A systematic review on the use of topical hemostats in trauma and emergency surgery

Recent advancements in cellulose-based biomaterials for management of infected wounds

INTRODUCTION

Chronic wounds are a substantial burden on the healthcare system. Their treatment requires advanced dressings, which can provide a moist wound environment, prevent bacterial infiltration, and act as a drug carrier. Cellulose is biocompatible, biodegradable, and can be functionalized according to specific requirements, which makes it a highly versatile biomaterial. Antimicrobial cellulose dressings are proving to be highly effective against infected wounds.

AREAS COVERED

This review briefly addresses the mechanism of wound healing and its pathophysiology. It also discusses wound infections, biofilm formation, and progressive emergence of drug-resistant bacteria in chronic wounds and the treatment strategies for such types of infected wounds. It also summarizes the general properties, method of production, and types of cellulose wound dressings. It explores recent studies and advancements regarding the use of cellulose and its derivatives in wound management.

EXPERT OPINION

Cellulose and its various functionalized derivatives represent a promising choice of wound dressing material. Cellulose-based dressings loaded with antimicrobials are very useful in controlling infection in a chronic wound. Recent studies showing its efficacy against drug-resistant bacteria make it a favorable choice for chronic wound infections. Further research and large-scale clinical trials are required for better clinical evidence of its efficiency.

Hemostatic Efficacy and Biocompatibility Evaluation of a Novel Absorbable Porous Starch Hemostat

BACKGROUND

A novel absorbable porous starch hemostat (APSH) based on calcium ion-exchange crosslinked porous starch microparticles (Ca²⁺CPSM) was developed to improve hemostasis during surgeries for irregular cuts. The aim of this study was to compare its hemostatic efficacy and biocompatibility in a standard rat liver injury model relatively to Arista AH, Quickclean, and crosslinked porous starch microparticles (CPSM, without calcium ion).

METHODS

72 Wistar rats (220g-240 g) were randomly assigned to six groups (Arista, Quickclean, CPSM, Ca²⁺CPSM, native potato starch, and untreated control group, n =12 per group). 30 mg of each hemostatic agent was applied to a standard circular liver excision (8 mm in diameter and 3 mm deep) in rats. Following their hemostatic efficacy, in vivo biocompatiblity evaluation was examined. The native potato starch (NPS) group was used as the negative group.

RESULTS

Ca²⁺CPSM had almost the same hemostatic efficacy compared with Arista; meanwhile, all the 4 hemostatic agents had good blood compatibility. In terms of in vivo tissue compatibility, Ca²⁺CPSM had relatively fast degradation and absorption rate with good histocompatibility. As the morphological, anatomic observation and H&E staining of liver defects after implantation, Ca²⁺CPSM was almost completely absorbed by liver tissue after 14 days.

CONCLUSION

According to our study, Ca²⁺CPSM could effectively achieve hemostasis in the standard rat liver injury model and exhibited good blood compatibility and in vivo tissue compatibility. These finding suggested that Ca²⁺CPSM as a new kind of APSH had its extensive clinical application value.

Frequency and Management of Hemorrhagic Malignant Wounds: A Retrospective, Single-Center, Observational Study

CONTEXT

The prevalence of bleeding episodes in malignant wounds (MW) is poorly documented, with no distinction between minor and potentially severe bleedings. This affects the quality of care.

OBJECTIVES

Assessing the frequency and management of hemorrhagic malignant wounds at Institut Curie hospital, an anti cancer center.

METHODS

Retrospective study conducted from the medical records of patients followed up by the Research and Wound Care Unit from Curie Institute (Paris, France), between 2017 and 2018. Patients >18 years of age, seen at least once by the Unit, and with an MW > 10 cm² were included.

RESULTS

Ninety patients were included, 74.4% female and 25.6% male, with a median age of 64 years (32-92). The most frequent etiologies were breast cancer (52.2%), sarcomas (12.2%), squamous cell carcinoma ear, nose and throat (11%), and pelvic cancer (8.9%). The median survival of patients after their first consultation was 5.6 months (95% CI: 4.6-8.4). Minor bleedings were observed in 38.9% of situations. Bleedings were significantly higher in malignant fungating wounds (P < 0.01). They were treated by the application of alginate or nonadherent dressings. The presence of at least one minor bleeding significantly increased the risk of more severe bleedings (P < 0.001). Hemorrhagic episodes were reported in 18.9% of patients, and 2.2% of patients died as a result of these bleeding episodes. Hemorrhages were fully controlled by hemostatic dressings in 70.6% of cases. The appearance of bleeding (minor or hemorrhagic) was significantly associated with survival (P < 0.001).

