Pilot Study of a Novel Swine Model for Controlling Junctional Hemorrhage Using the iTClamp in Conjunction With Hemostatic Agents

Comprehensive Assessment of Collagen/Sodium Alginate-Based Sponges as Hemostatic Dressings

In our search for a biocompatible composite hemostatic dressing, we focused on the design of a novel biomaterial composed of two natural biological components, collagen and sodium alginate (SA), cross-linked using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) and oxidized sodium alginate (OSA). We conducted a series of tests to evaluate the physicochemical properties, acute systemic toxicity, skin irritation, intradermal reaction, sensitization, cytotoxicity, and in vivo femoral artery hemorrhage model. The results demonstrated the excellent biocompatibility of the collagen/sodium alginate (C/SA)-based dressings before and after crosslinking. Specifically, the femoral artery hemorrhage model revealed a significantly shortened hemostasis time of 132.5 ± 12.82 s for the EDC/NHS cross-linked dressings compared to the gauze in the blank group (hemostasis time of 251.43 ± 10.69 s). These findings indicated that C/SA-based dressings exhibited both good biocompatibility and a significant hemostatic effect, making them suitable for biomedical applications.

Preparation of healing-promoting and fibrosis-inhibiting asymmetric poly(ethylene glycol-b-L-phenylalanine)/cRGD-modified hyaluronate sponges and their applications in hemorrhage and nasal mucosa repair

Acute or chromic bleeding, such as epistaxis, requires hemostatic materials to assist hemostasis. Even in complex cases, hemostatic materials must have other functions, including the promotion of healing and prevention of adhesion. Herein, a series of fibrosis-suppressive functional cRGD-modified crosslinking hyaluronic acid sponges were prepared. The in vitro hemostatic efficiency and mechanism were determined using blood clotting time, blood coagulation index, lactate dehydrogenase (LDH) and thromboxane B2 (TX-B2) ELISA, and proteomics. Among the prepared sponges, both poly(ethylene-b-L-Phe) (PEBP)-and cRGD contained SPN4 and exhibited the highest platelet concentration and activation efficiency as well as the most effective coagulative effect. In addition, no significant cytotoxicity was observed for the sponges in rat airway epithelial cells. The in vivo hemostatic and adhesion-preventive effects of the sponges were evaluated using rat models of liver injury and sidewall defect-cecum abrasion. PEBP-containing sponges effectively prevented postoperative adhesion and cRGD-modified sponges exhibited excellent hemostatic effects. Finally, the comprehensive repair effects of the sponges were evaluated using a rabbit maxillary sinus mucosal injury model, based on CT, MRI examination, and pathological staining. SPN4 exhibited the best comprehensive reparative effects, including the promotion of mucosal repair and infection inhibition. Thus, SPN4 is a promising multifunctional hemostatic material.

Progress in injectable hydrogels for the treatment of incompressible bleeding: an update

Uncontrollable haemorrhage from deep, noncompressible wounds remains a persistent and intractable challenge, accounting for a very high proportion of deaths in both war and disaster situations. Recently, injectable hydrogels have been increasingly studied as potential haemostatic materials, highlighting their enormous potential for the management of noncompressible haemorrhages. In this review, we summarize haemostatic mechanisms, commonly used clinical haemostatic methods, and the research progress on injectable haemostatic hydrogels. We emphasize the current status of injectable hydrogels as haemostatic materials, including their physical and chemical properties, design strategy, haemostatic mechanisms, and application in various types of wounds. We discuss the advantages and disadvantages of injectable hydrogels as haemostatic materials, as well as the opportunities and challenges involved. Finally, we propose cutting-edge research avenues to address these challenges and opportunities, including the combination of injectable hydrogels with advanced materials and innovative strategies to increase their biocompatibility and tune their degradation profile. Surface modifications for promoting cell adhesion and proliferation, as well as the delivery of growth factors or other biologics for optimal wound healing, are also suggested. We believe that this paper will inform researchers about the current status of the use of injectable haemostatic hydrogels for noncompressible haemorrhage and spark new ideas for those striving to propel this field forward.

Speed, Skill Retention, and End User Perceptions of iTClamp Application by Navy Corpsmen on a Manikin Model of Femoral Hemorrhage

INTRODUCTION

Tactical Combat Casualty Care guidelines recommend packing junctional wounds with gauze, applying direct pressure for 3 minutes, and then securing with an external pressure dressing. This method is time-consuming, which can be problematic in a combat environment. Alternatively, the iTClamp has documented efficacy and rapid application. However, no studies have evaluated device application by military prehospital medical providers, such as Navy corpsmen, or their user experience with the device.

