A Modern Case Series of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in an Out-of-Hospital, Combat Casualty Care Setting

Consensus on resuscitative endovascular balloon occlusion of the aorta in civilian (prehospital) trauma care: A Delphi study

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) could prevent lethal exsanguination and support cardiopulmonary resuscitation. In prehospital trauma and medical emergency settings, a small population with high mortality rates could potentially benefit from early REBOA deployment. However, its use in these situations remains highly disputed. Since publication of the first Delphi study on REBOA, in which consensus was not reached on all addressed topics, new literature has emerged. The aim of this study was to establish consensus on the use and implementation of REBOA in civilian prehospital settings for noncompressible truncal hemorrhage and out-of-hospital cardiac arrest as well as for various in-hospital settings.

METHODS

A Delphi study consisting of three rounds of questionnaires was conducted based on a review of recent literature. REBOA experts with different medical specialties, backgrounds, and work environments were invited for the international panel. Consensus was reached when a minimum of 75% of panelists responded to a question and at least 75% (positive) or less than 25% (negative) of these respondents agreed on the questioned subject.

RESULTS

Panel members reached consensus on potential (contra)indications, physiological thresholds for patient selection, the use of ultrasound and practical, and technical aspects for early femoral artery access and prehospital REBOA.

CONCLUSION

The international expert panel agreed that REBOA can be used in civilian prehospital settings for temporary control of noncompressible truncal hemorrhage, provided that personnel are properly trained and protocols are established. For prehospital REBOA and early femoral artery access, consensus was reached on (contra)indications, physiological thresholds and practical aspects. The panel recommends the initiation of a randomized clinical trial investigating the use of prehospital REBOA for noncompressible truncal hemorrhage.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level V.

The employment of resuscitative endovascular balloon occlusion of the aorta in deployed settings

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been often used in place of open aortic occlusion for management of hemorrhagic shock in trauma. There is a paucity of data evaluating REBOA usage in military settings.

STUDY DESIGN AND METHODS

We queried the Department of Defense Trauma Registry (DODTR) for all cases with at least one intervention or assessment available within the first 72 h after injury between 2007 and 2023. We used relevant procedural codes to identify the use of REBOA within the DODTR, and we used descriptive statistics to characterize its use.

RESULTS

We identified 17 cases of REBOA placed in combat settings from 2017 to 2019. The majority of these were placed in the operating room (76%) and in civilian patients (70%). A penetrating mechanism caused the injury in 94% of cases with predominantly the abdomen and extremities having serious injuries. All patients subsequently underwent an exploratory laparotomy after REBOA placement, with moderate numbers of patients having spleen, liver, and small bowel injuries. The majority (82%) of included patients survived to hospital discharge.

DISCUSSION

We describe 17 cases of REBOA within the DODTR from 2007 to 2023, adding to the limited documentation of patients undergoing REBOA in military settings. We identified patterns of injury in line with previous studies of patients undergoing REBOA in military settings. In this small sample of military casualties, we observed a high survival rate.

Outcomes Associated With Aortic Balloon Occlusion Time in Patients With Zone 1 Resuscitative Endovascular Balloon Occlusion of the Aorta

INTRODUCTION

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has the potential to cause clinically relevant systemic ischemic burden with long durations of aortic occlusion (AO). We aimed to examine the association between balloon occlusion time and clinical complications and mortality outcomes in patients undergoing zone 1 REBOA.

METHODS

A retrospective cohort analysis of American Association for the Surgery of Trauma Aortic Occlusion for Resuscitation in Trauma and Acuteregistry patients with Zone 1 REBOA between 2013 and 2022 was performed. Patients with cardiopulmonary resuscitation on arrival or who did not survive past the emergency department were excluded. Total AO times were categorized as follows: <15 min, 15-30 min, 31-60 min, and >60 min. Clinical and procedural variables and in-hospital outcomes were compared across groups using bivariate and multivariate regression analyses.

RESULTS

There were 327 cases meeting inclusion criteria (n = 51 < 15 min, 83 15-30 min, 98 31-60 min, and 95 > 60 min, respectively). AO >60 min had higher admission lactate (8 ± 6; P = 0.004) compared to all other time groups, but injury severity score, heart rate, and systolic blood pressure were similar. Group average times from admission to definitive hemorrhage control ranged from 82 to 103 min and were similar across groups (85 min in AO >60 group). Longer AO times were associated with greater red blood cell, fresh frozen plasma transfusions (P < 0.001), and vasopressor use (P = 0.001). Mortality was greatest in the >60 min group (73%) versus the <15 min, 15-30 min, and 31-60 min groups (53%, 43%, and 45%, P < 0.001). With adjustment for injury severity score, systolic blood pressure, and lactate, AO >60 min had greater mortality (OR 3.7, 95% CI 1.6-9.4; P < 0.001) than other AO duration groups. Among 153 survivors, AO >60 min had a higher rate of multiple organ failure (15.4%) compared to the other AO durations (0%, 0%, and 4%, P = 0.02). There were no differences in amputation rates (0.7%) or spinal cord ischemia (1.4%). acute kidney injury was seen in 41% of >60 min versus 21%, 27%, and 33%, P = 0.42.

CONCLUSIONS

Though greater preocclusion physiologic injury may have been present, REBOA-induced ischemic insult was correlated with poor patient outcomes, specifically, REBOA inflation time >60 min had higher rates of mortality and multiple organ failure. Minimizing AO duration should be prioritized, and AO should not delay achieving definitive hemostasis. Partial REBOA may be a solution to extend safe AO time and deserves further study.

REBOA Improves Outcomes in Hybrid Surgery for Ruptured Abdominal Aortic Aneurysms

BACKGROUND

Despite advancements in diagnostic methods and emergency interventions, mortality rates of ruptured abdominal aortic aneurysm (rAAA) continue to remain high. To address this issue, the resuscitative endovascular balloon occlusion of the aorta (REBOA) technique has been designed to provide temporary control of bleeding. We aimed to compare the impact of the REBOA technique during open aortic surgery for rAAA.

METHODS

Between January 2014 and November 2021, 53 consecutive patients (46 males, 7 females; mean age 71.9 ± 7.9 years; range 51-89 years) who underwent emergency open aortic surgery for rAAA were retrospectively analyzed. Patients were divided into REBOA (21 patients) and non-REBOA (32 patients) groups. The primary outcomes were postoperative 24-hr and 30-day mortality. The secondary outcomes were intensive care unit (ICU) stay, in-hospital stay, bleeding, postoperative renal failure, bowel ischemia, and transient ischemic attack (TIA)/stroke rate.

RESULTS

The REBOA group showed a significant reduction in mortality rates at both 24 hr (9.5% vs. 37.5%, P = 0.029) and 30 days (14.2% vs. 43.7%, P = 0.035) compared to the non-REBOA group. In-hospital stay (12.8 ± 3.48 vs. 15.6 ± 4.74 days, P = 0.02) and ICU stay (2.42 ± 2.08 vs. 5.09 ± 5.79 days, P = 0.048) were shorter among the REBOA group. Total procedure time and bleeding were reduced among the REBOA group without significant differences in terms of postoperative renal failure, bowel ischemia, and TIA/stroke rate.

CONCLUSIONS

The REBOA group demonstrated significantly improved survival rates compared to the non-REBOA group, without a significant difference in complication rates. REBOA is considered a less invasive option compared to the traditional method for open aortic cross-clamping. This study demonstrated that the use of REBOA may be considered as a first-line treatment option for open surgery in cases of rAAA particularly when an off-the-shelf endovascular aneurysm repair device is not suitable.

Vascular access complications associated with resuscitative endovascular balloon occlusion of the aorta in adult trauma patients: A systematic review and meta-analysis

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is gaining popularity worldwide for managing hypotensive trauma patients. Vascular access complications related to REBOA placement have been reported, with some cases resulting in permanent morbidity. We aim to capitalize on the increase in literature to further describe and estimate the incidence of REBOA-associated vascular access complications in adult trauma patients.

METHODS

We searched Medline, EMBASE, Scopus, and CINAHL for studies reporting vascular access complications of REBOA in adult trauma patients from inception to October 14, 2021. Studies reporting data from adult trauma patients who underwent REBOA insertion were eligible. Exclusion criteria included patients 15 years and younger, nontrauma patients, non-REBOA use, non-vascular access complications and patient duplication. Study data was abstracted using the PRISMA checklist and verified independently by three reviewers. Meta-analysis of proportions was performed using a random effects model with Freeman-Turkey double-arcsine transformation. Post hoc meta-regression by year of publication, sheath-size, and geographic region was also performed. The incidence of vascular access complications from REBOA insertion was the primary outcome of interest. Subgroup analysis was performed by degree of bias, sheath size, technique of vascular access, provider specialty, geographical region, and publication year.

