KEY ISSUES IN ADVANCED BLEEDING CARE IN TRAUMA

The pathophysiology of pelvic ring injuries: a review

Traumatic pelvic ring injuries continue to represent a major challenge due to the high rates of post-injury mortality of around 30-40% in the peer-reviewed literature. The main root cause of potentially preventable mortality relates to the delayed recognition of the extent of retroperitoneal hemorrhage and post-injury coagulopathy. The understanding of the underlying pathophysiology of pelvic trauma is predicated by classification systems for grading of injury mechanism and risk stratification for developing post-injury coagulopathy with subsequent uncontrolled exsanguinating hemorrhage. This review article elaborates on the current understanding of the pathophysiology of severe pelvic trauma with a focus on the underlying mechanisms of retroperitoneal bleeding and associated adverse outcomes.

Inflammatory response to the ischaemia-reperfusion insult in the liver after major tissue trauma

BACKGROUND

Polytrauma is often accompanied by ischaemia-reperfusion injury to tissues and organs, and the resulting series of immune inflammatory reactions are a major cause of death in patients. The liver is one of the largest organs in the body, a characteristic that makes it the most vulnerable organ after multiple injuries. In addition, the liver is an important digestive organ that secretes a variety of inflammatory mediators involved in local as well as systemic immune inflammatory responses. Therefore, this review considers the main features of post-traumatic liver injury, focusing on the immuno-pathophysiological changes, the interactions between liver organs, and the principles of treatment deduced.

METHODS

We focus on the local as well as systemic immune response involving the liver after multiple injuries, with emphasis on the pathophysiological mechanisms.

RESULTS

An overview of the mechanisms underlying the pathophysiology of local as well as systemic immune responses involving the liver after multiple injuries, the latest research findings, and the current mainstream therapeutic approaches.

CONCLUSION

Cross-reactivity between various organs and cascade amplification effects are among the main causes of systemic immune inflammatory responses after multiple injuries. For the time being, the pathophysiological mechanisms underlying this interaction remain unclear. Future work will continue to focus on identifying potential signalling pathways as well as target genes and intervening at the right time points to prevent more severe immune inflammatory responses and promote better and faster recovery of the patient.

State-of-the-Art Review: Sex Hormone Therapy in Trauma-Hemorrhage

ABSTRACT

Trauma-hemorrhage is the leading cause of prehospital and early in-hospital deaths, while also significantly contributing to the later development of multisystem organ dysfunction/failure and sepsis. Common and advanced resuscitative methods would potentially demonstrate benefits in the prehospital setting; however, they face a variety of barriers to application and implementation. Thus, a dialogue around a novel adjunct has arisen, sex hormone therapy. Proposed candidates include estradiol and its derivatives, metoclopramide hydrochloride/prolactin, dehydroepiandrosterone, and flutamide; with each having demonstrated a range of salutary effects in several animal model studies. Several retrospective analyses have observed a gender-based dimorphism in mortality following trauma-hemorrhage, thus suggesting that estrogens contribute to this pattern. Trauma-hemorrhage animal models have shown estrogens offer protective effects to the cardiovascular, pulmonary, hepatic, gastrointestinal, and immune systems. Additionally, a series of survival studies utilizing 17α-ethinylestradiol-3-sulfate, a potent, water-soluble synthetic estrogen, have demonstrated a significant survival benefit and beneficial effects on cardiovascular function. This review presents the findings of retrospective clinical studies, preclinical animal studies, and discusses how and why 17α-ethinylestradiol-3-sulfate should be considered for investigation within a prospective clinical trial.

Thromboelastography is predictive of mortality, blood transfusions, and blood loss in patients with traumatic pelvic fractures: a retrospective cohort study

PURPOSE

In patients with traumatic pelvic fractures, thromboelastography (TEG) is a useful tool to rapidly evaluate and identify coagulation disturbances. The purpose of this study was to examine the coagulation kinetics of patients with traumatic pelvic fractures (pelvic ring and/or acetabulum) by analyzing the TEG results at initial presentation and its relationship with mortality and blood loss.

METHODS

A retrospective review at our Level-1 trauma center was conducted to identify Full Trauma Team activations (FTTa) with traumatic pelvic and/or acetabular fractures who were evaluated with a TEG on initial presentation between 2012 and 2016. In-hospital mortality, product transfusion, and hemoglobin changes were analyzed. Subgroup analysis was performed based on pelvic fracture type.

RESULTS

141 patients with a mean age of 49.0 ± 20.8 years and mean Injury Severity Score (ISS) of 25.18 ± 12.8 met inclusion criteria. PRBC transfusion occurred in 78.0% of patients; a total of 1486 blood products were transfused. A total of 65 patients (46.1%) underwent operative treatment for the pelvic injuries, and 18 patients (12.7%) required embolization. The overall in-hospital mortality rate was 14.9%. The degree of clot lysis at 30 min (LY30) was significantly associated with blood loss (p < 0.0001), units of packed red blood cells (PRBCs) transfused (p < 0.0001), and mortality rate (p = 0.0002).

CONCLUSION

Increased fibrinolysis evidenced by an elevated LY30 on initial TEG in patients with traumatic pelvic fractures is associated with increased blood loss, blood product transfusions, and mortality. Future studies should evaluate the clinical utility of reversing hyperfibrinolysis on initial TEG.

LEVEL OF EVIDENCE

Prognostic level III.

The Role of TEG and ROTEM in Damage Control Resuscitation

ABSTRACT

Trauma-induced coagulopathy is associated with very high mortality, and hemorrhage remains the leading preventable cause of death after injury. Directed methods to combat coagulopathy and attain hemostasis are needed. The available literature regarding viscoelastic testing, including thrombelastography (TEG) and rotational thromboelastometry (ROTEM), was reviewed to provide clinically relevant guidance for emergency resuscitation. These tests predict massive transfusion and developing coagulopathy earlier than conventional coagulation testing, within 15 min using rapid testing. They can guide resuscitation after trauma, as well. TEG and ROTEM direct early transfusion of fresh frozen plasma when clinical gestalt has not activated a massive transfusion protocol. Reaction time and clotting time via these tests can also detect clinically significant levels of direct oral anticoagulants. Slowed clot kinetics suggest the need for transfusion of fibrinogen via concentrates or cryoprecipitate. Lowered clot strength can be corrected with platelets and fibrinogen. Finally, viscoelastic tests identify fibrinolysis, a finding associated with significantly increased mortality yet one that no conventional coagulation test can reliably detect. Using these parameters, guided resuscitation begins within minutes of a patient's arrival. A growing body of evidence suggests this approach may improve survival while reducing volumes of blood products transfused.

The alteration of neuronal activities of the cuneiform nucleus in non-hypovolemic and hypovolemic hypotensive conditions

BACKGROUND

The cuneiform nucleus is located in the center of the circuit that mediates autonomic responses to stress. Hemorrhagic hypotension leads to chemoreceptor anoxia, which consequently results in the reduction of baroreceptor discharge and stimulation of the chemoreceptor.

OBJECTIVE

Using the single-unit recording technique, the neuronal activities of the cuneiform nucleus were investigated in hypotensive states induced by hemorrhage and administration of an anti-hypertensive drug (hydralazine).

METHODS

Thirty male rats were divided into the control, hemorrhage, and hydralazine groups. The femoral artery was cannulated for the recording of cardiovascular responses, including systolic blood pressure, mean arterial pressure, and heart rate. Hydralazine was administered via tail vein. The single-unit recording was performed from the cuneiform nucleus.

