Abdominal insufflation for control of bleeding after severe splenic injury

Emerging Therapies for Prehospital Control of Hemorrhage

BACKGROUND

The aim of this review was to describe emerging therapies that could serve as a prehospital intervention to slow or stop noncompressible torso hemorrhage in the civilian and military settings. Hemorrhage accounts for 90% of potentially survivable military deaths and 30%-40% of trauma deaths. There is a great need to develop novel therapies to slow or stop noncompressible torso hemorrhage at the scene of the injury.

METHODS

A comprehensive literature search was performed using PubMed (1966 to present) for therapies not approved by the Food and Drug Administration for noncompressible torso hemorrhage in the prehospital setting. Therapies were divided into compressive versus intravascular injectable therapies. Ease of administration, skill required to use the therapy, safety profile, stability, shelf-life, mortality benefit, and efficacy were reviewed.

RESULTS

Multiple potential therapies for noncompressible torso hemorrhage are currently under active investigation. These include (1) tamponade therapies, such as gas insufflation and polyurethane foam injection; (2) freeze-dried blood products and alternatives such as lyophilized platelets; (3) nanoscale injectable therapies such as polyethylene glycol nanospheres, polyethylenimine nanoparticles, SynthoPlate, and tissue factor-targeted nanofibers; and (4) other injectable therapies such as polySTAT and adenosine, lidocaine, and magnesium. Although each of these therapies shows great promise at slowing or stopping hemorrhage in animal models of noncompressible hemorrhage, further research is needed to ensure safety and efficacy in humans.

CONCLUSIONS

Multiple novel therapies are currently under active investigation to slow or stop noncompressible torso hemorrhage in the prehospital setting and show promising results.

Feasibility of a Portable Abdominal Insufflation Device for Controlling Intraperitoneal Bleeding After Abdominal Blunt Trauma

Uncontrolled bleeding contributes to 30% to 40% of trauma-related deaths and is the leading cause of potentially preventable deaths. Currently, there is no effective method available to first responders for temporary control of noncompressible intraabdominal bleeding while patients are transported to the hospital. Our previous studies demonstrated that abdominal insufflation provides effective temporary bleeding control. The study aims to prove the feasibility (insufflation to a target pressure) and safety (cardiovascular and respiratory effects) of a novel portable abdominal insufflation device (PAID) designed to control the intraperitoneal bleeding caused by abdominal trauma. The PAID prototype is based on a patented design and manufactured via additive manufacturing. PAID contains a 16-g CO2cartridge and an electronic pressure transducer. PAID was tested on a bench top and a swine animal model. For the animal model study, the intraperitoneal pressure as well as cardiorespiratory parameters (hearth rate, SpO2[peripheral capillary oxygen saturation], and blood pressure) were continuously monitored during the insufflation procedure. The prototype functioned according to specifications on both bench top and animal models. CO2insufflation of the peritoneal cavity was delivered up the target 20 mm Hg and maintained for 30 minutes from 1 or 2 cartridges in the swine model. No intraoperative incidents were registered, and all the recorded physiological parameters were within normal limits. The PAID prototype is a feasible, easy to use device that provides quick, controlled, and safe insufflation of the peritoneal cavity. Future studies will focus on testing the next-generation, semiautomatic PAID prototype in a severe intraabdominal injury model.

A novel model of highly lethal uncontrolled torso hemorrhage in swine

INTRODUCTION

A reproducible, lethal noncompressible torso hemorrhage model is important to civilian and military trauma research. Current large animal models balancing clinical applicability with standardization and internal validity. As such, large animal models of trauma vary widely in the surgical literature, limiting comparisons. Our aim was to create and validate a porcine model of uncontrolled hemorrhage that maximizes reproducibility and standardization.

METHODS

Seven Yorkshire-cross swine were anesthetized, instrumented, and splenectomized. A simple liver tourniquet was applied before injury to prevent unregulated hemorrhage while creating a traumatic amputation of 30% of the liver. Release of the tourniquet and rapid abdominal closure following injury provided a standardized reference point for the onset and duration of uncontrolled hemorrhage. At the moment of death, the liver tourniquet was quickly reapplied to provide accurate quantification of intra-abdominal blood loss. Weight and volume of the resected and residual liver segments were measured. Hemodynamic parameters were recorded continuously throughout each experiment.

RESULTS

This liver injury was rapidly and universally lethal (11.2 ± 4.9 min). The volume of hemorrhage (35.8% ± 6% of total blood volume) and severity of uncontrolled hemorrhage (100% of animals deteriorated to a sustained mean arterial pressure <35 mmHg for 5 min) were consistent across all animals. Use of the tourniquet effectively halted preprocedure and postprocedure blood loss allowing for accurate quantification of amount of hemorrhage over a defined period. In addition, the tourniquet facilitated the creation of a consistent liver resection weight (0.0043 ± 0.0003 liver resection weight: body weight) and as a percentage of total liver resection weight (27% ± 2.2%).

