The Pathophysiology and Management of Hemorrhagic Shock in the Polytrauma Patient

Sex-related disparities in vehicle crash injury and hemodynamics

Objective

Multiple studies evaluate relative risk of female vs. male crash injury; clinical data may offer a more direct injury-specific evaluation of sex disparity in vehicle safety. This study sought to evaluate trauma injury patterns in a large trauma database to identify sex-related differences in crash injury victims.

Methods

Data on lap and shoulder belt wearing patients age 16 and up with abdominal and pelvic injuries from 2018 to 2021 were extracted from the National Trauma Data Bank for descriptive analysis using injuries, vital signs, International Classification of Disease (ICD) coding, age, and injury severity using AIS (Abbreviated Injury Scale) and ISS (Injury Severity Score). Multiple linear regression was used to assess the relationship of shock index (SI) and ISS, sex, age, and sex*age interaction. Regression analysis was performed on multiple injury regions to assess patient characteristics related to increased shock index.

Results

Sex, age, and ISS are strongly related to shock index for most injury regions. Women had greater overall SI than men, even in less severe injuries; women had greater numbers of pelvis and liver injuries across severity categories; men had greater numbers of injury in other abdominal/pelvis injury regions.

Conclusions

Female crash injury victims' tendency for higher (AIS) severity of pelvis and liver injuries may relate to how their bodies interact with safety equipment. Females are entering shock states (SI > 1.0) with lesser injury severity (ISS) than male crash injury victims, which may suggest that female crash patients are somehow more susceptible to compromised hemodynamics than males. These findings indicate an urgent need to conduct vehicle crash injury research within a sex-equity framework; evaluating sex-related clinical data may hold the key to reducing disparities in vehicle crash injury.

Sodium bicarbonate Ringer's solution for hemorrhagic shock: A meta-analysis comparing crystalloid solutions

BACKGROUND

The choice of fluid resuscitation in Traumatic Hemorrhagic shock (THS) remains a critical aspect of patient management. Bicarbonated Ringers solution (BRS) has shown promise due to its composition resembling human Extracellular Fluid and its potential benefits on hemodynamics.

OBJECTIVE

To evaluate the efficacy, mortality rates, hemodynamic effects, and adverse outcomes of Sodium Bicarbonate Ringer's Solution in the treatment of hemorrhagic shock, as compared to other relevant interventions.

METHOD

A comprehensive examination of the available literature was performed by conducting systematic searches in prominent databases such as Cochrane, EMBASE, MEDLINE, and PubMed. The process employed predefined criteria to extract relevant data and evaluate the quality of the studies. The outcome measures considered encompassed survival rates, mortality, mean arterial pressure (MAP), heart rate (HR), and adverse events.

RESULT

The meta-analysis of three studies showed that compared to the other crystalloids, the use of BRS had an odds ratio for survival of 1.86 (95% CI: 0.94, 3.71; p = 0.08; I2 = 0%), an odds ratio for total adverse events of 0.14 (95% CI: 0.06, 0.35; p < 0.0001; I2 = 22%), a mean difference in heart rate of -4.49 (95% CI: -7.55, -1.44; p = 0.004; I2 = 13%), and a mean difference in mean arterial pressure of 2.31 (95% CI: -0.85, 5.47; p = 0.15; I2 = 66%).

CONCLUSION

BRS demonstrated a significant reduction in complications, including adult respiratory distress syndrome (ARDS), Multiple Organ Dysfunction (MODS), and Total Adverse Effects, when compared to other solutions in the treatment of THS. Additionally, THS patients resuscitated with BRS experienced a notable decrease in heart rate. The findings suggest BRS may contribute to organ stability and potential survival improvement due to its similarity to human Extracellular Fluid and minimal impact on the liver.

Experimental study of a novel mouse model of tibial shaft fracture combined with blunt chest trauma

BACKGROUD

Thoracic Trauma and Limb Fractures Are the Two most Common Injuries in Multiple Trauma. However, there Is Still a Lack of Mouse Models of Trauma Combining Tibial Shaft Fracture (TSF) and Thoracic Trauma. In this Study, we Attempted to Develop a Novel Mouse Model of TSF Combined with Blunt Chest Trauma (BCT).

