Superimposed traumatic brain injury modulates vasomotor responses in third-order vessels after hemorrhagic shock

The reverse shock index multiplied by Glasgow coma scale (rSIG) is predictive of mortality in trauma patients according to age

OBJECTIVE

The role of reverse shock index multiplied Glasgow coma scale (rSIG) in patients post-trauma with traumatic brain injury (TBI) has not yet been defined well. Our study aimed to investigate the predictive performance of rSIG according to age group.

METHOD

This is a prospective multi-national and multi-center cohort study using Pan-Asian Trauma Outcome Study registry in Asian-Pacific, conducted on patients post-trauma who visited participating hospitals. The main exposure was low rSIG measured at emergency department. The main outcome was in-hospital mortality. We performed multilevel logistic regression analysis to estimate the association low rSIG and study outcomes. Interaction analysis between rSIG and age group were also conducted.

RESULTS

Low rSIG was significantly associated with an increase in in-hospital mortality in patients post-trauma with and without TBI (aOR (95% CI): 1.49 (1.04-2.13) and 1.71 (1.16-2.53), respectively). The ORs for in-hospital mortality differed according to the age group in patients post-trauma with TBI (1.72 (1.44-1.94) for the young group and 1.13 (1.07-1.52) for the old group; p < 0.05).

CONCLUSION

Low rSIG is associated with an increase in in-hospital mortality in adult patients post-trauma. However, in patients with TBI, the prediction of mortality is significantly better in younger patient group.

POLYDATIN AMELIORATES TRAUMATIC BRAIN INJURY-INDUCED SECONDARY BRAIN INJURY BY INHIBITING NLRP3-INDUCED NEUROINFLAMMATION ASSOCIATED WITH SOD2 ACETYLATION

ABSTRACT

Traumatic brain injury (TBI) is a kind of disease with high morbidity, mortality, and disability, and its pathogenesis is still unclear. Research shows that nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) activation in neurons and astrocytes is involved in neuroinflammatory cascades after TBI. What is more, polydatin (PD) has been shown to have a protective effect on TBI-induced neuroinflammation, but the mechanisms remain unclear. Here, we speculated that PD could alleviate TBI-induced neuroinflammatory damage through the superoxide dismutase (SOD2)-NLRP3 signal pathway, and SOD2 might regulate NLRP3 inflammasome activation. The model of lateral fluid percussion for in vivo and cell stretching injury for in vitro were established to mimic TBI. NLRP3 chemical inhibitor MCC950, SOD2 inhibitor 2-methoxyestradiol, and PD were administered immediately after TBI. As a result, the expression of SOD2 acetylation (SOD2 Ac-K122), NLRP3, and cleaved caspase-1 were increased after TBI both in vivo and in vitro , and using SOD2 inhibitor 2-methoxyestradiol significantly promoted SOD2 Ac-K122, NLRP3, and cleaved caspase-1 expression, as well as exacerbated mitochondrial ROS (mtROS) accumulation and mitochondrial membrane potential (MMP) collapse in PC12 cells. However, using NLRP3 inhibitor MCC950 significantly inhibited cleaved caspase-1 activation after TBI both in vivo and in vitro ; meanwhile, MCC950 inhibited mtROS accumulation and MMP collapse after TBI. More importantly, PD could inhibit the level of SOD2 Ac-K122, NLRP3, and cleaved caspase-1 and promote the expression of SOD2 after TBI both in vivo and in vitro. Polydatin also inhibited mtROS accumulation and MMP collapse after stretching injury. These results indicated that PD inhibited SOD2 acetylation to alleviate NLRP3 inflammasome activation, thus acting a protective role against TBI neuroinflammation.

The role of S100B/RAGE-enhanced ADAM17 activation in endothelial glycocalyx shedding after traumatic brain injury

Background

Traumatic brain injury (TBI) remains one of the main causes for disability and death worldwide. While the primary mechanical injury cannot be avoided, the prevention of secondary injury is the focus of TBI research. Present study aimed to elucidate the effects and mechanisms of S100B and its receptor RAGE on mediating secondary injury after TBI.

Methods

This study established TBI animal model by fluid percussion injury in rats, cell model by stretch-injured in astrocytes, and endothelial injury model with conditioned medium stimulation. Pharmacological intervention was applied to interfere the activities of S100B/RAGE/ADAM17 signaling pathway, respectively. The expressions or contents of S100B, RAGE, syndecan-1 and ADAM17 in brain and serum, as well as in cultured cells and medium, were detected by western blot. The distribution of relative molecules was observed with immunofluorescence.