CONCLUSIONS

This novel tourniquet-assisted noncompressible torso hemorrhage model creates a standardized, reproducible, highly lethal, and clinically applicable injury in swine. Use of the tourniquet allowed for consistent liver injury and precise control over hemorrhage. Recorded blood loss was similar across all animals. Improving reproducibility and standardization has the potential to offer improvements in large animal translational models of hemorrhage.

LEVEL OF EVIDENCE

Level I.

Prehospital control of life-threatening truncal and junctional haemorrhage is the ultimate challenge in optimizing trauma care; a review of treatment options and their applicability in the civilian trauma setting

Introduction

Exsanguination following trauma is potentially preventable. Extremity tourniquets have been successfully implemented in military and civilian prehospital care. Prehospital control of bleeding from the torso and junctional area’s remains challenging but offers a great potential to improve survival rates. This review aims to provide an overview of potential treatment options in both clinical as preclinical state of research on truncal and junctional bleeding. Since many options have been developed for application in the military primarily, translation to the civilian situation is discussed.

Methods

Medline (via Pubmed) and Embase were searched to identify known and potential prehospital treatment options. Search terms were|: haemorrhage/hemorrhage, exsanguination, junctional, truncal, intra-abdominal, intrathoracic, intervention, haemostasis/hemostasis, prehospital, en route, junctional tourniquet, REBOA, resuscitative thoracotomy, emergency thoracotomy, pelvic binder, pelvic sheet, circumferential. Treatment options were listed per anatomical site: axilla, groin, thorax, abdomen and pelvis Also, the available evidence was graded in (pre) clinical stadia of research.

Results

Identified treatment options were wound clamps, injectable haemostatic sponges, pelvic circumferential stabilizers, resuscitative thoracotomy, resuscitative endovascular balloon occlusion of the aorta (REBOA), intra-abdominal gas insufflation, intra-abdominal self-expanding foam, junctional and truncal tourniquets. A total of 70 papers on these aforementioned options was retrieved. No clinical reports on injectable haemostatic sponges, intra-abdominal insufflation or self-expanding foam injections and one type of junctional tourniquets were available.

Conclusion

Options to stop truncal and junctional traumatic haemorrhage in the prehospital arena are evolving and may offer a potentially great survival advantage. Because of differences in injury pattern, time to definitive care, different prehospital scenario’s and level of proficiency of care providers; successful translation of various military applications to the civilian situation has to be awaited. Overall, the level of evidence on the retrieved adjuncts is extremely low.

Traumatic intra-abdominal hemorrhage control: has current technology tipped the balance toward a role for prehospital intervention?

BACKGROUND

The identification and control of traumatic hemorrhage from the torso remains a major challenge and carries a significant mortality despite the reduction of transfer times. This review examines the current technologies that are available for abdominal hemorrhage control within the prehospital setting and evaluates their effectiveness.

METHODS

A systematic search of online databases was undertaken. Where appropriate, evidence was highlighted using the Oxford levels of clinical evidence. The primary outcome assessed was mortality, and secondary outcomes included blood loss and complications associated with each technique.

RESULTS

Of 89 studies, 34 met the inclusion criteria, of which 29 were preclinical in vivo trials and 5 were clinical. Techniques were subdivided into mechanical compression, endovascular control, and energy-based hemostatic devices. Gas insufflation and manual pressure techniques had no associated mortalities. There was one mortality with high intensity focused ultrasound. The intra-abdominal infiltration of foam treatment had 64% and the resuscitative endovascular balloon occlusion of the aorta had 74% mortality risk reduction. In the majority of cases, morbidity and blood loss associated with each interventional procedure were less than their respective controls.

CONCLUSION

Mortality from traumatic intra-abdominal hemorrhage could be reduced through early intervention at the scene by emerging technology. Manual pressure or the resuscitative endovascular balloon occlusion of the aorta techniques have demonstrated clinical effectiveness for the control of major vessel bleeding, although complications need to be carefully considered before advocating clinical use. At present, fast transfer to the trauma center remains paramount.

LEVEL OF EVIDENCE

Systematic review, level IV.