METHODS

A total of 84 C57BL/6J male mice were used as the multiple trauma model. BCT was induced by hitting the chests of mice with heavy objects, and TSF was induced by hitting the tibia of mice with heavy objects after intramedullary fixation. Serum specimens of mice were received by cardiac puncture at defined time points of 0, 6, 12, 24, 48, and 72 h.

RESULTS

Body weight and body temperature tended to decrease within 24 h after multiple trauma. Hemoglobin analyses revealed a decrease during the first 24 h after multiple trauma. Some animals died by cardiac puncture immediately after chest trauma. These animals exhibited the most severe pulmonary contusion and hemorrhage. The level of lung damage varied in diverse mice but was apparent in all animals. Classic hematoxylin and eosin (H&E)-stained paraffin pulmonary sections of mice with multiple trauma displayed hemorrhage and an immunoinflammatory reaction. Bronchoalveolar lavage fluid (BALF) and serum samples of mice with multiple trauma showed an upregulation of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-1α (TNF-1α) compared with the control group. Microimaging confirmed the presence of a tibia fracture and pulmonary contusion.

CONCLUSIONS

The novel mouse multiple trauma model established in this study is a common trauma model that shows similar pathological mechanisms and imaging characteristics in patients with multiple injuries. This study is useful for determining whether blockade or intervention of the cytokine response is beneficial for the treatment of patients with multiple trauma. Further research is needed in the future.

Is the shock index correlated with blood loss? An experimental study on a controlled hemorrhagic shock model in piglets

INTRODUCTION

The quantification of blood loss in a severe trauma patient allows prognostic quantification and the engagement of adapted therapeutic means. The Advanced Trauma Life Support classification of hemorrhagic shock, based in part on hemodynamic parameters, could be improved. The search for reproducible and non-invasive parameters closely correlated with blood depletion is a necessity. An experimental model of controlled hemorrhagic shock allowed us to obtain hemodynamic and echocardiographic measurements during controlled blood spoliation. The primary aim was to demonstrate the correlation between the Shock Index (SI) and blood depletion volume (BDV) during the hemorrhagic phase of an experimental model of controlled hemorrhagic shock in piglets. The secondary aim was to study the correlations between blood pressure (BP) values and BDV, SI and cardiac output (CO), and pulse pressure (PP) and stroke volume during the same phase.

METHODS

We analyzed data from 66 anesthetized and ventilated piglets that underwent blood spoliation at 2 mL.kg-1.min-1 until a mean arterial pressure (MAP) of 40 mmHg was achieved. During this bleeding phase, hemodynamic and echocardiographic measurements were performed regularly.

RESULTS

The correlation coefficient between the SI and BDV was 0.70 (CI 95%, [0.64; 0.75]; p < 0.01), whereas between MAP and BDV, the correlation coefficient was -0.47 (CI 95%, [-0.55; -0.38]; p < 0.01). Correlation coefficient between SI and CO and between PP and stroke volume were - 0.45 (CI 95%, [-0.53; -0.37], p < 0.01) and 0.62 (CI 95%, [0.56; 0.67]; p < 0.01), respectively.

CONCLUSIONS

In a controlled hemorrhagic shock model in piglets, the correlation between SI and BDV seemed strong.

Can a Therapeutic Strategy for Hypotension Improve Cerebral Perfusion and Oxygenation in an Experimental Model of Hemorrhagic Shock and Severe Traumatic Brain Injury?

BACKGROUND

Restoration of brain tissue perfusion is a determining factor in the neurological evolution of patients with traumatic brain injury (TBI) and hemorrhagic shock (HS). In a porcine model of HS without neurological damage, it was observed that the use of fluids or vasoactive drugs was effective in restoring brain perfusion; however, only terlipressin promoted restoration of cerebral oxygenation and lower expression of edema and apoptosis markers. It is unclear whether the use of vasopressor drugs is effective and beneficial during situations of TBI. The objective of this study is to compare the effects of resuscitation with saline solution and terlipressin on cerebral perfusion and oxygenation in a model of TBI and HS.

