Pathophysiology of polytrauma

Innate immune responses to trauma

Trauma can affect any individual at any location and at any time over a lifespan. The disruption of macrobarriers and microbarriers induces instant activation of innate immunity. The subsequent complex response, designed to limit further damage and induce healing, also represents a major driver of complications and fatal outcome after injury. This Review aims to provide basic concepts about the posttraumatic response and is focused on the interactive events of innate immunity at frequent sites of injury: the endothelium at large, and sites within the lungs, inside and outside the brain and at the gut barrier.

Plasma free carnitine in severe trauma: Influence of the association with traumatic brain injury

BACKGROUND

Metabolic response to severe trauma requires early nutritional resuscitation. Carnitine is essential for lipolysis, the energy source during this hypercatabolic phase. However l-carnitine is not present in nutritional replacement solutions. Furthermore, free carnitine depletion, defined as carnitine plasma level under 36μmol/L, was not adequately reported in adult patients with severe trauma. The aim of this study was to assess plasma free carnitine levels and factors of variation in severe trauma.

METHOD

Our observational study concerned 38 trauma patients including 18 with traumatic brain injury (TBI). On the third day after trauma, plasma free carnitine concentration was determined (by enzymatic method) while patients received artificial nutrition.

RESULTS

Low plasmatic free carnitine concentration was evidenced in 95% of the patients with a median value of 18μmol/L (11-47). Univariate analysis showed that mean arterial pressure, serum urea, CKD-EPI and patients with TBI were significantly associated with plasma free carnitine concentration less than 18μmol/L. Lower plasma free carnitine concentration was observed in the group of patients with TBI with 17.72μmol/L (11-36) versus 21.5μmol/L (11-47) for others patients (p=0.031). Logistic regression analysis showed that severe trauma with TBI and CKD-EPI above 94mL/min/1.73m2 appeared to be independent predictor of lower free carnitine plasmatic concentration (Goodness of fit=0.87 and AUC=0.89).

CONCLUSION

Our observations support hypotheses that plasma free carnitine concentration is lowered in severe injured patients especially for TBI patients and patients with estimated GFR above 94mL/min/1.73m².

Bone Marrow Mesenchymal Stem Cells Suppress Acute Lung Injury Induced by Lipopolysaccharide Through Inhibiting the TLR2, 4/NF-κB Pathway in Rats with Multiple Trauma

BACKGROUND

Multiple trauma normally leads to acute lung injury (ALI) and other multiple organ dysfunction syndrome (MODS). Finding effective treatments for ALI remains a medical as well as socioeconomic challenge. Several studies show that bone marrow mesenchymal stem cells (BMSCs) have the potent anti-inflammation activity and transfusion of BMSCs can effectively inhibit inflammatory and autoimmune diseases.

METHODS

In this study, we investigated the TLR2, 4/NF-κB signaling pathway to determine the therapeutic value of BMSCs on lipopolysaccharide (LPS)-induced ALI. To investigate the immunosuppression effects of BMSCs, rats subjected to multiple trauma were administrated with LPS to induce ALI and then treated with BMSCs. The histology of the lung was examined. Serum levels of the pro-inflammatory factors TNFα, interleukin (IL)-6, and IL-1β, as well as anti-inflammatory factor IL-10 were measured at 3, 6, 12, and 24 h after the treatment. Moreover, expressions of TLR2 and TLR4 at the mRNA and protein levels, as well as phosphorylation of p65 in the lungs, were assessed at these time points.

RESULTS

We found that BMSCs reduced inflammatory injury, inhibited LPS-induced upregulation of TLR2 and TLR4 expression at the mRNA and protein levels, and compromised p65 phosphorylation. In addition, infusion of BMSCs also downregulated the abundance of pro-inflammatory TNFα, IL-6, and IL-1β and upregulated the abundance of anti-inflammatory IL-10 levels in the serum.

CONCLUSIONS

Our results suggest that BMSCs suppress the inflammatory reactions through inhibition of the TLR2, 4 mediated NF-κB signal pathway, which hints that BMSCs can potentially be used to treat ALI in multiple trauma.

Plasma Levels of Receptor Interacting Protein Kinase-3 (RIP3), an Essential Mediator of Necroptosis, are Associated with Acute Kidney Injury in Critically Ill Trauma Patients

BACKGROUND

Receptor interacting protein kinase-3 (RIP3) is a key mediator of necroptosis, a form of regulated cell death recently implicated in murine models of renal ischemia-reperfusion injury and transfusion-associated endothelial injury. The importance of necroptosis in human AKI is unknown. We hypothesized that plasma RIP3 concentrations would be associated with acute kidney injury (AKI) after severe trauma.

METHODS

We performed a case-control study nested in a prospective cohort of critically ill trauma patients. AKI was defined by AKI Network creatinine criteria within 6 days of presentation. Of 158 cohort subjects, we selected 13 who developed AKI stage 2 or 3, 27 with AKI stage 1, and 40 without AKI. We compared plasma RIP3 concentrations across these groups at presentation and 48 h. Since red blood cell (RBC) transfusion is an AKI risk factor, we also tested the association of RBCs transfused during resuscitation with RIP3 levels.

RESULTS

Median plasma RIP3 concentration rose more than 10-fold from presentation (15.6 (interquartile range 15.6-41.3) pg/mL) to 48 h (164.7 (66.9-300.6) pg/mL; P <0.001). RIP3 concentrations at 48 h were associated with AKI stage (no AKI: 144.8 (58.6-234.9) pg/mL; AKI stage 1: 165.8 (43.0-310.9) pg/mL; AKI stage 2-3: 365.5 (155.1-727.5) pg/mL; P = 0.010) whereas this association was not seen at presentation (P = 0.324). RBC transfusions were also associated with 48-h plasma RIP3 (no RBCs: 99.4 (15.6-166.1) pg/mL; 1-5 units: 182.6 (98.5-274.1) pg/mL; >5 units: 341.8 (150.1-423.8) pg/mL; P <0.001).

CONCLUSIONS

In critically ill trauma patients, plasma levels of the necroptosis mediator RIP3 at 48 h were associated with AKI stage and RBC transfusions.

Thioredoxin-1 Increases Survival in Sepsis by Inflammatory Response Through Suppressing Endoplasmic Reticulum Stress

Sepsis is the main cause of death in critically ill patients, pathogenesis of which is still unclear. The nuclear factor κB (NF-κB) inflammatory signal pathway mediated by endoplasmic reticulum stress is involved in sepsis. Thioredoxin-1 (Trx-1) is an important protein of regulating oxidative stress. It plays a crucial role in the anti-oxidation, anti-apoptosis, and anti-inflammation. However, the role and the mechanism of Trx-1 in sepsis have not been extensively studied. In the present study, we showed that the survival was longer in sepsis induced by cecal ligation and puncture in Trx-1 overexpression transgenic (Tg) mice compared with wild-type mice. Wet/dry lung weight ratio was decreased in Trx-1 Tg mice. The levels of TNF-α and IL-1β in plasma and lung tissue were inhibited in Tg mice. The expressions of glucose-regulated protein 78, inositol-requiring enzyme 1α (IRE1α), tumor necrosis factor receptor-associated factor 2, C/EBP homologous protein, NF-κB, and inhibitors of NF-κBα were increased in lung tissue. More importantly, the overexpression of Trx-1 in transgenic mice suppressed NF-κB inflammatory signal pathway by inhibiting the activation of molecules involved in ER stress. Our results suggest that Trx-1 may play protective role in extending survival in sepsis by regulating inflammatory response through suppressing ER stress.

Using 3-Dimensional Modeling to Customize Titanium Plates for Repair of Chest Wall Trauma

BACKGROUND

Open reduction and internal fixation of rib fractures is recommended to decrease mortality, shorten the duration of mechanical ventilation, and lower hospital length of stay. Prosthetic titanium plates are frequently used to repair chest wall trauma, and are typically contoured to the patient's anatomy at the time of implant in the operating room. We describe the use of 3-dimensional (3D) digitally corrected rapid prototyping to generate a model of a patient's skeletal anatomy for the purposes of preoperative customization of standard titanium plates for fixation of rib fractures.