Intravenous hemostats: challenges in translation to patients

Excessive bleeding and the resulting complications are a leading killer of young people globally. There are many successful methods to halt bleeding in the extremities, including compression, tourniquets, and dressings. However, current treatments for internal hemorrhage (including from head or truncal injuries), termed non-compressible bleeding, are inadequate. For these non-compressible injuries, blood transfusions are the current treatment standard. However, they must be refrigerated, may potentially transfer disease, and are of limited supply. In addition, time is of the essence for halting hemorrhage, since more than a third of civilian deaths due to hemorrhage from trauma occur before the patient even reaches the hospital. As a result, particles that can cross-link activated platelets through the glycoprotein IIb/IIIa receptor expressed on activated platelets are being investigated as an alternative treatment for non-compressible bleeding. Ideally, these particles would interact specifically with platelets to stabilize the platelet plug. Initial designs used biologically derived microparticles with red blood cell fragment or albumin cores decorated with RGD or fibrinogen, which bind to GPIIb/IIIa. More recently there has been research into the use of fully synthetic nanoparticles with liposomal or polymer cores that crosslink platelets through a targeting peptide bound to the surface. Some of the challenges for the development of these particles include appropriate sizing to prevent blocking the capillaries of the lungs, immune system evasion to prevent strong reactions and increase circulation time, and storage and resuspension so that first responders can easily use the particles. In addition, the effectiveness of the variety of animal bleeding models in predicting outcomes must be examined before test results can be fully understood. Progress has been made in the development of particles to combat hemorrhage, but issues of immune sensitivity and storage must be resolved before these types of particles can be translated for human use.

Hemorrhage control of liver injury by short electrical pulses

Trauma is a leading cause of death among young individuals globally and uncontrolled hemorrhage is the leading cause of preventable death. Controlling hemorrhage from a solid organ is often very challenging in military as well as civilian setting. Recent studies demonstrated reversible vasoconstriction and irreversible thrombosis following application of microseconds-long electrical pulses. The current paper describes for the first time reduction in bleeding from the injured liver in rat and rabbit model in-vivo. We applied short (25 and 50 µs) electrical pulses of 1250 V/cm to rats and rabbit liver following induction of standardized penetrating injury and measured the amount of bleeding into the abdominal cavity one hour post injury. We found a 60 and 36 percent reduction in blood volume in rats treated by 25 µs and 50 µs, respectively (P<0.001). Similar results were found for the rabbit model. Finite element simulation revealed that the effect was likely non-thermal. Histological evaluation found local cellular injury with intravascular thrombosis. Further research should be done to fully explore the mechanism of action and the potential use of short electric pulses for hemorrhage control.

Development of a lethal, closed-abdomen grade V hepato-portal injury model in non-coagulopathic swine

BACKGROUND

Hemorrhage within an intact abdominal cavity remains a leading cause of preventable death on the battlefield. Despite this need, there is no existing closed-cavity animal model to assess new hemostatic agents for the preoperative control of intra-abdominal hemorrhage.

METHODS

We developed a novel, lethal liver injury model in non-coagulopathic swine by strategic placement of two wire loops in the medial liver lobes including the hepatic and portal veins. Distraction resulted in grade V liver laceration with hepato-portal injury, massive bleeding, and severe hypotension. Crystalloid resuscitation was started once mean arterial pressure (MAP) fell below 65 mm Hg. Monitoring continued for up to 180 min.

RESULTS

We demonstrated 90% lethality (9/10) in swine receiving injury and fluid resuscitation, with a mean survival time of 43 min. Previous efforts in our laboratory to develop a consistently lethal swine model of abdominal solid organs, including preemptive anticoagulation, a two-hit injury with controlled hemorrhage prior to liver trauma, and the injury described above without resuscitation, consistently failed to result in lethal injury.

CONCLUSION

This model can be used to screen other interventions for pre hospital control of noncompressible.

Blood loss during laparoscopic radical prostatectomy - is it significant or not?

Introduction

The traditional assessment of blood loss during laparoscopic radical prostatectomy (LRP) is based on the blood volume collected intraoperatively in the suction device bottles. While this method is not perfect, analysis of changes in blood cell count (BCC) resulting from LRP is advisable.

Material and methods

71 men were submitted to LRP due to prostate cancer in our institution over an 18-month time period. From this group, we isolated 60 men with clinically minimal intraoperative blood loss (<200 ml) and included them into the study. Mean age of the cohort was 62.8 years. We performed standard BCC on the day before and 6 hours after the surgery. At the same time points, we measured creatinine serum concentration and calculated eGFR to avoid the data misinterpretation resulting from impaired renal function in the postoperative period.

Results

Statistically and clinically significant differences regarding all BCC parameters measured pre- and postoperatively were observed. The number of red blood cells, hemoglobin concentration, and hematocrit diminished by 17.5% (4.68T/l vs. 3.86T/l, p <0.02), 17.0% (8.93 mmol/l vs. 7.41 mmol/l, p < 0.02), and 17.9% (0.429 vs. 0.352, p <0.02), respectively. Simultaneously, renal function was stable with no significant change in eGFR (82.9 ml/min/1.73 m^2 vs. 79.09 ml/min/1.73 m^2, p = 0.28).