RESULTS

Twenty-four articles were included in the systematic review and the meta-analysis, for a total of 675 trauma patients who underwent REBOA insertion. The incidence of vascular access complications was 8% (95% confidence interval, 5%-13%). In post hoc meta-regression adjusting for year of publication and geographic region, the use of a smaller (7-Fr) sheath was associated with a decreased incidence of vascular access complications (odds ratio, 0.87; 95% confidence interval, 0.75-0.99; p = 0.046; R 2 = 35%; I 2 = 48%).

CONCLUSION

This study provides a benchmark for quality of care in terms of vascular access complications related to REBOA insertion in adult trauma patients. Smaller sheath size may be associated with a decrease in vascular access complications.

LEVEL OF EVIDENCE

Systematic Review and Meta-Analysis; Level III.

Management of non-compressible torso hemorrhage of the abdomen in civilian and military austere environments: a scoping review

Background

Non-compressible abdominal hemorrhage (NCAH) is the leading cause of potentially preventable deaths in both civilian and military austere environments, and an improvement in mortality due to this problem has not been demonstrated during the past quarter century. Several innovations have been developed to control hemorrhage closer to the point of injury.

Objective

This review assessed NCAH interventions in civilian and military settings, focusing on austere environments. It identified innovations, effectiveness, and knowledge gaps for future research.

Methodology

The Joanna Briggs Institute for Evidence Synthesis methodology guided this scoping review to completion. Studies evaluating NCAH with human participants in civilian and military austere environments that were eligible for inclusion were limited to English language studies published between December 1990 and January 2023. The PCC (Participant, Concept, Context) framework was used for data synthesis. Deductive and inductive thematic analyses were used to assess the literature that met inclusion criteria, identify patterns/themes to address the research questions and identify common themes within the literature. A stakeholder consultation was conducted to review and provide expert perspectives and opinions on the results of the deductive and inductive thematic analyses.

Results

The literature search identified 868 articles; 26 articles met the inclusion criteria. Textual narrative analysis of the 26 articles resulted in the literature addressing four main categories: NCAH, penetrating abdominal trauma, resuscitative endovascular balloon occlusion of the aorta (REBOA), and ResQFoam. The deductive thematic analysis aimed to answer three research questions. Research question 1 addressed the effectiveness of REBOA, damage control resuscitation, and damage control surgery in managing NCAH in austere environments. No effectiveness studies were found on this topic. Research question 2 identified three knowledge gaps in NCAH management in austere environments. The analysis identified early hemorrhage control, prehospital provider decision-making ability, and REBOA implementation as knowledge gaps in NCAH. Research question 3 identified five innovations that may affect the management of NCAH in the future: transport of patients, advanced resuscitative care, expert consultation, REBOA implementation, and self-expanding foam implementation. The inductive thematic analysis resulted in four recurrent themes from the literature: prehospital care, decision-making, hemorrhage control, and mortality in NCAH. During the stakeholders' consultation, the results of the deductive and inductive thematic analyses were reviewed and agreed on by the stakeholders. Special emphasis and discussion were given to prehospital management, expert opinions in the prehospital environment, decision-making in the prehospital environment, transport and resuscitation in the prehospital setting, REBOA, alternative discussion for research, and research gaps.

Conclusion

NCAH is still a significant cause of preventable death in both military and civilian austere environments, even with ongoing research and interventions aimed at extending survival in such conditions. This scoping review has identified several potential concepts that could reduce the mortality associated with a preventable cause of death due to hemorrhage in austere environments.

[Effect of a 1-day "REBOA course" on the theoretical and practical skills for the prehospital REBOA setting : Experiences from the RIBCAP-HEMS project]

Resuscitative endovascular balloon occlusion of the aorta (REBOA) represents an endovascular procedure for aortic occlusion. The procedure can be used for temporary hemorrhage control as a bridge until surgical treatment for noncompressible abdominal or pelvic bleeding and to improve coronary and cerebral perfusion pressure during cardiopulmonary resuscitation. The prehospital administration is challenging and currently hardly possible in Germany. In the REBOA in bleeding and cardiac arrest in the prehospital care by helicopter emergency medical service (RIBCAP-HEMS) project, the prehospital use of REBOA will be tested in a feasibility study. This article describes the training course on the procedure in preparation for prehospital use, which was conducted before the start of the aforementioned feasibility study for the emergency physicians and paramedics (HEMS-TC) of the DRF Air Rescue Base in Halle (Saale). The course provided the necessary theoretical and practical skills to apply REBOA in the prehospital setting to patients in extremis in a safe, indications-conform and time-critical manner. The fact that all emergency physicians of the two air ambulances Christoph 84 and Christoph 85 in Halle are specialists in anesthesiology with corresponding experience in the placement of invasive arterial catheters proved to be advantageous. The training course was able to significantly improve the theoretical and practical abilities of the participants. The results of the currently ongoing study must show whether the procedure can be usefully integrated into the prehospital care of patients in extremis.

Using infrared cameras in drones to detect bleeding events

BACKGROUND

Hemorrhage is one of the main causes of death in trauma. Critical bleeding in patients needs to be detected as soon as possible to save the patient. Drones are gaining increasing importance in emergency services and can support rescue forces in accident scenarios such as a mass casualty incident.

METHODS

In this study, a simulated pelvic hemorrhage was detected using a drone from 7 m above the ground over a time span of 30 s.

RESULTS

The results allow a good detection of the pelvic hemorrhage. Nevertheless, the simulated blood cools down quickly. After 30 s, there was no significant temperature difference compared to the rest of the body. At this point, further assessment is only possible via the RGB image.

CONCLUSION

The findings suggest that bleeding from an open and continuously bleeding wound would most likely be detectable using the drone's thermal imaging camera, even over a longer period of time.

Management of Postpartum Hemorrhage in Critical Care Transport

Postpartum hemorrhage is a relatively common and highly morbid complication of the postpartum period that often requires management by specialized providers at tertiary care facilities. Critical care transport teams may be tasked with transporting postpartum patients who are already experiencing postpartum hemorrhage, but they should also be aware that other peripartum patients may be at risk for developing postpartum hemorrhage while in the process of transport. As such, it is imperative that transport providers understand the signs, symptoms, causes, and complications of postpartum hemorrhage as well as the options for intervention and treatment. This article reviews the current clinical evidence regarding resuscitation and medical management strategies that transport teams should be familiar with as well as more advanced and invasive management techniques they may encounter and be expected to monitor during transport, such as balloon tamponade and aortic balloon occlusion.

Do we need pre-hospital resuscitative endovascular balloon occlusion of the aorta (REBOA) in the civilian helicopter emergency medical services (HEMS)?

Pre-hospital resuscitative endovascular balloon occlusion of the aorta (REBOA) can be a life-saving procedure for patients with non-compressible torso hemorrhage. We aimed to evaluate the potential eligibility for REBOA in trauma patients of a civilian helicopter emergency medical service (HEMS) using a stepwise approach. A retrospective analysis using the electronic database (HEMSDER) of "DRF Luftrettung" HEMS covering the period from January 2015 to June 2021 was performed. Trauma patients aged ≥ 16 years and with a National Advisory Committee for Aeronautics (NACA) score of ≥ 4 were assessed for potential REBOA eligibility using two different decision trees based on assumed severe bleeding due to injuries of the abdomen, pelvis, and/or lower extremities and different vital signs on the scene and at hospital handover. Non-parametric statistical methods were used for comparison. A total of 22.426 patients met the inclusion criteria for data analysis. Of these, 0.15-2.24% were possible candidates for pre-hospital REBOA. No significant differences between groups on scene and at hospital handover regarding demographics, assumed injuries, and pre-hospital interventions were found. In the on-scene group, 21.1% of the patients remained unstable even at hospital handover despite pre-hospital care. In the handover group, 42.8% of the patients seemed initially stable but then deteriorated during the pre-hospital course. The number of potential pre-hospital REBOA in severely injured patients with a NACA score of ≥ 4 is < 3% or can be even < 1% if more strict criteria are used. There are some patients who may benefit from pre-hospital REBOA as a life-saving procedure. Further research on earlier diagnosis of life-threatening bleeding and proper indications of REBOA in trauma patients is needed.

Validation of a miniaturized handheld arterial pressure monitor for guiding full and partial REBOA use during resuscitation

PURPOSE

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a well-validated method for the control of noncompressible truncal hemorrhage. In lower resource or battlefield settings, the need for arterial line setup and monitoring is problematic and potentially prohibitive. We sought to evaluate the accuracy and precision of a miniaturized portable device (Centurion COMPASS^®) versus standard arterial pressure monitoring using standard ER-REBOA and partial REBOA (pREBOA) as a high-fidelity and space-/time-conserving alternative.

METHODS

A total of 40 swine underwent a four-phase validation/precision study (each phase using five ER-REBOAs and five pREBOAs). Phases I/II evaluated accuracy with full and pREBOA in uninjured animals. Phases III/IV duplicated the previous phases but in a severe hemorrhagic shock model. Carotid and femoral pressures were monitored with both intra-arterial pressure systems and the COMPASS^® device. The vascular flow was measured by aortic flow probes. Correlation and Bland-Altman analysis were performed.

