Surgical adjuncts to noncompressible torso hemorrhage as tools for patient blood management

Efficacy of partial and complete resuscitative endovascular balloon occlusion of the aorta in the hemorrhagic shock model of liver injury

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) can temporarily control traumatic bleeding. However, its prolonged use potentially leads to ischemia-reperfusion injury (IRI). Partial REBOA (pREBOA) can alleviate ischemic burden; however, its security and effectiveness prior to operative hemorrhage control remains unknown. Hence, we aimed to estimate the efficacy of pREBOA in a swine model of liver injury using an experimental sliding-chamber ballistic gun.

METHODS

Twenty Landrace pigs were randomized into control (no aortic occlusion) (n=5), intervention with complete REBOA (cREBOA) (n=5), continuous pREBOA (C-pREBOA) (n=5), and sequential pREBOA (S-pREBOA) (n=5) groups. In the cREBOA and C-pREBOA groups, the balloon was inflated for 60 min. The hemodynamic and laboratory values were compared at various observation time points. Tissue samples immediately after animal euthanasia from the myocardium, liver, kidneys, and duodenum were collected for histological assessment using hematoxylin and eosin staining.

RESULTS

Compared with the control group, the survival rate of the REBOA groups was prominently improved (all P<0.05). The total volume of blood loss was markedly lower in the cREBOA group (493.14±127.31 mL) compared with other groups (P<0.01). The pH was significantly lower at 180 min in the cREBOA and S-pREBOA groups (P<0.05). At 120 min, the S-pREBOA group showed higher alanine aminotransferase (P<0.05) but lower blood urea nitrogen compared with the cREBOA group (P<0.05).

CONCLUSION

In this trauma model with liver injury, a 60-minute pREBOA resulted in improved survival rate and was effective in maintaining reliable aortic pressure, despite persistent hemorrhage. Extended tolerance time for aortic occlusion in Zone I for non-compressible torso hemorrhage was feasible with both continuous partial and sequential partial measures, and the significant improvement in the severity of acidosis and distal organ injury was observed in the sequential pREBOA.

Emerging hemostatic materials for non-compressible hemorrhage control

Non-compressible hemorrhage control is a big challenge in both civilian life and the battlefield, causing a majority of deaths among all traumatic injury mortalities. Unexpected non-compressible bleeding not only happens in pre-hospital situations but also leads to a high risk of death during surgical processes throughout in-hospital treatment. Hemostatic materials for pre-hospital treatment or surgical procedures for non-compressible hemorrhage control have drawn more and more attention in recent years and several commercialized products have been developed. However, these products have all shown non-negligible limitations and researchers are focusing on developing more effective hemostatic materials for non-compressible hemorrhage control. Different hemostatic strategies (physical, chemical and biological) have been proposed and different forms (sponges/foams, sealants/adhesives, microparticles/powders and platelet mimics) of hemostatic materials have been developed based on these strategies. A summary of the requirements, state-of-the-art studies and commercial products of non-compressible hemorrhage-control materials is provided in this review with particular attention on the advantages and limitations of their emerging forms, to give a clear understanding of the progress that has been made in this area and the promising directions for future generations.

Facing Trauma and Surgical Emergency in Space: Hemorrhagic Shock

Although the risk of trauma in space is low, unpredictable events can occur that may require surgical treatment. Hemorrhage can be a life-threatening condition while traveling to another planet and after landing on it. These exploration missions call for a different approach than rapid return to Earth, which is the policy currently adopted on the International Space Station (ISS) in low Earth orbit (LEO). Consequences are difficult to predict, given the still scarce knowledge of human physiology in such environments. Blood loss in space can deplete the affected astronaut's physiological reserves and all stored crew supplies. In this review, we will describe different aspects of hemorrhage in space, and by comparison with terrestrial conditions, the possible solutions to be adopted, and the current state of the art.

Severe penetrating trauma in Switzerland: first analysis of the Swiss Trauma Registry (STR)

PURPOSE

The purpose of this study was to examine the epidemiology, demographics, injury characteristics and outcomes of patients who presented to Swiss trauma centers following severe penetrating trauma.

METHODS

Swiss Trauma Registry (STR)-cohort analysis including patients with severe (ISS ≥ 16 or AIS head ≥ 3) penetrating trauma between 2017 and 2019. Primary outcome was mortality. Secondary outcomes were hospital and intensive care unit (ICU) length of stay (LOS), and prehospital times.