Conclusions

Standard LRP brings on a significant blood loss. While clinically insignificant, this blood loss seems to be as high as approx. 600 ml based on laboratory findings. BCC seems to be a more accurate method of intraoperative blood loss estimation compared to measurement of blood volume collected intraoperatively in the suction device bottles.

Exsanguination in trauma: A review of diagnostics and treatment options

Trauma patients with haemorrhagic shock who only transiently respond or do not respond to fluid therapy and/or the administration of blood products have exsanguinating injuries. Recognising shock due to (exsanguinating) haemorrhage in trauma is about constructing a synthesis of trauma mechanism, injuries, vital signs and the therapeutic response of the patient. The aim of prehospital care of bleeding trauma patients is to deliver the patient to a facility for definitive care within the shortest amount of time by rapid transport and minimise therapy to what is necessary to maintain adequate vital signs. Rapid decisions have to be made using regional trauma triage protocols that have incorporated patient condition, transport times and the level of care than can be performed by the prehospital care providers and the receiving hospitals. The treatment of bleeding patients is aimed at two major goals: stopping the bleeding and restoration of the blood volume. Fluid resuscitation should allow for preservation of vital functions without increasing the risk for further (re)bleeding. To prevent further deterioration and subsequent exsanguinations 'permissive hypotension' may be the goal to achieve. Within the hospital, a sound trauma team activation system, including the logistic procedure as well as activation criteria, is essential for a fast and adequate response. After determination of haemorrhagic shock, all efforts have to be directed to stop the bleeding in order to prevent exsanguinations. A simultaneous effort is made to restore blood volume and correct coagulation. Reversal of coagulopathy with pharmacotherapeutic interventions may be a promising concept to limit blood loss after trauma. Abdominal ultrasound has replaced diagnostic peritoneal lavage for detection of haemoperitoneum. With the development of sliding-gantry based computer tomography diagnostic systems, rapid evaluation by CT-scanning of the trauma patient is possible during resuscitation. The concept of damage control surgery, the staged approach in treatment of severe trauma, has proven to be of vital importance in the treatment of exsanguinating trauma patients and is adopted worldwide. When performing 'blind' transfusion or 'damage control resuscitation', a predetermined fixed ratio of blood components may result in the administration of higher plasma and platelets doses and may improve outcome. The role of thromboelastography and thromboelastometry as point-of-care tests for coagulation in massive blood loss is emerging, providing information about actual clot formation and clot stability, shortly (10min) after the blood sample is taken. Thus, therapy guided by the test results will allow for administration of specific coagulation factors that will be depleted despite administration with fresh frozen plasma during massive transfusion of blood components.

Abdominal Insufflation Decreases Blood Loss without Worsening the Inflammatory Response: Implications for Prehospital Control of Internal Bleeding

Abdominal insufflation (AI) by carbon dioxide has been shown to decrease the rate of bleeding in different swine models of abdominal organ injuries. With development of appropriate tools, AI could be used to control bleeding temporarily in the prehospital setting. Concerns have been raised about the inflammatory response to AI, which could damage organs at a later stage despite initial hemostasis. We hypothesized that AI controls bleeding without inducing an unfavorable inflammatory response. An experimental splenic injury was caused in 28 Yorkshire pigs, which were randomized to: 1) standard resuscitation (n = 14) with crystalloids to a mean arterial pressure of 60 mm Hg, or 2) standard resuscitation and AI (n = 14) to an abdominal pressure of 20 cmH2O. The experiment lasted for 30 minutes, and intra-abdominal blood loss was measured. Blood serum interleukin 1β (IL-1β), transforming growth factor β1, and lung tissue heat shock protein 70 gene expression were measured at 0, 15, and 30 minutes, as markers of the inflammatory response. All animals survived to the end of the experiment. Total blood loss was significantly less in the AI group compared with the other standard resuscitation animals (733 ± 76 vs 1094 ± 153 mL, P = 0.049). The pH at the end of the experiment was significantly lower in the AI group (7.28 ± 0.02 vs 7.44 ± 0.05, P < 0.01) but there was no difference in lactate levels (1.5 ± 0.4 vs 1.7 ± 0.3, P = 0.7). Similarly, there was no difference in IL-1β, transforming growth factor β1, or lung tissue heat shock protein 70 gene expression between the two groups at any time point, although there was a trend towards lower IL-1β levels in the AI group. Our conclusion is that AI reduces blood loss from splenic injury without a measurable effect on the early inflammatory response in a clinically relevant animal model.