METHODS

A computed tomography imaging Digital Imaging and Communication in Medicine data set was segmented. Rib fractures were virtually realigned using the mirrored normal anatomy as a guide. The model was printed and used to customize titanium rib fixation plates prior to the procedure.

RESULTS

Preoperative shaping of 5 titanium plates using the final 3D model required a total of 5.65 minutes. Surgical fixation of 4 of the patient's 5 fractures was accomplished using the titanium plates that were preoperatively shaped using our 3D model.

DISCUSSION

We demonstrate successful use of a digitally rendered model to preoperatively customize standard titanium rib fixation plates. Compared with intraoperative contouring of rib fixation plates, we believe that this approach facilitates repair of complex rib fractures, saving time in the operating room. We believe this technique can improve the accuracy of reductions, increase the ease and efficiency of these procedures, and afford benefits in reducing surgical stress on patients who have already suffered significant trauma.

Epileptogenesis following experimentally induced traumatic brain injury - a systematic review

Traumatic brain injury (TBI) is a complex neurotrauma in civilian life and the battlefield with a broad spectrum of symptoms, long-term neuropsychological disability, as well as mortality worldwide. Posttraumatic epilepsy (PTE) is a common outcome of TBI with unknown mechanisms, followed by posttraumatic epileptogenesis. There are numerous rodent models of TBI available with varying pathomechanisms of head injury similar to human TBI, but there is no evidence for an adequate TBI model that can properly mimic all aspects of clinical TBI and the first successive spontaneous focal seizures follow a single episode of neurotrauma with respect to epileptogenesis. This review aims to provide current information regarding the various experimental animal models of TBI relevant to clinical TBI. Mossy fiber sprouting, loss of dentate hilar neurons along with recurrent seizures, and epileptic discharge similar to human PTE have been studied in fluid percussion injury, weight-drop injury, and cortical impact models, but further refinement of animal models and functional test is warranted to better understand the underlying pathophysiology of posttraumatic epileptogenesis. A multifaceted research approach in TBI model may lead to exploration of the potential treatment measures, which are a major challenge to the research community and drug developers. With respect to clinical setting, proper patient data collection, improved clinical trials with advancement in drug delivery strategies, blood-brain barrier permeability, and proper monitoring of level and effects of target drug are also important.

Mouse Injury Model of Polytrauma and Shock

Severe injury and shock remain major sources of morbidity and mortality worldwide. Immunologic dysregulation following trauma contributes to these poor outcomes. Few, if any, therapeutic interventions have benefited these patients, and this is due to our limited understanding of the host response to injury and shock. The Food and Drug Administration requires preclinical animal studies prior to any interventional trials in humans; thus, animal models of injury and shock will remain the mainstay for trauma research. However, adequate animal models that reflect the severe response to trauma in both the acute and subacute phases have been limited. Here we describe a novel murine model of polytrauma and shock that combines hemorrhagic shock, cecectomy, long bone fracture, and soft-tissue damage. This model produces an equivalent Injury Severity Score associated with adverse outcomes in humans, and may better recapitulate the human leukocyte, cytokine, transcriptomic, and overall inflammatory response following injury and hemorrhagic shock.

Nitric oxide elevation in polytrauma is driven by oxygen radicals

A common problem in management of polytrauma - a simultaneous injury to more than one organ or organ system, at least one of them lethal without intervention - is a discrepancy between a relatively good initial state and a serious subsequent development. Since nitric oxide (NO) is produced in high quantities during tissue injury, we assumed that serum levels of NO (and its oxidation products, NOx) might serve as a prognostic marker of polytrauma severity. However, we found recently that NOx was increased in polytrauma, but not in the most severe cases. The present study was undertaken to test the hypothesis that serum NOx is reduced in severe polytrauma by concomitant overproduction of reactive oxygen species (ROS). Polytrauma was induced in rats under anesthesia by bilateral fracture of femurs and tibiae plus incision of the right liver lobe through laparotomy. Serum NOx was measured by chemiluminescence after hot acidic reduction. The role of ROS was assessed by treatment with an antioxidant, N-acetyl-L-cysteine (NAC). Experimental polytrauma elevated NOx from 11.0+/-0.7 to 23.8+/-4.5 ppb. This was completely prevented by NAC treatment (9.1+/-2.2 ppb). Serum NOx is elevated in severe polytrauma, and this is not reduced by ROS. On the contrary, ROS are necessary for the NOx elevation, probably because ROS produced by inflammatory cells activated by the polytrauma induce massive NO production.

Early Definitive Fracture Fixation is Safely Performed in the Presence of an Open Abdomen in Multiply Injured Patients

OBJECTIVE

To investigate the safety and feasibility of performing definitive fracture fixation in multiply injured patients in the presence of an open abdomen after laparotomy.

DESIGN

Retrospective observational cohort study.

SETTING

Level-I academic trauma center.

PATIENTS

Adult polytrauma patients with the presence of an open abdomen after "damage control" laparotomy and associated major fractures of long bones, acetabulum, pelvis, or spine, requiring surgical repair (n = 81).

INTERVENTION

Timing of definitive fracture fixation in relation to the timing of abdominal wall closure.

MAIN OUTCOME MEASURE

Incidence of orthopedic surgical site infections.

RESULTS

During a 15-year time window from January 1, 2000 until December 31, 2014, we identified a cohort of 294 consecutive polytrauma patients with an open abdomen after laparotomy. Surgical fixation of associated fractures was performed after the index laparotomy in 81 patients. In group 1 (n = 32), fracture fixation occurred significantly sooner despite a concurrent open abdomen, compared with group 2 (n = 49) with abdominal wall closure before fixation (mean 4.4 vs. 11.8 days; P = 0.01). The incidence of orthopaedic surgical site infections requiring a surgical revision was significantly lower in group 1 (3.1%) compared to group 2 (30.6%; P = 0.002).

CONCLUSIONS

Definitive fracture fixation in the presence of an open abdomen is performed safely and associated with a significant decrease in clinically relevant surgical site infections, compared with delaying fracture fixation until abdominal wall closure. These data suggest that the strategy of imposing a time delay in orthopaedic procedures while awaiting abdominal wall closure is unjustified.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Global Gene Expression Change Induced by Major Thoracoabdominal Surgery

OBJECTIVE

To test the hypothesis that major thoracoabdominal surgery induces gene expression changes associated with adverse outcomes.

BACKGROUND

Widely different traumatic injuries evoke surprisingly similar gene expression profiles, but there is limited information on whether the iatrogenic injury caused by major surgery is associated with similar patterns.

METHODS

With informed consent, blood samples were obtained from 50 patients before and after open transhiatal esophagectomy or pancreaticoduodenectomy. Twelve cases with complicated recoveries (death, infection, venous thromboembolism) were matched with 12 cases with uneventful recoveries. Global gene expression was assayed using human microarray chips. A 2-fold change with a corrected P < 0.05 was considered differentially expressed.

RESULTS

In these 24 patients, 522 genes were differentially expressed after surgery; 248 (48%) were upregulated (innate immunity and inflammation) and 274 (52%) were downregulated [adaptive immunity (antigen presentation, T-cell function)]. Hierarchical clustering of the profile reliably predicted pre- and postoperative status. The within-patient change was 3.08 ± 0.91-fold. There was no measurable association with age, malignancy, procedure, surgery length, operative blood loss, or transfusion requirements, but was positively associated with postoperative infection (3.81 ± 0.97 vs 2.79 ± 0.73; P = 0.009) and hospital length of stay (r = 0.583, P = 0.003). Venous thromboembolism and mortality each occurred in one patient, thus no associations were possible.