METHODS

Thirty-two pigs weighing 20-30 kg were randomly allocated into four groups: control (no treatment), saline (60 ml/kg of 0.9% NaCl), terlipressin (2 mg of terlipressin), and saline plus terlipressin (20 ml/kg of 0.9% NaCl + 2 mg of terlipressin). Brain injury was induced by lateral fluid percussion, and HS was induced through pressure-controlled bleeding, aiming at a mean arterial pressure (MAP) of 40 mmHg. After 30 min of circulatory shock, resuscitation strategies were initiated according to the group. The systemic and cerebral hemodynamic and oxygenation parameters, lactate levels, and hemoglobin levels were evaluated. The data were subjected to analysis of variance for repeated measures. The significance level established for statistical analysis was p < 0.05.

RESULTS

The terlipressin and saline plus terlipressin groups showed an increase in MAP that lasted until the end of the experiment (p < 0.05). There was a notable increase in intracranial pressure in all groups after starting treatment for shock. Cerebral perfusion pressure and cerebral oximetry showed no improvement after hemodynamic recovery in any group. The groups that received saline at resuscitation had the lowest hemoglobin concentrations after treatment.

CONCLUSIONS

The treatment of hypotension in HS with saline and/or terlipressin cannot restore cerebral perfusion or oxygenation in experimental models of HS and severe TBI. Elevated MAP raises intracranial pressure owing to brain autoregulation dysfunction caused by TBI.

Prehospital mSOFA Score for Quick Prediction of Life-Saving Interventions and Mortality in Trauma Patients: A Prospective, Multicenter, Ambulance-based, Cohort Study

Background: Prehospital emergency medical services (EMS) are the main gateway for trauma patients. Recent advances in point-of-care testing and the development of early warning scores have allowed EMS to improve patient classification. We aimed to identify patients presenting with major trauma involving life-saving interventions (LSI) using the modified Sequential Organ Failure Assessment (mSOFA) score in the prehospital scenario, and to compare these results with those of other trauma scores. Methods: This was a prospective, ambulance-based, multicenter, training-validation study in trauma patients who were treated in a prehospital setting and subsequently transported to a hospital. The study involved six Advanced Life Support units, 38 Basic Life Support units, and four hospitals. The primary outcome was LSI performed at the scene or en route and intensive care unit (ICU) admission and all-cause two-day in-hospital mortality. We collected epidemiological variables, creatinine, lactate, base excess, international normalized ratio, and vital signs. Discriminative power (area under the receiver operating characteristic curve [AUC]), calibration (observed vs predicted outcome agreement), and decision-curve analysis (DCA, clinical utility) were used to assess the reliability of the mSOFA in comparison to other scores. Results: Between January 1, 2020-April 30, 2022, a total of 763 patients were selected. The mSOFA score's AUC was 0.927 (95% confidence interval [CI] 0.898-0.957) for LSI, 0.845 (95% CI 0.808-0.882) for ICU admission, and 0.979 (95% CI 0.966-0.991) for two-day mortality. Conclusion: The mSOFA score outperformed the other scores, allowing a quick identification of high-risk patients. The routine implementation in EMS of mSOFA could provide critical support in the decision-making process in time-dependent trauma injuries.

Effects of Vasopressin Receptor Agonists during the Resuscitation of Hemorrhagic Shock: A Systematic Review and Meta-Analysis of Experimental and Clinical Studies

BACKGROUND

The clinical impact of vasopressin in hemorrhagic shock remains largely unknown.

OBJECTIVE

This systematic review and meta-analysis was designed to investigate the effects of vasopressin receptor agonists during the resuscitation of hemorrhagic shock.

METHODS

A systematic search of PubMed (MEDLINE), Scopus, and PubMed Central was conducted for relevant articles. Experimental (animal) and clinical studies were included. The primary objective was to investigate the correlation of vasopressin receptor agonist use with mortality and various hemodynamic parameters.

RESULTS

Data extraction was possible in thirteen animal studies and two clinical studies. Differences in risk of mortality between patients who received a vasopressin receptor agonist were not statistically significant when compared to those who were not treated with such agents [RR (95% CI): 1.17 (0.67, 2.08); p = 0.562; I² = 50%]. The available data were insufficient to conduct a meta-analysis assessing the effect of vasopressin receptor agonists on hemodynamics. Drawing safe conclusions from animal studies was challenging, due to significant heterogeneity in terms of species and dosage of vasopressin receptor agonists among studies.

