Use of recombinant factor VIIa for adjunctive hemorrhage control in trauma and surgical patients

Platelet Transfusion-Insights from Current Practice to Future Development

Since the late sixties, therapeutic or prophylactic platelet transfusion has been used to relieve hemorrhagic complications of patients with, e.g., thrombocytopenia, platelet dysfunction, and injuries, and is an essential part of the supportive care in high dose chemotherapy. Current and upcoming advances will significantly affect present standards. We focus on specific issues, including the comparison of buffy-coat (BPC) and apheresis platelet concentrates (APC); plasma additive solutions (PAS); further measures for improvement of platelet storage quality; pathogen inactivation; and cold storage of platelets. The objective of this article is to give insights from current practice to future development on platelet transfusion, focusing on these selected issues, which have a potentially major impact on forthcoming guidelines.

Hemostatic strategies for uncontrolled bleeding: A comprehensive update

Uncontrolled bleeding remains the leading cause of morbidity and mortality across the entire macrocosm. It refers to excessive loss of blood that occurs inside of body, due to unsuccessful platelet plug formation at the injury site. It is not only limited to the battlefield, but remains the second leading cause of death amongst the civilians, as a result of traumatic injury. Startlingly, there are no effective treatments currently available, to cater the issue of internal bleeding, even though early intervention is of utmost significance in minimizing the mortality rates associated with it. The fatal issue of uncontrolled bleeding is ineffectively being dealt with the use of pressure dressings, tourniquet, and surgical procedures. This is not a practical approach in combat arenas or in emergency situations, where the traumatic injury inflicted is deep inside the body, and cannot be addressed externally, by the application of topical dressings. This review focuses on the traditional hemostatic agents that are used to augment the process of hemostasis, such as mineral zeolites, chitosan based products, biologically active agents, anti-fibrinolytics, absorbable agents, and albumin and glutaraldehyde, as well as the micro- and nano-based hemostatic agents such as synthocytes, thromboerythrocytes, thrombosomes, and the synthetic platelets.

Engineering Intravenously Administered Nanoparticles to Reduce Infusion Reaction and Stop Bleeding in a Large Animal Model of Trauma

Bleeding from traumatic injury is the leading cause of death for young people across the world, but interventions are lacking. While many agents have shown promise in small animal models, translating the work to large animal models has been exceptionally difficult in great part because of infusion-associated complement activation to nanomaterials that leads to cardiopulmonary complications. Unfortunately, this reaction is seen in at least 10% of the population. We developed intravenously infusible hemostatic nanoparticles that were effective in stopping bleeding and improving survival in rodent models of trauma. To translate this work, we developed a porcine liver injury model. Infusion of the first generation of hemostatic nanoparticles and controls 5 min after injury led to massive vasodilation and exsanguination even at extremely low doses. In naïve animals, the physiological changes were consistent with a complement-associated infusion reaction. By tailoring the zeta potential, we were able to engineer a second generation of hemostatic nanoparticles and controls that did not exhibit the complement response at low and moderate doses but did at the highest doses. These second-generation nanoparticles led to cessation of bleeding within 10 min of administration even though some signs of vasodilation were still seen. While the complement response is still a challenge, this work is extremely encouraging in that it demonstrates that when the infusion-associated complement response is managed, hemostatic nanoparticles are capable of rapidly stopping bleeding in a large animal model of trauma.

Adjuncts to Resuscitation

Damage control resuscitation has been increasingly adopted and practiced over the last decade. The concepts used are not new to this era of medicine but are novel in combination. This chapter will focus on adjuncts to damage control resuscitation (DCR) including massive transfusion protocols, the “other” tenets of damage control resuscitation, hypertonic saline, tranexamic acid, pharmacologic resuscitation, Factor VIIa, and prothrombin complex, and viscoelastic testing.