CONCLUSIONS

Major surgery induces a quantifiable pattern of gene expression change that is associated with adverse outcome. This could reflect early impaired adaptive immunity and suggests potential therapeutic targets to improve postoperative recovery.

Alteration of Transthyretin Microheterogeneity in Serum of Multiple Trauma Patients

Transthyretin (TTR) which exists in various isoforms, is a valid marker for acute phase response and subclinical malnutrition. The aim of the study was to investigate the relationship between inflammation, oxidative stress and the occurrence of changes in microheterogeneity of TTR.

A prospective, observational study at a level-I trauma center of a large urban medical university was performed. Patients were severely injured (n = 18; injury severity score (ISS): 34–66), and were observed within the first 24 hours of admittance and over the following days until day 20 after injury. 20 healthy subjects, matched by age and sex, were used as controls.

TTR was enriched by immunoprecipitation. Microheterogeneity of TTR was determined by linear matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). Four major mass signals were observed for TTR representing native, S-cysteinylated, S-cysteinglycinylated and S-glutathionylated TTR. In the course of their ICU stay, 14 of the 18 patients showed a transient change in microheterogeneity in favour of the S-cysteinglycinylated form of TTR (p < 0.05 vs. controls). The occurrence of this variant was not associated with the severity of trauma or the intensity of the acute-phase response, but was associated with oxidative stress as evidenced by Trolox.

Our results demonstrate that changes in microheterogeneity of TTR occur in a substantial number of ICU trauma patients. The diagnostic values of these changes remains to be elucidated. It is speculated that TTR modification may well be the mechanism underlying the morphological manifestation of amyloidose or Alzheimer's diseases in patients surviving multiple trauma.

Frequency and perforin expression of different lymphocyte subpopulations in patients with lower limb fracture and thoracic injury

INTRODUCTION

Trauma with multiple injuries is associated with a high risk of complications, which may be related to excessive stimulation of inflammatory and anti-inflammatory responses. Although the effects of polytrauma on the immune response have been well established at the cellular and molecular levels, there is little information about the changes in the cytolytic potential of immunocompetent cells, including expression of cytotoxic molecules such as perforin. Therefore, the objective of the present study was to analyse and compare differences in the frequency and perforin expression of leukocyte subpopulations in the peripheral blood of patients with lower limb fracture, thoracic injury, and simultaneous lower limb fracture and thoracic injury.

PATIENTS AND METHODS

Forty-five patients with trauma injury (15 patients with lower limb injury, 15 patients with thoracic injury, and 15 patients with simultaneous lower limb and thoracic injury) were included in the study. Peripheral blood of 15 sex- and age-matched healthy volunteers served as the control group. Peripheral blood samples were taken from all subjects included in the study and peripheral blood mononuclear cells were isolated by gradient centrifugation. The frequency of T lymphocytes, natural killer (NK) and NK T cells, and their subsets, as well as their perforin expression levels were simultaneously detected and analysed by flow cytometry.

RESULTS

There was a statistically significant decrease in the frequency of T lymphocytes, NK and NK T cells as well as perforin expression in the patients with simultaneous lower limb and thoracic injury compared with the other two groups, with a predominantly marked decrease in NK and NK T cells.

CONCLUSION

The decrease in the frequency and cytotoxic potential of peripheral blood lymphocytes is related to the severity of trauma injury, which can explain the underlying mechanism contributing to complication occurrence.

Innate immunity and tolerance toward mitochondria

Mitochondria are intracellular organelles that originate from a bacterial symbiont, and they retain multiple features of this bacterial ancestry. The immune system evolved to detect the presence of invading pathogens, including bacteria, to eliminate them by a diversity of antimicrobial mechanisms and to mount long-term protective immunity. Due to their bacterial ancestry, mitochondria are sensed by the innate immune system, and trigger inflammatory responses comparable to those induced by pathogenic bacteria. In both cases, innate sensing mechanisms involve Toll-Like Receptors, Formyl Peptide Receptors, inflammasomes or the cGAS/STING pathway. Stressed mitochondria release mitochondrial molecules, such as cardiolipin and mitochondrial DNA, which are sensed as cellular damage potentially caused by infections. Recent research has identified several conditions in which mitochondrial stress-induced immunity is essential to effective antimicrobial defenses. But, in pathological conditions, the abnormal activation of the innate immune system by damaged mitochondria results in auto-inflammatory or autoimmune diseases. To prevent undesirable mitochondria-targeted responses, immune tolerance toward mitochondria must be established, involving regulation of mitophagy and mitochondrial permeability, as well as activation of specific nucleases and pro-apoptotic caspases. Overall, recent findings identify mitochondria as central in the induction of innate immunity, and provide new insights as to how immune responses to these multi-functional organelles might be exploited therapeutically in various disease states.

Neuroimmunology of Traumatic Brain Injury: Time for a Paradigm Shift

Traumatic brain injury (TBI) is a leading cause of morbidity and disability, with a considerable socioeconomic burden. Heterogeneity of pathoanatomical subtypes and diversity in the pathogenesis and extent of injury contribute to differences in the course and outcome of TBI. Following the primary injury, extensive and lasting damage is sustained through a complex cascade of events referred to as "secondary injury." Neuroinflammation is proposed as an important manipulable aspect of secondary injury in animal and human studies. Because neuroinflammation can be detrimental or beneficial, before developing immunomodulatory therapies, it is necessary to better understand the timing and complexity of the immune responses that follow TBI. With a rapidly increasing body of literature, there is a need for a clear summary of TBI neuroimmunology. This review presents our current understanding of the immune response to TBI in a chronological and compartment-based manner, highlighting early changes in gene expression and initial signaling pathways that lead to activation of innate and adaptive immunity. Based on recent advances in our understanding of innate immune cell activation, we propose a new paradigm to study innate immune cells following TBI that moves away from the existing M1/M2 classification of activation states toward a stimulus- and disease-specific understanding of polarization state based on transcriptomic and proteomic profiling.

Interleukin-17 as a predictor of sepsis in polytrauma patients: a prospective cohort study

Sepsis is one of the most serious complications after major trauma, and may be associated with increased mortality. We sought to determine whether there is an association between serum levels of interleukin-17 (IL-17) at the time of admission to the intensive care unit (ICU) and the development of sepsis. We evaluated 100 adult patients with major trauma admitted to the surgical ICU over a 6-month period. Serum levels of IL-17, IL-6, and TNF-α were determined by enzyme-linked immunosorbent assays (ELISA). The IL-17 rs1974226 genotype was determined by real-time PCR. In both non-adjusted and adjusted analyses, IL-17 was the only biomarker significantly associated with sepsis [median serum IL-17 of 72 pg/mL in sepsis versus 37 pg/mL in those without sepsis, P = 0.0001; adjusted odds ratio (OR) 3.2, P = 0.02]. No significant association was found among IL-17 rs1974226 genotypes and related serum cytokine levels. These data suggest that elevated serum IL-17 may increase the susceptibility for septic complications in polytrauma patients and so could be a useful biomarker for trauma patient management.

Auxiliary activation of the complement system and its importance for the pathophysiology of clinical conditions

Activation and regulation of the cascade systems of the blood (the complement system, the coagulation/contact activation/kallikrein system, and the fibrinolytic system) occurs via activation of zymogen molecules to specific active proteolytic enzymes. Despite the fact that the generated proteases are all present together in the blood, under physiological conditions, the activity of the generated proteases is controlled by endogenous protease inhibitors. Consequently, there is remarkable little crosstalk between the different systems in the fluid phase. This concept review article aims at identifying and describing conditions where the strict system-related control is circumvented. These include clinical settings where massive amounts of proteolytic enzymes are released from tissues, e.g., during pancreatitis or post-traumatic tissue damage, resulting in consumption of the natural substrates of the specific proteases and the available protease inhibitor. Another example of cascade system dysregulation is disseminated intravascular coagulation, with canonical activation of all cascade systems of the blood, also leading to specific substrate and protease inhibitor elimination. The present review explains basic concepts in protease biochemistry of importance to understand clinical conditions with extensive protease activation.