RESULTS

There was a strong correlation in accuracy testing of proximal and distal COMPASS^® devices compared to standard intra-arterial pressure monitoring (r = 0.94, 0.8; p < 0.005) as well as during precision testing (r = 0.98, 0.89 p < 0.005) in the uninjured phases. Similar accuracy and reliability were demonstrated in hemorrhagic shock, with a strong correlation for the proximal and distal COMPASS^® devices (r = 0.98, 0.97; p < 0.005), as well as during precision testing (r = 0.99, 0.95; p < 0.005) in both full and pREBOA scenarios. Bland-Altman analysis showed extremely low bias between the COMPASS^® and arterial line for both proximal (bias = 1.9) and distal (bias = 0.8) pressure measurements.

CONCLUSION

The COMPASS^® provides accurate and precise pressure measurements during standard and partial REBOA in both uninjured and shock conditions. This device may help extend and enhance capability in any low-resource/battlefield settings, or even eliminate the need for standard intra-arterial invasive pressure monitoring and external setup.

Advanced bleeding control in combat casualty care: An international, expert-based Delphi consensus

BACKGROUND

Hemorrhage from truncal and junctional injuries is responsible for the vast majority of potentially survivable deaths in combat casualties, causing most of its fatalities in the prehospital arena. Optimizing the deployment of the advanced bleeding control modalities required for the management of these injuries is essential to improve the survival of severely injured casualties. This study aimed to establish consensus on the optimal use and implementation of advanced bleeding control modalities in combat casualty care.

METHODS

A Delphi method consisting of three rounds was used. An international expert panel of military physicians was selected by the researchers to complete the Delphi surveys. Consensus was reached if 70% or greater of respondents agreed and if 70% or greater responded.

RESULTS

Thirty-two experts from 10 different nations commenced the process and reached consensus on which bleeding control modalities should be part of the standard equipment, that these modalities should be available at all levels of care, that only trained physicians should be allowed to apply invasive bleeding control modalities, but all medical and nonmedical personnel should be allowed to apply noninvasive bleeding control modalities, and on the training requirements for providers. Consensus was also reached on the necessity of international registries and guidelines, and on certain indications and contraindications for resuscitative endovascular balloon occlusion of the aorta (REBOA) in military environments. No consensus was reached on the role of a wound clamp in military settings and the indications for REBOA in patients with chest trauma, penetrating axillary injury or penetrating neck injury in combination with thoracoabdominal injuries.

CONCLUSION

Consensus was reached on the contents of a standard bleeding control toolbox, where it should be available, providers and training requirements, international registries and guidelines, and potential indications for REBOA in military environments.

AI-Enabled, Ultrasound-Guided Handheld Robotic Device for Femoral Vascular Access

Hemorrhage is a leading cause of trauma death, particularly in prehospital environments when evacuation is delayed. Obtaining central vascular access to a deep artery or vein is important for administration of emergency drugs and analgesics, and rapid replacement of blood volume, as well as invasive sensing and emerging life-saving interventions. However, central access is normally performed by highly experienced critical care physicians in a hospital setting. We developed a handheld AI-enabled interventional device, AI-GUIDE (Artificial Intelligence Guided Ultrasound Interventional Device), capable of directing users with no ultrasound or interventional expertise to catheterize a deep blood vessel, with an initial focus on the femoral vein. AI-GUIDE integrates with widely available commercial portable ultrasound systems and guides a user in ultrasound probe localization, venous puncture-point localization, and needle insertion. The system performs vascular puncture robotically and incorporates a preloaded guidewire to facilitate the Seldinger technique of catheter insertion. Results from tissue-mimicking phantom and porcine studies under normotensive and hypotensive conditions provide evidence of the technique's robustness, with key performance metrics in a live porcine model including: a mean time to acquire femoral vein insertion point of 53 ± 36 s (5 users with varying experience, in 20 trials), a total time to insert catheter of 80 ± 30 s (1 user, in 6 trials), and a mean number of 1.1 (normotensive, 39 trials) and 1.3 (hypotensive, 55 trials) needle insertion attempts (1 user). These performance metrics in a porcine model are consistent with those for experienced medical providers performing central vascular access on humans in a hospital.

Development of Optimized Tissue-Factor-Targeted Peptide Amphiphile Nanofibers to Slow Noncompressible Torso Hemorrhage

Noncompressible torso hemorrhage accounts for a significant portion of preventable trauma deaths. We report here on the development of injectable, targeted supramolecular nanotherapeutics based on peptide amphiphile (PA) molecules that are designed to target tissue factor (TF) and, therefore, selectively localize to sites of injury to slow hemorrhage. Eight TF-targeting sequences were identified, synthesized into PA molecules, coassembled with nontargeted backbone PA at various weight percentages, and characterized via circular dichroism spectroscopy, transmission electron microscopy, and X-ray scattering. Following intravenous injection in a rat liver hemorrhage model, two of these PA nanofiber coassemblies exhibited the most specific localization to the site of injury compared to controls (p < 0.05), as quantified using immunofluorescence imaging of injured liver and uninjured organs. To determine if the nanofibers were targeting TF in vivo, a mouse saphenous vein laser injury model was performed and showed that TF-targeted nanofibers colocalized with fibrin, demonstrating increased levels of nanofiber at TF-rich sites. Thromboelastograms obtained using samples of heparinized rat whole blood containing TF demonstrated that no clots were formed in the absence of TF-targeted nanofibers. Lastly, both PA nanofiber coassemblies decreased blood loss in comparison to sham and backbone nanofiber controls by 35-59% (p < 0.05). These data demonstrate an optimal TF-targeted nanofiber that localizes selectively to sites of injury and TF exposure, and, interestingly, reduces blood loss. This research represents a promising initial phase in the development of a TF-targeted injectable therapeutic to reduce preventable deaths from hemorrhage.

Endovascular Perfusion Augmentation for Critical Care: Partial Aortic Occlusion for Treatment of Severe Ischemia-Reperfusion Shock

BACKGROUND

The resuscitation of patients in shock is materially intensive and many patients are refractory to maximal therapy. We hypothesized that partial inflation of an intra-aortic balloon, termed Endovascular Perfusion Augmentation for Critical Care (EPACC), would minimize material requirements while improving physiologic metrics.

METHODS

Swine underwent a 25% controlled bleed and 45 min of complete aortic occlusion to create a severe ischemia-reperfusion shock state. Animals received either standardized critical care (SCC) composed of IV fluids and norepinephrine delivered through an algorithmically controlled platform or EPACC in addition to SCC. Physiologic parameters were collected, and blood was sampled for analysis. Primary outcomes were total IV fluids and average MAP during the critical care phase. Differences (P < 0.05) were measured with t test (continuous data) and Wilcoxon rank-sum test (ordinal data).

RESULTS

There were no differences in baseline characteristics. There were no differences in the maximum lactate; however, animals in the EPACC group had a higher average MAP (EPACC 65 mmHg, 95% confidence interval [CI], 65-66; SCC 60 mmHg, 95% CI, 57-63; P < 0.01) and remained within goal MAP for a greater period of time (EPACC 95.3%, 95% CI, 93.2-97.4; SCC 51.0%, 95% CI, 29.5-72.6; P < 0.01). EPACC animals required less IV fluids when compared with the SCC group (EPACC 21 mL/kg, 95% CI, 0-42; SCC 96 mL/kg, 95% CI, 76-117; P < 0.01). There were no differences in final lactate. Animals in the EPACC group had a higher final creatinine (EPACC 2.3 mg/dL, 95% CI, 2.1-2.5; SCC 1.7 mg/dL, 95% CI, 1.4-2.0; P < 0.01), but there were no differences in renal cellular damage on histology (P = 0.16).

CONCLUSION

Using a swine model of severe shock, the addition of EPACC to SCC significantly reduced fluid resuscitation requirements and improved blood pressure. This is the first description of a new therapy for patients in refractory shock or in resource-limited settings.

The effectiveness of junctional tourniquets: A systematic review and meta-analysis

BACKGROUND

Junctional tourniquets have been incorporated into tactical combat casualty care for junctional vascular trauma. They apply external compression to stop blood flow in the groin and axilla.

OBJECTIVES

The primary outcome was effectiveness in achieving arterial occlusion. Secondary outcomes included time to application and pain scores.

DATA SOURCES

Medline and EMBASE databases were searched.

STUDY APPRAISAL AND SYNTHESIS METHODS

A random-effects meta-analysis was conducted to estimate the average effectiveness and time to effective application for each device.

