Pre-hospital haemostatic dressings: a systematic review

Platelet-Rich Plasma-Embedded Porous Polycaprolactone Film with a Large Surface Area for Effective Hemostasis

BACKGROUND

Uncontrollable and widespread bleeding caused by surgery or sudden accidents can lead to death if not treated with appropriate hemostasis. To prevent excessive life-threatening bleeding, various hemostatic agents based on polymeric biomaterials with various additives for accelerated blood coagulation have been adopted in clinical fields. In particular, platelet-rich plasma (PRP), which contains many blood coagulation factors that can accelerate blood clot formation, is considered as one of the most effective hemostatic additives.

METHODS

We investigated a PRP-embedded porous film using discarded (expired) PRP and a film with a leaf-stacked structure (FLSS), as a hemostatic agent to induce rapid hemostasis. The film, which contained an LSS on one side (PCL-FLSS), was fabricated by a simple heating-cooling technique using tetraglycol and polycaprolactone (PCL) film. Activated PRP was obtained by the thawing of frozen PRP at the end of its expiration date (the platelet cell membrane is disrupted during the freezing and thawing of PRP, thus releasing various coagulation factors) and embedded in the PCL-FLSS (PRP-FLSS).

RESULTS

From in vitro and in vivo experiments using a rat hepatic bleeding model, it was recognized that PRP-FLSS is not only biocompatible but also significantly accelerates blood clotting and thus prevents rapid bleeding, probably due to a synergistic effect of the sufficient supply of various blood coagulants from activated PRP embedded in the LSS layer and the large surface area of the LSS itself.

CONCLUSION

The study suggests that PRP-FLSS, a combination of a porous polymer matrix with a unique morphology and discarded biofunctional resources, can be an advanced hemostatic agent as well as an upcycling platform to avoid the waste of biofunctional resources.

Ultra-Hydrophobic Gauze Driving Super-Haemostasis

Controlling bleeding by applying pressing cotton gauze is the most facile treatment in prehospital emergencies. However, the wettable nature of cotton fibers leads to unnecessary blood loss due to excessive blood absorption, inseparable adhesion-induced pain, and pliable to infection. Here, a kind of ultra-hydrophobic haemostatic anti-adhesive gauze whose surface is loaded with polydimethylsiloxane (PDMS) and hydrophobic-modified cellulose nanocrystals (CNCs), achieving a water contact angle of ≈160° is developed. It is demonstrated that the mechanism by which hydrophobic CNCs promote blood clotting is associated with their ability to activate coagulation factors, contributing to fibrin formation, and promoting platelet activation. The blood-restricting effect results from the low surface energy layer formed by PDMS and then the alkyl chains of hydrophobic CNCs are combined. The produced ultra-hydrophobic gauze resists blood flow and diffusion, decreases blood loss, is effortlessly peelable, and minimizes pathogen adhesion. Compared to the commercial cotton gauze, this gauze achieved effective haemostasis and antiadhesion by reducing blood loss by more than 90%, shortening haemostasis time by more than 75%, lowering peeling force by more than 90% and minifying bacterium attachment by more than 95%. This work presents promising applications in terms of prehospital first aid.

Development of an efficient hemostatic material based on cuttlefish ink nanoparticles loaded in cuttlebone biocomposite

Traumatic hemorrhage is one of the main causes of mortality in civilian and military accidents. This study aimed to evaluate the effectiveness of cuttlefish bone (cuttlebone, CB) and CB loaded with cuttlefish ink (CB-CFI) nanoparticles for hemorrhage control. CB and CB-CFI were prepared and characterized using different methods. The hemostasis behavior of constructed biocomposites was investigated in vitro and in vivo using a rat model. Results showed that CFI nanoparticles (NPs) are uniformly dispersed throughout the CB surface. CB-CFI10 (10 mg CFI in 1.0 g of CB) showed the best blood clotting performance in both in vitro and in vivo tests. In vitro findings revealed that the blood clotting time of CB, CFI, and CB-CFI10 was found to be 275.4 ± 12.4 s, 229.9 ± 19.9 s, and 144.0 ± 17.5 s, respectively. The bleeding time in rat liver injury treated with CB, CFI, and CB-CFI10 was 158.1 ± 9.2 s, 114.0 ± 5.7 s, and 46.8 ± 2.7 s, respectively. CB-CFI10 composite resulted in more reduction of aPTT (11.31 ± 1.51 s) in comparison with CB (17.34 ± 2.12 s) and CFI (16.79 ± 1.46 s) (p < 0.05). Furthermore, CB and CB-CFI10 exhibited excellent hemocompatibility. The CB and CB-CFI did not show any cytotoxicity on human foreskin fibroblast (HFF) cells. The CB-CFI has a negative surface charge and may activate coagulation factors through direct contact with their components, including CaCO3, chitin, and CFI-NPs with blood. Thus, the superior hemostatic potential, low cost, abundant, simple, and time-saving preparation process make CB-CFI a very favorable hemostatic material for traumatic bleeding control in clinical applications.

Granular Hemostatic Composite of Alginate, Calcium, and Zinc for Rapid and Effective Management of Post-Traumatic Hemorrhage

Post-traumatic hemorrhage, which can result from accidents or battlefield injuries, is a significant global concern due to the high prehospital mortality rate. Substantial efforts have been made to develop hemostatic agents that can effectively reduce hemorrhage in the immediate aftermath of a traumatic event. The present study investigated the potential efficacy of Ca2+ and Zn2+ supplemented sodium alginate-based dry hemostatic particles (SA-CZ DHP) to manage excessive blood loss or post-traumatic hemorrhage. SA-CZ DHP were developed, followed by their physical and biochemical characterization, cytocompatibility and hemocompatibility testing, and critical evaluation of the hemostatic potential in vitro and in vivo. The safe SA-CZ DHP showed high absorption and accelerated blood clotting kinetics with reduced coagulation time (≈70%, p < 0.0001) in whole human blood, observed with insignificant hemolysis and uninterrupted RBC morphology. SA-CZ DHP significantly reduced the mean blood loss (≈90% in SD rats tail incision), and bleeding time (≈60% in BALB/c mice tail incision) was at par with commercially available Celox hemostatic granules. In conclusion, the biocompatible SA-CZ DHP exhibited rapid and effective management of excessive blood loss. It is also pertinent to note that the developed formulation could be a cost-effective alternative to its commercial counterparts.