RESULTS

The maximal systolic blood pressure and the mean arterial pressure significantly decreased and heart rate significantly increased after the application of hydralazine as well as the following hemorrhage compared to the control group. Hypotension significantly increased the firing rate of the cuneiform nucleus in both the hemorrhage and hydralazine groups compared to the control group.

CONCLUSIONS

The present data indicate that the cuneiform nucleus activities following hypotension may play a crucial role in blood vessels and vasomotor tone.

Molecular and morphometric changes in the small intestine during hot and cold exposure in thermally manipulated broiler chickens

Background and Aim:

Thermal stress (hot or cold) is one of many environmental stressors that severely affects the health of broiler chickens. One negative effect of thermal stress is the disruption of the intestinal barrier function in broiler chickens. This study aimed to evaluate the effect of thermal manipulation (TM) on the small intestine in terms of histomorphometry as well as junctional, heat-shock, and immune response gene expression during post-hatch exposure to thermal stress.

Materials and Methods:

The experiment was conducted by dividing 928 fertile Ross eggs into three incubation groups: The control (C) group (incubated at 37.8°C and 56% relative humidity [RH] for the whole incubation period), the TM using low temperature TML group (incubated at 36°C and 56% RH for 18 h/day from embryonic days 7 to 16), and the TM using high temperature (TMH) group (incubated at 39°C and 65% RH for 18 h/day from embryonic days 7 to 16). On post-hatch day 21, 90 chicks were randomly selected from each incubation group and were equally subdivided into three subgroups for the post-hatch thermal stress experiment: The TN subgroup (room temperature maintained at 24°C), the heat stress (HS) subgroup (room temperature maintained at 35°C), and the cold stress (CS) subgroup (room temperature maintained at 16°C). After 1 day of thermal stress exposure (age 22 days), five birds from each subgroup were euthanized and ileum samples were collected to evaluate the transcription of the Claudin (CLDN1), CLDN-5, Occludin, Cadherin-1, heat shock factors (HSF1), HSF3, 70 kilodalton heat shock protein, 90 kilodalton heat shock protein, Interleukin6 (IL6), IL8, toll-like receptors-2 (TLR2), and TLR4 genes by Real-Time Quantitative Reverse Transcription polymerase chain reaction analysis. Finally, after 4 and 7 days of thermal stress (age 25 and 28 days, respectively), nine chicks were euthanized, and their jejunum and ileum were collected for histomorphometric analysis.

Results:

After exposure to 1 day of thermal stress, the C subgroups exposed to thermal stress (HS and CS) possessed significantly increased expression of junctional, heat-shock, and immune response genes compared to the C-TN subgroup, and similar results were observed for the TMH. In contrast, thermally stressed TMH subgroups had significantly lower expression of the studied genes compared to C subgroups exposed to thermal stress. Furthermore, no significant changes were detected between the TML subgroups exposed to thermal stress and TML-TN. Moreover, significant alterations in villus height (VH), villus surface area, crypt depth (CD), and VH to CD ratio were observed between the TML, TMH, and C subgroups exposed to CS.

Conclusion:

It might be suggested that TM may have a protective impact on the small intestine histomorphometry and epithelial integrity of broilers during post-hatch exposure to thermal stress.

Trauma-induced coagulopathy

Uncontrolled haemorrhage is a major preventable cause of death in patients with traumatic injury. Trauma-induced coagulopathy (TIC) describes abnormal coagulation processes that are attributable to trauma. In the early hours of TIC development, hypocoagulability is typically present, resulting in bleeding, whereas later TIC is characterized by a hypercoagulable state associated with venous thromboembolism and multiple organ failure. Several pathophysiological mechanisms underlie TIC; tissue injury and shock synergistically provoke endothelial, immune system, platelet and clotting activation, which are accentuated by the 'lethal triad' (coagulopathy, hypothermia and acidosis). Traumatic brain injury also has a distinct role in TIC. Haemostatic abnormalities include fibrinogen depletion, inadequate thrombin generation, impaired platelet function and dysregulated fibrinolysis. Laboratory diagnosis is based on coagulation abnormalities detected by conventional or viscoelastic haemostatic assays; however, it does not always match the clinical condition. Management priorities are stopping blood loss and reversing shock by restoring circulating blood volume, to prevent or reduce the risk of worsening TIC. Various blood products can be used in resuscitation; however, there is no international agreement on the optimal composition of transfusion components. Tranexamic acid is used in pre-hospital settings selectively in the USA and more widely in Europe and other locations. Survivors of TIC experience high rates of morbidity, which affects short-term and long-term quality of life and functional outcome.

Development of hemorrhage identification model using non-invasive vital signs

OBJECTIVE

Early detection and timely management of bleeding is critical as failure to recognize physiologically significant bleeding is associated with significant morbidity and mortality. Many such instances are detected late, even in highly monitored environments, contributing to delay in recognition and intervention. We propose a non-invasive early identification model to detect bleeding events using continuously collected photoplethysmography (PPG) and electrocardiography (ECG) waveforms.

APPROACH

Fifty-nine York pigs undergoing fixed-rate, controlled hemorrhage were involved in this study and a least absolute shrinkage and selection operator regression-based early detection model was developed and tested using PPG and ECG derived features. The output of the early detection model was a risk trajectory indicating the future probability of bleeding.

MAIN RESULTS

Our proposed models were generally accurate in predicting bleeding with an area under the curve of 0.89 (95% CI 0.87-0.92) and achieved an average time of 16.1 mins to detect 16.8% blood loss when a false alert rate of 1% was tolerated. Models developed on non-invasive data performed with similar discrimination and lead time to hemorrhage compared to models using invasive arterial blood pressure as monitoring data.

SIGNIFICANCE

A bleed detection model using only non-invasive monitoring performs as well as those using invasive arterial pressure monitoring.

A Brain Phantom Study of a Noncontact Single Inductive Coil Device and the Attendant Algorithm for First Stage Diagnosis of Internal Bleeding in the Head

Hemorrhagic stroke is one of the leading causes of premature death among economically disadvantaged populations. Treatments of these conditions require an early diagnosis. While computed tomography and magnetic resonance imaging are the medical gold standard for early diagnosis, these imaging modalities are rarely available in low- and middle-income countries. We present an unsophisticated noncontact single coil inductive device and a simple algorithm for detection of changes in fluid/tissue ratio in the head which simulates blood vessel bursting in the brain. Experiments were performed on a typical phantom model of the head and internal bleeding was simulated by injection of physiological saline at two locations in the head phantom. The primary motivation for this work is the need for a simple and robust detection device and algorithm for diagnosis of hemorrhagic stroke in low- and middle-income countries. This phantom-based study shows that the technology and in particular the algorithm introduced here are robust and could replace conventional imaging for first stage diagnosis of internal bleeding in the head, and thereby save millions of lives every year. Clinical studies are required to further examine the technology and the algorithm.

Endothelial glycocalyx in acute care surgery - what anaesthesiologists need to know for clinical practice

The endothelial glycocalyx (EG) is the thin sugar-based lining on the apical surface of endothelial cells. It has been linked to the physiological functioning of the microcirculation and has been found to be damaged in critical illness and after acute care surgery. This review aims to describe the role of EG in severely injured patients undergoing surgery, discuss specific situations (e.G. major trauma, hemorrhagic shock, trauma induced coagulopathy) as well as specific interventions commonly applied in these patients (e.g. fluid therapy, transfusion) and specific drugs related to perioperative medicine with regard to their impact on EG.EG in acute care surgery is exposed to damage due to tissue trauma, inflammation, oxidative stress and inadequate fluid therapy. Even though some interventions (transfusion of plasma, human serum albumin, hydrocortisone, sevoflurane) are described as potentially EG protective there is still no specific treatment for EG protection and recovery in clinical medicine.The most important principle to be adopted in routine clinical practice at present is to acknowledge the fragile structure of the EG and avoid further damage which is potentially related to worsened clinical outcome.