RESULTS

Eight studies reported the effectiveness of junctional tourniquets in healthy volunteers. The average effectiveness was 52% (95% confidence interval [CI], 15-87%) for the abdominal application of the abdominal aortic and junctional tourniquet (AAJT), 83% (95% CI, 73-89%; 26%) for the junctional Emergency Treatment Tool, 87% (95% CI, 79-92%; 15%) for the SAM junctional tourniquet (SJT), and 95% (95% CI, 90-98%) for the Combat Ready Clamp. The groin application of the AAJT was studied in two articles with 100% in both studies. The average time to application was 101 seconds for the SAM junctional tourniquet (95% CI, 50-152 seconds) and the Combat Ready Clamp (95% CI, 63-139 seconds), while it was 130 seconds (95% CI, 85-176 seconds) for the Junctional Emergency Treatment Tool. The abdominal application of AAJT had an average time to application of 92 and 171 seconds in two studies.

LIMITATIONS

All studies were conducted in healthy volunteers.

CONCLUSION AND IMPLICATIONS

Junctional tourniquets may meet a medical need in combat, and in the civilian environment, to control hemorrhage from these difficult injuries. All four Food and Drug Administration-approved devices demonstrate the ability to achieve vascular occlusion in healthy volunteers; however, effectiveness in patient transport has not been evaluated, and outcomes of their use in the field need to be captured and reported.

LEVEL OF EVIDENCE

Systematic review, level III.

Computed tomography correlation of skeletal landmarks and vascular anatomy in civilian adult trauma patients: Implications for resuscitative endovascular balloon occlusion of the aorta

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a valuable resuscitative adjunct in a variety of clinical settings. In resource-limited or emergency environments, REBOA may be required with delayed or absent image-guidance or verification. Catheter insertion lengths may be informed by making computed tomography (CT) correlations of skeletal landmarks with vascular lengths.

METHODS

Between 2000 and 2015 at a single civilian tertiary care center, 2,247 trauma patients with CT imaging were identified, yielding 1,789 patients with adequate contrast opacification of the arterial system in the chest, abdomen, and pelvis. Individual scans were analyzed using MATLAB software, with custom high-throughput image processing algorithms applied to correlate centerline vascular anatomy with musculoskeletal landmarks. Data were analyzed using R version 3.3.

RESULTS

The median centerline distance from the skin access to the aortic bifurcation was longer by 0.3 cm on the right than on the left side. Median aortic zone I length was 21.6 (interquartile range, 20.3-22.9) cm, while zone III was 8.7 (7.8-9.5) cm. Torso extent (TE) correlation to zone I was much higher than that for zone III (R2, 0.58 vs. 0.26 (right) and 0.58 vs. 0.27 (left); p < 0.001). Assuming a 4-cm balloon length, optimal fixed insertion length would be 48 cm and 28 cm for zones I and III (error, 0.4% vs. 33.3%), respectively, although out of zone placements can be reduced if adjusted for TE (error, 0% vs. 26.4%).

CONCLUSION

Computed tomography morphometry suggests that a fixed REBOA catheter insertion length of 48 cm for zone I and 28 cm for zone III is optimal (on average, for average-height individuals), with improved accuracy by formulaic adjustments for TE. High residual error for zone III placement may require redesign of existing catheter balloon lengths or consideration of the relative risk associated with placing the balloon catheter too low or too high.

LEVEL OF EVIDENCE

Prognostic/epidemiological, level III.

Transition from abdominal aortic and junctional tourniquet to zone 3 resuscitative endovascular balloon occlusion of the aorta is feasible with hemodynamic support after porcine class IV hemorrhage

BACKGROUND

Traumatic hemorrhage remains a major cause of death in rural civilian and combat environments. Potential interventions to control hemorrhage from the pelvis and lower junctional regions include the abdominal aortic and junctional tourniquet (AAJT) and resuscitative endovascular balloon occlusion of the aorta (REBOA). The AAJT requires low technical skills and may thus be used by nonmedical professionals, but is associated with time-dependent ischemic complications. In combination with delayed patient evacuation, it may therefore be deleterious. Transition to zone 3 REBOA in higher levels of care may be a possibility to maintain hemostasis, mitigate adverse effects and enable surgery in patients resuscitated with the AAJT. It is possible that a transition between the interventions could lead to hemodynamic penalties. Therefore, we investigated the feasibility of replacing the AAJT with zone 3 REBOA in a porcine model of uncontrolled femoral hemorrhage.

METHODS

Domestic pigs (n = 12) averaging 57 kg were exposed to a class IV uncontrolled hemorrhage from the common femoral artery. The animals were randomized to 60-minute AAJT (n = 6) or 30-minute AAJT with transition to 30-minute zone 3 REBOA. Hemodynamic and metabolic parameters and ultrasonographic measurements of the common femoral artery were collected.

RESULTS

Transition from AAJT to zone 3 REBOA caused a significant decrease in mean arterial pressure (25 mm Hg). Hemostasis was maintained. The common femoral artery diameter decreased by 1.8 mm (38%) after hemorrhage and further 0.7 mm (23%) after aortic occlusion.

CONCLUSION

Transition from AAJT to zone 3 REBOA after a class IV bleeding is feasible with hemodynamic support. Vascular access to the femoral artery for REBOA insertion poses a technical challenge after hemorrhage and AAJT application.

LEVEL OF EVIDENCE

Laboratory animal study, level IV.

Effect of partial and complete aortic balloon occlusion on survival and shock in a swine model of uncontrolled splenic hemorrhage with delayed resuscitation

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is accepted as a resuscitation adjunct and bridge to definitive hemostasis. The ischemic burden of REBOA may be mitigated by a partial REBOA (P-REBOA) strategy permitting longer occlusion times and military use for combat trauma. We evaluated REBOA and P-REBOA in a swine multiple trauma model with uncontrolled solid organ hemorrhage and delayed resuscitation and surgical hemostasis.

METHODS

Anesthetized swine (51.9 ± 2.2 kg) had 20 mL/kg hemorrhage and closed femur fracture. Splenic transection was performed and free bleeding permitted for 10 minutes. Controls (n = 5) were hemorrhaged but had no REBOA, REBOA (n = 8) had 60 minutes complete zone 1 occlusion, P-REBOA (n = 8) had 15 minutes complete occlusion and 45 minutes 50% occlusion. Splenectomy was performed and plasma (15 mL/kg) resuscitation initiated 5 minutes prior to deflation. Resuscitation goal was 80 mm Hg systolic with epinephrine as needed. Animals were monitored for 6 hours.

RESULTS

An initial study with 120-minute occlusion had universal fatality in three REBOA (upon deflation) and three P-REBOA animals (after 60 minutes inflation). With 60-minute occlusion, mortality was 100%, 62.5%, and 12.5% in the control, REBOA, and P-REBOA groups, respectively (p < 0.05). Survival time was shorter in controls (120 ± 89 minutes) than REBOA and P-REBOA groups (241 ± 139, 336 ± 69 minutes). Complete REBOA hemorrhaged less during inflation (1.1 ± 0.5 mL/kg) than Control (5.6 ± 1.5) and P-REBOA (4.3 ± 1.4), which were similar. Lactate was higher in the REBOA group compared with the P-REBOA group after balloon deflation, remaining elevated. Potassium increased in REBOA after deflation but returned to similar levels as P-REBOA by 120 minutes.

CONCLUSION

In a military relevant model of severe uncontrolled solid organ hemorrhage 1-hour P-REBOA improved survival and mitigated hemodynamic and metabolic shock. Two hours of partial aortic occlusion was not survivable using this protocol due to ongoing hemorrhage during inflation. There is potential role for P-REBOA as part of an integrated minimally invasive field-expedient hemorrhage control and resuscitation strategy.

Radiofrequency Identification of the ER-REBOA: Confirmation of Placement Without Fluoroscopy

INTRODUCTION

Non-compressible torso hemorrhage accounts for 70% of battlefield deaths. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emerging technology used to mitigate massive truncal hemorrhage. Use of REBOA on the battlefield is limited by the need for radiographic guided balloon placement. Radiofrequency identification (RFID) is a simple, portable, real-time technology utilized to detect retained sponges during surgery. We investigated the feasibility of RFID to confirm the placement of ER-REBOA.

MATERIALS AND METHODS

This was a single-arm prospective proof-of-concept experimental study approved by the institutional review board at Naval Medical Center San Diego. The ER-REBOA (Prytime Medical Devices, Inc, Boerne, TX, USA) was modified by placement of a RFID tag. The tagged ER-REBOA was placed in zone I or zone III of the aorta in a previously perfused cadaver. Exact location was documented with X-ray. Five blinded individuals used the RF Assure Detection System (Medtronic, Minneapolis, MN, USA) handheld detection wand to predict catheter tip location from the xiphoid process (zone I) or pubic tubercle (zone III).

RESULTS

In zone I, actual distance (Da) of the catheter tip was 11 cm from the xiphoid process. Mean predicted distance (Dp) from Da was 1.52 cm (95% CI 1.19-1.85). In zone III, Da was 14 cm from the pubic tubercle. Mean Dp from Da was 4.11 cm (95% CI 3.68-4.54). Sensitivity of detection was 100% in both zones. Specificity (Defined as Dp within 2 cm of Da) was 86% in zone I and 16% in zone III.