Multiple Non-Covalent Cross-Linked Multifunctional Strong Hemostatic Agent for Dynamic Exposure Hemostasis

Trauma requires immediate hemostasis during primary care, as well as durable hemostasis that can withstand dynamic wound exposure. Although current hemostatic materials can treat bleeding sites in emergency situations, their mechanical strength and storage conditions limit their practical application. The simultaneous combination of good mechanical properties, storage stability, biocompatibility, and rapid hemostasis of hemostatic materials remains a challenge. In this paper, a novel hemostatic material based on multiple non-covalent bond crosslinking, which has excellent mechanical properties, good biocompatibility, storage stability, and rapid hemostasis ability, is reported. Under the drive of multiple non-covalent bonds, the flowability of hydrogel micro-modules (HM) decreases rapidly within 20 s after exposure to physiological saline. The HM form a gel barrier with a tensile strength of 62.10 kPa and an elongation at break of 1976% under multiple non-covalent bonding. Furthermore, the mechanical properties do not change significantly after 30 days of storage. Cell viability is maintained at over 80% after 3 days of incubation with the cells, and the hemolysis test shows a very low hemolysis rate (2.08%). The hemostatic gel formed by HM effectively prevents secondary bleeding in dynamic hemostasis experiments simulating transportation. This work provides a hemostatic material with comprehensive properties for practical applications.

Chemical modification of chitosan for developing of new hemostatic materials: A review

Uncontrolled bleeding that occurs during surgery, trauma, and in combat conditions is critical and require immediate action. Chitosan is a polysaccharide, obtained from natural sources with unique biological properties. It is often used as basis for local hemostatic agents (LHA). We summarized the data on hemostatic properties of chitosan, commercially available chitosan-based products with focus in the field of chemical modification of chitosan. Various approaches are used to enhance hemostatic activity of chitosan-based materials. The approach with chemical modification of chitosan allows changing the properties of the polymer in order to obtain an active macromolecule that contributes to hemostasis. Ongoing research on the mechanism of interaction with blood components in the case of different chitosan derivatives will make it possible to identify promising directions for chemical modification to obtain an effective LHA.

Alkylated chitosan-attapulgite composite sponge for rapid hemostasis

This study reported the development of a composite sponge (ACATS) based on alkylated chitosan (AC) and attapulgite (AT) for rapid hemostasis. The well-designed ACATS, with an optimal AC N-alkylation of 5.9 % and an optimal AC/AT mass ratio of 3:1, exhibited a hierarchical porous structure with a favorable biocompatibility. The ACATS can effectively and rapidly stop the uncontrolled bleeding in 235 ± 64 s with a total blood loss of 8.4 ± 4.0 g in comparison with those of Celox as a positive control (602 ± 101 s and 22.3 ± 2.4 g, respectively) using rabbit carotid artery injury model in vivo. ACATS could rapidly interact with blood and its components, including platelets (PLs), red blood cells (RBCs), and coagulation factors, resulting in these blood components rapidly accumulation and the following thrombus formation and coagulation factors activation.

Evaluation of novel hemostatic agents in a coagulopathic swine model of junctional hemorrhage

BACKGROUND

Hemostatic dressings are used extensively in both military and civilian trauma to control lethal noncompressible hemorrhage. The ideal topical hemostatic agent would provide reliable hemostasis in patients with profound acidosis, coagulopathy, and shock. This study aimed to compare next-generation hemostatic agents against the current military standard in a translational swine model of vascular injury and coagulopathy.

METHODS

Female Yorkshire swine were randomized to eight groups (total n = 63; control n = 14, per group n = 7) of hemostatic agents and included: QuikClot Combat Gauze (Teleflex, Morrisville, NC), which served as the control; BloodSTOP IX (LifeScience Plus, Mountain View, CA); Celox Rapid (Medtrade Product, Crewe, United Kingdom); ChitoSAM 100 (Sam Medical, Tualatin, OR); EVARREST Fibrin Sealant Patch (Ethicon, Raritan, NJ); TAC Wrapping Gauze (H&H Medical, Williamsburg, VA); ChitoGauze XR Pro (Tricol Biomedical, Portland, OR); and X-Stat 30 (RevMedX, Wilsonville, OR). Hemodilution via exchange transfusion of 6% hetastarch was performed to induce acidosis and coagulopathy. An arteriotomy was created, allowing 30 seconds of free bleeding followed by application of the hemostatic agent and compression via an external compression device. A total of three applications were allowed for continued/recurrent bleeding. All blood loss was collected, and hemostatic agents were weighed to calculate blood volume loss. Following a 180-minute observation period, angiography was completed to evaluate for technical complication and distal perfusion of the limb. Finally, the limb was ranged five times to assess for rebleeding and clot stability.

RESULTS

All swine were confirmed coagulopathic with rotational thromboelastography and acidotic (pH 7.2 ± 0.02). BloodSTOP IX allowed a significant increase in blood loss and number of applications required to obtain hemostasis compared with all other groups. BloodSTOP IX demonstrated a decreased survival rate (29%, p = 0.02). All mortalities were directly attributed to exsanguination as a result of device failure. In surviving animals, there was no difference in extravasation. BloodSTOP IX had an increased rebleeding rate after ranging compared with QuikClot Combat Gauze ( p = 0.007).