rFVIIa in trauma: a review and opinion-based guidelines

Recombinant activated factor seven (rFVIIa) is a novel and emerging therapy for the acquired coagulopathy associated with massive bleeding and hemorrhagic shock. The intent of this paper is to review the mechanism of action of rFVIIa, to discuss the current state of evidence regarding the safety and efficacy of rFVIIa, and to offer guidance regarding its use in severely traumatized patients. No study has demonstrated a survival benefit in humans. rFVIIa, is safe to use in the setting of severe trauma associated with ongoing bleeding and acquired coagulopathy. Doses of 80—200 μg/kg may be used after correction of thrombocytopenia and acidosis. Hypothermia should be corrected in any traumatized patient, but should not be a barrier to its administration. Definitive evidence supporting the use of rFVIIa is lacking, but ongoing studies will delineate survival benefits, dosing regimens, and adverse events associated with its use.

Halting hemorrhage with self-propelling particles and local drug delivery

Approaches to locally deliver drugs to specific regions of the body are being developed for many clinical applications, including treating hemorrhage. Increasing the concentration of therapeutic coagulants in areas where clots are forming and growing can be achieved by directing them to the injury, such as with catheters or external delivery devices, or by systemically administering therapeutics that target molecular signals of vascular damage. Treating severe hemorrhage by external measures is challenging because blood flow pushes hemostatic agents outward, reducing their efficacy. This review explains that self-propelling particles may be used for delivering therapeutics, such as coagulation factors, small molecules, or other chemical or biological agents, deep into wounds during hemorrhage. A recent example of self-propelling particles is highlighted, where propulsion enhanced the efficacy of a formulation of thrombin and tranexamic acid in treating bleeding in two murine models of hemorrhage and a porcine model of fatal, non-compressible hemorrhage. Many agents exist which modulate clotting, and novel approaches that facilitate their safe delivery to sites of vascular injury could reduce the enormous number of deaths from hemorrhage that occur globally.

Hemostatic Nanoparticles Improve Survival Following Blunt Trauma Even after 1 Week Incubation at 50 °C

According to the CDC, the leading cause of death for both men and women between the ages of 5 and 44 is traumatic injury. Blood loss is the primary cause of death at acute time points post trauma. Early intervention is critical to save lives, and yet there are no treatments to stop internal bleeding that can be deployed in the field. In this work, we developed hemostatic nanoparticles that are stable at high temperatures (50 °C for 7 days) and are still effective at stopping bleeding and improving survival over the one hour time period in a rat liver injury model. These particles are exceptionally simple: PLA-based nanospheres functionalized with PEG terminated with variants of the RGD motif. This simple system can be stored at temperatures up to 50°C and maintain size, shape, and efficacy. The particles lead to a reduction in bleeding and increased acute survival with significance compared to both control particles and saline. Overall, these hemostatic nanoparticles offer an important step towards an immediate intervention in the field to stop bleeding and improve survival.

The Effect of Intravenous Administration of Active Recombinant Factor VII on Postoperative Bleeding in Cardiac Valve Reoperations; A Randomized Clinical Trial

BACKGROUND

Postoperative bleeding after cardiac reoperations is among the most complicating problems, both for the physicians and for the patients. Many modalities have been used to decrease its adverse effects and the need for blood products administration.

OBJECTIVES

In a randomized double-blinded clinical trial of redo cardiac valve surgery in adult, the effect of active recombinant factor VII (rFVIIa) on postoperative bleeding was compared with placebo. Chest tube drainage was used for comparison of bleeding between the two groups.

PATIENTS AND METHODS

Two groups of 18 patients undergoing redo valve surgeries were treated and compared regarding chest tube drainage, need for blood products, prothrombin time (PT), partial thromboplastin time (PTT), hemoglobin and hematocrit, platelet count, and international normalized ratio (INR) in first 24 hours after surgery. Bleeding was assessed at 3rd, 12th, and 24th hour after operation. In rFVIIa group, 40 µg/kg of AryoSeven was administered before end of surgery and same volume of normal saline was administered as placebo in the control group.