CONCLUSIONS

Using RFID to confirm the placement of ER-REBOA is feasible with specificity highest in zone I. Future work should focus on refining this technology for the forward-deployed setting.

First Russian experience with endovascular balloon occlusion of the aorta in a zone of combat operations

Resuscitative endovascular balloon occlusion of the aorta has increasingly been used all the world over for arresting ongoing intraabdominal and intrapelvic bleeding accompanied by unstable haemodynamics. However, the use of resuscitative endovascular balloon occlusion of the aorta in a zone of military operations has been limited to sporadic cases only. This article deals with 3 clinical case reports regarding rendering medical care for the wounded presenting with extremely unstable haemodynamics and/or a terminal state in a field hospital, where insertion of a balloon into the aorta made it possible to stabilize the condition, to perform the basic scope of diagnosis, and to finally control the continuing bleeding: in one case - intraabdominal (due to splenic rupture) and in 2 cases - intrapelvic (unstable fractures of pelvic bones). In two cases, despite low readings of blood pressure, puncture of the femoral artery was performed 'blindly' and in one case - in an open fashion. The balloons used were the 7 Fr Rescue Balloon (Japan) and 10 Fr balloons manufactured by the Limited Liability Company 'Minimally Invasive Technologies' (Russia). The balloons were positioned in the aorta also 'blindly' and only in one case we managed to perform an X-ray examination confirming the correct position of the balloon. The mean time of occlusion of the thoracic aorta in the survivors amounted to 20 minutes. The operations were accompanied by intensive therapy and massive haemotransfusion. The introducers were removed using the fascia suture technique (without closure of the arterial wall). Two of the three wounded were saved, to be evacuated to a central hospital and discharged 170 and 75 days thereafter, which was due to long-term treatment of severe concomitant fractures of pelvic bones and lower extremities. No complications on the background of resuscitative endovascular balloon occlusion of the aorta were revealed. Two years after surgery both men continue serving in the Armed Forces, with no significant functional impairments. Our third injured patient delivered in a condition of clinical death, despite restoration of the rhythm after inflation of the balloon unfortunately died. Our case reports demonstrate high efficacy of resuscitative endovascular balloon occlusion of the aorta in unstable haemodynamics induced by combat injury to the abdomen and pelvis. The technique of this method makes it possible not only to stabilize haemodynamics, to improve perfusion of the vital organs but also to staunch continuing haemorrhage, hence allowing additional time to carry out haemotransfusion. In future, resuscitative endovascular balloon occlusion of the aorta may become one of the methods of the extended protocol of prehospital care.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is associated with improved survival in severely injured patients: A propensity score matching analysis

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a technique for temporary control of arterial hemorrhage. However, its effectiveness and clinical outcomes are unclear.

METHODS

Using a nationwide database (2004-2016) in Japan, trauma patients with survival data were identified. Patients were divided between REBOA and non-REBOA groups, and a propensity score was developed using multivariate logistic regression. Survival to discharge was compared between the groups after propensity score matching.

RESULTS

Among 82,371 patients included in this study, 385 were treated with REBOA. After propensity score matching, 117 pairs were selected. Survival to discharge was significantly higher among patients treated with REBOA than among those treated without REBOA (53 [45.3%] vs. 38 [32.5%]; odds ratio = 1.72; 95% CI = 1.01-2.93; p = 0.04).

CONCLUSIONS

REBOA use was associated with improved survival to discharge and should therefore be considered during the management of severely injured trauma patients.

Recent advances in austere combat surgery: Use of aortic balloon occlusion as well as blood challenges by special operations medical forces in recent combat operations

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) for control of noncompressible torso hemorrhage is a technology that is increasingly being utilized in the combat casualty setting. Its use in the resource restricted environment holds potential to improve hemorrhage control, decrease blood product utilization, decrease morbidity, and improve combat mortality. The objective of this report is to present the single largest series of REBOA use on severely injured combat casualties.

METHODS

Over an 18-month period, austere surgical teams comprised of coalition partners provided initial damage control resuscitation (DCR) and surgical stabilization for over 2,300 combat casualties prior to transferring patients to the next level of trauma care.

RESULTS

Twenty patients presented with injuries from explosion and gunshot wounds with mean initial heart rate of 129 bpm and mean initial systolic blood pressure of 71 mm Hg. Femoral cutdowns were used in six patients. Aortic occlusion was achieved with REBOA catheter placement in Zone 1 (n = 17) and Zone 3 (n = 2). Systolic blood pressure increased an average of 56 mm Hg with aortic occlusion. There were no access related site complications. All patients survived transport to the next level of care. The majority of blood products transfused in this cohort were whole blood, largely supported by emergent blood drives.

CONCLUSION

This series demonstrates the potential for REBOA as a lifesaving technique for the patient who presents with hemodynamic instability and noncompressible torso hemorrhage. Resuscitative endovascular balloon occlusion of the aorta allows austere surgical teams to rapidly stabilize severely injured combat casualties, expand capability, and provide enhanced DCR while minimizing personnel, resources, and blood product utilization. The use of "whole blood only" strategy for DCR shows potential to be superior to traditional component therapy, and when combined with "proactive" REBOA utilization, provides significant improvements in hemodynamics and hemorrhage control.

LEVEL OF EVIDENCE

Case series, level V.

No wire? No problem: Resuscitative endovascular balloon occlusion of the aorta can be performed effectively and more rapidly with a wire-free device

BACKGROUND

A wire-free device is available for resuscitative endovascular balloon occlusion of the aorta (REBOA) providing aortic occlusion (AO) without lengthy platform guide-wires and large sheaths.

METHODS

This was a retrospective, single-institution review of patients who received REBOA from May 2014 to September 2017. Timing of procedural steps was measured in seconds using time-stamped videography.

RESULTS

Seventy-four patients received REBOA: 29 with a platform guidewire, 12-Fr sheath, and balloon catheter (W group), and 45 with a 7-Fr sheath and wire-free device (WF group). Mean age (p = 0.22) and ISS (p = 0.80) were similar between groups. Fifty-nine patients received REBOA at Zone 1, 15 patients at Zone 3. There was no difference in median [interquartile range] time to common femoral artery (CFA) access between the WF (194 [98-313] seconds) and W (193 [126-280] seconds) groups (p = 0.96). Both median time to AO after CFA access (WF, 158 [109-264] seconds vs. W, 307 [222-390] seconds, p < 0.001) and median total procedural time (WF, 366 [263-596] seconds vs. W, 511 [441-597] seconds; p = 0.012) were significantly shorter with the wire-free system. The rates of percutaneous versus open CFA access was not different between groups (p = 0.48). Both groups had a similar physiologic response to AO as measured by pre- and post-AO SBP (p = 0.86). Overall mortality rate was 74%, 90% in the W group, and 64% in the WF group (p = 0.027). The procedure-related complication rate was not significantly different between groups with regard to compartment syndrome (W, 3% vs. WF, 4%, p = 1.0), access-related complications (W, 0 vs. WF, 6%, p = 0.28), or systemic complication (W, 0 vs. WF, 9%, p = 0.15).

CONCLUSION

Once CFA access is obtained, AO with a smaller wire-free device reduces procedural time by approximately 50%. When perfusion to proximal organs is essential, the seconds saved to achieve AO may contribute to improved mortality. Time to obtain CFA access is not dependent on introducer sheath size.

LEVEL OF EVIDENCE

Therapeutic, level V.

For debate: advanced bleeding control potentially saves lives in armed forces and should be considered

INTRODUCTION

Advanced bleeding control options for truncal and junctional haemorrhage including resuscitative endovascular balloon occlusion of the aorta (REBOA) have been used in managing catastrophic bleeding. The primary aim is to report on potential indications for advanced bleeding control in combat casualties during the Dutch deployment in Uruzgan, Afghanistan, between August 2006 and August 2010. The secondary aim is to report on training methods for advanced bleeding control in (para)medical personnel.

METHODS

The trauma registry from the Dutch role 2 enhanced medical treatment facility at Tarin Kowt, Uruzgan, Afghanistan, was used to analyse patients who sustained a battle injury with major haemorrhage. Furthermore, a comprehensive search was performed on training (para)medical personnel in advanced bleeding control.

RESULTS

There were 212 possible indications for advanced bleeding control with mortality of 28.8% (61/212). These possible indications consisted of 1.9% (4/212) junctional lower extremity injuries with a 75% (3/4) mortality rate, 59% (125/212) visceral vascular injuries with a mortality rate of 12.5% (26/125). The junctional and visceral injuries (n=129) were all potential indications for advanced bleeding control options, such as REBOA. Further 39.2% (83/212) casualties with central thoracic or neck injuries had a mortality rate of 38.6% (32/83). Based on an Abbreviated Injury Scale chest or abdomen score ≥461 indications for advanced bleeding control were identified. A 24-hour average of 8.8 packets of red blood cells, 4.2 packets of plasma and 1.9 packets of platelets was used to prevent exsanguination. The total out-of-hospital survival rate was 64% (39/61).