A systematic review of large animal models of combined traumatic brain injury and hemorrhagic shock

Traumatic brain injury (TBI) and severe blood loss (SBL) frequently co-occur in human trauma, resulting in high levels of mortality and morbidity. Importantly, each of the individual post-injury cascades is characterized by complex and potentially opposing pathophysiological responses, complicating optimal resuscitation and therapeutic approaches. Large animal models of poly-neurotrauma closely mimic human physiology, but a systematic literature review of published models has been lacking. The current review suggests a relative paucity of large animal poly-neurotrauma studies (N = 52), with meta-statistics revealing trends for animal species (exclusively swine), characteristics (use of single biological sex, use of juveniles) and TBI models. Although most studies have targeted blood loss volumes of 35-45%, the associated mortality rates are much lower relative to Class III/IV human trauma. This discrepancy may result from potentially mitigating experimental factors (e.g., mechanical ventilation prior to or during injury, pausing/resuming blood loss based on physiological parameters, administration of small volume fluid resuscitation) that are rarely associated with human trauma, highlighting the need for additional work in this area.

A review of the application of cellulose hemostatic agent on trauma injuries

Introduction

Planning for management of bleeding in trauma injuries is very important. The initial purpose in emergency situations should be immediate establishment of an efficient hemostasis, principally in its topical application. In this study, we aimed to review the major relevant articles in the case of application of cellulose hemostatic agent on trauma injuries.

Methods

We searched the online databases such as PubMed, MEDLINE, Wiley, EMBASE, ISI Web of Knowledge, and Scopus. Two reviewers independently searched and assessed the titles and abstracts of all articles.

Results

Upon screening the titles and abstracts, 24 studies were identified for full-text review. The oxidized cellulose had the best clotting times, while it demonstrated low absorption ability. Surgical and thermosensitive chitosan hemostatic could be valuable for managing hemorrhage from liver injuries in trauma patients.

Conclusion

Recently, the application of cellulose hemostatic agents has been one of the main improvements obtained for controlling bleeding in trauma injuries. However, generally according to the literature review, the decision about using each agent should be made on a case-by-case basis. However, it can be mentioned that the perfect hemostatic agent has not been still identified.

Trauma-induced coagulopathy: The past, present, and future

Trauma remains a leading cause of death worldwide, and most early preventable deaths in both the civilian and military settings are due to uncontrolled hemorrhage, despite paradigm advances in modern trauma care. Combined tissue injury and shock result in hemostatic failure, which has been identified as a multidimensional molecular, physiologic and clinical disorder termed trauma-induced coagulopathy (TIC). Understanding the biology of TIC is of utmost importance, as it is often responsible for uncontrolled bleeding, organ failure, thromboembolic complications, and death. Investigations have shown that TIC is characterized by multiple phenotypes of impaired hemostasis due to altered biology in clot formation and breakdown. These coagulopathies are attributable to tissue injury and shock, and encompass underlying endothelial, immune and inflammatory perturbations. Despite the recognition and identification of multiple mechanisms and mediators of TIC, and the development of targeted treatments, the mortality rates and associated morbidities due to hemorrhage after injury remain high. The purpose of this review is to examine the past and present understanding of the multiple distinct but highly integrated pathways implicated in TIC, in order to highlight the current knowledge gaps and future needs in this evolving field, with the aim of reducing morbidity and mortality after injury.

Comparison of portable blood-warming devices under simulated pre-hospital conditions: a randomised in-vitro blood circuit study

Pre-hospital transfusion of blood products is a vital component of many advanced pre-hospital systems. Portable fluid warmers may be utilised to help prevent hypothermia, but the limits defined by manufacturers often do not reflect their clinical use. The primary aim of this randomised in-vitro study was to assess the warming performance of four portable blood warming devices (Thermal Angel, Hypotherm X LG, °M Warmer, Buddy Lite) against control at different clinically-relevant flow rates. The secondary aim was to assess haemolysis rates between devices at different flow rates. We assessed each of the four devices and the control, at flow rates of 50 ml.min^-1 , 100 ml.min^-1 and 200 ml.min^-1 , using a controlled perfusion circuit with multisite temperature monitoring. Free haemoglobin concentration, a marker of haemolysis, was measured at multiple points during each initial study run with spectrophotometry. At all flow rates, the four devices provided superior warming performance compared with the control (p < 0.001). Only the °M Warmer provided a substantial change in temperature at all flow rates (mean (95%CI) temperature change of 21.1 (19.8-22.4) °C, 20.4 (19.1-21.8) °C and 19.4 (17.7-21.1) °C at 50 ml.min^-1 , 100 ml.min^-1 and 200 ml.min^-1 , respectively). There was no association between warming and haemolysis with any device (p = 0.949) or flow rate (p = 0.169). Practical issues, which may be relevant to clinical use, also emerged during testing. Our results suggest that there were significant differences in the performance of portable blood warming devices used at flow rates encountered in clinical practice.

A case report: Veno-venous extracorporeal membrane oxygenation for severe blunt thoracic trauma

Introduction

The use of veno-venous extracorporeal membrane oxygenation (VV-ECMO) in trauma patients has been controversial, but VV-ECMO plays a crucial role when the lungs are extensively damaged and when conventional management has failed. VV-ECMO provides adequate tissue oxygenation and an opportunity for lung recovery. However, VV-ECMO remains contraindicated in patients with a risk of bleeding because of systemic anticoagulation during the treatment. The most important point is controlling the bleeding from severe trauma.

Case

A 32-year-old male experienced blunt trauma due to a traffic accident. He presented with bilateral hemopneumothorax and bilateral flail chest. We performed emergency thoracotomy for active bleeding and established circulatory stability. After surgery, the oxygenation deteriorated under mechanical ventilation, so we decided to establish VV-ECMO. However, bleeding from the bilateral lung contusions increased after VV-ECMO was established, and the patient was switched to heparin-free ECMO. After conversion, we could control the bronchial bleeding, especially the lung hematomas, and the oxygenation recovered. The patient was discharged without significant complications. VV-ECMO and mechanical ventilation were stopped on days 10 and 11, respectively. He was discharged from the ICU on day 15.

Conclusion

When we consider the use of ECMO for patients with uncontrollable, severe bleeding caused by blunt trauma, it may be necessary to use a higher flow setting for heparin-free ECMO than typically used for patients without trauma to prevent thrombosis.

Gender differences in trauma, shock and sepsis

Despite efforts in prevention and intensive care, trauma and subsequent sepsis are still associated with a high mortality rate. Traumatic injury remains the main cause of death in people younger than 45 years and is thus a source of immense social and economic burden. In recent years, the knowledge concerning gender medicine has continuously increased. A number of studies have reported gender dimorphism in terms of response to trauma, shock and sepsis. However, the advantageous outcome following trauma-hemorrhage in females is not due only to sex. Rather, it is due to the prevailing hormonal milieu of the victim. In this respect, various experimental and clinical studies have demonstrated beneficial effects of estrogen for the central nervous system, the cardiopulmonary system, the liver, the kidneys, the immune system, and for the overall survival of the host. Nonetheless, there remains a gap between the bench and the bedside. This is most likely because clinical studies have not accounted for the estrus cycle. This review attempts to provide an overview of the current level of knowledge and highlights the most important organ systems responding to trauma, shock and sepsis. There continues to be a need for clinical studies on the prevailing hormonal milieu following trauma, shock and sepsis.