CONCLUSION

MWs with bleedings appear to be associated with a poor prognosis and could be a reason for early palliative care even if the patient's general condition is preserved. Palliative care must incorporate wound care skills to provide the most appropriate solutions to this anxiety-provoking symptom.

Fast acting hemostatic agent based on self-assembled hybrid nanofibers from chitosan and casein

Hemorrhage is a leading cause of preventable death in both military combat and civilian accidents. To overcome these challenges, an affordable and effective bandage is must required substance. A novel strategy is reported for developing chitosan-casein (CC) based self-assembled nanofibrous polyelectrolyte complex (PEC) for rapid blood clotting. The amide group (1630 cm^-1) and phosphate group (910 cm^-1) of chitosan-casein can form PEC at pH 8.2 ± 0.2. The PECs contain intertwined nanofibers (≤100 nm diameter) with a high surface area. Increasing chitosan percentage from 30% (CC30) to 50% (CC50) or 70% (CC70) results, increase in zeta potential of PEC from -9.14 ± 3.3 to 7.46 ± 3.7 and 14.8 ± 3.3 mV, respectively. Under in vitro conditions, the CC30, CC50, and CC70 PECs allow platelet adhesion and rapidly absorbs blood fluid to form mechanically stable blood clots within 9 ± 3, 16 ± 3, and 30 ± 4 s, respectively, which are better than Celox™ (90 ± 3 s). In vivo application of PEC (CC50) causes clotting within 37 ± 6 s of large (1 cm) arterial incision in rabbit models. The PEC is biocompatible with promising hemostatic efficiency. This is the first report of nanofibrous PEC from chitosan and casein for rapid clotting, to the best of our knowledge.

Rapid Hemostatic Biomaterial from a Natural Bath Sponge Skeleton

Uncontrolled bleeding is the main cause of mortality from trauma. Collagen has been developed as an important hemostatic material due to its platelet affinity function. A bath sponge skeleton is rich in collagen, also known as spongin. To understand the hemostatic effect of spongin, spongin materials, SX, SFM and SR were prepared from the bath sponge Spongia officinalis, and hemostatic experiments were performed. The SX, SFM and SR were significantly better than the positive control, type I collagen, in shortening the whole blood clotting time in vitro and hemostasis upon rat tail amputation. In a hemostatic experiment of rabbit common carotid artery injury, the hemostatic time and 3 h survival rate of the SFM group were 3.00 ± 1.53 min and 100%, respectively, which are significantly better than those of the commercial hemostat CELOX-A (10.33 ± 1.37 min and 67%, respectively). Additionally, the SFM showed good coagulation effects in platelet-deficient blood and defibrinated blood, while also showing good biocompatibility. Through a variety of tests, we speculated that the hemostatic activity of the SFM is mainly caused by its hyperabsorbency, high affinity to platelets and high effective concentration. Overall, the SFM and spongin derivates could be potential hemostatic agents for uncontrolled bleeding and hemorrhagic diseases caused by deficiency or dysfunction of coagulation factors.

Management of intraoperative complications during laparoscopic right colectomy

BACKGROUND

Minimally invasive right colectomy is increasingly performed as standard treatment for diseases of right colon. Complete mesocolic excision has been introduced for cancer treatment to improve oncological results. Both standard and complete mesocolic excision techniques are associated with intraoperative complications. The purpose of this study was to analyse incidence and management of intraoperative complications in patients who underwent laparoscopic right colectomy with complete mesocolic excision in a single institution.

METHODS

This is a retrospective study conducted in a single Italian centre from April 2017 to October 2020. Data of non-metastatic cancer patients who underwent laparoscopic right colectomy were collected to analyse onset of intraoperative complications, their management and rate of conversion to open surgery.