RESULTS

During the 3-year study period, 134 (1.6% of entire STR) patients with severe penetrating trauma were identified [64 (48%) gunshot wounds (GSW), 70 (52%) stab wounds (SW)]. Median age was 40.5 (IQR 29.0-59.0) and 82.8% were male. Mortality rate was 50% for GSW; 9% for SW. Overall, prehospital time [incident to arrival emergency department (ED)] was 65 (IQR 45-94) minutes. The median number of patients admitted for a severe GSW/SW per center and year was 2 (range 0-14). Of 64 patients who sustained a GSW, 42 (65.6%) were self-inflicted. Mortality in self-inflicted GSW reached 66.7%, with the head being severely injured in 78.6%. The 67 patients with severe isolated torso GSW/SW had an ISS of 20 (IQR 16-26) and a mortality of 15%. Multivariable analysis identified severe chest trauma, ED Glasgow Coma Scale ≤ 8, age, self-infliction, massive blood transfusion and ISS as independent predictors for mortality.

CONCLUSION

Severe penetrating trauma is very rare in Switzerland. Mortality ranges from 9% in SW to 67% in self-inflicted GSW. Particularly in the setting of GSW/SW to the torso, reduction in prehospital time may further improve patient outcomes.

Hemostatic agents for prehospital hemorrhage control: a narrative review

Hemorrhage is the leading cause of preventable death in combat trauma and the secondary cause of death in civilian trauma. A significant number of deaths due to hemorrhage occur before and in the first hour after hospital arrival. A literature search was performed through PubMed, Scopus, and Institute of Scientific Information databases for English language articles using terms relating to hemostatic agents, prehospital, battlefield or combat dressings, and prehospital hemostatic resuscitation, followed by cross-reference searching. Abstracts were screened to determine relevance and whether appropriate further review of the original articles was warranted. Based on these findings, this paper provides a review of a variety of hemostatic agents ranging from clinically approved products for human use to newly developed concepts with great potential for use in prehospital settings. These hemostatic agents can be administered either systemically or locally to stop bleeding through different mechanisms of action. Comparisons of current hemostatic products and further directions for prehospital hemorrhage control are also discussed.

Tranexamic acid suppresses the release of mitochondrial DNA, protects the endothelial monolayer and enhances oxidative phosphorylation

Damage-associated molecular patterns, including mitochondrial DNA (mtDNA) are released during hemorrhage resulting in the development of endotheliopathy. Tranexamic acid (TXA), an antifibrinolytic drug used in hemorrhaging patients, enhances their survival despite the lack of a comprehensive understanding of its cellular mechanisms of action. The present study is aimed to elucidate these mechanisms, with a focus on mitochondria. We found that TXA inhibits the release of endogenous mtDNA from granulocytes and endothelial cells. Furthermore, TXA attenuates the loss of the endothelial monolayer integrity induced by exogenous mtDNA. Using the Seahorse XF technology, it was demonstrated that TXA strongly stimulates mitochondrial respiration. Studies using Mitotracker dye, cells derived from mito-QC mice, and the ActivSignal IPAD assay, indicate that TXA stimulates biogenesis of mitochondria and inhibits mitophagy. These findings open the potential for improvement of the strategies of TXA applications in trauma patients and the development of more efficient TXA derivatives.

Trauma vascular na Amazônia: atualizando o desafio

RESUMO Objetivo: avaliar dados epidemiológicos dos pacientes operados por trauma vascular em hospital de referência para traumatismos vasculares do Estado do Pará, determinar as variáveis que aumentam o risco de óbito e fazer uma análise comparativa com os resultados previamente publicados pela mesma instituição. Métodos: estudo retrospectivo analítico realizado através da coleta de dados de pacientes operados por lesões vasculares, entre março de 2013 e março de 2017. Foram analisados dados demográficos e epidemiológicos, como o mecanismo e topografia da lesão, distância entre o local do trauma e o hospital, tipo de tratamento e complicações. Foi feito ainda o estudo de uma matriz de correlação com regressão logística entre as variáveis e a ocorrência de óbito. Resultados: foram estudados 288 pacientes, com 430 lesões; 92,7% era do sexo masculino, 49,7% entre 25 e 49 anos de idade; 47,2% das lesões foi ocasionada por projéteis de arma de fogo; 47,2% das lesões situava-se nos membros superiores, 42,7% nos membros inferiores, 8% em região cervical, 3,1% torácicas e 0,7% abdominais; 52,8% dos pacientes teve hospitalização por sete dias ou menos. Amputação foi necessária em 6,9% e a mortalidade foi 7,93%. Conclusão: distâncias superiores a 200km foram associadas à internação prolongada e maior probabilidade de amputação de membros. Foi encontrada correlação significativa entre a ocorrência de óbito e o fato de haver lesão arterial, lesão vascular na topografia cervical e lesão vascular na topografia torácica.

