in the meta-analysis. Embolization-related pelvic complications did not significantly differ between patients with nonselective and selective angioembolization (OR 1.581, 95% confidence interval [CI] 0.592 to 4.225, I(2) = 0%). However, in-hospital mortality was more likely to be higher in the nonselective group (OR 2.232, 95% CI 1.014 to 4.913, I(2) = 0%) than in the selective group. In the quality assessment, two studies were found to have a moderate risk of bias, whereas two studies exhibited a serious risk of bias. Conclusions: Despite the favorable outcomes observed with nonselective angioembolization concerning embolization-related pelvic complications, determining the exact effect sizes was limited owing to the significant risk of bias and heterogeneity. Nonetheless, the low incidence of ischemic pelvic complications appears to be a promising result.
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.
Patients in civilian and military settings who had a tourniquet applied for the management of acute limb trauma (86 studies).
Scoping review investigating the relationship between time and distance on metabolic complications, limb salvage and mortality following tourniquet use.
Most included studies (55) were based in civilian environments, 32 were based in military settings, and 1 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 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.
Characterization and Analysis of Chitosan-Gelatin Composite-Based Biomaterial Effectivity as Local Hemostatic Agent: A Systematic Review
Chitosan and gelatin were the most widely used natural materials in pharmaceutical and medical fields, especially as local hemostatic agents, independently or as a composite material with the addition of other active substances. Chitosan and gelatin have excellent properties in biocompatibility, biodegradability, non-toxicity and water absorption capacity. The objective of this review was to analyze the characteristics of chitosan-gelatin (CG) composite-based biomaterial and its effectivity as a local hemostatic agent. We used PRISMA guidelines and the PICO framework to compile this review. The findings demonstrated that the CG composite-based biomaterial had excellent physical, chemical, mechanical properties and local hemostatic agent activity by adding other active substances such as oxidized fibers (OF), silica nanoparticles (SiNPs), calcium (Ca) and biphasic calcium phosphate (BCP) or by setting the CG composite proportion ratio.
The Impact of the Addition of a Virtual Reality Trainer on Skill Retention of Tourniquet Application for Hemorrhage Control Among Emergency Medical Technician Students: A Pilot Study
INTRODUCTION Trauma is a leading cause of preventable death in the United States. Emergency Medical Technicians (EMTs) often arrive first at the scene of traumatic injuries to perform life-saving skills such as tourniquet placement. While current EMT courses teach and test tourniquet application, studies have shown efficacy and retention of EMT skills such as tourniquet placement decay over time, with educational interventions needed to improve retention of skills. METHODS A prospective randomized pilot study was conducted to determine differences in retention of tourniquet placement among 40 EMT students after initial training. Participants were randomly assigned to either a virtual reality (VR) intervention or a control group. The VR group received instruction from a refresher VR program 35 days after initial training as a supplement to their EMT course. Both the VR and control participants' tourniquet skills were assessed 70 days after initial training by blinded instructors. Results: There was no significant difference in correct tourniquet placement between both groups (Control, 63% vs Intervention, 57%, p = 0.57). It was found that 9/21 participants (43%) in the VR intervention group failed to correctly apply the tourniquet while 7/19 of the control participants (37%) failed in tourniquet application. Additionally, the VR group was more likely to fail the tourniquet application due to improper tightening than the control group during the final assessment (p = 0.04). Conclusion: In this pilot study, using a VR headset in conjunction with in-person training did not improve the efficacy and retention of tourniquet placement skills. Participants who received the VR intervention were more likely to have errors relating to haptics, rather than procedure-related errors.
Artificial intelligence and machine learning for hemorrhagic trauma care
Military Medical Research. 2023;10(1):6
Artificial intelligence (AI), a branch of machine learning (ML) has been increasingly employed in the research of trauma in various aspects. Hemorrhage is the most common cause of trauma-related death. To better elucidate the current role of AI and contribute to future development of ML in trauma care, we conducted a review focused on the use of ML in the diagnosis or treatment strategy of traumatic hemorrhage. A literature search was carried out on PubMed and Google scholar. Titles and abstracts were screened and, if deemed appropriate, the full articles were reviewed. We included 89 studies in the review. These studies could be grouped into five areas: (1) prediction of outcomes; (2) risk assessment and injury severity for triage; (3) prediction of transfusions; (4) detection of hemorrhage; and (5) prediction of coagulopathy. Performance analysis of ML in comparison with current standards for trauma care showed that most studies demonstrated the benefits of ML models. However, most studies were retrospective, focused on prediction of mortality, and development of patient outcome scoring systems. Few studies performed model assessment via test datasets obtained from different sources. Prediction models for transfusions and coagulopathy have been developed, but none is in widespread use. AI-enabled ML-driven technology is becoming integral part of the whole course of trauma care. Comparison and application of ML algorithms using different datasets from initial training, testing and validation in prospective and randomized controlled trials are warranted for provision of decision support for individualized patient care as far forward as possible.