RESULTS

A total of 92 patients were included in this study. The 1.09% of patients were converted to open surgery due to adhesions and bowel occlusion. The 5.43% of patients had intraoperative complications: bleeding from Henle's trunk, pre-pancreatic plane and ileocolic artery stump account for 3.26%, gonadal vessel injury for 1.09% and bowel lesion for 1.09%.

CONCLUSIONS

Despite the limits of this study, it shows that bleeding is one of the most frequent complications in laparoscopic right colectomy. Bleeding, occlusion and adhesions are most common reasons for conversion to open surgery.

Hemostatic efficacy evaluation of radiation-crosslinked carboxymethyl cellulose granules and kappa-carrageenan/polyethylene oxide/polyethylene glycol dressing in rat bleeding models

Carboxymethyl cellulose granules (CMC-G) and kappa-carrageenan/polyethylene oxide/polyethylene glycol dressing (KPP-D) hemostatic agents, developed through radiation-induced crosslinking and sterilization, were tested in Sprague-Dawley rats using three bleeding models: (a) deep wound with the puncture of femoral artery; (b) aortic puncture; and (c) partial nephrectomy. Dressing and granules were applied in the animals without sustained compression and monitored for a period of 7 or 14 days. Comparisons were made against the commercial chitosan-based agent, Celox (CLX). Primary outcomes observed were bleeding time, the incidence of re-bleeding, animal survival, as well as gross and microscopic changes. The KPP-D group showed the shortest bleeding time for all bleeding models (a. 2.75 ± 0.64, b. 1.63 ± 0.54, c. 2.05 ± 0.62), significantly faster than all the other treatment groups. KPP-D also registered the highest survival rate of 100% with no display of gross abnormalities. CMC-G showed comparable bleeding time with CLX products but had a better survival rate at 98% compared to 96%. The incidence of re-bleeding was greater in CLX treated groups as well as more occurrence of granular adhesions that impacted mortality outcomes. Findings indicate the efficacy of KPP-D in the treatment of severe hemorrhage due to traumatic injury and intraoperative cases, while CMC-G was more suited for external trauma. Complications arising from inflammation, granules deposition, and adhesions emphasize stringent handling and removal of granular hemostat as a critical consideration in hemostat development and testing.

Review of topical gelatin-based haemostatic agents; an insidious culprit of intraoperative anaphylaxis?

BACKGROUND

An under-recognized complication of gelatin-based haemostatic agents is their potential to cause anaphylactic reactions. This review aims to collate and analyse case in the literature of intraoperative anaphylaxis secondary to locally applied haemostatic agents.

METHODS

An electronic search was performed on databases Medline, Embase, Pubmed and ProQuest. A total of 7671 articles were reviewed from title and abstract. After exclusion criteria and duplicates removed, 19 articles with 21 cases were included for analysis. Data extracted from each of the articles included patient demographics, haemostatic agent used, surgery type, known allergies and any objective evidence of hypersensitivity post anaphylactic episode, that is tryptase levels, IgE levels, skin prick testing.

RESULTS

Fifty-seven percent of cases involved patients <18 years of age; 57% of cases involved spinal surgery; 100% of cases displayed objective evidence of hypersensitivity (tryptase levels, bovine or porcine IgE levels, or skin prick testing). Thirty-three percent of patients had exposure preoperatively to a known agent causing anaphylaxis or allergy which would preclude the use of a gelatin-based haemostat. These products included vaccines, spam meats, red meat, Jell-O and CollaPlug. Gelatin-based haemostat agents included Floseal, Gelfoam, Surgiflo, fibrin glue, Avitene, haemofibrine sponge, topical bovine thrombin and thrombin-soaked gelatin.

CONCLUSION

Increased awareness of allergy to gelatin-based haemostats for surgical and anaesthetic is imperative, with 33% of cases having a known contraindication to gelatin-based haemostat. This review highlights important aspects in the pre-operative patient history and post-event patient investigation that could assist anaesthetists and surgeons in the prevention of future events.