Alterations in endothelin receptors following hemorrhage and resuscitation by centhaquin

Endothelin-1 (ET-1) acts on ET(A) and ET(B) receptors and has been implicated in hemorrhagic shock (shock). We determined effect of shock and resuscitation by hypertonic saline (saline) or centhaquin on ET(A) and ET(B) receptor expression. Rats were anesthetized, a pressure catheter was placed in the left femoral artery; blood was withdrawn from the right femoral artery to bring mean arterial pressure (MAP) to 35 mm Hg for 30 min, resuscitation was performed and 90 min later sacrificed to collect samples for biochemical estimations. Resuscitation with centhaquin decreased blood lactate and increased MAP. Protein levels of ET(A) or ET(B) receptor were unaltered in the brain, heart, lung and liver following shock or resuscitation. In the abdominal aorta, shock produced an increase (140 %) in ET(A) expression which was attenuated by saline and centhaquin; ET(B) expression was unaltered following shock but was increased (79 %) by centhaquin. In renal medulla, ET(A) expression was unaltered following shock, but was decreased (-61 %) by centhaquin; shock produced a decrease (-34 %) in ET(B) expression which was completely attenuated by centhaquin and not saline. Shock induced changes in ET(A) and ET(B) receptors in the aorta and renal medulla are reversed by centhaquin and may be contributing to its efficacy.

Thromboelastometry-guided hemostatic therapy for hemorrhagic shock in the postoperative period of vascular surgery: a case report

Background

Hemorrhagic shock is a medical emergency that often complicates vascular surgery and can lead to death. Hemorrhagic shock is characterized by hypoperfusion and hemodynamic abnormalities leading to the collapse of homeostasis due to massive blood loss. Early diagnosis is critical for a favorable outcome. Thromboelastometry has been considered an effective tool for bleeding management in critically ill patients. Thromboelastometry can guide transfusion therapy quickly, reducing the need for blood products. Therefore, it could be an alternative test to guide hemostatic therapy in complex cases of hemorrhagic shock as a result of vascular surgeries. We report our successful experience with a case of hemorrhagic shock in postoperative care in vascular surgery, in which bleeding management was guided by thromboelastometry and bleeding control was achieved with hemostatic drugs and coagulation factor concentrates.

Case presentation

We report a case of an 82-year-old Afro-Brazilian man who presented to the intensive care unit with hemorrhagic shock in the postoperative period of vascular surgery. He underwent surgery for correction of iliac artery aneurysm with endoleak. His laboratory tests revealed severe anemia (hemoglobin 7.4 mg/dL), metabolic acidosis (bicarbonate 10 mEq/L, pH 7.11), acute kidney injury (creatinine 3.1 mg/dL), thrombocytopenia (platelets count 83 × 10³/mm³), hypofibrinogenemia (70 mg/dL), international nationalized ratio 1.95, activated partial thromboplastin time 64.5 seconds, and lactate 87 mmol/L. There was active bleeding in surgical site. Bleeding management was guided by thromboelastometry. The first test showed fulminant hyperfibrinolysis, which was corrected with the administration of tranexamic acid. The second thromboelastometry test showed improvement of hyperfibrinolysis but severe hypocoagulability. Fibrinogen concentrate, platelet apheresis, cryoprecipitate, and prothrombin complex concentrate were sequentially administrated. Thromboelastometry was completely corrected after 2 hours. Arteriography to evaluate mechanical cause of bleeding was normal. No more bleeding was identified, and neither was any further transfusion needed. He was discharged from the intensive care unit from the ward 3 days after admission.

Conclusions

Thromboelastometry may be considered a useful, feasible and safe tool to monitor and manage coagulopathy in patients with hemorrhagic shock. Moreover, it has the potential benefit of allowing rapid diagnosis,  goal-directed therapy with hemostatic drugs and coagulation factor concentrates and thus, avoiding unnecessary blood component transfusion.

Splenic trauma: WSES classification and guidelines for adult and pediatric patients

Spleen injuries are among the most frequent trauma-related injuries. At present, they are classified according to the anatomy of the injury. The optimal treatment strategy, however, should keep into consideration the hemodynamic status, the anatomic derangement, and the associated injuries. The management of splenic trauma patients aims to restore the homeostasis and the normal physiopathology especially considering the modern tools for bleeding management. Thus, the management of splenic trauma should be ultimately multidisciplinary and based on the physiology of the patient, the anatomy of the injury, and the associated lesions. Lastly, as the management of adults and children must be different, children should always be treated in dedicated pediatric trauma centers. In fact, the vast majority of pediatric patients with blunt splenic trauma can be managed non-operatively. This paper presents the World Society of Emergency Surgery (WSES) classification of splenic trauma and the management guidelines.

Hypoxia serves a key function in the upregulated expression of vascular adhesion protein‑1 in vitro and in a rat model of hemorrhagic shock

Hemorrhagic shock following major trauma results in mortality, but the function of vascular adhesion protein-1 (VAP-1), implicated in intracranial hemorrhage, remains unknown. This study aimed to determine whether expression of the AOC3 gene and its encoded protein, VAP-1, is altered by hypoxia. Rat hepatic sinusoidal endothelial cells (RHSECs) and rat intestinal microvascular endothelial cells (RIMECs) were transduced with a viral vector carrying AOC3, and AOC3 mRNA expression levels were measured by reverse transcription-quantitative polymerase chain reaction. VAP-1 protein expression levels were measured by western blot analysis and compared between normoxic and hypoxic conditions. Following this, AOC3 mRNA and VAP-1 protein expression levels in hepatic and intestinal tissues were assessed in a rat model of hemorrhagic shock with or without fluid resuscitation; and serum semicarbazide-sensitive amine oxidase (SSAO) activity was measured by fluorometric assays. The effects of 2-bromoethylamine (2-BEA) on AOC3/VAP-1 levels and 24 h survival were investigated. AOC3 mRNA and VAP-1 protein levels were increased in RHSECs and RIMECs by hypoxia, and in hepatic and intestinal tissues from rats following hemorrhagic shock. Hypoxia increased serum SSAO activity in these animals. 2-BEA reduced AOC3 mRNA and VAP-1 protein levels in hepatic and intestinal tissues from rats following hemorrhagic shock, and appeared to improve survival in animals not receiving resuscitation following hemorrhagic shock. In conclusion, hemorrhagic shock upregulates AOC3/VAP-1 expressions, and this potentially occurs via hypoxia. Therefore, inhibition of VAP-1 may be beneficial in the setting of hemorrhagic shock. Further studies are required to confirm these findings and to establish whether VAP-1 may be a valid target for the development of novel therapies for hemorrhagic shock.

Histological and Immunohistochemical Basis of the Effect of Aminoguanidine on Renal Changes Associated with Hemorrhagic Shock in a Rat Model

Acute kidney failure is the main cause of death among patients with severe trauma due to massive blood loss and hemorrhagic shock (HS). Renal cell injury is caused by tissue ischemia. Renal ischemia initiates a complex and interconnected chain of events resulting in cell injury and renal cell necrosis. Nitric oxide plays a crucial role in renal function and can be inhibited by aminoguanidine (AG). We studied whether AG can ameliorate pathological renal changes associated with HS syndrome in a rat model and explored the AG protection mechanism. Rats were intraperitoneally injected with heparin sodium and mean arterial blood pressure was monitored. Animals were divided into three groups: control (without hemorrhage), with or without intra-arterially injected AG; HS (blood continuously withdrawn or reinfused to maintain an MABP of 35-40 mmHg); and HS with AG. We found that AG decreased plasma concentrations of urea, creatinine, and nitrates; ameliorated histological changes of HS-induced rats; and decreased the expressions of inducible nitrogen oxide synthase (iNOS), proapoptotic protein (BAX), and vitamin D receptors (VDR). AG ameliorated kidney injury by inhibiting iNOS resulting in decreased BAX and VDR expressions. Therefore, a therapeutic strategy targeting AG may provide new insights into kidney injury during severe shock.