Efficacy of the Military Tactical Emergency Tourniquet for Lower Extremity Arterial Occlusion Compared with the Combat Application Tourniquet: A Randomized Crossover Study
Journal of special operations medicine : a peer reviewed journal for SOF medical professionals. 2023
INTRODUCTION Extremity bleeding and subsequent hemorrhagic shock is one of the main causes of preventable battlefield death, leading to mass-fielding of modern tourniquets, such as the Combat Application Tourniquet (CAT; Composite Resources). Numerous look-alike tourniquets, such as the Military Tactical Emergency Tourniquet (MTET; SZCTKlink), flood commercial markets, offering visually near-identical tourniquets for drastically reduced prices. We examined the performance of the MTET compared with that of the CAT. METHODS We undertook a randomized crossover trial to observe self-applied tourniquets to the lower extremity by combat medics, comparing the CAT to the MTET in application time and success rates, proven by loss of distal pulse assessed by Doppler ultrasound in <1 minute. RESULTS All 50 participants (100%) successfully applied the CAT versus 40 participants (80%) using the MTET (p = .0001). Median application time for the CAT (29.03 seconds; range, 18.63 to 59.50 seconds) was significantly less than those of successful MTET applications (35.27 seconds; range, 17.00 to 58.90 seconds) or failed MTET applications (72.26 seconds; range, 62.84 to 83.96 seconds) (p = .0012). Of 10 MTET failures, three (30%) were from application time >1 minute and seven (70%) from tourniquet mechanical failure. CONCLUSION The MTET performed worse than the CAT did in all observed areas. Despite identical appearance, look-alike tourniquets should not be assumed to be equivalent in quality or functionality to robustly tested tourniquets.
The Untrained Public's Ability to Apply the Layperson Audiovisual Assist Tourniquet vs a Combat Application Tourniquet: A Randomized Controlled Trial
Journal of the American College of Surgeons. 2022
BACKGROUND While the Stop the Bleed (STB) campaign's impact is encouraging, gaps remain. These gaps include rapid skill decay, a lack of easy-to-use tourniquets for the untrained public, and training barriers that prevent scalability. A team of academic and industry partners developed the Layperson Audiovisual Assist Tourniquet (LAVA TQ) - the first audiovisual-enabled tourniquet for public use. LAVA TQ addresses known tourniquet application challenges and is novel in its design and technology. METHODS This study is a prospective, randomized, superiority trial comparing the ability of the untrained public to apply LAVA TQ to a simulated leg versus their ability to apply a Combat Application Tourniquet (CAT). The study team enrolled participants in Boston, Maryland, and Sweden in 2022. The primary outcome was the proportion of successful applications of each tourniquet. Secondary outcomes included: mean time to application, placement position, reasons for failed application, and comfort with the devices. RESULTS Participants applied the novel LAVA TQ successfully 93% (n=66 of 71) of the time compared to 22% (n=16 of 73) success applying CAT [RR 4.24 95% CI (2.74-6.57)] (P < 0.001). Participants applied LAVA TQ faster (74.1s) compared to CAT (126s) (P <0.001) and experienced a greater gain in comfort using LAVA TQ than CAT. CONCLUSION The untrained public is four times more likely to apply LAVA TQ correctly than CAT. The public also applies LAVA TQ faster than CAT and has more favorable opinions about its usability. LAVA TQ's highly intuitive design and built-in audiovisual guidance solve known problems of layperson education and skill retention and could improve public bleeding control.
Untrained members of the public (n= 147).
Layperson Audiovisual Assist Tourniquet (LAVA TQ), (n= 73)
Combat Application Tourniquet (CAT), (n= 74).
Participants applied the novel LAVA TQ successfully 93% (n= 66 of 71) of the time compared to 22% (n= 16 of 73) success applying CAT [relative risk: 4.24 95% CI (2.74-6.57)]. Participants applied LAVA TQ faster (74.1 seconds) compared to CAT (126 seconds) and experienced a greater gain in comfort using LAVA TQ than CAT.