Mitochondrial dysfunction in rat splenocytes following hemorrhagic shock

The regulation of mitochondrial function is critical in cellular homeostasis following hemorrhagic shock. Hemorrhagic shock results in fluid loss and reduced availability of oxygen and nutrients to tissues. The spleen is a secondary lymphoid organ playing a key role in 'filtering the blood' and in the innate and adaptive immune responses. To understand the molecular basis of hemorrhagic shock, we investigated the changes in splenocyte mitochondrial respiration, and concomitant immune and metabolic alterations. The hemorrhagic injury (HI) in our rat model was induced by bleeding 60% of the total blood volume followed by resuscitation with Ringers lactate. Another group of animals was subjected to hemorrhage, but did not receive fluid resuscitation. Oxygen consumption rate of splenocytes were determined using a Seahorse analyzer. We found a significantly reduced oxygen consumption rate in splenocytes following HI compared to sham operated rats. The mitochondrial stress test revealed a decreased basal oxygen consumption rate, ATP production, maximal respiration and spare respiratory capacity. The mitochondrial membrane potential, and citrate synthase activity, were also reduced in the splenocytes following HI. Hypoxic response in the splenocyte was confirmed by increased gene expression of Hif1α. Elevated level of mitochondrial stress protein, hsp60 and induction of high mobility group box1 protein (HMGB1) were observed in splenocytes following HI. An increased inflammatory response was demonstrated by significantly increased expression of IL-6, IFN-β, Mip-1α, IL-10 and NFκbp65. In summary, we conclude that splenocyte oxidative phosphorylation and metabolism were severely compromised following HI.

Incidence and etiology of mortality in polytrauma patients in a Dutch level I trauma center

BACKGROUND

Earlier studies assessing mortality in polytrauma patients have focused on improving trauma care and reducing complications during hospital stay. The same studies have shown that the complication rate in these patients is high, often resulting in death. The aim of this study was to assess the incidence and causes of mortality in polytrauma patients in our institute. Secondarily, we assessed the donation and autopsy rates and outcome in these patients.

PATIENTS AND METHODS

All polytrauma patients (injury severity score≥16) transported to and treated in our institute during a period of 6 years were retrospectively analyzed. We included all patients who died during hospital stay. Prehospital and in-hospital data were collected on patients' condition, diagnostics, and treatment. The chance of survival was calculated according to the TRISS methodology. Patients were categorized according to the complications during treatment and causes of death. Logistic regression analysis was used to design a prediction model for mortality in major trauma. A statistical analysis was carried out.

RESULTS

Of the 1073 polytrauma patients who were treated in our institute during the study period, 205 (19.1%) died during hospital stay. The median age of the deceased patients was 58.8 years and 125 patients were men. Their mean injury severity score was 30.4. The most common mechanism of injury involved fall from height, followed by bicycle accidents. Almost 50% of the patients underwent an emergency intervention. Almost 92% of the total population died because of the effects of the accident (primary trauma). Of these, 24% died during primary assessment in the emergency department. Most patients died because of the effects of severe head injury (63.4%), followed by exsanguination (17.6%). The most common type of complications causing death during treatment was respiratory failure (6.3%), followed by multiple organ failure (1.5%). Autopsy was performed in 10.4%. Organ donation procedure was performed in 14.5%. Permission for donation was not provided in almost 20% of the population.

CONCLUSION

The mortality rate in polytrauma patients in our institute is considerable and comparable with the international literature. Most patients die because of the effects of the accident (primary trauma). Autopsy and organ donation rates are low in our institution and leave room for substantial improvements in the future.

Sepsis in the burn patient: a different problem than sepsis in the general population

Sepsis has recently been defined as "life-threatening organ dysfunction caused by a dysregulated host response to infection". A great amount of effort has been made to develop early treatments for sepsis through the Surviving Sepsis Campaign. There are similar but slightly different recommendations for the treatment of sepsis in the pediatric population. These international efforts have led to earlier diagnosis and treatments for sepsis that have led to improvements in survival. Sepsis is also the leading cause of death in the burn patient but most clinical sepsis studies have excluded burns. The reason for the exclusion is that the sepsis found in burn patients is different than that of the general population. The early treatment strategies, such as those directed by the Surviving Sepsis Campaign, focus on patients presenting to hospitals with recent signs of infection. Burn patients lose their primary barrier to infection, the skin, and thus the risk of infection persists as long as that barrier is absent. Efforts have been made to define sepsis, septic shock and infection in the burn population but there is constant need for revisions. One focus of this review is to discuss the differences in burn sepsis versus sepsis of the general population. Children often have profound responses to sepsis but can also make remarkable recoveries. This review will also explore problems specific to pediatric burns. The treatment of burns requires a continuous vigilance to watch for the subtle early signs of sepsis and then expeditious initiation of aggressive therapy. Strategies covering optimal management of pediatric burn sepsis will also be summarized.

The traumatic bone: trauma-induced heterotopic ossification

Heterotopic ossification (HO) is a common occurrence after multiple forms of extensive trauma. These include arthroplasties, traumatic brain and spinal cord injuries, extensive burns in the civilian setting, and combat-related extremity injuries in the battlefield. Irrespective of the form of trauma, heterotopic bone is typically endochondral in structure and is laid down via a cartilaginous matrix. Once formed, the heterotopic bone typically needs to be excised surgically, which may result in wound healing complications, in addition to a risk of recurrence. Refinements of existing diagnostic modalities, like micro- and nano-CT are being adapted toward early intervention. Trauma-induced HO is a consequence of aberrant wound healing, systemic and local immune system activation, infections, extensive vascularization, and innervation. This intricate molecular crosstalk culminates in activation of stem cells that initiate heterotopic endochondral ossification. Development of animal models recapitulating the unique traumatic injuries has greatly facilitated the mechanistic understanding of trauma-induced HO. These same models also serve as powerful tools to test the efficacy of small molecules which specifically target the molecular pathways underlying ectopic ossification. This review summarizes the recent advances in the molecular understanding, diagnostic and treatment modalities in the field of trauma-induced HO.

Early decreased neutrophil responsiveness is related to late onset sepsis in multitrauma patients: An international cohort study

Background

Severe trauma can lead to the development of infectious complications after several days, such as sepsis. Early identification of patients at risk will aid anticipating these complications. The aim of this study was to test the relation between the acute (<24 hours) inflammatory response after injury measured by neutrophil responsiveness and the late (>5 days) development of septic complications and validate this in different trauma populations.

Methods and findings

Two prospective, observational, cohort series in the Netherlands and South Africa, consisting of severely injured trauma patients. Neutrophil responsiveness by fMLF-induced active FcγRII was measured in whole blood flowcytometry, as read out for the systemic immune response within hours after trauma. Sepsis was scored daily. Ten of the 36 included Dutch patients developed septic shock. In patients with septic shock, neutrophils showed a lower expression of fMLF-induced active FcγRII immediately after trauma when compared to patients without septic shock (P = 0.001). In South Africa 11 of 73 included patients developed septic shock. Again neutrophils showed lower expression of fMLF induced active FcγRII (P = 0.001). In the combined cohort, all patients who developed septic shock demonstrated a decreased neutrophil responsiveness.

Conclusions

Low responsiveness of neutrophils for the innate stimulus fMLF immediately after trauma preceded the development of septic shock during admission by almost a week and did not depend on a geographical/racial background, hospital protocols and health care facilities. Decreased neutrophil responsiveness appears to be a prerequisite for septic shock after trauma. This might enable anticipation of this severe complication in trauma patients.