Results

We found that TBI could activate the release of S100B, mostly from astrocytes, and S100B and RAGE could mutually regulate their expression and activation. Most importantly, present study revealed an obvious increase of syndecan-1 in rat serum or in endothelial cultured medium after injury, and a significant decrease in tissue and in cultured endothelial cells, indicating TBI-induced shedding of endothelial glycocalyx. The data further proved that the activation of S100B/RAGE signaling could promote the shedding of endothelial glycocalyx by enhancing the expression, translocation and activity of ADAM17, an important sheddase, in endothelial cells. The damage of endothelial glycocalyx consequently aggravated blood brain barrier (BBB) dysfunction and systemic vascular hyper-permeability, overall resulting in secondary brain and lung injury.

Conclusions

TBI triggers the activation of S100B/RAGE signal pathway. The regulation S100B/RAGE on ADAM17 expression, translocation and activation further promotes the shedding of endothelial glycocalyx, aggravates the dysfunction of BBB, and increases the vascular permeability, leading to secondary brain and lung injury. Present study may open a new corridor for the more in-depth understanding of the molecular processes responsible for cerebral and systemic vascular barrier impairment and secondary injury after TBI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02412-2.

Polydatin alleviates severe traumatic brain injury induced acute lung injury by inhibiting S100B mediated NETs formation

Severe traumatic brain injury (sTBI)-induced acute lung injury (sTBI-ALI) is regarded as the most common complication of sTBI that is an independent predictor of poor outcomes in patients with sTBI and strongly increases sTBI mortality. Polydatin (PD) has been shown to have a potential therapeutic effect on sTBI-induced neurons injury and sepsis-induced acute lung injury (ALI), therefore, it is reasonable to believe that PD has a protective effect on sTBI-ALI. Here, to clarify the PD protective effect following sTBI-ALI, a rat brain injury model of lateral fluid percussion was established to mimic sTBI. As a result, sTBI induced ALI, and caused an increasing of wet/dry weight ratio and lung vascular permeability, as well as sTBI promoted oxidative stress response in the lung; sTBI caused inflammatory cytokines release, such as IL-6, IL-1β, TNF-α and MCP-1; and sTBI promoted NETs formation, mainly including an increasing expression of MPO, NE and CitH3. Simultaneously, sTBI induced a significant increase in the level of S100B; however, when inhibition of S100B, the expression of MPO, NE and CITH3 were significantly inhibited following sTBI. Inhibition of S100B also promoted lung vascular permeability recovery and alleviated oxidative stress response. Furthermore, PD treatmentreduced the pathological lung damage, promoted lung vascular permeability recovery, alleviated oxidative stress response and inflammatory cytokines release; more importantly, PD inhibited the expression of S100B, and NETs formation in the lung following sTBI. These results indicate that PD alleviates sTBI-ALI by inhibiting S100B mediated NETs formation. Thus, PD may be valuable in sTBI-ALI treatment.

Polydatin prevents the induction of secondary brain injury after traumatic brain injury by protecting neuronal mitochondria

Polydatin is thought to protect mitochondria in different cell types in various diseases. Mitochondrial dysfunction is a major contributing factor in secondary brain injury resulting from traumatic brain injury. To investigate the protective effect of polydatin after traumatic brain injury, a rat brain injury model of lateral fluid percussion was established to mimic traumatic brain injury insults. Rat models were intraperitoneally injected with polydatin (30 mg/kg) or the SIRT1 activator SRT1720 (20 mg/kg, as a positive control to polydatin). At 6 hours post-traumatic brain injury insults, western blot assay was used to detect the expression of SIRT1, endoplasmic reticulum stress related proteins and p38 phosphorylation in cerebral cortex on the injured side. Flow cytometry was used to analyze neuronal mitochondrial superoxide, mitochondrial membrane potential and mitochondrial permeability transition pore opened. Ultrastructural damage in neuronal mitochondria was measured by transmission electron microscopy. Our results showed that after treatment with polydatin, release of reactive oxygen species in neuronal mitochondria was markedly reduced; swelling of mitochondria was alleviated; mitochondrial membrane potential was maintained; mitochondrial permeability transition pore opened. Also endoplasmic reticulum stress related proteins were inhibited, including the activation of p-PERK, spliced XBP-1 and cleaved ATF6. SIRT1 expression and activity were increased; p38 phosphorylation and cleaved caspase-9/3 activation were inhibited. Neurological scores of treated rats were increased and the mortality was reduced compared with the rats only subjected to traumatic brain injury. These results indicated that polydatin protectrd rats from the consequences of traumatic brain injury and exerted a protective effect on neuronal mitochondria. The mechanisms may be linked to increased SIRT1 expression and activity, which inhibits the p38 phosphorylation-mediated mitochondrial apoptotic pathway. This study was approved by the Animal Care and Use Committee of the Southern Medical University, China (approval number: L2016113) on January 1, 2016.