MATERIALS AND METHODS

Research data derived from a protocol were approved by the Naval Medical Center Portsmouth's Institutional Review Board in compliance with all applicable federal regulations governing the protection of human subjects. Navy corpsmen with the current Tactical Combat Casualty Care certification applied the iTClamp or standard pressure dressing on a manikin model of femoral hemorrhage in a crossover study design. Each participant used both devices in a randomized fashion. Time to application was recorded, and participants completed Likert scale surveys to evaluate both devices for preference, ease of use, and physical assessment. A repeat assessment was performed 1 month later to assess skill atrophy. Repeated-measures ANOVA was used to compare application time. Likert scale survey data were analyzed using Mann-Whitney and Wilcoxon tests to compare survey data within and between time points, respectively.

RESULTS

The application of the iTClamp was more than twice as fast as the application of pressure dressings at both the initial and follow-up evaluations. There was no statistically significant difference in application times between the first evaluation and the 30-day assessment of either device, indicating no atrophy in skill. While 65% and 52% of the participants expressed preference in for the iTClamp in their surveys during the initial and follow-up respective visits, the difference in preference was not statistically significant for either the initial or the follow-up survey. Open-ended survey responses yielded both perceived advantages and disadvantages for each treatment option.

CONCLUSIONS

In austere or hostile environments, speed of treatment and extrication can have significant implications for the safety of both the patient and the medical providers. Hemorrhage control interventions must be both effective and easy to use for a prehospital provider to ensure its efficacy in a live battlefield situation. The iTClamp is small, simple, and fast to use, but its wide adoption in the field may be based on limitations perceived by participants, including narrow indications for use. However, based on our findings, it is reasonable to field the iTClamp depending on provider preference.

Euryale ferox stem-inspired anisotropic quaternized cellulose/xanthan-based antibacterial sponge with high absorbency and compressibility for noncompressible hemorrhage

Uncontrollable hemorrhage from deep noncompressible wounds remains an intractable challenge. Herein, inspired by the euryale ferox stem which is capable of transporting water and nutrient substances efficiently along longitudinally aligned channels, an anisotropic sponge with rapidly liquid absorption capacity, excellent mechanical compressibility and antibacterial property based on quaternized cellulose (QC), xanthan gum (XG) and reduced graphene oxide (rGO), was constructed. The euryale ferox stem-like structure and multiple interactions, involving hydrogen bonding, electrostatic interaction and chemical crosslinking, endowed the sponge with excellent fatigue resistance, elasticity and efficient liquid absorption capacity. In vivo rat liver injury, tail amputation and liver noncompressible hemorrhage model experiments confirmed that the sponge exhibited superior hemostatic performance than commercial gelatin sponge, attributing to the positive charge, efficient absorption capacity and rough surface of the sponge, which synergistically promoting the aggregation and activation of red blood cells and platelets as well as formation of fibrin network, leading to accelerated blood coagulation process. Besides, the sponge showed favorable cytocompatibility, hemocompatibility and antibacterial property. Overall, the bioinspired sponge had fantastic potential for controlling deep noncompressible hemorrhage and providing a new idea for designing hemostatic materials.

Traditional uterine tamponade and vacuum-induced uterine tamponade devices in obstetrical hemorrhage management

Obstetrical hemorrhage is the leading cause of maternal morbidity and mortality worldwide, and the rates of severe hemorrhage are increasing. There is a crucial need to expand treatment options for hemorrhage to address this global crisis. Over the last decade, the evolution of hemorrhage control devices has contributed to advancements in obstetrical hemorrhage management. The number of existing hemorrhage control devices and techniques has increased markedly in recent years, and new devices are in development. The current evidence for established and investigational hemorrhage control devices has been summarized in this review. Of note, 2 main categories of devices exist: traditional uterine tamponade and vacuum-induced uterine tamponade. Although traditional intrauterine balloon tamponade devices are currently used widely in postpartum hemorrhage management, novel hemorrhage control devices and techniques have been developed. These include the minisponge tamponade device, the Jada System, a modified Bakri balloon technique, and a suction tube uterine tamponade technique. Reassuring safety data and preliminary efficacy data from pilot studies of these novel techniques support the powerful role intrauterine devices can play in obstetrical hemorrhage management. This review aimed to improve awareness of device options so that continued efforts can be made to integrate new technology into hemorrhage management protocols. Well-designed studies inclusive of new hemorrhage control devices are essential to understanding where new technology fits into preexisting obstetrical hemorrhage algorithms. In addition, access to new tamponade technology remains limited on a global scale. Programs aimed at both increasing access to devices and expanding educational initiatives are essential to make new technology a standard component for hemorrhage management.