Granulocyte-Colony Stimulating Factor (G-CSF) Accelerates Wound Healing in Hemorrhagic Shock Rats by Enhancing Angiogenesis and Attenuating Apoptosis

Background

Following severe trauma, treatment of cutaneous injuries is often delayed by inadequate blood supply. The aim of the present study was to determine whether granulocyte-colony stimulating factor (G-CSF) protects endothelial cells (ECs) and enhances angiogenesis in a rat model of hemorrhagic shock (HS) combined with cutaneous injury after resuscitation.

Material/Methods

The HS rats with full-thickness defects were resuscitated and randomly divided into a G-CSF group (200 μg/kg body weight), a normal saline group, and a blank control group. Histological staining was to used estimate the recovery and apoptosis of skin. Apoptosis- and angiogenesis-related factors were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot (WB). Scratch assay, tube formation, and WB experiments were performed to verify the functional effects of G-CSF on HUVECs in vitro.

Results

H&E staining and Masson trichrome staining showed earlier inflammation resolution and collagen synthesis in the G-CSF-treated group. Angiogenesis-related factors were elevated at mRNA and protein levels. TUNEL staining suggested fewer apoptotic cells in the G-CSF group. The apoptotic-related factors were down-regulated and anti-apoptotic factors were up-regulated in the G-CSF-treated group. Scratch assay and tube formation experiments revealed that G-CSF facilitated migration ability and angiogenic potential of HUVECs. The angiogenic and anti-apoptotic effects were also enhanced in vitro.

Conclusions

Our results suggest that G-CSF after resuscitation attenuates local apoptosis and accelerates angiogenesis. These findings hold great promise for improving therapy for cutaneous injury in severe trauma and ischemia diseases.

Helping prometheus: liver protection in acute hemorrhagic shock

Acute hemorrhagic hypovolemic shock is caused by a significant high blood loss and leads to hemodynamic instability. The decrease in intravascular volume results in cellular hypoxia and finally in damage to organs such as the liver and the kidney. The liver plays a decisive role in the development or prevention of multiple organ failure after hemorrhagic shock. Despite the large number of experimental studies, the knowledge of pathophysiological mechanisms in the liver after hemorrhagic shock is incomplete. The aim of this mini review was to provide an overview of the pathophysiological changes in liver function after acute hemorrhagic shock and to address treatment options to improve liver perfusion.

Can leukocyte antisedimentation rate (LAR) predict septic complications and critical care survival early in polytrauma and burn victims?

BACKGROUND

In polytrauma and burn injury Systemic Inflammatory Response Syndrome (SIRS) develops. SIRS is presented in many hospitalized patients, including those who never develop infection or sepsis. Both in SIRS and sepsis the leukocyte activation occurs. In acute phase reaction leukocytes' upward flotation i.e. leukocyte antisedimentation rate (LAR) can indicate infectious origin.

OBJECTIVE

To evaluate the predictive power of LAR, serum C-reactive protein (CRP) and procalcitonin (PCT) levels regarding mortality risk and development of septic complications.

METHODS

In a prospective, observational study, 36 patients were followed for 5 days (T1-T5) after admission to a critical care unit immediately with severe polytrauma or burn injury. Eleven patients developed septic complications, their LAR, CRP and PCT levels were analyzed before and after 3 days of sepsis was declared.

RESULTS

Ten patients died due to septic complications. In survivors LAR at T1 (p < 0.001) and T2 (p < 0.001) as well as CRP at T1 (p < 0.05) were significantly higher compared to controls and non survivors. In septic patients LAR (p < 0.05) and CRP (p < 0.05) showed a significant drop one day before sepsis was declared. PCT levels failed to predict this.

CONCLUSIONS

Drop in LAR and CRP levels may be warning signs regarding the onset of septic complications after severe polytrauma and burn injury.

The influence of metabolic imbalances and oxidative stress on the outcome of critically ill polytrauma patients: a review

The critically ill polytrauma patient presents with a series of associated pathophysiologies secondary to the traumatic injuries. The most important include systemic inflammatory response syndrome (SIRS), sepsis, oxidative stress (OS), metabolic disorders, and finally multiple organ dysfunction syndrome (MODS) and death. The poor outcome of these patients is related to the association of the aforementioned pathologies. The nutrition of the critically ill polytrauma patient is a distinct challenge because of the rapid changes in terms of energetic needs associated with hypermetabolism, sepsis, SIRS, and OS. Moreover, it has been proven that inadequate nutrition can prolong the time spent on a mechanical ventilator and the length of stay in an intensive care unit (ICU). A series of mathematical equations can predict the energy expenditure (EE), but they have disadvantages, such as the fact that they cannot predict the EE accurately in the case of patients with hypermetabolism. Indirect calorimetry (IC) is another method used for evaluating and monitoring the energy status of critically ill patients. In this update paper, we present a series of pathophysiological aspects associated with the metabolic disaster affecting the critically ill polytrauma patient. Furthermore, we present different non-invasive monitoring methods that could help the intensive care physician in the adequate management of this type of patient.

Hepatocytes express the antimicrobial peptide HBD-2 after multiple trauma: an experimental study in human and mice

Background

Human-beta defensins (HBD) belong to the family of acute phase peptides and hold a broad antimicrobial spectrum that includes gram-positive and gram-negative bacteria. HBD are up-regulated after severe injuries but the source of posttraumatic HBD expression has not been focused on before.

In the current study we analysed the role of liver tissue in expression of HBD after multiple trauma in human and mice.

Methods

HBD-2 expression has been detected in plasma samples of 32 multiple trauma patients (ISS > 16) over 14 days after trauma by ELISA. To investigate major sources of HBD-2, its expression and regulation in plasma samples, polymorphonuclear neutrophils (PMN) and human tissue samples of liver and skin were analysed by ELISA. As liver samples of trauma patients are hard to obtain we tried to review findings in an established trauma model. Plasma samples and liver samples of 56 male C57BL/6 N-mice with a thorax trauma and a femur fracture were analysed by ELISA, real-time PCR and immunohistochemistry for murine beta defensin 4 (MBD-4) and compared with the expression of control group without trauma.

The induction of HBD-2 expression in cultured hepatocytes (Hep G2) was analysed after incubation with IL-6, supernatant of Staphylococcus aureus (SA) and Lipopolysaccharides (LPS). One possible signalling pathway was tested by blocking toll-like receptor 2 (TLR2) in hepatocytes.

Results

Compared to healthy control group, plasma of multiple traumatized patients and mice showed significantly higher defensin levels after trauma. Compared to skin cells, which are known for high beta defensin expression, liver tissue showed less HBD-2 expression, but higher HBD-2 expression compared to PMN. Immunhistochemical staining demonstrated upregulated MBD-4 in hepatocytes of traumatised mice. In HepG2 cells HBD-2 expression could be increased by stimulation with IL-6 and SA. Neutralization of HepG2 cells with αTLR2 showed reduced HBD-2 expression after stimulation with SA.

Conclusion

Plasma samples of multiple traumatized patients showed high expression of HBD-2, which may protect the severely injured patient from overwhelming bacterial infection. Our data support the hypothesis that liver is one possible source for HBD-2 in plasma while posttraumatic inflammatory response.

Assessment of resuscitation as measured by markers of metabolic acidosis and features of injury

AIMS

The best time for definitive orthopaedic care is often unclear in patients with multiple injuries. The objective of this study was make a prospective assessment of the safety of our early appropriate care (EAC) strategy and to evaluate the potential benefit of additional laboratory data to determine readiness for surgery.

PATIENTS AND METHODS

A cohort of 335 patients with fractures of the pelvis, acetabulum, femur, or spine were included. Patients underwent definitive fixation within 36 hours if one of the following three parameters were met: lactate < 4.0 mmol/L; pH ≥ 7.25; or base excess (BE) ≥ -5.5 mmol/L. If all three parameters were met, resuscitation was designated full protocol resuscitation (FPR). If less than all three parameters were met, it was designated an incomplete protocol resuscitation (IPR). Complications were assessed by an independent adjudication committee and included infection; sepsis; PE/DVT; organ failure; pneumonia, and acute respiratory distress syndrome (ARDS).