CONCLUSION

Retrospective analysis revealed 212 potential indications for advanced bleeding control with a mortality of 28.8% (61/212). Advanced bleeding control, such as REBOA, might have improved survival in approximately 61 of 212 casualties. Advanced bleeding control could be used as an adjunct to improve outcomes in major truncal or junctional haemorrhage in prehospital, remote settings and implementation should be considered. Vascular access training and REBOA placement for (para)medical military personnel should be explored in future research.

Resuscitative endovascular balloon occlusion of the aorta: an option for noncompressible torso hemorrhage?

PURPOSE OF REVIEW

Hemorrhage is the major cause of early death in severely injured patients. In civilian emergency medical services, the majority of life-threatening bleedings are found in noncompressible body regions (e.g. abdomen and pelvis). Resuscitative endovascular balloon occlusion of the aorta (REBOA) has therefore been discussed in recent years as a possible lifesaving procedure and numerous studies, meta-analyses and guidelines have been published. In this review, the data situation of REBOA in the management of bleeding trauma patients is discussed and practical implementation is depicted.

RECENT FINDINGS

The typical indication for REBOA is a traumatic life-threatening hemorrhage below the diaphragm in patients unresponsive or only transiently responsive to the usual conservative therapeutic measures. REBOA appears to be a safe and effective procedure to reduce blood loss and stabilize the patient's hemodynamic status. However, surgical hemostasis has to be achieved within 30-60 min after occlusion of the aorta. Data on clear advantages of REBOA over resuscitative thoracostomy are inconclusive.

SUMMARY

REBOA could play an important role in the management of the severely bleeding patient in the future. Together with transfusion and therapy of coagulation disorders, REBOA may be an additional tool in the anesthetist's hands for trauma management in interprofessional care concepts.

Consensus on resuscitative endovascular balloon occlusion of the Aorta: A first consensus paper using a Delphi method

BACKGROUND

To further strengthen the evidence base on the use of Resuscitative Endovascular Balloon occlusion of the Aorta (REBOA) we performed a Delphi consensus. The aim of this paper is to establish consensus on the indications and contraindications for the use of REBOA in trauma and non-trauma patients based on the existing evidence and expertise.

STUDY DESIGN

A literature review facilitated the design of a three-round Delphi questionnaire. Delphi panelists were identified by the investigators. Consensus was reached when at least 70% of the panelists responded to the survey and more than 70% of respondents reached agreement or disagreement.

RESULTS

Panel members reached consensus on potential indications, contra-indications and settings for use of REBOA (excluding the pre hospital environment), physiological parameters for patient selection and indications for early femoral access. Panel members failed to reach consensus on the use of REBOA in patients in extremis (no pulse, no blood pressure) and the use of REBOA in patients with two major bleeding sites.

CONCLUSIONS

Consensus was reached on indications, contra indications, physiological parameters for patient selection for REBOA and early femoral access. The panel did not reach consensus on the use of REBOA in patients in pre-hospital settings, patients in extremis (no pulse, no blood pressure) and in patients with 2 or more major bleeding sites. Further research should focus on the indications of REBOA in pre hospital settings, patients in near cardiac arrest and REBOA inflation times.

A meta-analysis of the incidence of complications associated with groin access after the use of resuscitative endovascular balloon occlusion of the aorta in trauma patients

BACKGROUND

Serious complications related to groin access have been reported with the use of resuscitative endovascular balloon occlusion of the aorta (REBOA). We performed a systematic review and meta-analysis to estimate the incidence of complications related to groin access from the use of REBOA in adult trauma patients.

METHODS

We identified articles in MEDLINE and EMBASE. We reviewed all studies that involved adult trauma patients who underwent the placement of a REBOA and included only those that reported the incidence of complications related to groin access. A meta-analysis of proportions was performed.

RESULTS

We identified 13 studies with a total of 424 patients. REBOA was inserted most commonly by trauma surgeons or emergency room physicians. Information regarding puncture technique was reported in 12 studies and was available for a total of 414 patients. Percutaneous access and surgical cutdown were performed in 304 (73.4%) and 110 (26.5%) patients, respectively. Overall, complications related to groin access occurred in 5.6% of patients (n = 24/424). Lower limb amputation was required in 2.1% of patients (9/424), of which three cases (3/424 [0.7%]) were directly related to the vascular puncture from the REBOA insertion. A meta-analysis that used the logit transformation showed a 5% (95% CI 3%-9%) incidence of complications without significant heterogeneity (LR test: χ = 0.73, p = 0.2, Tau-square = 0.2). In a second meta-analysis, we used the Freeman-Tukey double arcsine transformation and found an incidence of complications of 4% (95% CI 2%-7%) with low heterogeneity (I = 16.3%).

CONCLUSION

We found that the incidence of complications related to groin access was of 4-5% based on a meta-analysis of 13 studies published worldwide. Currently, there are no benchmarks or quality measures as a reference to compare, and thus, further work is required to identify these benchmarks and improve the practice of REBOA in trauma surgery.

LEVEL OF EVIDENCE

Systematic review and meta-analysis, level III.

Lower extremity cooling reduces ischemia-reperfusion injury following Zone 3 REBOA in a porcine hemorrhage model

BACKGROUND

New strategies to mitigate ischemia during REBOA and to prolong its maximal duration are needed. We hypothesized that simple external cooling of the hind limbs would decrease ischemia-reperfusion injury following prolonged Zone 3 REBOA.

METHODS

Twelve swine were anesthetized, instrumented, splenectomized, and then underwent 15% total blood volume hemorrhage. Animals were randomized to hypothermia or control followed by 4 hours of Zone 3 REBOA, resuscitation with shed blood, and 3 hours of critical care. Physiologic parameters were continuously recorded, and laboratory specimens were obtained at regular intervals. Baseline and end-of-study muscle biopsies were obtained for histologic analysis.

RESULTS

There were no significant differences between groups at baseline or after hemorrhage. Maximum creatine kinase was significantly lower in the hypothermia group compared with the normothermia group (median [interquartile range] = 3,445 U/mL [3,380-4,402 U/mL] vs. 22,544 U/mL [17,030-24,981 U/mL]; p < 0.01). Maximum serum myoglobin was also significantly lower in the hypothermia group (1,792 ng/mL [1,250-3,668 ng/mL] vs. 21,186 ng/mL [14,181-24,779 ng/mL]; p < 0.01). Fascial compartment pressures were significantly lower during critical care in the hypothermia group (p = 0.03). No histologic differences were observed in hind limb skeletal muscle.

CONCLUSIONS

External cooling during prolonged Zone 3 REBOA decreased ischemic muscle injury and resulted in lower compartment pressures following reperfusion. Hypothermia may be a viable option to extend the tolerable duration of Zone 3 occlusion, beyond what is currently achievable. Future survival studies are required to assess functional outcomes.

Resuscitative endovascular balloon occlusion of the aorta (REBOA): indications: advantages and challenges of implementation in traumatic non-compressible torso hemorrhage

Background

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is regaining popularity in the treatment of traumatic non-compressible torso bleeding. Advances in invasive radiology coupled with new damage control measures assisted in the refinement of the technique with promising outcomes. The literature continues to have substantial heterogeneity about REBOA indications, applications, and the challenges confronted when implementing the technique in a level I trauma center. Scoping reviews are excellent platforms to assess the diverse literature of a new technique. It is for the first time that a scoping review is adopted for this topic. Advances in invasive radiology coupled with new damage control measures assisted in the refinement of the technique with promising outcomes. The literature continues to have substantial heterogeneity about REBOA indications, applications, and the challenges confronted when implementing the technique in a level I trauma center. Scoping reviews are excellent platforms to assess the diverse literature of a new technique. It is for the first time that a scoping review is adopted for this topic.

Methods

Critical search from MEDLINE, EMBASE, BIOSIS, COCHRANE CENTRAL, PUBMED and SCOPUS were conducted from the earliest available dates until March 2018. Evidence-based articles, as well as gray literature at large, were analyzed regardless of the quality of articles.

Results

We identified 1176 articles related to the topic from all available database sources and 57 reviews from the gray literature search. The final review yielded 105 articles. Quantitative and qualitative variables included patient demographics, study design, study objectives, methods of data collection, indications, REBOA protocol used, time to deployment, zone of deployment, occlusion time, complications, outcome, and the level of expertise at the concerned trauma center.

Conclusion

Growing levels of evidence support the use of REBOA in selected indications. Our data analysis showed an advantage for its use in terms of morbidities and physiologic derangement in comparison to other resuscitation measures. Current challenges remain in the selective application, implementation, competency assessment, and credentialing for the use of REBOA in trauma settings. The identification of the proper indication, terms of use, and possible advantage of the prehospital and partial REBOA are topics for further research.

Level of evidence

Level III.