CONCLUSIONS

Differences in risk of mortality between patients who received a vasopressin receptor agonist were not statistically significant when compared to those who were not treated with such agents after hemorrhagic shock. More data are needed to deduce certain conclusions.

VASCULAR-PLATELET HEMOSTASIS OF INJURED PATIENTS: PROSPECTIVE OBSERVATIONAL STUDY

OBJECTIVE

The aim: We study vascular-platelet hemostasis peculiarities in patients with severe trauma.

PATIENTS AND METHODS

Materials and methods: We included 50 patients, who were divided into control (n=15) and study (n=35) groups. The control group included patients without traumatic injuries, study group - patients with severe trauma. The study group was divided into the I subgroup (patients received 1 g tranexamic acid IV at the prehospital stage), and the II subgroup (1 g tranexamic acid IV after hospital admission).

RESULTS

Results: The main changes in the I subgroup started on the 3rd day, while in the II subgroup - on the 1st day. Patients of both subgroups on the 1st and 3rd days had a normal number of platelets in venous blood, however, on the 3rd day, there was a decreasing level of discocytes whereas the level of discoechinocytes, spherocytes, spheroechinocytes, and the sum of active forms of platelets were increased in comparison with the control group (p<0.05).

CONCLUSION

Conclusions: The changes in vascular-platelet hemostasis in patients appeared in the I subgroup on the 3rd day, while in the II subgroup - on the 1st day. For the I subgroup was the decreasing level of discocytes, whereas the level of discoechinocytes, spherocytes, spheroechinocytes, and the sum of active forms of platelets were increased. For the II subgroup on the 1st day, there was an increasing sum of active forms of platelets, on the 3rd day - the level of discocytes was decreased, and levels of discoechinocytes, spherocytes, spheroechinocytes, and the sum of active forms of platelets were increased.

Risks in the Management of Polytrauma Patients: Clinical Insights

Polytrauma, a patient's condition with multiple injuries that involve multiple organs or systems, is the leading cause of mortality in young adults. Trauma-related injuries are a major public health concern due to their associated morbidity, high disability, associated death, and socioeconomic consequences. Management of polytrauma patients has evolved over the last few decades due to the development of trauma systems, improved pre-hospital assessment, transport and in-hospital care supported by complementary investigations. Recognising the mortality patterns in trauma has led to significant changes in the approach to managing these patients. A structured approach with application of advanced trauma life support (ATLS) algorithms and optimisation of care based on clinical and physiological parameters has led to the development of early appropriate care (EAC) guidelines to treat these patients, with subsequent improved outcomes in such patients. The journey of a polytrauma patient through the stages of pre-hospital care, emergency resuscitation, in-hospital stabilization and rehabilitation pathway can be associated with risks at any of these phases. We describe the various risks that can be anticipated during the management of polytrauma patients at different stages and provide clinical insights into early recognition and effective treatment of these to improve clinical outcomes.

Management of Hemorrhagic Shock: Physiology Approach, Timing and Strategies

Hemorrhagic shock (HS) management is based on a timely, rapid, definitive source control of bleeding/s and on blood loss replacement. Stopping the hemorrhage from progressing from any named and visible vessel is the main stem fundamental praxis of efficacy and effectiveness and an essential, obligatory, life-saving step. Blood loss replacement serves the purpose of preventing ischemia/reperfusion toxemia and optimizing tissue oxygenation and microcirculation dynamics. The "physiological classification of HS" dictates the timely management and suits the 'titrated hypotensive resuscitation' tactics and the 'damage control surgery' strategy. In any hypotensive but not yet critical shock, the body's response to a fluid load test determines the cut-off point between compensation and progression between the time for adopting conservative treatment and preparing for surgery or rushing to the theater for rapid bleeding source control. Up to 20% of the total blood volume is given to refill the unstressed venous return volume. In any critical level of shock where, ab initio, the patient manifests signs indicating critical physiology and impending cardiac arrest or cardiovascular accident, the balance between the life-saving reflexes stretched to the maximum and the insufficient distal perfusion (blood, oxygen, and substrates) remains in a liable and delicate equilibrium, susceptible to any minimal change or interfering variable. In a cardiac arrest by exsanguination, the core of the physiological issue remains the rapid restoration of a sufficient venous return, allowing the heart to pump it back into systemic circulation either by open massage via sternotomy or anterolateral thoracotomy or spontaneously after aorta clamping in the chest or in the abdomen at the epigastrium under extracorporeal resuscitation and induced hypothermia. This is the only way to prevent ischemic damage to the brain and the heart. This is accomplishable rapidly and efficiently only by a direct approach, which is a crush laparotomy if the bleeding is coming from an abdominal +/- lower limb site or rapid sternotomy/anterolateral thoracotomy if the bleeding is coming from a chest +/- upper limbs site. Without first stopping the bleeding and refilling the heart, any further exercise is doomed to failure. Direct source control via laparotomy/thoracotomy, with the concomitant or soon following venous refilling, are the two essential, initial life-saving steps.