RESULTS

In total, 66 patients (19.7%) developed 90 complications. An historical cohort of 1441 patients had a complication rate of 22.1%. The complication rate for patients with only one EAC parameter at the point of protocol was 34.3%, which was higher than other groups (p = 0.041). Patients who had IPR did not have significantly more complications (31.8%) than those who had FPR (22.6%; p = 0.078). Regression analysis showed male gender and injury severity score to be independent predictors of complications.

CONCLUSIONS

This study highlights important trends in the IPR and FPR groups, suggesting that differences in resuscitation parameters may guide care in certain patients; further study is, however, required. We advocate the use of the existing protocol, while research is continued for high-risk subgroups. Cite this article: Bone Joint J 2017;99-B:122-7.

Impaired Surface Expression of HLA-DR, TLR2, TLR4, and TLR9 in Ex Vivo-In Vitro Stimulated Monocytes from Severely Injured Trauma Patients

Objective. Trauma patients (TP) frequently develop an imbalanced immune response that often causes infectious postinjury complications. Monocytes show a diminished capability of both producing proinflammatory cytokines and antigen presentation after trauma. TLR2, TLR4, and TLR9 recognize pathogens and subsequently activate monocytes. While there are conflictive data about TLR2 and TLR4 expression after trauma, no studies about the expression of TLR2, TLR4, TLR9, and HLA-DR on monocytes from TP after their secondary ex vivo-in vitro "hit" have been reported. Methods/Results. Ex vivo-in vitro lipopolysaccharide- (LPS-) stimulated blood from TP showed diminished interleukin- (IL-) 1β-release in TP for five postinjury days compared to healthy volunteers (HV). The recovery was observed at day 5. In parallel, monocytes from TP showed an impaired capability of TLR2, TLR4, and TLR9 expression after secondary stimulation compared to HV, while the measurement of unstimulated samples showed significant reduction of TLR4 and TLR9 at ED. Furthermore, HLA-DR decreased after trauma and was even more profound by stimulation of monocytes. Ratio of monocytes to leukocytes was significantly increased at days 6 and 7 after trauma compared to HV. Conclusion. Impaired expression of TLRs and HLA-DR in acute inflammatory conditions may be responsible for the well-described monocyte paralysis after severe trauma.

Dexamethasone promotes long-term functional recovery of neuromuscular junction in a murine model of tourniquet-induced ischaemia-reperfusion

AIM

Tourniquet-induced ischaemia and subsequent reperfusion cause serious ischaemia-reperfusion (IR) injury in the neuromuscular junction (NMJ) and skeletal muscle. Here, we investigated whether dexamethasone (Dex) promotes long-term functional recovery of the NMJ and skeletal muscle in tourniquet-induced hindlimb IR.

METHODS

Unilateral hindlimb of C57/BL6 mice was subjected to 3 h of ischaemia following 6 weeks of reperfusion (6-wk IR). Dex treatment began on the day of IR induction and lasted for different periods. Sciatic nerve-stimulated gastrocnemius muscle contraction was detected in situ. Function of the NMJ was measured in situ using electrophysiological recording of the miniature endplate potential (mEPP) and endplate potential (EPP). Western blot was used to detect protein expression of nicotinic acetylcholine receptors (nAChRs) in gastrocnemius muscles.

RESULTS

Gastrocnemius muscle contraction in mice with 6-wk IR was about 60% of normal skeletal muscle contraction recorded in age-matched sham mice. The amplitude of the mEPP and EPP was lower in mice with 6-wk IR, compared to sham mice. Dex treatment for 1 or 3 days did not restore the function of the NMJ and improve gastrocnemius muscle contraction in mice with 6-wk IR. Dex treatment for 1 week exerted a maximum effect on improving the function of the NMJ and skeletal muscle, with the effect of Dex gradually lessening with prolonged Dex treatment. There are no significant differences in protein expression of nAChR-α1 and nAChR-β1 subunits in the gastrocnemius muscle among all groups.

CONCLUSION

Dex promotes repair of the NMJ and subsequently restores skeletal muscle contractile function in tourniquet-induced 6-wk IR.

Non-traumatic incidental findings in patients undergoing whole-body computed tomography at initial emergency admission

OBJECTIVE

To evaluate the number, localisation and importance of non-traumatic incidental findings (IFs) in patients with suspected or obvious multiple trauma undergoing whole-body CT (WBCT) in a level-1 trauma centre.

METHODS

Between January 2009 and December 2013, a total of 2440 patients with trauma undergoing WBCT at admission to a level-1 trauma centre of a university hospital were retrospectively analysed, through imaging IFs unrelated to trauma with the radiological reports. All IFs were grouped into four categories according to their clinical relevance. Category 1: urgent treatment or further clarification needed; category 2: further examination and follow-up within 3-6 months required; category 3: findings with no immediate consequences for the treatment of the patient but of potential relevance in the future; category 4: harmless findings.

RESULTS

Altogether, 5440 IFs in 2440 patients (1735 male, 705 female; mean age 45.1 years) were documented. In 204 patients (8.4%) urgent category 1 findings were reported, 766 patients (31.4%) had category 2 findings, 1236 patients (50.7%) had category 3 findings and 1173 patients (48.1%) had category 4 findings. Most IFs were detected in the abdomen/pelvis (42.5%). 602 (24.7%) of the patients had no IFs.

CONCLUSIONS

WBCT scans of unrelated trauma patients demonstrate a high rate of IF. A substantial percentage (8.4%) of patients had urgent category 1IFs and a high percentage (31.4%) had category 2 IFs requiring a follow-up. This high number of patients with polytrauma undergoing WBCT, having IFs of high relevance, poses a major challenge for the level-1 trauma centre in the acute and postacute management of these patients.

OBESITY AND CRITICAL ILLNESS: INSIGHTS FROM ANIMAL MODELS

Critical illness is a major cause of morbidity and mortality around the world. While obesity is often detrimental in the context of trauma, it is paradoxically associated with improved outcomes in some septic patients. The reasons for these disparate outcomes are not well understood. A number of animal models have been used to study the obese response to various forms of critical illness. Just as there have been many animal models that have attempted to mimic clinical conditions, there are many clinical scenarios that can occur in the highly heterogeneous critically ill patient population that occupies hospitals and intensive care units. This poses a formidable challenge for clinicians and researchers attempting to understand the mechanisms of disease and develop appropriate therapies and treatment algorithms for specific subsets of patients, including the obese. The development of new, and the modification of existing animal models, is important in order to bring effective treatments to a wide range of patients. Not only do experimental variables need to be matched as closely as possible to clinical scenarios, but animal models with pre-existing comorbid conditions need to be studied. This review briefly summarizes animal models of hemorrhage, blunt trauma, traumatic brain injury, and sepsis. It also discusses what has been learned through the use of obese models to study the pathophysiology of critical illness in light of what has been demonstrated in the clinical literature.

OXYGEN MITIGATES THE INFLAMMATORY RESPONSE IN A MODEL OF HEMORRHAGE AND ZYMOSAN-INDUCED INFLAMMATION

Sequential insults (hits) may change the inflammatory reaction that develops in response to separate single hits (e.g., injury, infection); however, their effects on the long-term clinical outcome are still only partially elucidated. Double-hit models are typically severe and fatal. We characterized in C57BL/6 mice a moderate double-hit model of hemorrhage (35%-40% of total blood volume) and resuscitation, followed by peritoneal injection of zymosan A that induced local and systemic inflammation with 58% mortality. This model allowed exploration of the inflammatory response over time in the surviving mice. We show that after 2 days, mice subjected to the double-hit model had elevated proinflammatory systemic and local peritoneal cytokine response (interleukin [IL]-1β, tumor necrosis factor-α, IL-6) and moderately elevated anti-inflammatory cytokines (IL-10, transforming growth factor-β), compared with the single-hit and sham mice. However, this dynamically changed, and by day 7, proinflammatory cytokines were reduced, and anti-inflammatory cytokines were markedly (P < 0.05) elevated in the double-hit group. Mice in the double-hit group that inhaled 100% oxygen intermittently for 6 h every day exhibited markedly reduced serum proinflammatory cytokines as early as day 2 (P < 0.05), inhibited macrophage infiltration into the peritoneum (by 13-fold; P < 0.05), and substantially increased survival rates of 85% (P = 0.00144). Oxygen mitigates the inflammatory response and exerts a beneficial effect on survival in a double-hit model of hemorrhage and zymosan-induced inflammation.