CONCLUSION

Most novel hemostatic agents demonstrated comparable efficacy compared with the currently military standard hemostatic dressing, CG.

Review: Application of chitosan and its derivatives in medical materials

Chitin is a natural polymeric polysaccharide extracted from marine crustaceans, and chitosan is obtained by removing part of the acetyl group (usually more than 60 %) in chitin's structure. Chitosan has attracted wide attention from researchers worldwide due to its good biodegradability, biocompatibility, hypoallergenic and biological activities (antibacterial, immune and antitumor activities). However, research has shown that chitosan does not melt or dissolve in water, alkaline solutions and general organic solvents, which greatly limits its application range. Therefore, researchers have carried out extensive and in-depth chemical modification of chitosan and prepared a variety of chitosan derivatives, which have expanded the application field of chitosan. Among them, the most extensive research has been conducted in the pharmaceutical field. This paper summarizes the application of chitosan and chitosan derivatives in medical materials over the past five years.

A novel sodium polyacrylate-based stasis dressing to treat lethal hemorrhage in a penetrating trauma swine model

BACKGROUND

Control of massive hemorrhage from penetrating wound sites is difficult in both combat and civilian settings. A new hemostatic dressing, sodium polyacrylate (PAAs)-based bag (PB), based on PAAs is designed for the first aid of massive penetrating hemorrhage. This study aimed to investigate the efficacy of PB in a penetrating trauma model in swine.

METHODS

A complex groin penetrating injury was produced in swine by completely excising the femoral vessels and surrounding muscles. After 15-second free bleeding, 18 healthy Guizhou female swine were administered PB (n = 6), CELOX-A (n = 6; Medtrade Products, Crewe, United Kingdom), or standard gauze (n = 6) for hemostatic intervention, followed by 3-minute compression if the bleeding persisted, with subsequent observation continuing for 1 hour. The primary outcomes included initial hemostasis, the incidence of applying manual pressure, and application time.

RESULTS

Sodium polyacrylate could rapidly absorb the liquid to expand, crosslink with a large number of red blood cells, induce cellular morphological alteration, and promote blood coagulation. Sodium polyacrylate-based bag and CELOX-A initiated and sustained hemostasis for 60 minutes, whereas 0% of the standard gauze achieved initial hemostasis. Maximum number of manual compressions were applied in standard gauze (6 of 6 [100%]), followed by CELOX-A (5 of 6 [80%]), while no manual pressure was required in the case of PB (0 of 6 [0%]). Application time for PB (19.0 ± 4.6 seconds) was significantly less than CELOX-A (169.0 ± 73.5 seconds) and standard gauze (187.8 ± 1.7 seconds).

CONCLUSION

We prepared a type of superabsorbent PAAs and made an original hemostatic dressing, PB. It can rapidly achieve durable hemostasis in the groin-penetrating trauma hemorrhage swine model without any external compression. The packet form makes PB easy to deploy and remove from wounds. Therefore, PB could be a promising hemostatic candidate for controlling penetrating hemorrhage.

Characterization and Analysis of Chitosan-Gelatin Composite-Based Biomaterial Effectivity as Local Hemostatic Agent: A Systematic Review

Chitosan and gelatin were the most widely used natural materials in pharmaceutical and medical fields, especially as local hemostatic agents, independently or as a composite material with the addition of other active substances. Chitosan and gelatin have excellent properties in biocompatibility, biodegradability, non-toxicity and water absorption capacity. The objective of this review was to analyze the characteristics of chitosan-gelatin (CG) composite-based biomaterial and its effectivity as a local hemostatic agent. We used PRISMA guidelines and the PICO framework to compile this review. The findings demonstrated that the CG composite-based biomaterial had excellent physical, chemical, mechanical properties and local hemostatic agent activity by adding other active substances such as oxidized fibers (OF), silica nanoparticles (SiNPs), calcium (Ca) and biphasic calcium phosphate (BCP) or by setting the CG composite proportion ratio.

Advances in the development and optimization strategies of the hemostatic biomaterials

Most injuries are accompanied by acute bleeding. Hemostasis is necessary to relieve pain and reduce mortality in these accidents. In recent years, the traditional hemostatic materials, including inorganic, protein-based, polysaccharide-based and synthetic materials have been widely used in the clinic. The most prominent of these are biodegradable collagen sponges (Helistat^®, United States), gelatin sponges (Ethicon^®, SURGIFOAM^®, United States), chitosan (AllaQuixTM, ChitoSAMTM, United States), cellulose (Tabotamp^®, SURGICEL^®, United States), and the newly investigated extracellular matrix gels, etc. Although these materials have excellent hemostatic properties, they also have their advantages and disadvantages. In this review, the performance characteristics, hemostatic effects, applications and hemostatic mechanisms of various biomaterials mentioned above are presented, followed by several strategies to improve hemostasis, including modification of single materials, blending of multiple materials, design of self-assembled peptides and their hybrid materials. Finally, the exploration of more novel hemostatic biomaterials and relative coagulation mechanisms will be essential for future research on hemostatic methods.

Perspective: the top 11 priorities to improve trauma outcomes, from system to patient level

BACKGROUND

The Haemorrhage, Airway, Breathing, Circulation, Disability, Exposure/Environmental control approach to individual patient management in trauma is well established and embedded in numerous training courses worldwide. Further improvements in trauma outcomes are likely to result from a combination of system-level interventions in prevention and quality improvement, and from a sophisticated approach to clinical innovation.