Nanofibrous hemostatic materials: Structural design, fabrication methods, and hemostatic mechanisms

Development of rapid and effective hemostatic materials has always been the focus of research in the healthcare field. Nanofibrous materials which recapitulate the delicate nano-topography feature of fibrin fibers produced during natural hemostatic process, offer large length-to-diameter ratio and surface area, tunable porous structure, and precise control in architecture, showing great potential for staunching bleeding. Here we present a comprehensive review of advances in nanofibrous hemostatic materials, focusing on the following three important parts: structural design, fabrication methods, and hemostatic mechanisms. This review begins with an introduction to the physiological hemostatic mechanism and current commercial hemostatic agents. Then, it focuses on recent progress in electrospun nanofibrous hemostatic materials in terms of composition and structure control, surface modification, and in-situ deposition. The article emphasizes the development of three-dimensional (3D) electrospun nanofibrous materials and their emerging evolution for improving hemostatic function. Next, it discusses the fabrication of self-assembling peptide or protein-mimetic peptide nanofibers, co-assembling supramolecular nanofibers, as well as other nanofibrous hemostatic agents. Further, the article highlights the external and intracavitary hemostatic management based on various nanofiber aggregates. In the end, this review concludes with the current challenges and future perspectives of nanofibrous hemostatic materials. STATEMENT OF SIGNIFICANCE: This article reviews recent advances in nanofibrous hemostatic materials including fabrication methods, composition and structural control, performance improvement, and hemostatic mechanisms. A variety of methods including electrospinning, self-assembly, grinding and refining, template synthesis, and chemical vapor deposition, have been developed to prepare nanofibrous materials. These methods provide robustness in control of the nanofiber architecture in the forms of hydrogels, two-dimensional (2D) membranes, 3D sponges, or composites, showing promising potential in the external and intracavitary hemostasis and wound healing applications. This review will be of great interest to the broad readers in the field of hemostatic materials and multifunctional biomaterials.

Cellulose fibers-reinforced self-expanding porous composite with multiple hemostatic efficacy and shape adaptability for uncontrollable massive hemorrhage treatment

Uncontrollable hemorrhage leads to high mortality and thus effective bleeding control becomes increasingly important in the military field and civilian trauma arena. However, current hemostats not only present limitation when treating major bleeding, but also have various side effects. Here we report a self-expanding porous composites (CMCP) based on novel carboxymethyl cellulose (CMC) fibers and acetalized polyvinyl alcohol (PVA) for lethal hemorrhage control. The CMC fibers with uniform fibrous structure, high liquid absorption and procoagulant ability, are evenly interspersed inside the composite matrix. The obtained composites possess unique fiber-porous network, excellent absorption capacity, fast liquid-triggered self-expanding ability and robust fatigue resistance, and their physicochemical performance can be fine-tuned through varying the CMC content. In vitro tests show that the porous composite exhibits strong blood clotting ability, high adhesion to blood cells and protein, and the ability to activate platelet and the coagulation system. In vivo hemostatic evaluation further confirms that the CMCP presents high hemostatic efficacy and multiple hemostatic effects in swine femoral artery major hemorrhage model. Additionally, the CMCP will not fall off from the injury site, and is also easy to surgically remove from the wound cavity after the hemostasis. Importantly, results of CT tomography and 3D reconstruction indicate that CMCP can achieve shape adaptation to the surrounding tissues and the wound cavities with different depths and shapes, to accelerate hemostasis while protecting wound tissue and preventing infection.

Management of non-compressible torso hemorrhage: An update

With the widespread adoption of advanced tourniquets, the mortality rate of limb wound hemorrhage has decreased significantly, and non-compressible torso hemorrhage has gradually occupied the leading position of potentially preventable death, both in military and civilian circumstances. With the emergence of novel hemostatic devices and materials, strategies for the management of non-compressible torso hemorrhage have changed significantly. This review summarizes the current treatment strategies and types of equipment for non-compressible torso hemorrhage and suggests future research directions, hoping to provide a comprehensive review for the medical personnel and researchers engaging in this field.

Efficacy of Hemostatic Gauzes in a Swine Model of Prolonged Field Care with Limb Movement

INTRODUCTION

Prolonged field care for junctional wounds is challenging and involves limb movement to facilitate transport. No studies to date have explored the efficacy of gauze products to limit rebleeding in these scenarios.

MATERIALS AND METHODS

We randomly assigned 48 swine to QuikClot Combat Gauze, ChitoGauze, NuStat Tactical, or Kerlix treatment groups (12 each) and then inflicted a severe groin injury by utilizing a modified Kheirabadi model of a 6-mm femoral artery punch followed by unrestricted bleeding for 60 seconds. We reassessed rebleed following limb movement at 30 minutes of stabilization and 4 hours after stabilization.