A novel gene recombinant collagen hemostatic sponge with excellent biocompatibility and hemostatic effect

Effect and biosafety are the most noteworthy aspect of the hemostatic materials for trauma treatment. In this work, we evaluated the biocompatibility and hemostatic effect of a novel recombinant collagen hemostatic sponge according to ISO 10993. In addition, the interaction between the recombinant collagen hemostatic sponge and blood cells was observed by scanning electron microscopy, moreover, the hemostatic effect was evaluated by blood clotting assay in vitro and liver hemorrhage models in vivo. As the results, the novel recombinant collagen hemostatic sponge enables to be biodegradable completely in vivo, without stimulation, sensitization, acute toxicity, hematolysis or obvious immune rejection. The procoagulant effect of recombinant hemostatic sponge in vitro is significantly more excellent than that of natural collagen sponge due to the more promotive capacity of blood cell adhesion. Meanwhile, the liver hemorrhage models showed that the hemostatic time of recombinant collagen sponge was 19.33 ± 4.64 s, which was significantly better than that of natural collagen sponge (hemostatic time 31.62 ± 5.63 s). Therefore, the novel recombinant collagen hemostatic sponge with satisfactory biocompatibility and significant hemostatic effect can be performed as a potential novel type of clinical hemostatic products for research and development.

Versatility and clinical effectiveness of a synthetic sealing hemostatic patch as alternative to parenchyma suturing in laparoscopic partial nephrectomy

BACKGROUND

Improvements in laparoscopic partial nephrectomy (LPN) in order to minimize perioperative warm ischemia time (WIT), complications, and consequently patient outcome are desirable. Veriset™ is a ready-to-use hemostatic patch of absorbable oxidized cellulose and hydrogel components that has earlier been implemented in vascular and hepatic surgery. We report our experience using this device in LPN.

METHODS

Patients with a solitary malignant renal mass suspicious for renal cancer underwent LPN with either the use of Veriset™ hemostatic patch (n = 40) or conventional suture technique (n = 40). Patient characteristics, operation time and WIT, postoperative course and complications were recorded retrospectively. Tumor complexity was calculated according to the R.E.N.A.L. score. Outcome was determined according to the "trifecta" criteria (negative surgical margin, WIT < 25 min, no complications within 30 days).

RESULTS

No significant differences with regard to clinical parameters and median R.E.N.A.L. score (6) were observed between both groups. Operation time (mean 127.1 min vs. 162. 8 min; p = 0.001) and WIT were both lower in the Veriset™ group (14.6 min vs. 20.6 min; p = 0.01). No differences in surgical margins (p = 0.602) and overall complication rates at 30 (p = 0.599) and 90 days (p = 0.611) postoperatively were noticed. The surgical outcome according to "trifecta" was achieved in 65% of patients using Veriset™ and in 57.5% of patients by suture closure, respectively.

CONCLUSION

The hemostatic Veriset™ patch can successfully be implemented in LPN. Handling and application appear favorable, thereby reducing operation time and WIT. The present results suggest that the device may represent an alternative to parenchyma suturing in LPN.

Comparison of fibrin sealants in peripheral vascular surgery: A systematic review and network meta-analysis

Background

Evidence comparing fibrin sealants (FSs) in surgery are limited. This study evaluated the efficacy and safety of FSs, and manual compression in peripheral vascular surgery.

Methods

A systematic review of randomized trials was conducted in Medline, Embase, and Cochrane databases within the last 15 years. Data were available to conduct a network meta-analysis (NMA) in peripheral vascular surgery. Fibrin sealant treatment arms were further broken-down and assessed by clotting time (i.e., 2-min [2C] or 1-min [1C]). The primary efficacy outcome was the proportion of patients achieving hemostasis by 4 min (T4). Treatment-related serious and non-serious adverse events (AEs) were qualitatively assessed.