ALTERATION OF AKT1-GSK3Β SIGNALING PATHWAY IN TRAUMA HEMORRHAGIC SHOCK PATIENTS

ABSTRACT

Trauma hemorrhagic shock (THS) is a major cause of death and disability worldwide. It is the leading cause of death with or without sepsis in approximately 50% of patients. In THS, there is an incidence of cellular apoptosis, which contributes majorly to cellular dysfunction, organ failure, and mortality. The Akt (protein kinase B) isoform, Akt1, and glycogen synthase kinase 3β (Akt1-GSK3β) signaling pathway controls cell survival and apoptosis. Deleterious consequences of alteration of this signaling system might lead to inflammation, cytokine storm, and other diseases. Hence, in the present study, we investigated the role of this signaling system by measuring the phosphorylation levels of Akt1-GSK3β. Here, we demonstrated that the downregulation of pAkt1 and upregulation of pGSK3β in THS were significantly associated with the severity of the shock, apoptosis of immune cells, altered glucose metabolism, inflammation, cytokine storm, hemostasis, and acidosis, causing mortality with or without sepsis. For the first time, this study shows that a dysregulated pAkt1-GSK3β pathway causes contrasting cell fates in THS, leading to trauma pathology. Hence, the delineation and the implications of this signaling system may provide a new important target for the treatment of THS. In addition, Akt activation may become a potential strategy for increasing the survival rate following THS.

Assessment of left ventricle myocardial deformation in a hemorrhagic shock swine model by two-dimensional speckle tracking echocardiography

BACKGROUND

Trauma-induced secondary cardiac injury has been associated with significant adverse cardiovascular events. Speckle tracking echocardiography is a novel technology that allows an accurate and reproducible cardiac structure and function assessment. We evaluated the left ventricle (LV) myocardial deformation by speckle tracking echocardiography in a hemorrhagic shock (HS) swine model.

METHODS

Seven healthy male Landrace pigs were included in this study. Severe HS was reached through three sequentially blood withdraws of 20% of estimated blood volume, and it was maintained for 60 minutes. Volume resuscitation was performed using all precollected blood volume. A 1.8- to 4.2-MHz phased-array transducer was used to acquire the two-dimensional echocardiography images. Strain measurements were obtained semiautomatically by wall motion tracking software. Results are presented as medians and interquartile ranges and compared using Wilcoxon rank-sum test. A p value of <0.05 was considered statistically significant.

RESULTS

The median weight was 32 (26.1-33) kg, and the median total blood volume withdrawn was 1,100 (1,080-1,190) mL. During the severe HS period, the median arterial systemic pressure was 39 (36-46) mm Hg, and the cardiac index was 1.7 (1.6-2.0) L/min/m 2 . There was statistically significant absolute decrease in the global longitudinal strain 2 hours postresuscitation comparing with the basal measurements (-9.6% [-10.7 to -8.0%] vs. -7.9% [-8.1 to -7.4%], p = 0.03). There were no statistically significant differences between the basal and 2 hours postresuscitation assessments in the invasive/noninvasive hemodynamic, other two-dimensional echocardiogram (LV ejection fraction, 49.2% [44-54.3%] vs. 53.2% [51.5-55%]; p = 0.09), and circumferential strain (-10.6% [-14.4 to -9.0%] vs. -8.5% [-8.6 to -5.2%], p = 0.06) parameters.

CONCLUSION

In this experimental swine model of controlled HS, LV global longitudinal strain analysis accurately characterizes the timing and magnitude of subclinical cardiac dysfunction associated with trauma-induced secondary cardiac injury.