Analysis of skeletal muscle microcirculation in a porcine polytrauma model with haemorrhagic shock

Polytraumatised patients with haemorrhagic shock are prone to develop systemic complications, such as SIRS (systemic inflammatory response syndrome), ARDS (acute respiratory distress syndrome) and MOF (multiple organ failure). The pathomechanism of severe complications following trauma is multifactorial, and it is believed that microcirculatory dysfunction plays an important role. The aim of this study was to determine the changes in the microcirculation in musculature over time during shock and subsequent resuscitation in a porcine model of haemorrhagic shock and polytrauma. Twelve pigs (German Landrace) underwent femur fracture, liver laceration, blunt chest trauma, and haemorrhagic shock under standard anaesthesia and intensive care monitoring. Microcirculation data were measured from the vastus lateralis muscle using a combined white light spectrometry and laser spectroscopy system every 15 min during the shock and resuscitation period, and at 24, 48, and 72 h. Oxygen delivery and oxygen consumption were calculated and compared to baseline. The relative haemoglobin, local oxygen consumption, and saturation values in the microcirculation were observed significantly lower during shock, however, no changes in the microcirculatory blood flow and microcirculatory oxygen delivery were observed. After resuscitation, the microcirculatory blood flow and relative haemoglobin increased and remained elevated during the whole observation period (72 h). In this study, we observed changes in microcirculation during the trauma and shock phases. Furthermore, we also measured persistent dysfunction of the microcirculation over the observation period of 3 days after resuscitation and haemorrhagic shock. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1377-1382, 2018.

Microcirculatory Disorders and Protective Role of Xuebijing in Severe Heat Stroke

This study was conducted to explore underlying mechanism of microcirculation dysfunction and protectiverole of Xuebijing in heat stroke. Forty rats were divided into: control, vehicle + heat stress (HS), superoxide dismutase (SOD) + HS, and Xuebijing + HS groups. Rats in heat stress groups were subjected to continuous heat stress in infant incubator 1 h after tail vein injection of the tested compound and spinotrapezius preparation. Velocity of blood flow through micro-vessels and vascular diameter were detected in real time. Another 27 rats were divided into: vehicle, SOD, and Xuebijing groups, then further divided into three subgroups each: control, Tcore = 38 °C, Tcore = 41 °C. Rats were sacrificed, and spinotrapezius single-cell suspensions were prepared for detecting SOD and reactive oxygen species (ROS). The results showed that heat stress decreased SOD activity, increased ROS levels, and reduced the blood flow rate. Xuebijing increased SOD activity, decreased ROS levels and exhibited a protective effect in terms of blood flow rate but was less protective than SOD. The survival time in Xuebijing + HS group was longer than that in vehicle group but shorter than that in SOD + HS group. The results suggested Xuebijing could decrease ROS levels and have protective effects in severe heat stroke.

Microcirculatory Disorders and Protective Role of Antioxidant in Severe Heat Stroke: A Rat Study

This study aims to examine microcirculation and systemic hemodynamic disturbances in severe heat stroke (HS). A total of 147 rats were divided into HS group (HS), pretreated with superoxide dismutase (SOD+HS) group, and pretreated with normal saline (NS+HS) group. Heat stress was induced by incubating the animals in certain temperatures. Blood flow and vascular reactivity were monitored dynamically with intravital microscopy. Pulmonary permeability was reflected by wet-to-dry weight ratio, the concentration of Evans Blue (EB), and histopathology of lung. The results showed that heat stress could induce blood flow rate reduced, and SOD exhibited better protective role in blood flow rate. The arteriolar reactivity threshold to norepinephrine was markedly reduced at core temperature of 41°C, but no significant decrease occurred in SOD+HS group. Water content and EB concentration in lung tissue in HS group were increased along with temperature rise. SOD treatment could attenuate those changes. The pathological lung injury caused by heat stress was also milder in SOD+HS group than that in other two groups. Mean arterial pressure decreased at early stages of heat stress, but there was no decrease in SOD+HS group. There was a significant body weight loss during heat stress in all groups. Survival time in SOD+HS group was longer than that in other two groups. These results suggest that microcirculation disturbance occurs not only at the early stage but also before systemic hemodynamic disorder, monitoring microcirculation following HS is of prognostic value, and intervention with antioxidative agents may have certain protecting effects in severe HS.