Results

Five studies (n = 693), were included in the NMA. Results predicted VISTASEAL 2C, followed by EVICEL 1C, had the highest probability of achieving T4. Compared with manual compression, significant improvements in T4 were found with VISTASEAL 2C (relative risk [RR] = 2.67, 95% CrI: 2.13–3.34), EVICEL 1C (RR = 2.58, 95% CrI: 2.04–3.23), VISTASEAL 1C (RR = 2.00, 95% CrI: 1.45–2.65), and TISSEEL 2C (RR = 1.99, 95% CrI: 1.48–2.60). TISSEEL 1C was not significantly different than manual compression (RR = 1.40, 95% CrI: 0.70–2.33). Among FSs, VISTASEAL 2C was associated with a significant improvements in T4 compared with VISTASEAL 1C (RR = 1.33, 95% CrI: 1.02–1.82), TISSEEL 2C (RR = 1.34, 95% CrI: 1.05–1.77), and TISSEEL 1C (RR = 1.90, 95% CrI: 1.18–3.74). Treatment-related serious and non-serious AE rates were typically lower than 2%.

Conclusions

In peripheral vascular surgeries, VISTASEAL 2C and EVICEL 1C were shown to have the highest probabilities for achieving rapid hemostasis among the treatments compared. Future studies should expand networks across surgery types as data become available.

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Fibrin sealants can control perioperative bleeding, yet comparative evidence is limited.

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This network meta-analysis compared fibrin sealants and compression in peripheral vascular surgery.

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VISTASEAL and EVICEL had the highest probability of achieving hemostasis by 4 min.

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These results show differences exist between fibrin sealants in peripheral vascular surgery.

Hemostatic performance and biocompatibility of chitosan-based agents in experimental parenchymal bleeding

The uncontrolled parenchymatic bleeding is still a cause of serious complications in surgery and require new effective hemostatic materials. In recent years, numerous chitosan-based materials have been intensively studied for parenchymatic bleeding control but still require to increased safety and effectiveness. The current research is devoted to new hemostatic materials made of natural polymer (chitosan) developed using electrospinning and microwave-assisted methods. Hemostatic performance, biocompatibility, degradation, and in-vivo effectiveness were studied to assess functional properties of new materials. Chitosan-based agents demonstrated considerable hemostatic performance, moderate biodegradation pace and high biocompatibility in vitro. Using the electrospinning-made chitosan-copolymer significantly improved in vivo biocompatibility and degradation of Chitosan-based agents that provides opportunities for its implementation for visceral bleeding management. Chitosan aerogel could be effectively applied in hemostatic patch development due to high antibacterial activity but it is not recommended for visceral application due to moderate inflammatory effect and slow degradation.

Advances in Topical Hemostatic Agent Therapies: A Comprehensive Update

Severe hemorrhage causes significant metabolic and cellular dysfunction secondary to deficient tissue perfusion and oxygen delivery. If bleeding continues, hemodynamic destabilization, hypoxemia, multiple organ failure, and death will occur. Techniques employed to promote hemostasis include surgical suture ligatures, cautery, chemical agents, self-assembling nanoparticles, and physical methods, like mechanical pressure. Improved understanding of the natural clotting cascade has allowed newly designed agents to become more targeted for clinical and military use. Topically-applied hemostatic agents have enormous clinical applications in achieving hemostasis. This manuscript describes currently available and developing topical hemostatic materials, including topical active agents, mechanical agents, synthetic/hemisynthetic hemostatic agents, and external hemostatic dressings for clinical practice.

Polymeric Hydrogel Systems as Emerging Biomaterial Platforms to Enable Hemostasis and Wound Healing

Broad interest in developing new hemostatic technologies arises from unmet needs in mitigating uncontrolled hemorrhage in emergency, surgical, and battlefield settings. Although a variety of hemostats, sealants, and adhesives are available, development of ideal hemostatic compositions that offer a range of remarkable properties including capability to effectively and immediately manage bleeding, excellent mechanical properties, biocompatibility, biodegradability, antibacterial effect, and strong tissue adhesion properties, under wet and dynamic conditions, still remains a challenge. Benefiting from tunable mechanical properties, high porosity, biocompatibility, injectability and ease of handling, polymeric hydrogels with outstanding hemostatic properties have been receiving increasing attention over the past several years. In this review, after shedding light on hemostasis and wound healing processes, the most recent progresses in hydrogel systems engineered from natural and synthetic polymers for hemostatic applications are discussed based on a comprehensive literature review. Most studies described used in vivo models with accessible and compressible wounds to assess the hemostatic performance of hydrogels. The challenges that need to be tackled to accelerate the translation of these novel hemostatic hydrogel systems to clinical practice are emphasized and future directions for research in the field are presented.