Pelvic trauma: WSES classification and guidelines

Complex pelvic injuries are among the most dangerous and deadly trauma related lesions. Different classification systems exist, some are based on the mechanism of injury, some on anatomic patterns and some are focusing on the resulting instability requiring operative fixation. The optimal treatment strategy, however, should keep into consideration the hemodynamic status, the anatomic impairment of pelvic ring function and the associated injuries. The management of pelvic trauma patients aims definitively to restore the homeostasis and the normal physiopathology associated to the mechanical stability of the pelvic ring. Thus the management of pelvic trauma must be multidisciplinary and should be ultimately based on the physiology of the patient and the anatomy of the injury. This paper presents the World Society of Emergency Surgery (WSES) classification of pelvic trauma and the management Guidelines.

Bleeding and damage control surgery

PURPOSE OF REVIEW

Bleeding is still a major cause of death in trauma patients. Damage control surgery is a strategy that aims to control bleeding and avoid secondary contamination of the cavity. This article checks the principles and indications of damage control surgery, bleeding management, and the role of the anesthesiologist in trauma context. The efficient treatment of severe trauma and exsanguinated patients includes a surgical approach to the patient performed as quickly as possible. Volemic resuscitation, hemostatic transfusion, prevention and/or treatment of coagulopathy, hypothermia, and acidosis are strategies that reduce bleeding, as well as permissive hypotension.

RECENT FINDINGS

Specialized literature shows us that the adoption of all of these principles along with reduced surgical time has led to a broader concept called damage control resuscitation.

SUMMARY

Damage control resuscitation is a treatment strategy in which the recovery of physiological variables is initially prioritized over anatomical variables and can be required in severe trauma patients.

The effect of Chinese herbal medicine on hemorrhagic shock: A systematic review and meta-analysis

BACKGROUND

Chinese herbal medicine (CHM) has been widely used in the treatment of hemorrhagic shock (HS) in China. Many controlled trials have been undertaken to investigate its efficacy.

OBJECTIVE

To evaluate the effectiveness and safety of CHM for Hemorrhagic Shock patients.

METHODS

We screening the Web of ScienceDirect database, PubMed, the Cochrane Library, EMBASE, China Biomedical Database web (CBM), China National Knowledge Infrastructure (CNKI) and WanFang database (WF), from inception to January 2015. All the randomized controlled trials (RCTs) that compared CHM plus conventional therapy with conventional therapy alone for HS patients were included. Meta-analysis on included studies was performed using fixed-effects model with RevMan 5.2. Risk ratio (RR) or mean difference (MD) with a 95% confidence interval (CI) was used as effect measure. STATA 12.0 was used for publication bias.

RESULTS

Fifteen RCTs involving 1076 participants were included in the meta-analysis. CHM combined with conventional therapy was tested to be more effective in reduce mortality (RR=0.24, 95%CI:0.13-0.46, P<0.0001), reduce the incidence of MODS (RR=0.47, 95%CI: 0.34-0.66,P<0.00001), symptomatic improvement: increase blood pressure (BP) (MD=8.83, 95%CI:6.82-10.84,P<0.00001), regulate heart rate (MD=-7.6,95%CI:-9.17 to -6.02,P<0.00001), increase urine volume (MD=7.26, 95%CI:5.00-9.53, P<0.00001), compared with conventional therapy alone. No serious adverse events were reported.

CONCLUSIONS

CHM combined with conventional therapy seems to be more effective on HS patients. However, the analysis results should be interpreted with caution due to the low methodological quality of the included trials. Future, the rigorously designed, high methodological quality, multicenter and large-scale trials are needed to confirm these conclusions.

Performance comparison of improvised prehospital blood warming techniques and a commercial blood warmer

INTRODUCTION

Prehospital transfusion of packed red blood cells (PRBC) may be life saving for hypovolaemic trauma patients. PRBCs should preferably be warmed prior to administration but practical prehospital devices have only recently become available. The effectiveness of purpose designed prehospital warmers compared with previously used improvised methods of warming has not previously been described.

MATERIALS AND METHODS

Expired units of PRBCs were randomly assigned to a warming method in a bench study. Warming methods were exposure to body heat of an investigator, leaving the blood in direct sunlight on a dark material, wrapping the giving set around gel heat pads or a commercial fluid warmer (Belmont Buddy Lite). Methods were compared with control units that were run through the fluid circuit with no active warming strategy.

RESULTS

The mean temperature was similar for all methods on removal from the fridge (4.5°C). The mean temperatures (degrees centigrade) for all methods were higher than the control group at the end of the circuit (all P≤0.001). For each method the mean (95% CI) temperature at the end of the circuit was; body heat 17.2 (16.4-18.0), exposure to sunlight 20.2 (19.4-21.0), gel heat pads 18.8 (18.0-19.6), Buddy Lite 35.2 (34.5-36.0) and control group 14.7 (13.9-15.5).

CONCLUSIONS

All of the warming methods significantly warmed the blood but only the Buddy Lite reliably warmed the blood to a near normal physiological level. Improvised warming methods therefore cannot be recommended.

Protective Effects of Estradiol on Myocardial Contractile Function Following Hemorrhagic Shock and Resuscitation in Rats

BACKGROUND

Hemorrhagic shock (HS) results in myocardial contractile dysfunction. Studies showed that 17β-estradiol protects the myocardium against contractile dysfunction. The study investigated the cardioprotective effects of treatment with 17β-estradiol before resuscitation following 1 h of HS and resuscitation.

METHODS

Male Sprague-Dawley rats were assigned to 2 sets of experimental protocols: Ex vivo and in vivo treatment and resuscitation. Each set had three experimental groups (n = 6 per group): Normotensive (N), HS and resuscitation (HS-R) and HS rats treated with 17β-estradiol (E) and resuscitated (HS-E-R). Rats were hemorrhaged over 60-min to reach a mean arterial blood pressure of 40 mmHg. In the ex vivo group, hearts were resuscitated by perfusion in the Langendorff system. In the 17β-estradiol treated group, 17β-estradiol 280 µg/kg was added for thefirst 5 min. Cardiac function was measured. Left ventricular generated pressure (LVGP) and +dP/dt were calculated. In the in vivo group, rats were treated with 17β-estradiol 280 µg/kg s.c. after 60-min HS. Resuscitation was performed in vivo by the reinfusion of the shed blood for 30-min to restore normotension.

RESULTS

Treatment with 17β-estradiol before resuscitation in ex vivo treated and resuscitated isolated hearts and in the in vivo treated and resuscitated rats following HS improved myocardial contractile function. In the in vivo treated group, LVGP and +dP/dt max were significantly higher in 17β-estradiol treated rats compared to the untreated group (LVGP 136.40 ± 6.61 compared to 47.58 ± 17.55, and +dP/dt 661.85 ± 49.88 compared to 88.18 ± 0.85). Treatment with 17β-estradiol improved LVGP following HS.

CONCLUSIONS

The results indicate that treatment with 17β-estradiol before resuscitation following HS protects the myocardium against dysfunction.

Overview of Agents Used for Emergency Hemostasis

CONTEXT

In today's modern world, despite the multiple advances made in the field of medicine, hemorrhagic shock is still the main cause of battlefield mortality and the second most prevalent cause of mortality in civilian trauma. Hemostatic agents can play a key role in establishing hemostasis in prehospital situations and preventing hemorrhage-associated death. In this respect, this article aims to review different aspects of known hemostatic agents.