RESULTS

Study groups showed no difference regarding baseline variables. Three patients in rFVIIa group (16.67%) and 13 in placebo group (72.23%) received blood products (P < 0.01). Chest tube blood drainage at 24th hour after operation was 315 ± 177 mL in rFVIIa group and 557 ± 168 mL in control group (P = 0.03). At third and 12th hour after operation, the difference was not statistically significant (P = 0.71 and P = 0.22, respectively). Postoperative ICU stay was not different; while extubation was longer in the placebo group (352 ± 57 vs. 287 ± 46 minutes; P = 0.003).

CONCLUSIONS

Our study demonstrated the efficacy of rFVIIa in controlling postoperative bleeding in redo cardiac valve surgeries regarding subsequent blood loss and transfusion requirement; however, outcome results remains to be defined.

Damage Control Resuscitation

Resuscitation of the hemorrhaging patient has undergone significant changes in the last decade resulting in the concept of damage control resuscitation (DCR). Hemostatic resuscitation aims to address the physiologic derangements found in the hemorrhaging patient, namely coagulopathy, acidosis, and hypothermia. Strategies to achieve this are permissive hypotension, high ratio of plasma and platelet transfusion to packed red blood cell transfusion, and limitation of crystalloid administration. Damage control surgery aims for early hemorrhage control and minimizing operative time by delaying definitive repair until the patient's physiologic status has normalized. Together these strategies constitute DCR and have led to improved outcomes for hemorrhaging patients over the last 2 decades. Recently, DCR has been augmented by both pharmacologic and laboratory adjuncts to improve the care of the hemorrhaging patient. These include thrombelastography as a detailed measure of the clotting cascade, tranexamic acid as an antifibrinolytic, and the procoagulant activated factor VII. In this review, we discuss the strategies that makeup DCR, their adjuncts, and how they fit into the care of the hemorrhaging patient.

Intravenously administered nanoparticles increase survival following blast trauma

Explosions account for 79% of combat-related injuries, leading to multiorgan hemorrhage and uncontrolled bleeding. Uncontrolled bleeding is the leading cause of death in battlefield traumas as well as in civilian life. We need to stop the bleeding quickly to save lives, but, shockingly, there are no treatments to stop internal bleeding. A therapy that halts bleeding in a site-specific manner and is safe, stable at room temperature, and easily administered is critical for the advancement of trauma care. To address this need, we have developed hemostatic nanoparticles that are administered intravenously. When tested in a model of blast trauma with multiorgan hemorrhaging, i.v. administration of the hemostatic nanoparticles led to a significant improvement in survival over the short term (1 h postblast). No complications from this treatment were apparent out to 3 wk. This work demonstrates that these particles have the potential to save lives and fundamentally change trauma care.

Damage control in trauma and abdominal sepsis

Damage control surgery, initially formalized <20 yrs ago, was developed to overcome the poor outcomes in exsanguinating abdominal trauma with traditional surgical approaches. The core concepts for damage control of hemorrhage and contamination control with abbreviated laparotomy followed by resuscitation before definitive repair, although simple in nature, have led to an alteration in which emergent surgery is handled among a multitude of problems, including abdominal sepsis and battlefield surgery. With the aggressive resuscitation associated with damage control surgery, understanding of abdominal compartment syndrome has expanded. It is probably through avoiding this clinical entity that the greatest improvement in surgical outcomes for various emergent surgical problems has occurred in the past two decades. However, with its success, new problems have emerged, including increases in enterocutaneous fistulas and open abdomens. But as with any crisis, innovative strategies are being developed. New approaches to control of the open abdomen and reconstruction of the abdominal wall are being developed from negative pressure dressing therapies to acellular allograft meshes. With further understanding of new resuscitative strategies, the need for damage control surgery may decline, along with its concomitant complications, at the same time retaining the success that damage control surgery has brought to the critically ill trauma and general surgery patient in the past few years.