TOP ELEVEN TRAUMA PRIORITIES

Based on a narrative review of remaining preventable mortality and morbidity in trauma, the top eleven priorities for those working throughout the spectrum of trauma care, from policy-makers to clinicians, should be: (1) investment in effective trauma prevention (likely to be the most cost-effective intervention); (2) prioritisation of resources, quality improvement and innovation in prehospital care (where the most preventable mortality remains); (3) building a high-performance trauma team; (4) applying evidence-based clinical interventions that stop bleeding, open & protect the airway, and optimise breathing most effectively; (5) maintaining enough circulating blood volume and ensuring adequate cardiac function; (6) recognising the role of the intensive care unit in modern damage control surgery; (7) prioritising good intensive care unit intercurrent care, especially prophylaxis for thromboembolic disease; (8) conducting a thorough tertiary survey, noting that on average the intensive care unit is where approximately 15% of injuries are detected; (9) facilitating early extubation; (10) investing in formal quantitative and qualitative quality assurance and improvement; and (11) improving clinical trial design.

CONCLUSION

Dramatic reductions in population trauma mortality and injury case fatality rate over recent decades have demonstrated the value of a comprehensive approach to trauma quality and process improvement. Continued attention to these principles, targeting areas with highest remaining preventable mortality while also prioritising functional outcomes, should remain the focus of both clinician and policy-makers.

Design of biopolymer-based hemostatic material: Starting from molecular structures and forms

Uncontrolled bleeding remains as a leading cause of death in surgical, traumatic, and emergency situations. Management of the hemorrhage and development of hemostatic materials are paramount for patient survival. Owing to their inherent biocompatibility, biodegradability and bioactivity, biopolymers such as polysaccharides and polypeptides have been extensively researched and become a focus for the development of next-generation hemostatic materials. The construction of novel hemostatic materials requires in-depth understanding of the physiological hemostatic process, fundamental hemostatic mechanisms, and the effects of material chemistry/physics. Herein, we have recapitulated the common hemostatic strategies and development status of biopolymer-based hemostatic materials. Furthermore, the hemostatic mechanisms of various molecular structures (components and chemical modifications) are summarized from a microscopic perspective, and the design based on them are introduced. From a macroscopic perspective, the design of various forms of hemostatic materials, e.g., powder, sponge, hydrogel and gauze, is summarized and compared, which may provide an enlightenment for the optimization of hemostat design. It has also highlighted current challenges to the development of biopolymer-based hemostatic materials and proposed future directions in chemistry design, advanced form and clinical application.

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Biopolymers possess sound biocompatibility, biodegradability and bioactivity for the design of hemostatic materials.

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Molecular structure designs including component and chemical modification are summarized from a microscopic perspective.

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Design of various forms of hemostatic materials is discussed and compared synthetically from a macroscopic perspective.

Recent advances in biopolymer-based hemostatic materials

Hemorrhage is the leading cause of trauma-related deaths, in hospital and pre-hospital settings. Hemostasis is a complex mechanism that involves a cascade of clotting factors and proteins that result in the formation of a strong clot. In certain surgical and emergency situations, hemostatic agents are needed to achieve faster blood coagulation to prevent the patient from experiencing a severe hemorrhagic shock. Therefore, it is critical to consider appropriate materials and designs for hemostatic agents. Many materials have been fabricated as hemostatic agents, including synthetic and naturally derived polymers. However, compared to synthetic polymers, natural polymers or biopolymers, which include polysaccharides and polypeptides, have greater biocompatibility, biodegradability, and processibility. Thus, in this review, we focus on biopolymer-based hemostatic agents of different forms, such as powder, particles, sponges, and hydrogels. Finally, we discuss biopolymer-based hemostats currently in clinical trials and offer insight into next-generation hemostats for clinical translation.

The effectiveness of portable ultrasound-guided resuscitative endovascular balloon occlusion of the aorta for stopping iliac artery hemorrhage during first aid pre-hospital: a randomized control animal trial

PURPOSE

This study aimed at to comparing the effectiveness of portable ultrasound guided REBOA vs. traditional manual extracorporeal compression in stopping iliac artery hemostasis.

METHODS

Twelve swine were included in this study (treatment group vs. control group, 6:6). A biopsy device was used to create an iliac artery rupture and hemorrhage in each swine. After 30 s of bleeding, the treatment group received REBOA under the guidance of ultrasound, whereas the control group received traditional manual extracorporeal compression. General physiological conditions were recorded at 0 s (baseline, T1), 30 s (initiation of therapies to stop bleeding, T2), 10 min (T3) and 30 min (T4) after bleeding. Intraperitoneal and retroperitoneal hemorrhage and specimens of iliac artery were collected after all swine were euthanized.

RESULTS

One swine was excluded because of accidental death not related to the experiment; thus, 11 swine were analyzed in this study. The general physiological characteristics of the two groups showed no difference at T1. Hemorrhagic shock occurred in both groups. After the hemostatic procedure was performed, systolic pressure, diastolic pressure and heart rate first increased significantly between T2 and T3, and then became stable between T3 and T4; these indicators in the control group deteriorated over time. The total blood loss in the treatment group (1245.23 ± 190.07 g) was much significantly less than that in the control group (2605.63 ± 291.67 g) with p < 0.001.

CONCLUSIONS

Performing REBOA under the guidance of portable ultrasound is an effective way to stop bleeding. It suggests a potential alternative method for iliac artery hemostasis in the pre-hospital setting.

Snake Venom Hydrogels as a Rapid Hemostatic Agent for Uncontrolled Bleeding

Uncontrolled bleeding from traumatic injury remains the leading cause of preventable death with loss of balance between blood clotting (coagulation) and blood clot breakdown (fibrinolysis). A major limitation of existing hemostatic agents is that they require a functioning clotting system to control the bleeding and are largely based on gauze delivery scaffolds. Herein, a novel rapid wound sealant, composed of two recombinant snake venom proteins, the procoagulant ecarin, to rapidly initiate blood clotting and the antifibrinolytic textilinin, to prevent blood clot breakdown within a synthetic thermoresponsive hydrogel scaffold is developed. In vitro, it is demonstrated that clotting is rapidly initiated with only nanomolar concentrations of venom protein and clot breakdown is effectively inhibited by textilinin. A stable clot is formed within 60 s compared to normal clot formation in 8 min. In vivo studies reveal that the snake venom hydrogel rapidly controls warfarin-induced bleeding, reducing the bleed volume from 48% to 12% and has demonstrated immune compatibility. A new class of hemostatic agents that achieve formation of rapid and stable blood clots even in the presence of blood thinners is demonstrated here.