The European guideline on management of major bleeding and coagulopathy following trauma: fifth edition

Background

Severe traumatic injury continues to present challenges to healthcare systems around the world, and post-traumatic bleeding remains a leading cause of potentially preventable death among injured patients. Now in its fifth edition, this document aims to provide guidance on the management of major bleeding and coagulopathy following traumatic injury and encourages adaptation of the guiding principles described here to individual institutional circumstances and resources.

Methods

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004, and the current author group included representatives of six relevant European professional societies. The group applied a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were re-examined and revised based on scientific evidence that has emerged since the previous edition and observed shifts in clinical practice. New recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated.

Results

Advances in our understanding of the pathophysiology of post-traumatic coagulopathy have supported improved management strategies, including evidence that early, individualised goal-directed treatment improves the outcome of severely injured patients. The overall organisation of the current guideline has been designed to reflect the clinical decision-making process along the patient pathway in an approximate temporal sequence. Recommendations are grouped behind the rationale for key decision points, which are patient- or problem-oriented rather than related to specific treatment modalities. While these recommendations provide guidance for the diagnosis and treatment of major bleeding and coagulopathy, emerging evidence supports the author group’s belief that the greatest outcome improvement can be achieved through education and the establishment of and adherence to local clinical management algorithms.

Conclusions

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. If incorporated into local practice, these clinical practice guidelines have the potential to ensure a uniform standard of care across Europe and beyond and better outcomes for the severely bleeding trauma patient.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2347-3) contains supplementary material, which is available to authorized users.

Use of open and endovascular surgical techniques to manage vascular injuries in the trauma setting: A review of the American Association for the Surgery of Trauma PROspective Observational Vascular Injury Trial registry

BACKGROUND

Vascular trauma data have been submitted to the American Association for the Surgery of Trauma PROspective Observational Vascular Injury Trial (PROOVIT) database since 2013. We present data to describe current use of endovascular surgery in vascular trauma.

METHODS

Registry data from March 2013 to December 2016 were reviewed. All trauma patients who had an injury to a named artery, except the forearm and lower leg, were included. Arteries were grouped into anatomic regions and by compressible and noncompressible region for analysis. This review focused on patients with noncompressible transection, partial transection, or flow-limiting defect injuries. Bivariate and multivariate analyses were used to assess the relationships between study variables.

RESULTS

One thousand one hundred forty-three patients from 22 institutions were included. Median age was 32 years (interquartile range, 23-48) and 76% (n = 871) were male. Mechanisms of injury were 49% (n = 561) blunt, 41% (n = 464) penetrating, and 1.8% (n = 21) of mixed aetiology. Gunshot wounds accounted for 73% (n = 341) of all penetrating injuries. Endovascular techniques were used least often in limb trauma and most commonly in patients with blunt injuries to more than one region. Penetrating wounds to any region were preferentially treated with open surgery (74%, n = 341/459). The most common indication for endovascular treatment was blunt noncompressible torso injuries. These patients had higher Injury Severity Scores and longer associated hospital stays, but required less packed red blood cells, and had lower in hospital mortality than those treated with open surgery. On multivariate analysis, admission low hemoglobin concentration and abdominal injury were independent predictors of mortality.

CONCLUSION

Our review of PROOVIT registry data demonstrates a high utilization of endovascular therapy among severely injured blunt trauma patients primarily with noncompressible torso hemorrhage. This is associated with a decreased need for blood transfusion and improved survival despite longer length of stay.

LEVEL OF EVIDENCE

Therapeutic/care management, level III.

Regional Anesthesia in the Combat Setting: Are ACGME Requirements Enough?

Introduction

Updated Joint Trauma System Clinical Practice Guidelines (CPG) indicate regional anesthesia and pain management (RAAPM) are important for combat casualty care. However, it is unclear whether military anesthesiology residents are receiving adequate RAAPM training to meet the CPGs. The goal of this study was to conduct a preliminary evaluation of resident-completed combat-relevant regional anesthesia procedures. It was hypothesized that most residents would perform an adequate number of each procedure to presume proficiency.

Materials and Methods

Resident-performed, combat-relevant regional anesthesia procedure frequency was extracted from a database maintained at a military anesthesiology residency program. Data collection was limited to a 1-year period. Univariate statistics described procedure distributions, frequencies, and proportion of residents achieving pre-defined, empirically-supported experience criteria for each technique. Analyses examined proportional differences in meeting experience criteria by training-year.

Results

Residents (N = 41) performed a variety of procedures. Simple procedures, such as saphenous peripheral nerve blocks, were performed at a greater frequency than more complicated procedures such as thoracic epidurals, continuous peripheral nerve blocks, and transverse abdominus plane blocks. The majority of residents met experience criteria for four out of the eight measured combat-relevant blocks. There were no proportional differences in meeting procedural experience criteria across the different training levels.

Conclusions

These results suggest a possible gap between the needs of the Military Health System during conflict and current residency training experiences. Reasons for this gap, as well as solutions, are explored.

Migration of Aortic Occlusion Balloons in an in vitro model of the human circulation

BACKGROUND

Aortic Occlusion Balloons (AOB) are used for hemorrhage control in hemodynamically unstable patients. Stability of an AOB is essential for reliable aortic occlusion. The primary aim of this study is to determine whether different types of AOB migrate after total, intermittent or partial occlusion in a porcine aorta positioned in an in vitro model.

MATERIALS AND METHODS

A porcine thoracic aortic section was positioned in a model of the human circulation. Primary and secondary migration was tested in Cook Coda™ 2-9.0-35-120-32 and 2-10-35-140-46, Cook Medical, USA; Rescue balloon™ Tokai RB-167080-E, Tokai Medical Products, Japan; Reliant™ AB46, Medtronic, USA; Russian prototype AOB; ER-REBOA™, Prytime Medical Devices, USA; LeMaitre™ 28 and 45 Aortic Occlusion Catheter, LeMaitre Vascular, USA. These AOB were tested in hypotensive, normotensive and hypertensive scenarios. Migration in total occlusion, intermittent occlusion and partial occlusion was recorded for all AOB.

RESULTS

Limited primary migration occurred in all AOB after total occlusion. The Cook Coda™ 2-9.0-35-120-32 balloon showed maximal migration in 1 test cycle. No migration occurred during intermittent occlusion. Kinking occurs in various degrees but does not seem to prevent a successful occlusion of the aorta. No migration occurred during partial occlusion except in the Russian prototype AOB. In a partial occlusion scenario, distal perfusion occurred only with 5 ml remaining in all balloon types.

CONCLUSIONS

All AOB were successful in full aortic occlusion. Limited primary migration occurred in all AOB after total occlusion only the Cook Coda™ 2-9.0-35-120-32 balloon showed maximal migration once. No migration occurred during intermittent occlusion, during partial occlusion only the Russian prototype AOB migrated. Stiffness and size of the catheter are important factors in preventing migration and kinking.

Extended resuscitative endovascular balloon occlusion of the aorta (REBOA)-induced type 2 myocardial ischemia: a time-dependent penalty

Background

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) increases cardiac-afterload and is used for patients in hemorrhagic shock. The cardiac tolerance of prolonged afterload augmentation in this context is unknown. The aim of this study is to quantify cardiac injury, if any, following 2, 3 and 4 hours of REBOA.

Methods

Anesthetized swine (70-90 kg) underwent a 40% controlled hemorrhage, followed by supraceliac resuscitative endovascular balloon occlusion of the aorta (REBOA) for 2 (n=5), 3 (n=5), and 4 hours (n=5). High-fidelity arterial wave form data were collected, and signal processing techniques were used to extract key inflection points. The adjusted augmentation index (AIx@75; augmentation pressure/pulse pressure, normalized for heart rate) was derived for use as a measure of aortic compliance (higher ratio = less compliance). Endpoints consisted of electrocardiographic, biochemical, and histologic markers of myocardial injury/ischemia. Regression modeling was used to assess the trend against time.

Results

All animals tolerated instrumentation, hemorrhage, and REBOA. The mean (±SD) systolic blood pressure (mm Hg) increased from 65±11 to 212±39 (p<0.001) during REBOA. The AIx@75 was significantly higher during REBOA than baseline, hemorrhage, and resuscitation phases (p<0.05). A time-dependent rise in troponin (R²=0.95; p<0.001) and T-wave deflection (R²=0.64; p<0.001) was observed. The maximum mean troponin (ng/mL) occurred at 4 hours (14.6±15.4) and maximum T-wave deflection (mm) at 65 minutes (3.0±1.8). All animals demonstrated histologic evidence of acute injury with increasing degrees of cellular myocardial injury.

Discussion

Prolonged REBOA may result in type 2 myocardial ischemia, which is time-dependent. This has important implications for patients where prolonged REBOA may be considered beneficial, and strategies to mitigate this effect require further investigation.

Level of evidence

II.