Comparison of the efficacy of five standard topical hemostats: a study in porcine liver and spleen models of surgical bleeding

Background

Several topical hemostats are available to help control surgical bleeding. Cutanplast is a highly absorbent and porous gelatin product that is available in Fast sponge and powder forms. This study investigated the hemostatic efficacy of Cutanplast Standard and Fast gelatin sponge and powder and Emosist oxidized regenerated cellulose (ORC) gauze in porcine liver and spleen surgical bleeding models.

Methods

Cutanplast Standard and Fast gelatin sponge and Emosist ORC gauze were tested in liver abrasion/incision, liver puncture and spleen incision/puncture injuries, and Cutanplast Standard and Fast gelatin powder products were tested in liver abrasion/incision injuries. There were 13 liver injury (five abrasion, five incision and three puncture) and six spleen injury (three puncture and three incision sites) sites per animal.

Results

Rapid hemostasis (≤ 2–5 min) was achieved in the liver abrasion and incision models with all Cutanplast gelatin sponge and powder products and Emosist ORC gauze, except in the liver incision model, time to hemostasis was > 5 min with Cutanplast Standard gelatin powder and Emosist ORC gauze. Rapid hemostasis occurred with Cutanplast Fast gelatin sponge and Emosist ORC gauze in the liver puncture and spleen puncture and incision models. In the spleen incision model, Cutanplast Standard gelatin sponge had a time to hemostasis approaching 10 min.

Conclusion

Cutanplast gelatin sponge and powder products and Emosist ORC gauze may be suitable for surgical applications involving parenchymal organ bleeding, but certain products may perform better than others, including Cutanplast gelatin powder in diffuse mild bleeding (such as liver abrasion), and Cutanplast Fast gelatin sponge and Emosist ORC gauze for splenic bleeding.

Use of hemostatic agents for surgical bleeding in laparoscopic partial nephrectomy: Biomaterials perspective

In recent years, there was an abrupt increase in the incidence of renal tumors, which prompt up the appearance of cutting-edge technology, including minimally invasive and organ-preserving approaches, such as laparoscopic partial nephrectomy (LPN). LPN is an innovative technique used to treat small renal masses that have been gaining popularity in the last few decades due to its promissory results. However, the bleeding control remains the main challenge since the majority of currently available hemostatic agents (HAs) used in other surgical specialities are inefficient in LPN. This hurried the search for effective HAs adapted for LPN surgical peculiarities, which resulted on the emergence of different types of topical HAs. The most promising are the natural origin HAs because of their inherent biodegradability, biocompatibility, and lowest toxicity. These properties turn them top interests' candidates as HAs in LPN. In this review, we present a deep overview on the progress achieved in the design of HAs based on natural origin polymers, highlighting their distinguishable characteristics and providing a clear understanding of their hemostat's role in LPN. This way it may be possible to establish a structure-composition properties relation, so that novel HAs for LPN can be designed to explore current unmet medical needs.

Limiting Blood Loss in Orthopaedic Trauma: Strategies and Effects

Trauma is a major cause of mortality globally, with post-traumatic hemorrhage being the leading cause of death amongst trauma patients. In this paper, the authors review the underlying pathophysiology of trauma-related hemorrhagic shock, specifically the factors which contribute to the development of the acute coagulopathy of trauma shock (ACoTS). We then review the best available evidence for treatment strategies in the pre-hospital setting, as well as the in-hospital setting. Interventions that are strongly supported in the literature include utilization of a well-organized trauma system with direct transport to a designated trauma centre, the early use of tranexamic acid, and damage control orthopaedic surgical techniques and resuscitation protocols. Targeted resuscitation is an evolving field, with use of thromboelastography to guide resuscitation being a particularly promising area. Special trauma populations at particularly high risk are also reviewed, including the geriatric population, as well as unstable pelvic fractures, which are each at increased risk for poor outcomes, and deserve special attention. Major advances have been made in this important area, and ongoing research into the understanding and correction of ACoTS will continue to guide practice.