EVIDENCE ACQUISITION

A comprehensive search of the academic scientific databases for relevant keywords was conducted; relevant articles were compiled and assessed.

RESULTS

Hemostatic agents can establish hemostasis by means of different mechanisms, including concentrating coagulation factors, adhesion to the tissues, in which traumatic hemorrhage occurred, and delivering procoagulant factors to the hemorrhage site. Presently, these hemostatics have been significantly improved with regard to efficacy and in adverse consequences, resulting from their use. Several hemostatic dressings have been developed to the degree that they have received FDA approval and are being used practically on the battlefield. In addition, there are currently several case reports on the use of such hemostatics in the hospital setting, in conditions where commonly known approaches fail to stop life-threatening bleeding.

CONCLUSIONS

The use of hemostatic dressings and agents is one of the main advancements achieved in recent decades. However, it can be claimed that the ideal hemostatic has not been recognized yet; therefore, this topic needs to be brought into focus and further addressed.

Valproic acid protects against haemorrhagic shock-induced signalling changes via PPARγ activation in an in vitro model

BACKGROUND AND PURPOSE

Valproic acid (VPA), a widely used epilepsy and bipolar disorder treatment, provides acute protection against haemorrhagic shock-induced mortality in a range of in vivo models through an unknown mechanism. In the liver, this effect occurs with a concomitant protection against a decrease in GSK3β-Ser(9) phosphorylation. Here, we developed an in vitro model to investigate this protective effect of VPA and define a molecular mechanism.

EXPERIMENTAL APPROACH

The human hepatocarcinoma cell line (Huh7) was exposed to conditions occurring during haemorrhagic shock (hypoxia, hypercapnia and hypothermia) to investigate the changes in GSK3β-Ser(9) phosphorylation for a 4 h period following treatment with VPA, related congeners, PPAR agonists, antagonists and siRNA.

KEY RESULTS

Huh7 cells undergoing combined hypoxia, hypercapnia, and hypothermia reproduced the reduced GSK3β-Ser(9) phosphorylation shown in vivo during haemorrhagic shock, and this change was blocked by VPA. The protective effect occurred through upstream PTEN and Akt signalling, and prevented downstream β-catenin degradation while increasing histone 2/3 acetylation. This effect was reproduced by several VPA-related compounds with known PPARγ agonist activity, independent of histone deacetylase (HDAC) inhibitory activity. Specific pharmacological inhibition (by T0070907) or knockdown of PPARγ blocked the protective effect of VPA against these signalling changes and apoptosis. In addition, specific activation of PPARγ using ciglitazone reproduced the changes induced by VPA in haemorrhagic shock-like conditions.

CONCLUSION AND IMPLICATIONS

Changes in GSK3β-Ser(9) phosphorylation in in vivo haemorrhagic shock models can be modelled in vitro, and this has identified a role for PPARγ activation in the protective role of VPA.

Health and economic outcomes associated with uncontrolled surgical bleeding: a retrospective analysis of the Premier Perspectives Database

Background

Bleeding remains a common occurrence in surgery. Data describing the burden of difficult-to-control bleeding and topical absorbable hemostat use are sparse. This study was conducted to estimate the clinical and economic impact that remains associated with uncontrolled surgical bleeding, even when hemostats are used during surgery.

Methods

This US retrospective analysis used the Premier Perspectives Database. Hospital discharges from 2012 were used to identify patients treated with hemostats during eight surgery types. Patients were included if they were ≥18 years, had an inpatient hospitalization with one of the eight surgeries, and received a hemostat on the day of surgery. Patients were stratified by procedure and presence or absence of major bleeding (uncontrolled) despite hemostat use. Outcomes were all-cause hospitalization costs, hemostat costs, length of stay, reoperation, and surgery-related complications (eg, mortality). Statistical significance was tested through chi-square or t-tests. Multivariate analyses were conducted for all-cause costs and length of stay using analysis of covariance.

Results

Among 25,048 procedures, major bleeding events occurred in 14,251 cases. Despite treatment with hemostats, major bleeding occurred in 32%–68% of cases. All-cause costs were significantly higher in patients with uncontrolled bleeding despite hemostat use versus controlled bleeding (US$24,203–$61,323 [uncontrolled], US$14,420–$45,593 [controlled]; P<0.001). Hemostat costs were significantly greater in the uncontrolled bleeding cohort for all surgery types except cystectomy and pancreatic surgery. Reoperation and mortality rates were significantly higher in the uncontrolled bleeding cohort in all surgical procedures except cystectomy and radical hysterectomy.

Conclusion

Uncontrolled intraoperative bleeding despite hemostat use is prevalent and associated with significantly higher hospital costs and worse clinical outcomes across several surgical procedures compared to controlled bleeding. There is an unmet need for newer hemostats that can more effectively control bleeding, improve outcomes, and reduce hospital resource use.

Strategies for the management of haemorrhage following pelvic fractures and associated trauma-induced coagulopathy

Exsanguination is the second most common cause of death in patients who suffer severe trauma. The management of haemodynamically unstable high-energy pelvic injuries remains controversial, as there are no universally accepted guidelines to direct surgeons on the ideal use of pelvic packing or early angio-embolisation. Additionally, the optimal resuscitation strategy, which prevents or halts the progression of the trauma-induced coagulopathy, remains unknown. Although early and aggressive use of blood products in these patients appears to improve survival, over-enthusiastic resuscitative measures may not be the safest strategy. This paper provides an overview of the classification of pelvic injuries and the current evidence on best-practice management of high-energy pelvic fractures, including resuscitation, transfusion of blood components, monitoring of coagulopathy, and procedural interventions including pre-peritoneal pelvic packing, external fixation and angiographic embolisation.

Shock index and prediction of traumatic hemorrhagic shock 28-day mortality: data from the DCLHb resuscitation clinical trials

INTRODUCTION

To assess the ability of the shock index (SI) to predict 28-day mortality in traumatic hemorrhagic shock patients treated in the diaspirin cross-linked hemoglobin (DCLHb) resuscitation clinical trials.

METHODS

We used data from two parallel DCLHb traumatic hemorrhagic shock efficacy trials, one in U.S. emergency departments, and one in the European Union prehospital setting to assess the relationship between SI values and 28-day mortality.

RESULTS

In the 219 patients, the mean age was 37 years, 64% sustained a blunt injury, 48% received DCLHb, 36% died, and 88% had an SI≥1.0 at study entry. The percentage of patients with an SI≥1.0 dropped by 57% (88 to 38%) from the time of study entry to 120 minutes after study resuscitation (p<0.001). Patients with a SI≥1.0, 1.4, and 1.8 at any time point were 2.3, 2.7, and 3.1 times, respectively, more likely to die by 28 days than were patients with SI values below these cutoffs (p<0.001). Similarly, after 120 minutes of resuscitation, patients with a SI≥1.0 were 3.9× times more likely to die by 28 days (40 vs. 15%, p<0.001). Although the distribution of SI values differed based on treatment group, the receiver operator characeristics data showed no difference in SI predictive ability for 28-day mortality in patients treated with DCLHb.

CONCLUSION

In these traumatic hemorrhagic shock patients, the shock index correlates with 28-day mortality, with higher SI values indicating greater mortality risk. Although DCLHb treatment did alter the distribution of SI values, it did not influence the ability of the SI to predict 28-day mortality.