Intravenous hemostat: nanotechnology to halt bleeding

Blood loss is the major cause of death in both civilian and battlefield traumas. Methods to staunch bleeding include pressure dressings and absorbent materials. For example, QuikClot effectively halts bleeding by absorbing large quantities of fluid and concentrating platelets to augment clotting, but these treatments are limited to compressible and exposed wounds. An ideal treatment would halt bleeding only at the injury site, be stable at room temperature, be administered easily, and work effectively for internal injuries. We have developed synthetic platelets based on Arg-Gly-Asp functionalized nanoparticles, which halve bleeding time after intravenous administration in a rat model of major trauma. The effects of these synthetic platelets surpass other treatments, including recombinant factor VIIa, which is used clinically for uncontrolled bleeding. Synthetic platelets were cleared within 24 hours at a dose of 20 mg/ml, and no complications were seen out to 7 days after infusion, the longest time point studied. These synthetic platelets may be useful for early intervention in trauma and demonstrate the role that nanotechnology can have in addressing unmet medical needs.

Role of factor VII in correcting dilutional coagulopathy and reducing re-operations for bleeding following non-traumatic major gastrointestinal and abdominal surgery

OBJECTIVE

The objective of this study is to evaluate the effectiveness of rfVIIa in reducing blood product requirements and re-operation for postoperative bleeding after major abdominal surgery.

BACKGROUND

Hemorrhage is a significant complication after major gastrointestinal and abdominal surgery. Clinically significant bleeding can lead to shock, transfusion of blood products, and re-operation. Recent reports suggest that activated rfVIIa may be effective in correcting coagulopathy and decreasing the need for re-operation.

METHODS

This study was a retrospective review over a 4-year period of 17 consecutive bleeding postoperative patients who received rfVIIa to control hemorrhage and avoid re-operation. Outcome measures were blood and clotting factor transfusions, deaths, thromboembolic complications, and number of re-operations for bleeding.

RESULTS

Seventeen patients with postoperative hemorrhage following major abdominal gastrointestinal surgery (nine pancreas, four sarcoma, two gastric, one carcinoid, and one fistula) were treated with rfVIIa. In these 17 patients, rfVIIa was administered for 18 episodes of bleeding (dose 2,400-9,600 mcg, 29.8-100.8 mcg/kg). Transfusion requirement of pRBC and FFP were each significantly less than pre-rfVIIa. Out of the 18 episodes, bleeding was controlled in 17 (94%) without surgery, and only one patient returned to the operating room for hemorrhage. There were no deaths and two thrombotic complications. Coagulopathy was corrected by rfVIIa from 1.37 to 0.96 (p < 0.0001).

CONCLUSION

Use of rfVIIa in resuscitation for hemorrhage after non-traumatic major abdominal and gastrointestinal surgery can correct dilutional coagulopathy, reducing blood product requirements and need for re-operation.

Hemostasis and hemostatic agents in minimally invasive surgery

As minimally invasive surgery (MIS) has grown in scope and complexity, new challenges have been introduced along the way, including the need for endoscopic hemostatic techniques. Traditional electrical and mechanical means are still the mainstay, but new technologies for hemostasis continue to emerge. Restricted access to the operative site can limit the use of some tools, and yet multiple chemical hemostats and tamponading agents are used in MIS today. Systemic agents also have been developed and have a role in certain MIS circumstances. These products allow surgeons to continue to approach more difficult procedures using minimally invasive techniques. On the horizon are the newer, even less-invasive approaches of natural orifice endoluminal and transluminal surgery, which will increase the difficulties with reliable hemostat agents and delivery mechanisms.

Indications for use of recombinant factor VIIa: a case study with implications for research

The purpose of this case study was to explore the current use of recombinant factor VIIa to control hemorrhage in the trauma patient. Despite aggressive blood product replacement and surgical intervention, uncontrolled bleeding and resultant coagulopathy are lethal to the trauma patient. What is the correlation between this drug and the hemorrhagic trauma patient? Quite simply--does it work? Curiosity may have killed the cat, but this case study clearly demonstrates the need for further research and satisfactory answers to questions illuminated by this case.