Recent advances in use of fresh frozen plasma, cryoprecipitate, immunoglobulins, and clotting factors for transfusion support in patients with hematologic disease

Hematologic diseases include a broad range of acquired and congenital disorders, many of which affect plasma proteins that control hemostasis and immune responses. Therapeutic interventions for these disorders include transfusion of plasma, cryoprecipitate, immunoglobulins, or convalescent plasma-containing therapeutic antibodies from patients recovering from infectious diseases, as well as concentrated pro- or anticoagulant factors. This review will focus on recent advances in the uses of plasma and its derivatives for patients with acquired and congenital hematologic disorders.

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.

A Comparative Efficacy Evaluation of Recombinant Topical Thrombin (RECOTHROM®) With A Gelatin Sponge Carrier Versus Topical Oxidized Regenerated Cellulose (TABOTAMP®/SURGICEL®) In A Porcine Liver Bleeding Model

PURPOSE

Topical hemostatic agents can be classified as active or passive. This study compared the hemostatic efficacy of an active agent, recombinant thrombin (RECOTHROM^® [rT]) plus gelatin sponge carrier versus a passive agent, oxidized regenerated cellulose (TABOTAMP^®/SURGICEL^® [ORC]), in a porcine liver abrasion model.

MATERIALS AND METHODS

Eight pigs were used, four of them were heparinized. A total of 80 liver lesions were created, 40 of them in heparinized pigs. Lesions were treated with rT plus gelatin sponge or ORC. Bleeding rate was quantified before treatment by applying pre-weighed gauze. Time to hemostasis was assessed visually for 10 minutes.

RESULTS

Seven of the 80 lesions were excluded for having initial bleeding rates exceeding the target of 10 g/min. Sixteen and 20 lesions were treated with rT plus gelatin sponge and 19 and 18 lesions were treated with ORC, in non-heparinized and heparinized animals, respectively. Time to hemostasis (median [IQR]) was significantly shorter with rT plus gelatin sponge (30 [30,30] seconds) in heparinized and non-heparinized animals versus ORC in non-heparinized (180 [120,210] seconds) and heparinized animals (215 [135,345] seconds); P < 0.0001 for both comparisons. In heparinized animals, ORC took longer to achieve hemostasis, with treatment failure in 2/18 lesions. Time to hemostasis with ORC was longer for lesions in heparinized animals with initial bleeding rates of >5-10 g/min (285 [225,394] seconds) versus ≤5 g/min (175 [108,290] seconds).

CONCLUSIONS

In this model, rT plus gelatin sponge carrier (active) was a more effective hemostat than ORC (passive) in both heparinized and non-heparinized animals.

Mechanistic insights into silk fibroin's adhesive properties via chemical functionalization of serine side chains

Bombyx mori-derived silk fibroin (SF) has recently gained interest for its intrinsic or engineered adhesive properties. In a previous study by our group, the mechanism of the protein's intrinsic adhesiveness to biological substrates such as leather has been hypothesized to rely on hydrogen bond formation between amino acid side chains of SF and the substrate. In this study, the serine side chains of SF were chemically functionalized with substituents with different hydrogen bonding abilities. The effect of these changes on adhesion to leather was investigated along with protein structural assessments. The results confirm our hypothesis that adhesive interactions are mediated by hydrogen bonds and indicate that the length and nature of the side chains are important for both adhesion and secondary structure formation.

A rapid hemostatic sponge based on large, mesoporous silica nanoparticles and N-alkylated chitosan

Rapid bleeding control is increasingly important in current civilian and military emergency medicine, but the rapid hemostasis achieved with current hemostatic products is often unsafe. In this study, mesoporous silica nanoparticles (MSNs) with large pores were coordinated with a glycerol-modified N-alkylated chitosan sponge (GACS) to develop a rapid and safe hemostatic sponge. Due to its coagulation-promoting structure, MSN-GACS exhibited unique hemostatic potency in serial in vitro coagulation tests. In addition to enhanced platelet adhesion and whole blood absorption, MSN-GACS exhibited better biocompatibility than Combat Gauze (CG), which is popular in the US military. Furthermore, in rabbit femoral artery and liver injury in vivo models, MSN-GACS showed better hemostatic efficiency and lower cardiovascular toxicity than CG. In conclusion, MSN-GACS is an excellent prehospital hemostatic agent for first-aid applications.