Use of Haemostatic Devices for the Control of Junctional and Abdominal Traumatic Haemorrhage: A Systematic Review

Catastrophic haemorrhage accounts for up to 40% of global trauma related mortality and is the leading cause of preventable deaths on the battlefield. Controlling abdominal and junctional haemorrhage is challenging, especially in the pre-hospital setting or ‘under fire’, yet there is no haemostatic agent which satisfies the seven characteristics of an ‘ideal haemostat’. We conducted a systematic search of Embase, Medline, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science to evaluate the feasibility and efficacy of three types of haemostatic devices. Participants included any trauma patient in a pre-hospital setting, perfused human cadavers, or healthy human volunteer simulations. The haemostatic devices reviewed were REBOA, iTClampTM, and four junctional tourniquets: AAJT, CRoC, JETT, and SJT. The SJT had the best user survey performance of the junctional tourniquets, and the four junctional tourniquets had an overall efficacy of 26.6–100% and an application time of 10–203 s. The iTClampTM had an efficacy of 60–100% and an application time of 10–60 s. REBOA had an efficacy of 71–100% and an application time ranging from 5 min to >80 min. In civilian and military trauma patients the use of junctional tourniquets, iTClamp, or REBOA, mortality varied from 0–100%. All of these studies were deemed low to very low in quality, hence the reliability of data presented in each of the studies is called into question. We conclude that despite limited data for these devices, their use in the pre-hospital environment or ‘under fire’ is feasible with the correct training, portable imaging, and patient selection algorithms. However, higher quality studies are required to confirm the true efficacy of these devices.

Antibacterial porous sponge fabricated with capric acid-grafted chitosan and oxidized dextran as a novel hemostatic dressing

This work aims to fabricate multifunctional hemostatic sponges (C-ODs). Porous C-ODs were first constructed by using capric acid-modified chitosan (CSCA) and oxidized dextrans (ODs) with different oxidation degrees. Batches of experiments showed that (i) CSCA (33.39% of grafting degree), ODs, and C-ODs (100-200 μm in pore size) were synthesized, evidenced by FT-IR, ¹H NMR, elemental analysis, hydroxylamine hydrochloride titration, and SEM results; (ii) among C-ODs, C-OD₂ had appropriate porosity (85.0%), swelling (20 times its dry weight), absorption, water retention, water vapor transmission, and mechanical properties; (iii) C-OD₂ possessed low toxicity (relative cell viability > 86%), low hemolysis rate (0.65%), suitable tissue adhesion (4.74 kPa), and strong antibacterial efficacy (five strains); and (iv) C-OD₂'s dynamic blood clotting was within 30 s. In three animal injury models, C-OD₂'s hemostasis time and blood loss were fairly lower than commercial gelatin sponge. Totally, C-OD₂ might serve as an ideal hemostatic dressing.

Advances in Hemostatic Wound Dressings: Clinical Implications and Insight

ABSTRACT

Hemorrhagic shock is one of the leading causes of prehospital death in the armed forces. In this state, the body begins to shut down because of blood volume depletion. In both civilian and military trauma, a significant number of hemorrhage deaths occur in the first several hours after injury. Researchers all over the globe are working to develop relatively inexpensive and easy-to-transport products to prevent soldiers from going into hemorrhagic shock. For example, many advances have been made during the last several years toward the development of ideal hemostatic dressings. No current hemostatic agents meet all of the requirements, but the ideal dressing would fulfill many important measures: minimizes or stops blood flow within minutes, contains hemostatic agents to enhance blood clotting, is easy to apply, does not need preapplication preparation, has a reasonably long shelf life, is safe to use, prevents bacterial or viral transmission, is stable at extreme temperatures, and is inexpensive. For this literature review, the authors conducted an extensive search of academic scientific databases for relevant keywords and assessed and summarized the results. This review aimed to identify recent advances in hemostatic wound dressings; summarize the currently available dressings and their supporting literature; and discuss the compositions, mechanisms of action, and clinical relevance of each category of dressing. In addition, case studies and suggestions for future research into hemorrhage control with new hemostatic agents are provided.

Paraffin-Coated Hydrophobic Hemostatic Zeolite Gauze for Rapid Coagulation with Minimal Adhesion

To solve the problem of strong adhesion and excessive blood loss caused by the use of hydrophilic zeolite gauze (Z-Gauze) in uncontrollable bleeding, we have modified the surface of commercial Z-Gauze with a paraffin coating and prepared a hydrophobic dressing PZ-Gauze. After paraffin coating, the adhesion of Z-Gauze was reduced without an obvious decrease in coagulation activity. The clotting time of the hydrophobic PZ-Gauze was reduced from 378.3 to 154.6 s compared with that of cotton gauze, and the peeling force was decreased from 348.8 to 84.7 mN compared with that of Z-Gauze. Besides, PZ-Gauze can efficiently cut down the blood loss during treatment. On the basis of in vitro and in vivo experiments, it is confirmed that surface hydrophobic modification does not change the procoagulant performance because of the maintained cation exchange capacity of zeolites, and the reduced blood loss as well as enhanced difficulty for fibrin adhesion is attributed to its hydrophobicity. This is different from the traditional gauze procoagulant theories, where gauze hydrophilicity and procoagulant performance are always positively correlated.