Platelets modulate the immune response following trauma by interaction with CD4+ T regulatory cells in a mouse model

CD4+ T regulatory cells (Tregs) play a pivotal role in the anti-inflammatory immune response following trauma. The mechanisms of CD4+ Treg activation are mostly unknown. Here, we hypothesize that platelets regulate CD4+ Treg activation following trauma. In a murine burn injury model (male C57Bl/6N mice), depletion of platelets or CD4+ Tregs was conducted. Draining lymph nodes, blood and spleen were harvested 2 h and 7 days after trauma. CD4+ Treg activation was measured using phospho- and conventional flow cytometry. Platelet activation was analyzed using thromboelastometry and flow cytometry. Trauma differentially activates CD4+ T cells, early after trauma only CD4+ Tregs are activated. Following burn injury, platelets augment the activation of CD4+ Tregs. This effect could only be seen early after trauma. While CD4+ Tregs influence hemostasis early following trauma, platelet activation markers were unchanged. Beyond their role in hemostasis, platelets are able to modulate the immunologic host response to trauma-induced injury by augmenting the activation of CD4+ Tregs. CD4+ Treg activation following trauma is considered protective. In addition, CD4+ Tregs are capable of modulating the hemostatic function of platelets. For the first time, we could show reciprocal activation of platelets and CD4+ Tregs as part of the protective immune response following trauma.

Early Prediction of Sepsis Incidence in Critically Ill Patients Using Specific Genetic Polymorphisms

Several diagnostic methods for the evaluation and monitoring were used to find out the pro-inflammatory status, as well as incidence of sepsis in critically ill patients. One such recent method is based on investigating the genetic polymorphisms and determining the molecular and genetic links between them, as well as other sepsis-associated pathophysiologies. Identification of genetic polymorphisms in critical patients with sepsis can become a revolutionary method for evaluating and monitoring these patients. Similarly, the complications, as well as the high costs associated with the management of patients with sepsis, can be significantly reduced by early initiation of intensive care.

Outcome measures of extracorporeal life support (ECLS) in trauma patients versus patients without trauma: a 7-year single-center retrospective cohort study

This single-center retrospective study included a total of 99 extracorporeal life support (ECLS) cannulated patients assigned to a traumatic extracorporeal life-support cohort (TECLS) or a non-traumatic extracorporeal life-support cohort (NTECLS). Forty-nine TECLS patients and 50 NTECLS patients were compared. The TECLS patients were significantly younger [49.9 years 16.6-86.2 vs. 57.1 (21.4-78.6); p = 0.007] and had lower body mass indices (BMIs) [27.7 kg/m² (20-37) vs. 32.5 (19-88.5); p = 0.001] than the NTECLS patients. The intensive care unit (ICU) survival rate [n = 34 (69.4%) vs. n = 13 (26%); p ≤ 0.001] and the hospital survival rate [n = 32 (65.3%) vs. n = 13 (26%); p ≤ 0.001] were significantly higher for the TECLS cohort than for the NTECLS cohort. The lengths of stay (LOSs) in the ICU [24 days (4.8-71.1) vs. 11.3 (0-88.6); p = 0.001] and in the hospital [46.6 days (2.9-197.6) vs. 21 (0.1-213.8); p = 0.001] were significantly longer for the TECLS patients than for the NTECLS patients.

Renal tissue pro-inflammatory gene expression is reduced by erythropoietin in rats subjected to hemorrhagic shock

BACKGROUND

Hemorrhagic shock (HS) is a condition produced by considerable loss of intravascular volume, which may eventually lead to organ damage and death.

OBJECTIVES

In the present study, the potential implication of the kidney tissue tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10) were evaluated in the protective effects of erythropoietin (EPO) during HS.

MATERIALS AND METHODS

Male Wistar rats were randomized into three experimental groups; Sham, HS (hemorrhagic shock and resuscitation), and EPO (erythropoietin). HS was induced by 50% blood volume hemorrhage over 30 minutes. After 2 hours, resuscitation was performed within 30 minutes. In the EPO group, EPO (300 IU/kg, i.v.) was administered 10 minutes before HS induction. Urine was collected to determine urinary N-acetyl-β-D-glucosaminidase (NAG) activity level. The kidney cytokines (TNF-α, IL-6 and IL-10) mRNA expressions were measured by real-time polymerase chain reaction (PCR).

RESULTS

HS rats showed significant increase in urinary NAG activity compared to the sham group. EPO significantly attenuated the rises in urinary NAG activity compared to the HS group. In the HS animals, renal TNF-α and IL-6 mRNA expressions increased whereas no difference was observed in IL-10 mRNA expression between the HS and sham groups. EPO was able to decrease renal TNF-α and IL-6 production and increase IL-10 mRNA expression.

CONCLUSIONS

In this study, we demonstrated that EPO attenuates kidney damage in rats subjected to HS. The beneficial effects of EPO may be at least partly mediated by modifications in the inflammatory cascade.

Effects of etomidate in the adrenal and cytokine responses to hemorrhagic shock in rats

Hemorrhagic shock (HS) induces a compensatory endocrine and cytokine response which aims to restore homeostasis. This response can be modulated by general anesthetics. To our knowledge, no studies have evaluated if etomidate modulates this response in experimental HS. After being premedicated with buprenorphine (0.05 mg/kg subcutaneously), male Wistar rats were anaesthetized with 5% isoflurane and divided into three groups: G1 (control, n = 16), G2 (n = 13), and G3 (n = 14). G2 and G3 were subjected to HS by collecting 30% of their blood volume and resuscitated 90 min later with the collected blood and normal saline, in a 1:3 ratio, respectively. G3 received etomidate (1 mg/kg IV) before HS. Blood gas analysis, adrenocorticotropic hormone (ACTH), corticosterone, and plasma levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-10 and of TNF-α, IL-6, and IL-10 mRNA obtained through real-time polymerase chain reaction (RT-PCR) were measured at 0, 90, 150, and 240 min after HS induction. Compared with G2, etomidate-treated animals had significantly lower corticosterone, PO2, PO2/FiO2, base excess and HCO3, and higher TNF-α, IL-6, IL-10, and TNF-α mRNA levels ( P <0.05). Etomidate-treated rats showed impaired adrenal and increased cytokine response to HS and evidence of worse tissue oxygenation and lung dysfunction. Based on these results, and until further studies are performed to confirm if these findings occur in clinical patients, we suggest that etomidate should be used cautiously in HS.

The association between illicit drug use and infectious complications among trauma patients

Management of patients with traumatic injury is a complex endeavor requiring a concerted effort of multi-organ stabilization and prevention of septic shock. Given that traumatic injury is frequently mediated by illicit drug use, which has previously been associated with immune suppression, it is hypothesized that infectious complications may occur more prevalently in this patient population. In this study, we evaluate the incidence of infectious complications in trauma patients who screened positive for illicit drug abuse. The national trauma databank was queried for all patients who underwent laboratory evaluation for drug use between 2002 and 2009 and between 2013 and 2014. Patient demographics, clinical outcomes (injury severity score [ISS], intensive care unit length of stay [ILOS], hospital length of stay [HLOS], mortality, risk-adjusted ILOS [rILOS] or HLOS [rHLOS]) and infectious complications (pneumonia, superficial surgical site infection, organ space infection, deep space surgical site infection and urinary tract infection) were attained. Out of 5,564,821 incidents, 525,052 admissions met the inclusion criteria. Patients were 41 ± 19 years of age and 72 % were male. Patients positive for drug use were 1.1-fold more likely to develop pneumonia, 1.2-fold more likely to develop superficial site infection, and 1.3-fold more likely to develop organ space infection. No statistically significant variations in ILOS, HLOS, rILOS, rHLOS or mortality were noted. Traumatic patients who screen positive for illicit drug use are more likely to develop infectious complications. Therefore, vigilance and appropriate preventative measures should be considered in this unique group of patients.