The role of follow-up ultrasound and clinical parameters after abdominal MDCT in patients with multiple trauma

BACKGROUND

Beside its value during the initial trauma work-up (focused assessment with sonography for trauma), ultrasound (US) is recommended for early follow-up examinations of the abdomen in multiple injured patients. However, multidetector CT (MDCT) has proven to reliably diagnose traumatic lesions of abdominal organs, to depict their extent, and to assess their clinical relevance.

PURPOSE

To evaluate the diagnostic impact of follow-up US studies after MDCT of the abdomen and to identify possible clinical parameters indicating the need of a follow-up US.

MATERIAL AND METHODS

During a 30-month period, patients with suspected multiple trauma were allocated. Patients with admission to the ICU, an initial abdominal MDCT scan, and an US follow-up examination after 6 and 24 h were included. Two patient cohorts were defined: patients with normal abdominal MDCT (group 1), patients with trauma-related pathologic abdominal MDCT (group 2). In all patients, parameters indicating alteration of vital functions or hemorrhage within the first 24 h were obtained by reviewing the medical charts.

RESULTS

Forty-four of 193 patients were included: 24 were categorized in group 1 (mean age, 41.1 years; range, 21-90 years), 20 in group 2 (mean age, 36.6 years; range, 16-71 years). In group 1, US did not provide new information compared to emergency MDCT. In group 2, there were no contradictory 6- and 24-h follow-up US findings. In patients with positive MDCT findings and alterations of clinical parameters, US did not detect progression of a previously diagnosed pathology or any late manifestation of such a lesion. In none of the patients with negative abdominal MDCT and pathological clinical parameters US indicated an abdominal injury.

CONCLUSION

Routine US follow-up does not yield additional information after abdominal trauma. In patients with MDCT-proven organ lesions, follow-up MDCT should be considered if indicated by abnormal clinical and/or laboratory findings.

Pulse pressure variation is comparable with central venous pressure to guide fluid resuscitation in experimental hemorrhagic shock with endotoxemia

INTRODUCTION

Pulse pressure variation (PPV) has been proposed as a promising resuscitation goal, but its ability to predict fluid responsiveness has been questioned in various conditions. The purpose of this study was to assess the performance of PPV in predicting fluid responsiveness in experimental hemorrhagic shock with endotoxemia, while comparing it with goals determined by a conventional set of guidelines.

METHODS

Twenty-seven pigs were submitted to acute hemorrhagic shock with intravenous infusion of endotoxin and randomized to three groups: (i) control; (ii) conventional treatment with crystalloids to achieve and maintain central venous pressure (CVP) 12 to 15 mmHg, mean arterial pressure of 65 mmHg or greater, and SvO2 (mixed venous oxygen saturation) of 65% or greater; (iii) treatment to achieve and maintain PPV of 13% or less. Parametric data were analyzed by two-way analysis of variance and Tukey test and differences in crystalloid volumes by t test. Predictive values of variables regarding fluid responsiveness were evaluated by receiver operating characteristic curves and multiple logistic regression.

RESULTS

Both treatments produced satisfactory hemodynamic recovery, without statistical differences in fluid administration (P = 0.066), but conventional treatment induced higher CVP (P = 0.001). Areas under receiver operating characteristic curves were larger for CVP (0.77; 95% confidence interval, 0.68-0.86) and PPV (0.74; 95% confidence interval, 0.65-0.83), and these variables were further selected by multiple logistic regression as independent predictors of responsiveness. Optimal PPV cutoff was 15%, with false-positive results involving mean pulmonary arterial pressure of 27 mmHg or greater.

CONCLUSIONS

Acute resuscitation guided by PPV was comparable with the strategy guided by CVP, mean arterial pressure, and SvO2. Central venous pressure and PPV were individually limited but independently predictive of fluid responsiveness.

Fibrin patch in a pig model with blunt liver injury under severe hypothermia

BACKGROUND

Rapid control of hemorrhage is one of the key aspects in trauma handling. To cope with bleeding, local hemostatic approaches are useful, along with surgical and systemic homostatic therapy. In this experimental study, we investigated the efficacy of a fibrinogen/thrombin containing collagen patch (TachoSil) in a coagulopathic pig model with blunt liver trauma under severe hypothermia.

METHODS

Eighteen anesthetized pigs underwent hemodilution by exchanging 70% of the blood volume with Ringer Lactate solution and hydroxyethyl starch 130/0.4 (1:1). Ten minutes after induction of a grade III blunt liver trauma, the animals randomly received treatment with TachoSil (FT-patch, n = 9) or a collagen patch (Tachotop, control group, n = 9). Blood loss, hemodynamics, and coagulation parameters were observed for 2 h. To confirm the consistency of liver trauma, pathologic examination of the liver tissue was performed.

RESULTS

Hypothermia (33.5°C ± 0.5°C) and hemodilution led to severe coagulopathy as measured by thromboelastometry and coagulation parameters. After trauma and patch application, thromboelastometry and coagulation parameters in the control group showed further deterioration compared with the stable parameters in the FT-patch group. The total blood loss was significantly reduced in the FT-patch group (FT-patch: 1195 mL; control group: 2495 mL; P < 0.001). Concordantly, the control animals were hemodynamically jeopardized to a higher degree. Microscopy confirmed a similar degree of liver injury.

CONCLUSIONS

Despite severe hypothermia and coagulopathy, TachoSil provided effective hemorrhage control in pigs with blunt liver injury. Therefore, TachoSil demonstrated usefulness as an additional early therapy in cases of uncontrolled bleeding following severe trauma.

Validation of a spectroscopic sensor for the continuous, noninvasive measurement of muscle oxygen saturation and pH

New patient monitoring technologies can noninvasively and directly provide an assessment of the adequacy of tissue perfusion through the simultaneous determination of muscle oxygen saturation (SmO2) and muscle pH (pHm). Non-pulsatile near infrared spectroscopy is used to determine these microvascular parameters. Two separate studies were conducted using an isolated perfused swine limb preparation to widely vary venous blood oxygen saturation (SviO2) and pH (pHvi) to assess the accuracy of a noninvasive sensor with the capability to simultaneously measure both parameters. The isolated limb model is necessary to establish equilibrium between the venous output of the perfusion circuit and the venule measurement of the spectroscopic sensor. The average absolute difference between SmO2 and SviO2 determined over 50 conditions of SviO2 between 13% and 83% on 3 pig limbs was 3.8% and the coefficient of determination (R(2)) was 0.95. The average absolute difference between pHm and pHvi determined over 69 conditions of pHvi between pHvi 6.9 and pHvi 7.5 on 3 pig limbs was 0.045 pH units with an R(2) of 0.92. Measured accuracy was acceptable to support clinically relevant decision making for the assessment of impaired tissue perfusion and acidosis. Sensors were also evaluated on human subjects. There was no statistical difference in SmO2 by gender or location when multiple sensors were evaluated on the right and left calf, deltoid, and thigh of resting men and women (N = 33). SmO2 precision for subjects at rest was 5.6% over the six locations with four different sensors.

The STOP the Bleeding Campaign

According to the World Health Organization, traumatic injuries worldwide are responsible for over 5 million deaths annually. Post-traumatic bleeding caused by traumatic injury-associated coagulopathy is the leading cause of potentially preventable death among trauma patients. Despite these facts, awareness of this problem is insufficient and treatment options are often unclear. The STOP the Bleeding Campaign therefore aims to increase awareness of the phenomenon of post-traumatic coagulopathy and its appropriate management by publishing European guidelines for the management of the bleeding trauma patient, by promoting and monitoring the implementation of these guidelines and by preparing promotional and educational material, organising activities and developing health quality management tools. The campaign aims to reduce the number of patients who die within 24 hours after arrival in the hospital due to exsanguination by a minimum of 20% within the next 5 years.