Storage of nitroglycerin (NTG) admixed with HBOC-201 for 30 days in polyolefin plastic bags: a pilot study

Hemorrhaged animals have benefited from resuscitation with the hemoglobin-based oxygen carrier (HBOC-201). Co-infusion of nitric oxide (NO) via separate intravascular lines is effective in attenuating HBOC-induced elevation of blood pressure. We tested whether nitroglycerin (NTG) and HBOC-201 can be packaged together as a single drug for resuscitation. Since NTG binds easily to plastics such as polyvinylchloride, we assessed the stability of this combination in oxygen barrier double-layer ethylene-vinyl alcohol/polyolefin bags over a 30-day period. Outcome measures indicative of the stability of HBOC/NTG were reported as changes in levels of hemoglobin (Hb), methemoglobin (MetHb), NTG, and nitrite over time. Individual tightly sealed small aliquots of HBOC/NTG were prepared under nitrogen and analyzed in a timely fashion from 0 to 30 days using hematology instruments, HPLC, FPLC, and chemiluminescence. The level of NTG in the HBOC/NTG mixture was reduced significantly over time whereas it was stable in control mixtures of NTG/saline. The level of total Hb in the HBOC/NTG and HBOC/saline mixtures remained stable over time. MetHb formed and increased to 6% up to day 1 and then slowly decreased in the HBOC/NTG mixture whereas it remained unchanged in the HBOC/saline mixture. Nitrite was produced in the HBOC/NTG group upon mixing, was increased at day 1, and then became undetectable. The reaction between HBOC-201 and NTG occurring upon mixing and developing over time in polyolefin bags makes the long-term storage of this mixed combination inappropriate.

Damage control surgery in weightlessness: A comparative study of simulated torso hemorrhage control comparing terrestrial and weightless conditions

BACKGROUND

Torso bleeding remains the most preventable cause of post-traumatic death worldwide. Remote damage control resuscitation (RDCR) endeavours to rescue the most catastrophically injured, but has not focused on prehospital surgical torso hemorrhage control (HC). We examined the logistics and metrics of intraperitoneal packing in weightlessness in Parabolic flight (0g) compared to terrestrial gravity (1g) as an extreme example of surgical RDCR.

METHODS

A surgical simulator was customized with high-fidelity intraperitoneal anatomy, a "blood" pump and flowmeter. A standardized HC task was to explore the simulator, identify "bleeding" from a previously unknown liver injury perfused at 80 mm Hg, and pack to gain hemostasis. Ten surgeons performed RDCR laparotomies onboard a research aircraft, first in 1g followed by 0g. The standardized laparotomy was sectioned into 20-second segments to conduct and facilitate parabolic flight comparisons, with "blood" pumped only during these time segments. A maximum of 12 segments permitted for each laparotomy.

RESULTS

All 10 surgeons successfully performed HC in both 1g and 0g. There was no difference in blood loss between 1g and 0g (p = 0.161) or during observation following HC (p = 0.944). Compared to 1g, identification of bleeding in 0g incurred less "blood" loss (p = 0.032). Overall surgeons rated their personal performance and relative difficulty of surgery in 0g as "harder" (median Likert, 2/5). However, conducting all phases of HC were rated equivalent between 1g and 0g (median Likert, 3/5), except for instrument control (rated slightly harder, 2.75/5).

CONCLUSION

Performing laparotomies with packing of a simulated torso hemorrhage in a high-fidelity surgical simulator was feasible onboard a research aircraft in both normal and weightless conditions. Despite being subjectively "harder," most phases of operative intervention were rated equivalently, with no statistical difference in "blood" loss in weightlessness. Direct operative control of torso hemorrhage is theoretically possible in extreme environments if logistics are provided.