Timing of fracture fixation from an Intensive Care Unit perspective: the obstacles to early fracture fixation

Trauma is one of the leading causes of death worldwide, with road traffic accidents being the leading cause of death in the age group of 15-29 years However, with modern advances in management and the introduction of specialised trauma centres, more and more are surviving severe and life-threatening trauma. The ideal timing of fracture fixation has been the subject of debate for a number of decades. There is evidence to suggest that fracture fixation in the patient with polytrauma is best achieved early on to reduce the incidence of morbidity and mortality, with damage control surgery in the more appropriate option in those patients who are haemodynamically unstable. However, early fracture fixation is not always possible, and the focus of this article is to review the common contributing factors resulting in delayed fixation. For the purpose of this discussion, we will consider all trauma as a single entity, taking into account that each type of fixation has its own complications, which are outside the scope of this article.

Coexistence of Th1/Th2 and Th17/Treg imbalances in patients with post traumatic sepsis

INTRODUCTION

Multiple organ dysfunction syndrome (MODS) developed due to the insult of trauma is a leading cause of death. The high mortality rate in these patients with and without sepsis has been reported up to 50%, throughout the world and thus required an urgent insight to overcome this problem.

OBJECTIVE

The aim of this study is to examine the differential changes in subsets of T cells, imbalance in cytokine profile, immune-paralysis (T cell anergy) in Trauma hemorrhagic shock (THS) and post traumatic sepsis patients.

METHODOLOGY

114, THS patients and 50 healthy controls were recruited in the present study. We have measured the T cell proliferation assay using dominant antigens of both gram positive (LTA, 100ng/ml) and gram negative (LPS-100ng/ml) bacteria and PHA (4μg/ml) using radioactive thymidine (1H³) assay. Simultaneously, we have measured the culture supernatant level of cytokines using Cytokine bead assay (CBA). The other parts of this study include the analysis of different subsets of T cells.

RESULTS AND CONCLUSION

We observed significantly (P<0.05) reduced T cell proliferation in THS patients as compared to control. Our study also showed patients died due to sepsis/septic shock, had significantly (p<0.05) lower T cell response and had significantly elevated levels of IL-4, IL-10andTGF-β, but low level of IL-2andIFN-γ in culture supernatant. THS patients who developed sepsis complication had significantly higher T regulatory cells and lower Th17 cells in comparison to non-sepsis. In conclusion, our study showed an imbalance in cell mediated immune response and disturbance in Th1/Th2/Th17 and T reg population of T helper cells and also the shifts towards Th2 and T17 in THS patients who had developed sepsis and showed poor outcomes.

Nanovesicular liposome-encapsulated hemoglobin (LEH) prevents multi-organ injuries in a rat model of hemorrhagic shock

The goals of resuscitation in hemorrhagic shock are to correct oxygen deficit and to maintain perfusion pressure to the vital organs. We created liposome-encapsulated hemoglobin (LEH) as a nanoparticulate oxygen carrier (216±2nm) containing 7.2g/dl hemoglobin, and examined its ability to prevent the systemic manifestations of hemorrhagic shock (45% blood loss) in a rat model. We collected plasma after 6h of shock and LEH resuscitation, and determined the circulating biomarkers of systemic inflammation and functions of liver, gut, heart, and kidney. As is typical of the shock pathology, a significant increase in the plasma levels of cardiac troponin, liver function enzymes, soluble CD163 (macrophage activation), and creatinine, and the liver/gut myeloperoxidase activity was observed in the hemorrhaged rats. The plasma levels of TNF-α, IL-6, IL-1α, CINC-1, and IL-22 also increased after hemorrhagic shock. LEH administration prevented the hemorrhagic shock-induced accumulation of the markers of injury to the critical organs and pro-inflammatory cytokines. LEH also decreased the plasma levels of stress hormone corticosterone in hemorrhaged rats. Although saline also reduced the circulating corticosterone and a few other tissue injury markers, it was not as effective as LEH in restraining the plasma levels of creatinine, alanine transaminase, CD163, TNF-α, IL-6, and IL-1α. These results indicate that resuscitation with nanoparticulate LEH creates a pro-survival phenotype in hemorrhaged rats, and because of its oxygen-carrying capacity, LEH performs significantly better than saline in hemorrhagic shock.

Predictive value of cytokines for developing complications after polytrauma

AIM: To investigate posttraumatic cytokine alterations and their value for predicting complications and mortality in polytraumatized patients.

METHODS: Studies on the use of specific cytokines to predict the development of complications and mortality were identified in MEDLINE, EMBASE, Web of Science and the Cochrane Library. Of included studies, relevant data were extracted and study quality was scored.

RESULTS: Forty-two studies published between 1988 and 2015 were identified, including 28 cohort studies and 14 “nested” case-control studies. Most studies investigated the cytokines interleukin (IL)-6, IL-8, IL-10 and tumor necrosis factor (TNF-α). IL-6 seems related to muliorgan dysfunction syndrome, multiorgan failure (MOF) and mortality; IL-8 appears altered in acute respiratory distress syndrome, MOF and mortality; IL-10 alterations seem to precede sepsis and MOF; and TNF-α seems related to MOF.

CONCLUSION: Cytokine secretion patterns appear to be different for patients developing complications when compared to patients with uneventful posttraumatic course. More research is needed to strengthen the evidence for clinical relevance of these cytokines.

Repetitive reduction lead to significant elevated IL-6 and decreased IL-10 levels in femoral osteotomies: A quantitative analysis of a robot-assisted reduction process in a rat model

INTRODUCTION

The field of robot-assisted fracture reduction has been developed by several research groups over more than one decade by now, with the main goals of increasing the fracture reduction accuracy. However, the influence of different reduction paths to patients' physiology is not fully known yet. The aim of our study was to compare the impacts of a robot-assisted direct reduction path versus an artificially prolonged reduction path by measuring the cytokine responses in an in vivo rat model.

MATERIALS AND METHODS

Thirty-six male CD(©) rats were assigned into three groups with an external fixator and osteotomy on the left femur. Seven days later, the robot was attached and one group was reduced in a single attempt, while the other group underwent 10 attempts by the robot. The third group was the control group without reduction. Before, and as well as 6, 24 and 48h after the reduction process blood samples were collected. IL-1, IL-6, IL-10, IL-17, and MCP-1 concentrations where analysed via ELISA or cytometric bead assay. Muscle biopsies in the osteotomy area were collected 48h after the reduction process for histological analyses. Statistical significance was set at p≤0.05.

RESULTS

Analysis of the cytokines showed that the pro-inflammatory cytokine IL-6 of the Ten-Attempts reduction group significantly increased 6h after reduction compared to the control group. IL-6 further showed markedly elevated levels 6h after surgery in the Ten-Attempts reduction group compared to the Single-Attempt reduction group. On the anti-inflammatory side, IL-10 showed a significant decrease in the Ten-Attempts reduction group 6h after reduction compared to the Single-Attempt reduction and control group. Muscle biopsies showed a significant increase of pathological changes in both reduction groups and an increase in the severity of bleedings of the Ten-Attempts reduction group compared to the Single-Attempt reduction and control group.

CONCLUSION

A direct and gentle reduction procedure as feasible by the aid of a robot is preferable over a prolonged reduction in terms of cytokine response and tissue changes.