Measuring the Effect of Audio Instructions on the Time and Effectiveness of Tourniquet Application by Laypeople
Prehospital emergency care. 2022;:1-7
Objective: The "Stop the Bleed" campaign was created to educate laypeople about bleeding control and make bleeding control kits available in public locations. Unfortunately, previous research has indicated that up to half of all laypeople cannot effectively apply a tourniquet. The purpose of this study was to determine if laypeople could apply tourniquets more effectively with just-in-time training using combined audio-written instructions versus written-only instructions.Methods: We conducted a prospective randomized study comparing the application of a tourniquet using a simulated bleeding arm. Participants were laypeople 18 years and older and excluded those with any previous tourniquet experience or training. Participants were randomized to just-in-time training using either audio-written or written-only instructions. Time in seconds to tourniquet application and the effectiveness of the tourniquet application was recorded. Effective application was defined as stopping the flow or significantly slowing the flow to a slow drip. Ineffective tourniquet placement was defined as not significantly changing the flow. Statistical analysis was performed using Fisher's exact, t-test, and linear regression.Results: Eighty-two participants were included; 40 were in the audio-written instructions group, and 58.5% were male. The audio-written group's effective application rate was 92.5% and that of the written-only group was 76.2%. A significantly higher rate of ineffective tourniquet application was noted for the written-only group, (23.8%), versus the audio-written group (7.5%), p=.04. Regardless of the type of instructions used, time to effective application of the tourniquet decreased as participant age increased (p = 0.02, 95%CI (-1.24, -0.13). There was no relationship between age and effective tourniquet application (p = 0.06). Time for tourniquet placement was not different between the audio-written (mean 100.4 seconds) and written-only (mean 106.1 seconds) groups (p = 0.58).Conclusion: This study suggests that combined audio-written instructions decrease the rate of ineffective tourniquet application by laypeople compared with written-only instructions. Further studies are needed to assess if audio instructions and just-in-time training can further maximize effective tourniquet application.
Simulation-based Education Improves Military Trainees' Skill Performance and Self- Confidence in Tourniquet Placement: A Randomized Controlled Trial
The journal of trauma and acute care surgery. 2022
BACKGROUND Tactical Combat Casualty Care (TCCC) is the standard of care for stabilization and treatment of military trauma patients. The DoD has mandated that all Service members receive role-based TCCC training and certification. Simulation education can increase procedural skills by providing opportunities for deliberate practice in safe, controlled environments. We developed and evaluated the effectiveness of a simulation-based TCCC training intervention to improve participants' skill performance and self-confidence in tourniquet placement. METHODS This study was a single-blinded, randomized trial with waitlist controls. Army ROTC cadets from a single training battalion comprised the study population. After randomization and baseline assessment of all participants, Group A alone received focused, simulation-based TCCC tourniquet application training. Three months later, all participants underwent repeat testing, and after crossover, the waitlist Group B received the same intervention. Two months later, all cadets underwent a third/final assessment. The primary outcome was tourniquet placement proficiency assessed by total score achieved on a standardized 8-item skill checklist. A secondary outcome was self-confidence in tourniquet application skill as judged by participants' Likert scale ratings. RESULTS Forty-three Army ROTC cadets completed the study protocol. Participants in both Group A (n = 25) and Group B (n = 18) demonstrated significantly higher performance from baseline to final assessment at five months and two months, respectively, following the intervention. Mean total checklist score of the entire study cohort increased significantly from 5.53 (SD = 2.00) at baseline to 7.56 (SD = 1.08) at Time 3, a gain of 36.7% (p < 0.001). Both groups rated their self-confidence in tourniquet placement significantly higher following the training. CONCLUSIONS A simulation-based TCCC curriculum resulted in significant, consistent, and sustained improvement in participants' skill proficiency and self-confidence in tourniquet placement. Participants maintained these gains two to five months after initial training. LEVEL OF EVIDENCE Level II - RCT with significant difference and only one negative criterion (<80% follow-up).
The role of direct peritoneal resuscitation in the treatment of hemorrhagic shock after trauma and in emergency acute care surgery: a systematic review
European Journal of Trauma and Emergency Surgery : Official Publication of the European Trauma Society. 2022;48(2):791-797
PURPOSE Direct peritoneal resuscitation (DPR) has been used to help preserve microcirculation by reversing vasoconstriction and hypoperfusion associated with the pathophysiological process of shock, which can occur despite appropriate intravenous resuscitation. This approach depends on infusing a hyperosmolar solution intraperitoneally via a percutaneous catheter with the tip ending near the pelvis or the root of the mesentery. The abdomen is usually left open with a negative pressure abdominal dressing to continuously evacuate the infused dialysate. Hypertonicity of the solution triggers visceral vasodilation to help maintain blood flow, even during shock, and is also associated with reduced local inflammatory cytokines and other mediators, preservation of endothelial cell function, and mitigation of organ edema and necrosis. It also has a direct effect on liver perfusion and edema, more rapidly corrects electrolyte abnormalities compared to intravenous resuscitation alone, and may requireless intravenous fluid to stabilize blood pressure, all of which shortens the time required to close patients' abdomen. METHODS An online query using the search term "direct peritoneal resuscitation" was carried out in PubMed, MEDLINE and SciELO, limited to publications indexed from January 2014 to June 2020. Of the 20 articles returned, full text was able to be obtained for 19. A manual review of included articles' references was resulted in the addition of 1 article, for a total of 20 included articles. RESULTS The 20 articles were comprised of 15 animal studies, 4 clinical studies,and 1 expert opinion. The benefits include both local and possibly systemic effects on perfusion, hypoxia, acidosis, and inflammation, and are associated with improved outcomes and reduced complications. CONCLUSION DPR shows promise in patients with hemorrhagic shock, septic shock, and other conditions resulting in an open abdomen after damage control laparotomy.