Haemostatic materials for wound healing applications

Wounds are one of the most common health issues, and the cost of wound care and healing has continued to increase over the past decade. The first step in wound healing is haemostasis, and the development of haemostatic materials that aid wound healing has accelerated in the past 5 years. Numerous haemostatic materials have been fabricated, composed of different active components (including natural polymers, synthetic polymers, silicon-based materials and metal-containing materials) and in various forms (including sponges, hydrogels, nanofibres and particles). In this Review, we provide an overview of haemostatic materials in wound healing, focusing on their chemical design and operation. We describe the physiological process of haemostasis to elucidate the principles that underpin the design of haemostatic wound dressings. We also highlight the advantages and limitations of the different active components and forms of haemostatic materials. The main challenges and future directions in the development of haemostatic materials for wound healing are proposed.

Hemostatic materials in wound care

Blood plays an essential role in the human body. Hemorrhage is a critical cause of both military and civilian casualties. The human body has its own hemostatic mechanism that involves complex processes and has limited capacity. However, in emergency situations such as battlefields and hospitals, when the hemostatic mechanism of the human body itself cannot stop bleeding effectively, hemostatic materials are needed for saving lives. In this review, the hemostatic mechanisms and performance of the most commonly used hemostatic materials, (including fibrin, collagen, zeolite, gelatin, alginate, chitosan, cellulose and cyanoacrylate) and the commercial wound dressings based on these materials, will be discussed. These materials may have limitations, such as poor tissue adhesion, risk of infection and exothermic reactions, that may lessen their hemostatic efficacy and cause secondary injuries. High-performance hemostatic materials, therefore, have been designed and developed to improve hemostatic efficiency in clinical use. In this review, hemostatic materials with advanced performances, such as antibacterial capacity, superhydrophobicity/superhydrophilicity, superelasticity, high porosity and/or biomimicry, will be introduced. Future prospects of hemostatic materials will also be discussed in this review.

Mesoporous Silica Nanoparticles and Mesoporous Bioactive Glasses for Wound Management: From Skin Regeneration to Cancer Therapy

Exploring new therapies for managing skin wounds is under progress and, in this regard, mesoporous silica nanoparticles (MSNs) and mesoporous bioactive glasses (MBGs) offer great opportunities in treating acute, chronic, and malignant wounds. In general, therapeutic effectiveness of both MSNs and MBGs in different formulations (fine powder, fibers, composites etc.) has been proved over all the four stages of normal wound healing including hemostasis, inflammation, proliferation, and remodeling. The main merits of these porous substances can be summarized as their excellent biocompatibility and the ability of loading and delivering a wide range of both hydrophobic and hydrophilic bioactive molecules and chemicals. In addition, doping with inorganic elements (e.g., Cu, Ga, and Ta) into MSNs and MBGs structure is a feasible and practical approach to prepare customized materials for improved skin regeneration. Nowadays, MSNs and MBGs could be utilized in the concept of targeted therapy of skin malignancies (e.g., melanoma) by grafting of specific ligands. Since potential effects of various parameters including the chemical composition, particle size/morphology, textural properties, and surface chemistry should be comprehensively determined via cellular in vitro and in vivo assays, it seems still too early to draw a conclusion on ultimate efficacy of MSNs and MBGs in skin regeneration. In this regard, there are some concerns over the final fate of MSNs and MBGs in the wound site plus optimal dosages for achieving the best outcomes that deserve careful investigation in the future.

Application and outlook of topical hemostatic materials: a narrative review

Bleeding complications can cause significant morbidities and mortalities in both civilian and military conditions. The formation of stable blood clots or hemostasis is essential to prevent major blood loss and death from excessive bleeding. However, the body's self-coagulation process cannot accomplish timely hemostasis without the assistance of hemostatic agents under some conditions. In the past two decades, topical hemostatic materials and devices containing platelets, fibrin, and polysaccharides have been gradually developed and introduced to induce faster or more stable blood clot formation, updating or iterating traditional hemostatic materials. Despite the various forms and functions of topical hemostatic materials that have been developed for different clinical conditions, uncontrolled hemorrhage still causes over 30% of trauma deaths across the world. Therefore, it is important to fabricate fast, efficient, safe, and ready-to-use novel hemostatic materials. It is necessary to understand the coagulation process and the hemostatic mechanism of different materials to develop novel topical hemostatic agents, such as tissue adhesives and sealants from various natural and synthetic materials. This review discusses the structural features of topical hemostatic materials related to the stimulation of hemostasis, summarizes the commercially available products and their applications, and reviews the ongoing clinical trials and recent studies concerning the development of different hemostatic materials.

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.

Effectiveness of kaolin-impregnated hemostatic gauze use in preperitoneal pelvic packing for patients with pelvic fractures and hemodynamic instability: A propensity score matching analysis

INTRODUCTION

We evaluated the effectiveness of kaolin-impregnated hemostatic gauze use in preperitoneal pelvic packing (PPP) for patients with hemodynamic instability due to severe pelvic fractures.

MATERIALS AND METHODS

Between May 2014 and October 2018, 53 of 75 patients who underwent PPP due to hemodynamic instability induced by pelvic fracture were enrolled. Their medical records were prospectively collected and retrospectively analyzed. QuikClot combat gauze (hydrophilic gauze impregnated with kaolin) and general surgical tape were used in 21 patients, while general surgical tape was used in the remaining 32 patients.

RESULTS

As there were differences in the characteristics of patients between the hemostatic gauze (HG) group and control group, propensity score matching (PSM) was performed to adjust for age, sex, and lactate levels. After PSM, the clinical characteristics between the two groups became similar. There were no differences in the rates of mortality and hemorrhage-induced mortality between the two groups. However, the packed red blood cell (RBC) requirement for an additional 12 hours in the HG group was significantly lower than that in the control group (4.1 ± 3.5 vs. 7.6 ± 6.1 units, p = 0.035). The lengths of intensive care unit and hospital stays tended to be shorter in the HG group than in the control group (11.6 vs. 18.5 days, p = 0.1582; 30.8 vs. 47.4 days, p = 0.1861, respectively).