RESULTS

Swine treated with Combat Gauze proved to have the lowest incidence of rebleeding, and conversely, NuStat Tactical had the highest incidence of rebleeding at wounds after limb movement. Importantly, rebleeds occurred at a rate of 25%-58% across all swine treatment groups at 30 minutes postinjury and 0%-42% at 270 minutes postinjury demonstrating that limb movements universally challenge hemostatic junctional wounds.

CONCLUSIONS

Our findings highlight the difficulty of controlling hemorrhage from junctional wounds with hemostatic gauze in the context of prolonged field care and casualty transport. Our research can guide selection of hemorrhage control gauze when patients have prolonged field extraction or difficult transport. Our data demonstrates the frequency of junctional wound rebleeding after movement and thus the importance of frequent patient reassessment.

Efficacy of New Zeolite-Based Hemostatic Gauze in a Gunshot Model of Junctional Femoral Artery Hemorrhage in Swine

BACKGROUND

This work sought to (1) establish a reliable gunshot model of junctional femoral artery rupture in swine that accurately simulates field rescue conditions and (2) use the gunshot model to compare the efficacy and ease of application of zeolite nanometer hemostatic gauze with other hemostatic materials.

METHODS

Thirty-six healthy landrace swine (body weight 50 ± 5 kg) were randomly divided into three groups which were treated with Combat Gauze (CG), FeiChuang hemostatic gauze (FG), or standard medical gauze (SG). A gunshot model of femoral artery hemorrhage in landrace swine was used with portable ultrasound to accurately position the wound. After the shooting, when mean arterial pressure of swine decreased by at least 30% for 10 s, wounds were pressed with standard packing (39 g) of gauze materials for 3 min to stop bleeding, then bandaged with pressure. Blood samples were taken 15 min before injury, then 10 min, 30 min, and 60 min after injury to determine hemodynamic, coagulation, and arterial blood gas indexes. Wound temperatures were taken at 5 min, 10 min, 30 min, and 60 min after injury, and survival times were recorded. The volume of blood loss and survival time were used to evaluate hemostatic effect, whereas the fill time, wound temperature, and physiological indexes were used to evaluate the safety and operation of the product.

RESULTS

The CG (11.15 ± 3.09 mL/kg) and FG (12.19 ± 3.5 mL/kg) groups had significantly less blood loss than the SG group (16.8 ± 5.14 mL/kg) (P = 0.04; P = 0.039, respectively). After gauze packing, bleeding in CG (5.85 ± 1.17 mL/kg) and FG (5.37 ± 0.93 mL/kg) groups remained significantly lower than that of the SG group (6.93 ± 1.03 mL/kg) (P = 0.011; P = 0.003, respectively). Wound temperature rose with time for all groups (P < 0.001). The wound temperatures in the FG group and the CG group were significantly higher than that of the SG group (P = 004 and 0.009, respectively). Survival rates and times were not significantly different among the three groups, although the FG group had the longest average survival time (standard deviation [SD] 204.8 s), compared with the SG group (SD 177.8 s) and CG (SD 187.5 s) groups. No significant differences in hemodynamics, blood gas, and coagulation were observed among the three groups.

CONCLUSIONS

The gunshot model of junctional femoral arterial hemorrhage guided by ultrasound had high accuracy for femoral arterial rupture by bullet wound and provided consistent and reproducible field-simulation conditions for comparison of hemostatic materials. FeiChuang zeolite hemostatic gauze effectively controlled bleeding as well as combat gauze, without excessive heat as found in other zeolite-based products. However, improvements to application technique, such as a packing device, are needed to improve operating time.

Management of Postpartum Hemorrhage With a Mini-Sponge Tamponade Device

BACKGROUND

Postpartum hemorrhage is a leading cause of maternal mortality globally. A tamponade agent that can be quickly and easily placed in a range of settings could advance the treatment of atonic hemorrhage.

METHOD

We adapted a highly effective trauma dressing for use in postpartum hemorrhage. This mini-sponge tamponade device is comprised of two components: compressed mini-sponges contained within a strong mesh pouch and a tubular applicator. Compressed mini-sponges rapidly absorb blood, expand within seconds, and exert sustained pressure uniformly to bleeding sites. The sponges are deployed within a mesh pouch to facilitate simple vaginal removal.

EXPERIENCE

We successfully placed the mini-sponge device in nine patients experiencing postpartum hemorrhage after vaginal birth, with resolution of bleeding within 1 minute. The mean time to place the device was 62 seconds. Uterine fill was documented in all cases by ultrasound scan, and device placement was rated as "easy" to "very easy." Mini-sponges were left in place on average for 1 hour (0.5 hours-14 hours). Bleeding did not recur. There were no adverse events; all patients remained afebrile and did not require subsequent surgical intervention.

CONCLUSION

This study supports further evaluation of the mini-sponge device for the management of postpartum hemorrhage.

FUNDING

This study was funded by OBSTETRX, Inc.

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.