Inhibition of endoplasmic reticulum stress alleviates secondary injury after traumatic brain injury

Apoptosis after traumatic brain injury has been shown to be a major factor influencing prognosis and outcome. Endoplasmic reticulum stress may be involved in mitochondrial mediated neuronal apoptosis. Therefore, endoplasmic reticulum stress has become an important mechanism of secondary injury after traumatic brain injury. In this study, a rat model of traumatic brain injury was established by lateral fluid percussion injury. Fluorescence assays were used to measure reactive oxygen species content in the cerebral cortex. Western blot assays were used to determine expression of endoplasmic reticulum stress-related proteins. Hematoxylin-eosin staining was used to detect pathological changes in the cerebral cortex. Transmission electron microscopy was used to measure ultrastructural changes in the endoplasmic reticulum and mitochondria. Our results showed activation of the endoplasmic reticulum stress-related unfolded protein response. Meanwhile, both the endoplasmic reticulum stress response and mitochondrial apoptotic pathway were activated at different stages post-traumatic brain injury. Furthermore, pretreatment with the endoplasmic reticulum stress inhibitor, salubrinal (1 mg/kg), by intraperitoneal injection 30 minutes before injury significantly inhibited the endoplasmic reticulum stress response and reduced apoptosis. Moreover, salubrinal promoted recovery of mitochondrial function and inhibited activation of the mitochondrial apoptotic pathway post-traumatic brain injury. These results suggest that endoplasmic reticulum stress might be a key factor for secondary brain injury post-traumatic brain injury.

Hemorrhagic Shock and the Microvasculature

The microvasculature plays a central role in the pathophysiology of hemorrhagic shock and is also involved in arguably all therapeutic attempts to reverse or minimize the adverse consequences of shock. Microvascular studies specific to hemorrhagic shock were reviewed and broadly grouped depending on whether data were obtained on animal or human subjects. Dedicated sections were assigned to microcirculatory changes in specific organs, and major categories of pathophysiological alterations and mechanisms such as oxygen distribution, ischemia, inflammation, glycocalyx changes, vasomotion, endothelial dysfunction, and coagulopathy as well as biomarkers and some therapeutic strategies. Innovative experimental methods were also reviewed for quantitative microcirculatory assessment as it pertains to changes during hemorrhagic shock. The text and figures include representative quantitative microvascular data obtained in various organs and tissues such as skin, muscle, lung, liver, brain, heart, kidney, pancreas, intestines, and mesentery from various species including mice, rats, hamsters, sheep, swine, bats, and humans. Based on reviewed findings, a new integrative conceptual model is presented that includes about 100 systemic and local factors linked to microvessels in hemorrhagic shock. The combination of systemic measures with the understanding of these processes at the microvascular level is fundamental to further develop targeted and personalized interventions that will reduce tissue injury, organ dysfunction, and ultimately mortality due to hemorrhagic shock. Published 2018. Compr Physiol 8:61-101, 2018.

SIRT1 plays a neuroprotective role in traumatic brain injury in rats via inhibiting the p38 MAPK pathway