CONCLUSIONS

The use of HG during PPP did not reduce hemorrhage-induced mortality, but did reduce the need for additional packed RBC transfusions in patients with hemodynamic instability due to severe pelvic fractures.

Efficacy of a Temporary Hemostatic Device in a Swine Model of Closed, Lethal Liver Injury

INTRODUCTION

Solid abdominal organ hemorrhage remains one of the leading causes of death both on the battlefield of modern warfare and in the civilian setting. A novel, temporary hemostatic device combining CELOX and direct intra-abdominal physical compression was invented to control closed SAOH during transport to a medical treatment facility.

MATERIALS AND METHODS

A swine model of closed, lethal liver injury was established to determine hemostasis. The animals were randomly divided into group A (extra-abdominal compression), group B (gauze packing), group C (intra-abdominal compression), group D (CELOX coverage), and group E (intra-abdominal compression and CELOX coverage) with six swines per group. Survival time (ST), blood loss (BL), vital signs, pathologic examination, and CT-scan were monitored to further observe the effectiveness of the device.

RESULTS

Group E had an average 30-minute extension in ST (74.3 ± 15.4 minutes versus 44.0 ± 13.8 minutes, p = 0.026) with less BL (46.0 ± 13.0 versus 70.8 ± 8.2 g/kg, p = 0.018), and maintained mean arterial pressure≥70 mmHg and cardiac output ≥ 3.5 L/minute for a longer time. No significant differences were observed in ST and BL of groups B and E, and there were no marked differences in ST and BL of groups A, C, and D. No CELOX clots were noted in the spleen, pancreas, lungs, heart, kidneys, or the adjacent large vessels in groups D and E. Compared to group A, the CT-scan showed better hepatic hemorrhage control in group E.

CONCLUSIONS

The device, which combined 20 g of CELOX particles and 20 pieces of CELOX (8 g) sponge tablets with 50-mmHg intra-abdominal compression for 10 minutes, prolonged the ST by an average of 30 minutes with less BL. It was not markedly different from the full four quadrants gauze packing of liver in hemostatic effect, with no CELOX clot formation in other organs.

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.

N-alkylated chitosan/graphene oxide porous sponge for rapid and effective hemostasis in emergency situations

N-alkylated chitosan (AC) sponges and graphene oxide (GO) sponges are promising candidates for emergency hemostat. However, AC sponges have weak mechanical strength and GO sponges may induce toxicity. To overcome these problems, a series of AC/GO composite spongs (ACGS) were prepared with various ratios (GO/AC, 0%, 5%, 10%, and 20%) using a dilute solution freeze phase separation and drying process. The sponges exhibit excellent absorption capacity, mechanical stability, and biocompatibility. In serial in vitro clotting tests, the higher the ratio of GO, the better the coagulation efficiency. ACGS with 20% ratio of GO (ACGS20) has shorter hemostatic time than Celox in a rabbit femoral injury test. Moreover, ACGS20 can accelerate erythrocyte and platelet adhesion. CD62p and intracellular Ca²⁺ measurements show that ACGS20 can promote the release of intracellular Ca²⁺ and stimulate platelet activation. These results suggest that ACGS20 is a good candidate composition for a safe and efficacious hemostatic dressing.

In vitro and in vivo evaluation of the duck's feet collagen sponge for hemostatic applications

Recently different hemostatic agents have been developed, but most of them are ineffective in severe bleeding and expensive or cause safety concerns. In this study, we fabricated duck's feet collagen-based porous sponges and investigated its use as a hemostatic agent. We determined the sponge's physical and biological characteristics and compared with Avitene via scanning electron microscope analysis, water-uptake abilities and porosity test, and cytotoxicity assay. The duck's feet collagen/silk sponge showed a larger interconnected porous structure compared to others sponges. The duck's feet collagen/silk sponge also exhibited significantly higher porosity than Avitene. Hemostatic properties of the sponges were evaluated by whole blood clotting and rat femoral artery hemorrhage experiment. The addition of silk to duck's feet collagen showed better blood clotting ability than Avitene in vitro. However, rat femoral artery hemorrhage test showed a similar hemostatic property between the duck's feet collagen-based sponges and Avitene. We suggest that duck's feet collagen-based sponge can be effectively used for hemostatic applications.

Zeolite-fibrin clot composite as a haemostatic agent for haemophilia A

Zeolite is a multifunctional material, which recently exhibited promising prospects in emerging biological and medical applications. This study reported a new bio-inorganic hybrid of zeolite-fibrin clot composite serving as haemostatic agent in haemophilia A. The zeolite-fibrin clot composite promoted haemocompatibility and helped to achieve short clotting time both in vitro (22 ± 3 s vs. >600 s) and in vivo (4.5 min vs. >60 min) compared to control in coagulation factor VIII deficiency bleeding model. Therefore, in situations of surgical operation or accidental injury, this effective and ready-to-use haemostatic agent may provide rapid haemostasis for haemophilia A patients.