Ringer's malate solution protects against the multiple organ injury and dysfunction caused by hemorrhagic shock in rats

Malic acid, in the form of its anion malate, is a key intermediate in the major biochemical energy-producing cycle known as the citric acid or Krebs cycle. In this study, the authors investigated the protective effect of a novel crystalloid solution of Ringer's malate following fluid resuscitation of hemorrhagic shock using a rat model. Under general anesthesia, Sprague-Dawley male rats were subjected to 60 min of hemorrhagic shock (40 mmHg for 60 min) followed by crystalloid resuscitation. Groups were as follows: (1) sham shock, (2) normal saline, (3) Ringer's lactate, and (4) Ringer's malate. The experiment was terminated at 4 h after resuscitation. Mean arterial blood pressure (MAP) and blood biophysical parameters were monitored during the experiment. The alanine aminotransferase, aspartate aminotransferase, urea, creatinine, superoxide dismutase, and malondialdehyde levels in plasma were detected. The intestine, liver, lung, and renal histopathology were measured. It was found that Ringer's malate could increase MAP immediately and maintain MAP for a long time. Ringer's malate could reduce the level of alanine aminotransferase, aspartate aminotransferase, urea, and creatinine. At the same time, the activity of superoxide dismutase was increased, and the level of malondialdehyde was decreased. Histopathology indicated that Ringer's malate can protect against the multiple organ injury caused by hemorrhagic shock in rats. Ringer's malate prevented circulatory failure and alleviated multiple organ dysfunction syndrome in animals with hemorrhagic shock. The study suggests that Ringer's malate solution could be a potential novel therapeutic agent for fluid resuscitation.

Continuous measurement of cerebral oxygen saturation (rSO₂) for assessment of cardiovascular status during hemorrhagic shock in a swine model

BACKGROUND

Early trauma care is dependent on subjective assessments and sporadic vital sign assessments. We hypothesized that near-infrared spectroscopy-measured cerebral oxygenation (regional oxygen saturation [rSO₂]) would provide a tool to detect cardiovascular compromise during active hemorrhage. We compared rSO₂ with invasively measured mixed venous oxygen saturation (SvO₂), mean arterial pressure (MAP), cardiac output, heart rate, and calculated pulse pressure.

METHODS

Six propofol-anesthetized instrumented swine were subjected to a fixed-rate hemorrhage until cardiovascular collapse. rSO₂ was monitored with noninvasively measured cerebral oximetry; SvO₂ was measured with a fiber optic pulmonary arterial catheter. As an assessment of the time responsiveness of each variable, we recorded minutes from start of the hemorrhage for each variable achieving a 5%, 10%, 15%, and 20% change compared with baseline.

RESULTS

Mean time to cardiovascular collapse was 35 minutes ± 11 minutes (54 ± 17% total blood volume). Cerebral rSO₂ began a steady decline at an average MAP of 78 mm Hg ± 17 mm Hg, well above the expected autoregulatory threshold of cerebral blood flow. The 5%, 10%, and 15% decreases in rSO₂ during hemorrhage occurred at a similar times to SvO₂, but rSO₂ lagged 6 minutes behind the equivalent percentage decreases in MAP. There was a higher correlation between rSO₂ versus MAP (R² =0.72) than SvO₂ versus MAP (R² =0.55).

CONCLUSIONS

Near-infrared spectroscopy-measured rSO₂ provided reproducible decreases during hemorrhage that were similar in time course to invasively measured cardiac output and SvO₂ but delayed 5 to 9 minutes compared with MAP and pulse pressure. rSO₂ may provide an earlier warning of worsening hemorrhagic shock for prompt interventions in patients with trauma when continuous arterial BP measurements are unavailable.

The use of the Revised Trauma Score as an entry criterion in traumatic hemorrhagic shock studies: data from the DCLHb clinical trials

INTRODUCTION

The Revised Trauma Score (RTS) has been proposed as an entry criterion to identify patients with mid-range survival probability for traumatic hemorrhagic shock studies.

HYPOTHESIS/PROBLEM

Determination of which of four RTS strata (1-3.99, 2-4.99, 1-4.99, and 2-5.99) identifies patients with predicted and actual mortality rates near 50% for use as an entry criterion in traumatic hemorrhagic shock clinical trials.

METHODS

Existing database analysis in which demographic and injury severity data from two prior international Diaspirin Cross-Linked Hemoglobin (DCLHb) clinical trials were used to identify an RTS range that could be an optimal entry criterion in order to find the population of trauma patients with mid-range predicted and actual mortality rates.

RESULTS

Of 208 study patients, the mean age was 37 years, 65% sustained blunt trauma, 49% received DCLHb, and 57% came from the European Union study arm. The mean values were: ISS, 31 (SD = 18); RTS, 5.6 (SD = 1.8); and Glasgow Coma Scale (GCS), 10.4 (SD = 4.8). The mean TRISS-predicted mortality was 34% and the actual 28-day mortality was 35%. The initially proposed 1-3.99 RTS range (n = 41) had the highest predicted (79%) and actual (71%) mortality rates. The 2-5.99 RTS range (n = 79) had a 62% predicted and 53% actual mortality, and included 76% blunt trauma patients. Removal of GCS <5 patients from this RTS 2-5.99 subgroup caused a 48% further reduction in eligible patients, leaving 41 patients (20% of 208 total patients), 66% of whom sustained a blunt trauma injury. This subgroup had 54% predicted and 49% actual mortality rates. Receiver operator curve (ROC) analysis found the GCS to be as predictive of mortality as the RTS, both in the total patient population and in the RTS 2-5.99 subgroup.

CONCLUSION

The use of an RTS 2-5.99 inclusion criterion range identifies a traumatic hemorrhagic shock patient subgroup with predicted and actual mortality that approach the desired 50% rate. The exclusion of GCS <5 from this RTS 2-5.99 subgroup patients yields a smaller, more uniform patient subgroup whose mortality is more likely related to hemorrhagic shock than traumatic brain injury. Future studies should examine whether the RTS or other physiologic criteria such as the GCS score are most useful as traumatic hemorrhagic shock study entry criteria.

Computational analysis of intersubject variability and thrombin generation in dilutional coagulopathy

BACKGROUND

Blood dilution is a frequent complication of massive transfusion during trauma and surgery. This article investigates the quantitative effects of blood plasma dilution on thrombin generation in the context of intersubject variability.

STUDY DESIGN AND METHODS

A thoroughly validated computational model was used to simulate thrombin generation curves for 472 healthy subjects in the Leiden Thrombophilia Study. Individual thrombin curves were calculated for undiluted blood and for different dilution scenarios. For every such curve, five standard quantitative parameters of thrombin generation were calculated and analyzed.

RESULTS

Thrombin generation parameters in diluted blood plasma displayed significant intersubject variability (with a coefficient of variation up to approx. 28%). Nevertheless, dilutional effects in the majority (or all) of the subjects in the study group were characterized by persistent patterns. In particular, the largest dilution-induced change typically occurred in the maximum slope (MS) of the thrombin curve, followed by a change in thrombin peak height (PH), whereas the smallest change often occurred in the area under the curve. The identified patterns demonstrated considerable robustness to variations in dilution scenario and tissue factor concentration.

CONCLUSION

Dilutional effects on thrombin generation in a human population can be predicted from trends identified for the "average" subject and then refined by performing an analysis of actual subjects in the study group. The MS and PH are dilution indicators that are both sensitive and reliable across a large subject group and could potentially be used as disease markers in the diagnosis of coagulopathic conditions.