Traumatic brain injury (TBI) is a major cause of disability and death in patients who experience a traumatic injury. Mitochondrial dysfunction is one of the main factors contributing to secondary injury in TBI-associated brain damage. Evidence of compromised mitochondrial function after TBI has been, but the molecular mechanisms underlying the pathogenesis of TBI are not well understood. Silent information regulator family protein 1 (SIRT1), a member of the NAD⁺-dependent protein deacetylases, has been shown to exhibit neuroprotective activities in animal models of various pathologies, including ischemic brain injury, subarachnoid hemorrhage and several neurodegenerative diseases. In this study, we investigated whether SIRT1 also exert neuroprotective effect post-TBI, and further explored the possible regulatory mechanisms involved in TBI pathogenesis. A lateral fluid-percussion (LFP) brain injury model was established in rats to mimic the insults of TBI. The expression levels of SIRT1, p-p38, cleaved caspase-9 and cleaved caspase-3 were all markedly increased and reached a maximum at 12 h post-TBI. In addition, mitochondrial function was impaired, evidenced by the presence of swollen and irregularly shaped mitochondria with disrupted and poorly defined cristae, a relative increase of the percentage of neurons with low ΔΨm, the opening of mPTP, and a decrease in neuronal ATP content, especially at 12 h post-TBI. Pretreatment with the SIRT1 inhibitor sirtinol (10 mg/kg, ip) induced p-p38 activation, exacerbated mitochondrial damage, and promoted the activation of the mitochondrial apoptosis pathway. In contrast, pretreatment with the p38 inhibitor SB203580 (200 μg/kg, ip) significantly attenuated post-TBI-induced expression of both cleaved caspase-9 and cleaved caspase-3 and mitochondrial damage, whereas it had no effects on SIRT1 expression. Together, these results reveal that the 12 h after TBI may be a crucial time at which secondary damage occurs; the activation of SIRT1 expression and inhibition of the p38 MAPK pathway may play a neuroprotective role in preventing secondary damage post-TBI. For this reason, both SIRT1 and p38 are likely to be important targets to prevent secondary damage post-TBI.

Is the shock index based classification of hypovolemic shock applicable in multiple injured patients with severe traumatic brain injury?-an analysis of the TraumaRegister DGU®

BACKGROUND

A new classification of hypovolemic shock based on the shock index (SI) was proposed in 2013. This classification contains four classes of shock and shows good correlation with acidosis, blood product need and mortality. Since their applicability was questioned, the aim of this study was to verify the validity of the new classification in multiple injured patients with traumatic brain injury.

METHODS

Between 2002 and 2013, data from 40 888 patients from the TraumaRegister DGU^® were analysed. Patients were classified according to their initial SI at hospital admission (Class I: SI < 0.6, class II: SI ≥0.6 to <1.0, class III SI ≥1.0 to <1.4, class IV: SI ≥1.4). Patients with an additional severe TBI (AIS ≥ 3) were compared to patients without severe TBI.

RESULTS

16,760 multiple injured patients with TBI (AIS_head ≥3) were compared to 24,128 patients without severe TBI. With worsening of SI class, mortality rate increased from 20 to 53% in TBI patients. Worsening SI classes were associated with decreased haemoglobin, platelet counts and Quick's values. The number of blood units transfused correlated with worsening of SI. Massive transfusion rates increased from 3% in class I to 46% in class IV. The accuracy for predicting transfusion requirements did not differ between TBI and Non TBI patients.

DISCUSSION

The use of the SI based classification enables a quick assessment of patients in hypovolemic shock based on universally available parameters. Although the pathophysiology in TBI and Non TBI patients and early treatment methods such as the use of vasopressors differ, both groups showed an identical probability of recieving blood products within the respective SI class.

CONCLUSION

Regardless of the presence of TBI, the classification of hypovolemic shock based on the SI enables a fast and reliable assessment of hypovolemic shock in the emergency department. Therefore, the presented study supports the SI as a feasible tool to assess patients at risk for blood product transfusions, even in the presence of severe TBI.

Cardiovascular Effects of Shock and Trauma in Experimental Models. A Review

Experimental models of human pathology are useful guides to new approaches towards improving clinical and surgical treatments. A systematic search through PubMed using the syntax (shock) AND (trauma) AND (animal model) AND (cardiovascular) AND ("2010/01/01"[PDat]: "2015/12/31"[PDat]) found 88 articles, which were reduced by manual inspection to 43 entries. These were divided into themes and each theme is subsequently narrated and discussed conjointly. Taken together, these articles indicate that valuable information has been developed over the past 5 years concerning endothelial stability, mesenteric lymph, vascular reactivity, traumatic injuries, burn and sepsis. A surviving interest in hypertonic saline resuscitation still exists.

Clinical relevance of midline fluid percussion brain injury: Acute deficits, chronic morbidities and the utility of biomarkers

BACKGROUND

After 30 years of characterisation and implementation, fluid percussion injury (FPI) is firmly recognised as one of the best-characterised reproducible and clinically relevant models of TBI, encompassing concussion through diffuse axonal injury (DAI). Depending on the specific injury parameters (e.g. injury site, mechanical force), FPI can model diffuse TBI with or without a focal component and may be designated as mild-to-severe according to the chosen mechanical forces and resulting acute neurological responses. Among FPI models, midline FPI may best represent clinical diffuse TBI, because of the acute behavioural deficits, the transition to late-onset behavioural morbidities and the absence of gross histopathology.