Evaluation of Hemostatic Behavior of Micro and Nano Gelatin/Silica Hybrid in Severe Bleeding

Background:

The pH variation of the injury site is an important factor in the failure of styptic and its structural damage. In this study, the behaviour of a gelatin-silica hybrid in severe bleeding was evaluated under different pH values. On the other hand, the effect of the hybrid particle size, which is one of the key physical properties of the hybrid, has been studied in rapid control of haemostasis. </P><P> Method: The hybrid haemostatic behaviour varied drastically by changing the particle size, so that the hybrid containing SiO2 with the average particle size of about 1 micro-meter (Hyb Gel-MSiO2) demonstrated very poor ability in platelet adhesion in neutral pH, about 24%. Also, the aPTT was not shorter than the normal time, whereas reduction of the particle size beyond a certain limit (with nanometer SiO2 for Hyb Gel-NSiO2) led to both increasing platelet adhesion to 32% and very considerable reduction of aPTT. </P><P> Results: Alignment of all results showed that the particle size reduction improves the haemostatic behaviour of the hybrid toward its best performance by controlling excessive bleeding. By changing the pH for a certain particle size, structural integrity, and thereby the hybrid haemostatic behaviour changed dramatically. Therefore, the nano-hybrid showed the most blood absorption (around 470%) in natural pH and acceded to a coherent structure. The results demonstrated that in alkaline or acidic environment, the hybrid haemostatic behaviour was limited. Based on the results of this study, it was found that changes in the hybrid behaviour in acidic pH were much more drastic than in alkaline pH, and also the hybrid with the optimum particle size (Hyb Gel-NSiO2) can maintain the structural integrity with rapid haemostasis (<3 seconds). </P><P> Conclusion: Based on the objective that the pH at the injury site change to the alkaline side, the resulting hybrid has an excellent ability to control excessive bleeding and can be proposed for further in vivo studies as a novel styptic.</P>

Systematic review of prehospital haemostatic dressings

Introduction

Haemorrhage is one of the leading causes of battlefield and prehospital death. Haemostatic dressings are an effective method of limiting the extent of bleeding and are used by military forces extensively. A systematic review was conducted with the aim of collating the evidence on current haemostatic products and to assess whether one product was more effective than others.

Methods

A systematic search and assessment of the literature was conducted using 13 health research databases including MEDLINE and CINAHL, and a grey literature search. Two assessors independently screened the studies for eligibility and quality. English language studies using current-generation haemostatic dressings were included. Surgical studies, studies that did not include survival, initial haemostasis or rebleeding and those investigating products without prehospital potential were excluded.

Results

232 studies were initially found and, after applying exclusion criteria, 42 were included in the review. These studies included 31 animal studies and 11 clinical studies. The outcomes assessed were subject survival, initial haemostasis and rebleeding. A number of products were shown to be effective in stopping haemorrhage, with Celox, QuikClot Combat Gauze and HemCon being the most commonly used, and with no demonstrable difference in effectiveness.

Conclusions

There was a lack of high-quality clinical evidence with the majority of studies being conducted using a swine haemorrhage model. Iterations of three haemostatic dressings, Celox, HemCon and QuikClot, dominated the studies, probably because of their use by international military forces and all were shown to be effective in the arrest of haemorrhage.

Well-ordered mesoporous silica and bioactive glasses: promise for improved hemostasis

Mesoporous silica and bioactive glasses with unique textural properties are new generations of inorganic hemostats with efficient hemostatic ability.

In-vitro study of species-specific coagulation differences in animals and humans using rotational thromboelastometry (ROTEM)

Animal tests are conducted in all fields of trauma research, but transferability of these data to humans is limited. For example, it is still unclear which animal species is most similar to humans in terms of physiology of blood coagulation. To improve transferability and raise awareness of the existing differences, we compared human coagulation to coagulation of different animals. Rotational thromboelastometry was used to analyse the blood of pigs, sheep, rabbits and dogs. Animal data were compared with human coagulation based on the number of significant differences of the test parameters and on a descriptive comparison of the extent of relative deviation of the single values. All animal species showed significant differences in coagulation properties when compared with humans. Coagulation parameters of dogs and sheep were on average most similar to humans. However, there is no animal which is most similar to humans concerning all aspects of coagulation. Differences in coagulation between humans and animals are significant. This must be taken into account when transferring animal test data to humans.

A review on recent advances in chitosan based composite for hemostatic dressings

High mortality rate in potentially survivable casualties due to severe hemorrhage is a major challenge in today's battlefield because technological advancements have revolutionized the combat tactics and complicated the type and severity associated with wound grades. Quality of pre-hospital care prior to patient evacuation is crucial in determining the survival rate in injured patients. To deal with this challenge, considerable improvements in the hemostatic dressings have been introduced and pre-hospital care has been upgraded in many tactical combat casually care guidelines. Combat Gauze has been widely used bandage which is now been replaced by different chitosan based hemostatic dressings. It not only exhibits anti-bacterial activity but also induces hemostasis via direct interaction with erythrocytes and platelets. Its hemostasis mechanism is not dependent on host coagulation pathway which makes it an ideal dressing to stop bleeding in coagulopathic patients. Different generations of chitosan bandages have been developed to overcome the limitations of previous ones. This review provides performance analysis of chitosan bandage generations and discusses the progress made in its fabrication methods during the recent years.

Catastrophic haemorrhage in military major trauma patients: a retrospective database analysis of haemostatic agents used on the battlefield

Objectives

Catastrophic haemorrhage is a leading cause of morbidity and mortality in trauma, in both military and civilian settings. There are numerous studies looking at the effectiveness of different haemostatic agents in the laboratory but few in a clinical setting. This study analyses the use of haemostatic dressings used in patients injured on the battlefield and their association with survival.

Method

A retrospective database review was undertaken using the UK Joint Theatre Trauma Registry from 2003 to 2014, during combat operations in Iraq and Afghanistan. Data included patient demographics, the use of haemostatic dressings, New Injury Severity Score (NISS) and patient outcome.

Results

Of 3792 cases, a haemostatic dressing was applied in 317 (either Celox, Hemcon or Quickclot). When comparing patients who had a haemostatic dressing applied versus no haemostatic agent, there was a 7% improvement in survival. Celox was the only individual haemostatic dressing that was associated with a statistically significant improvement in survival, which was most apparent in the more severely injured (NISS 36–75).

Conclusion

We have shown an association between use of haemostatic agents and improved survival, mostly in those with more severe injuries, which is particularly evident in those administered Celox. This supports the continued use of haemostatic agents as part of initial haemorrhage control for patients injured in conflict and suggests that civilian organisations that may need to deal with patients with similar injury patterns should consider their use and implementation.