Continuum of the United States military’s traumatic brain injury care: adjusting to the changing battlefield

Over the past 8 years, advances in the US Military Health System (MHS) have led to extensive changes in the way combat casualty care is provided to deployed service members with a traumatic brain injury (TBI). Changes include the application of cutting-edge Clinical Practice Guidelines, use of pioneering technologies, and advances in evacuation procedures. Compared with previous engagements, current operations occur on a much smaller scale, and more frequently in austere environments, such that effective medical support is increasingly challenging. In this paper, the authors describe key aspects of the current continuum of TBI care in the US military, from the point of injury through rehabilitation, with an emphasis on how emerging technologies and evidence-based Clinical Practice Guidelines assist MHS clinicians with providing the best clinical care possible in the changing battlefield.

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) Not Yet Applicable for Widespread Out-of-Hospital Use: A Case of Nonsurvivable Complication from Prolonged REBOA Inflation

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is being considered for temporizing catastrophic hemorrhage before arriving at a specialty center for definitive surgical management.

CASE

We describe the clinical case of a 72-year-old male with a ruptured infrarenal aortic abdominal aneurysm initially stabilized with REBOA at an outside facility and transferred to our care. Transport time was >100 minutes. Despite successful surgical repair of the ruptured aneurysm, the patient expired from multiple-organ failure likely related to ischemia-reperfusion injuries from prolonged balloon occlusion of the aorta.

CONCLUSIONS

Ischemia-mitigating techniques and therapies need to improve drastically before the clinical application of REBOA can be effectively extended to outside the vicinity of specialty centers.

Three cases of resuscitative endovascular balloon occlusion of the aorta (REBOA) in austere pre-hospital environment-technical and methodological aspects

Background

The present paper describes three cases where ER-REBOA® was used with partial aorta occlusion (AO), by performing a partial resuscitative endovascular balloon occlusion of the aorta or pREBOA, in an austere pre-hospital military environment.

In addition, because no specific REBOA algorithm for pre-hospital environment exists yet, this paper seeks to fill this gap, proposing a new pragmatic REBOA algorithm.

Methods

Belgian Special Operations Surgical Team applied REBOA in three patients according to a decisional algorithm, based on the MIST acronym used for trauma patients. Only 3 ml, in the first instance, was inflated in the balloon to get AO. The balloon was then progressively deflated, and reperfusion was tracked through changes of end-tidal carbon dioxide (EtCO₂).

Results

Systolic blood pressure (SBP) before ER-REBOA® placement was not higher than 60 mmHg. However, within the first 5 min after AO, SBP improved in all three cases. Due to the aortic compliance, a self-made pREBOA was progressively achieved while proximal SBP was raising with intravenous fluid infusion. Afterwards, during deflation, a steep inflection point was observed in SBP and EtCO₂.

Conclusions

ER-REBOA® is suitable for use in an austere pre-hospital environment. The MIST acronym can be helpful to select the patients for which it could be beneficial. REBOA can also be performed with pREBOA in a dynamic approach, inflating only 3 mL in the balloon and using the aortic compliance. Furthermore, while proximal SBP can be convenient to follow the occlusion, EtCO₂ can be seen as an easy and interesting marker to follow the reperfusion.

Fabrication of injectable and superelastic nanofiber rectangle matrices ("peanuts") and their potential applications in hemostasis

Uncontrolled hemorrhage, which typically involves the torso and/or limb junctional zones, remains a great challenge in the prehospital setting. Here, we for the first time report an injectable and superelastic nanofiber rectangle matrix ("peanut") fabricated by a combination of electrospinning, gas foaming, hydrogel coating and crosslinking techniques. The compressed nanofiber peanut is capable of re-expanding to its original shape in atmosphere, water and blood within 10 s. Such nanofiber peanuts exhibit greater capacity of water/blood absorption compared to current commercial products and high efficacy in whole blood clotting assay, in particular for thrombin-immobilized samples. These nanofiber peanuts are capable of being packed into a syringe for injection. Further in vivo tests indicated the effectiveness of nanofiber peanuts for hemostasis in a porcine liver injury model. This new class of nanofiber-based materials may hold great promise for hemostatic applications.

CE: The Use of Resuscitative Endovascular Balloon Occlusion of the Aorta in Treating Hemorrhagic Shock from Severe Trauma

: Hemorrhage is the leading cause of preventable death in trauma patients. In recent years, technological innovations and research efforts aimed at preventing death from hemorrhagic shock have resulted in the emergence of resuscitative endovascular balloon occlusion of the aorta (REBOA). REBOA offers a less invasive option for emergent hemorrhage control in noncompressible areas of the body without the added risks and morbidities of an ED thoracotomy. This article outlines the procedure and device used, describes the procedure's evolution, and discusses various considerations, pitfalls, and nursing implications.

Resuscitative Endovascular Balloon Occlusion of the Aorta: A Bridge to Flight Survival

Trauma endures as the leading cause of death worldwide, and most deaths occur in the first 24 hours after initial injury as a result of hemorrhage. Historically, about 90% of battlefield deaths occur before the injured person arrives at a theater hospital, and most are due to noncompressible hemorrhage of the torso. Resuscitative endovascular balloon occlusion of the aorta is an evolving technique to quickly place a balloon into the thoracic or abdominal aorta to efficiently block blood flow to distal circulation. Maneuvers, such as resuscitative endovascular balloon occlusion of the aorta, to control endovascular hemorrhage offer a potential intervention to control noncompressible hemorrhage. This technique can be performed percutaneously or open in prehospital environments to restore hemodynamic functions and serve as a survival bridge until the patient is delivered to a treatment facility for definitive surgical hemostasis. This article describes the indications, complications, and application of resuscitative endovascular balloon occlusion of the aorta to military and civilian aeromedical transport.

A systematic review and meta-analysis of the use of resuscitative endovascular balloon occlusion of the aorta in the management of major exsanguination

BACKGROUND

Circulatory collapse is a leading cause of mortality among traumatic major exsanguination and in ruptured aortic aneurysm patients. Approximately 40% of patients die before hemorrhage control is achieved. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an adjunct designed to sustain the circulation until definitive surgical or endovascular repair. A systematic review was conducted for the current clinical use of REBOA in patients with hemodynamic instability and to discuss its potential role in improving prehospital and in-hospital outcome.

METHODS

Systematic review and meta-analysis (1900-2017) using MEDLINE, Cochrane, EMBASE, Web of Science and Central and Emcare using the keywords "aortic balloon occlusion", "aortic balloon tamponade", "REBOA", and "Resuscitative Endovascular Balloon Occlusion" in combination with hemorrhage control, hemorrhage, resuscitation, shock, ruptured abdominal or thoracic aorta, endovascular repair, and open repair. Original published studies on human subjects were considered.

RESULTS

A total of 490 studies were identified; 89 met criteria for inclusion. Of the 1436 patients, overall reported mortality was 49.2% (613/1246) with significant differences (p < 0.001) between clinical indications. Hemodynamic shock was evident in 79.3%, values between clinical indications showed significant difference (p < 0.001). REBOA was favored as treatment in trauma patients in terms of mortality. Pooled analysis demonstrated an increase in mean systolic pressure by almost 50 mmHg following REBOA use.

CONCLUSION

REBOA has been used in trauma patients and ruptured aortic aneurysm patients with improvement of hemodynamic parameters and outcomes for several decades. Formal, prospective study is warranted to clarify the role of this adjunct in all hemodynamic unstable patients.

Feasibility of basic transesophageal echocardiography in hemorrhagic shock: potential applications during resuscitative endovascular balloon occlusion of the aorta (REBOA)

Background

There are numerous studies in the cardiovascular literature that have employed transesophageal echocardiography (TEE) in swine models, but data regarding the use of basic TEE in swine models is limited. The primary aim of this study is to describe an echocardiographic method that can be used with relative ease to qualitatively assess cardiovascular function in a porcine hemorrhagic shock model using resuscitative endovascular balloon occlusion of the aorta (REBOA).

Methods

Multiplane basic TEE exams were performed in 15 during an experimental hemorrhage model using REBOA. Cardiac anatomical structure and functional measurements were obtained. In a convenience sample (two animals from each group), advanced functional cardiovascular measurements were obtained before and after REBOA inflation for comparison with qualitative assessments.

Results

Basic TEE exams were performed in 15 swine. Appropriate REBOA placement was confirmed using TEE in all animals and verified with fluoroscopy. Left ventricular volume was decreased in all animals, and left ventricular systolic function increased following REBOA inflation. Right ventricular systolic function and volume remained normal prior to and after hemorrhage and REBOA use. Mean ejection fraction (EF) decreased from 64% (S.D. 9.6) to 62.1 (S.D. 16.8) after hemorrhage and REBOA inflation (p = 0.76); fractional area of change (FAC) decreased from 49.8 (S.D. 9.0) to 48.5 (S.D. 13.6) after hemorrhage and REBOA inflation (p = 0.82).

Conclusion

Basic TEE, which requires less training than advanced TEE, may be employed by laboratory investigators and practitioners across a wide spectrum of experimental and clinical settings.