REVIEW

The goal here was to review acute and chronic physiological and behavioural deficits and morbidities associated with diffuse TBI induced by midline FPI. In the absence of neurodegenerative sequelae associated with focal injury, there is a need for biomarkers in the diagnostic, prognostic, predictive and therapeutic approaches to evaluate outcomes from TBI.

CONCLUSIONS

The current literature suggests that midline FPI offers a clinically-relevant, validated model of diffuse TBI to investigators wishing to evaluate novel therapeutic strategies in the treatment of TBI and the utility of biomarkers in the delivery of healthcare to patients with brain injury.

Role of Microvascular Disruption in Brain Damage from Traumatic Brain Injury

Traumatic brain injury (TBI) is acquired from an external force, which can inflict devastating effects to the brain vasculature and neighboring neuronal cells. Disruption of vasculature is a primary effect that can lead to a host of secondary injury cascades. The primary effects of TBI are rapidly occurring while secondary effects can be activated at later time points and may be more amenable to targeting. Primary effects of TBI include diffuse axonal shearing, changes in blood-brain barrier (BBB) permeability, and brain contusions. These mechanical events, especially changes to the BBB, can induce calcium perturbations within brain cells producing secondary effects, which include cellular stress, inflammation, and apoptosis. These secondary effects can be potentially targeted to preserve the tissue surviving the initial impact of TBI. In the past, TBI research had focused on neurons without any regard for glial cells and the cerebrovasculature. Now a greater emphasis is being placed on the vasculature and the neurovascular unit following TBI. A paradigm shift in the importance of the vascular response to injury has opened new avenues of drug-treatment strategies for TBI. However, a connection between the vascular response to TBI and the development of chronic disease has yet to be elucidated. Long-term cognitive deficits are common amongst those sustaining severe or multiple mild TBIs. Understanding the mechanisms of cellular responses following TBI is important to prevent the development of neuropsychiatric symptoms. With appropriate intervention following TBI, the vascular network can perhaps be maintained and the cellular repair process possibly improved to aid in the recovery of cellular homeostasis.

The impact of severe traumatic brain injury on a novel base deficit- based classification of hypovolemic shock

Background

Recently, our group has proposed a new classification of hypovolemic shock based on the physiological shock marker base deficit (BD). The classification consists of four groups of worsening BD and correlates with the extent of hypovolemic shock in severely injured patients. The aim of this study was to test the applicability of our recently proposed classification of hypovolemic shock in the context of severe traumatic brain injury (TBI).

Methods

Between 2002 and 2011, patients ≥16 years in age with an AIS_head ≥ 3 have been retrieved from the German TraumaRegister DGU® database. Patients were classified into four strata of worsening BD [(class I (BD ≤ 2 mmol/l), class II (BD > 2.0 to 6.0 mmol/l), class III (BD > 6.0 to 10 mmol/l) and class IV (BD > 10 mmol/l)] and assessed for demographic and injury characteristics as well as blood product transfusions and outcomes. The cohort of severely injured patients with TBI was compared to a population of all trauma patients to assess possible differences in the applicability of the BD based classification of hypovolemic shock.

Results

From a total of 23,496 patients, 10,201 multiply injured patients with TBI (AIS_head ≥ 3) could be identified. With worsening of BD, a consecutive increase of mortality rate from 15.9% in class I to 61.4% in class IV patients was observed. Simultaneously, injury severity scores increased from 20.8 (±11.9) to 41.6 (±17). Increments in BD paralleled decreasing hemoglobin, platelet counts and Quick’s values. The number of blood units transfused correlated with worsening of BD. Massive transfusion rates increased from 5% in class I to 47% in class IV. Between multiply injured patients with TBI and all trauma patients, no clinically relevant differences in transfusion requirement or massive transfusion rates were observed.

Conclusion

The presence of TBI has no relevant impact on the applicability of the recently proposed BD-based classification of hypovolemic shock. This study underlines the role of BD as a relevant clinical indicator of hypovolaemic shock during the initial assessment in respect to haemostatic resuscitation and transfusion requirements.