Systemic acylcarnitine levels are affected in response to multiple injuries and hemorrhagic shock - an analysis of lipidomic changes in a standardized porcine model.

INTRODUCTION: Along with recent advances in analytical technologies, TCA-cycle intermediates are increasingly identified as promising makers for cellular ischemia and mitochondrial dysfunction during hemorrhagic shock (HS). For traumatized patients, the knowledge of the role of lipid oxidation substrates is sparse. In this study, we aimed to analyze the dynamics of systemic acylcarnitine (AcCa) release in a standardized polytrauma model with HS. METHODS: 52 male pigs (50 ± 5 kg) were randomized into two groups: Group IF (isolated fracture) was subject to a standardized femur shaft fracture. Group PT (polytrauma) was subject to a femur fracture, followed by blunt chest trauma, liver laceration and a pressure controlled hemorrhagic shock for 60 min. Resuscitation was performed with crystalloids. Fractures were stabilized by intramedullary nailing. Venous samples were collected at 6 timepoints (baseline, trauma, resuscitation, 2 h, 4 h and 6 h). Lipidomic analysis was performed via liquid chromatography coupled mass spectrometry. Measurements were collated with clinical markers and near-infrared spectrometry measurements (NIRS) of tissue perfusion. Longitudinal analyses were performed with linear mixed models and spearman's correlations were calculated. A p-value of 0.05 was defined as threshold for statistical significance. RESULTS: From a total of 303 distinct lipids, we identified two species of long-chain AcCas. Both showed a highly significant (p < 0.001) two-fold increase after HS in Group PT that promptly normalized after resuscitation. This increase was associated with a significant decrease of the base excess (p = 0.005) but recovery after resuscitation was faster. For both AcCas, there were significant correlations with decreased muscle tissue oxygen delivery (p = 0.008, p = 0.003) and significant time-lagged correlations with the increase of creatine kinase (p < 0.001, p < 0.001). CONCLUSION: Our results point to plasma AcCas as a possible indicator for mitochondrial dysfunction and cellular ischemia in HS. The more rapid normalization after resuscitation in comparison to acid base changes may warrant further investigation. STUDY TYPE: Experimental Animal Model. LEVEL OF EVIDENCE: N/A.

Elective implant removal in the upper extremity: only symptomatic patients benefit.

PURPOSE: Elective implant removal (IR) in the upper extremity remains controversial. Implants in the olecranon and clavicle are commonly removed for prominence, unlike in the distal radius. Patient-reported symptomatic cannot be verified, and nonspecific discomfort remains unquantified. In this study, indications and outcomes of IR at the clavicle, olecranon and distal radius were evaluated, with a focus on postoperative patient satisfaction. MATERIALS AND METHODS: In this retrospective, single-center cohort study, patients, who received elective IR of the clavicle, olecranon and distal radius were included. Patients were followed up at least six weeks after IR. Outcomes included patient satisfaction, symptom resolution, and complications. RESULTS: One hundred and eighty-nine patients were included. Unspecific symptoms of discomfort were the most prevalent indication for IR (48.7%), followed by pain (29.6%) and objective limited range of motion (ROM) (7%). Pain and limited ROM combined was observed in 13.8%. Subjective benefit following IR was described in 54%. Patients with limited ROM (OR 4.7, p < 0.001) or pain (OR 4.1, p < 0.001) were more likely to experience alleviation of complaints. Patients with unspecific symptoms of discomfort, often did not report improvement. Major complications occurred in 2%. Refractures were detected at the clavicle (3.7%) and at the olecranon (2.5%). Minor complication rate was 5%. CONCLUSION: IR is a safe procedure in the upper extremity. Indications based on unspecific symptoms of discomfort have a significant lower rate of patient satisfaction postoperatively. Elective IR should be considered cautiously, if it is driven primarily by unspecific symptoms of discomfort. Patient education is relevant to prevent dissatisfying outcome.

Timing of Spinal Surgery in Polytrauma: The Relevance of Injury Severity, Injury Level and Associated Injuries.

STUDY DESIGN: Retrospective database analysis. OBJECTIVE: Polytraumatized patients with spinal injuries require tailor-made treatment plans. Severity of both spinal and concomitant injuries determine timing of spinal surgery. Aim of this study was to evaluate the role of spinal injury localization, severity and concurrent injury patterns on timing of surgery and subsequent outcome. METHODS: The TraumaRegister DGU® was utilized and patients, aged ≥16 years, with an Injury Severity Score (ISS) ≥16 and diagnosed with relevant spinal injuries (abbreviated injury scale, AIS ≥ 3) were selected. Concurrent spinal and non-spinal injuries were analysed and the relation between injury severity, concurrent injury patterns and timing of spinal surgery was determined. RESULTS: 12.596 patients with a mean age of 50.8 years were included. 7.2% of patients had relevant multisegmental spinal injuries. Furthermore, 50% of patients with spine injuries AIS ≥3 had a more severe non-spinal injury to another body part. ICU and hospital stay were superior in patients treated within 48 hrs for lumbar and thoracic spinal injuries. In cervical injuries early intervention (<48 hrs) was associated with increased mortality rates (9.7 vs 6.3%). CONCLUSIONS: The current multicentre study demonstrates that polytrauma patients frequently sustain multiple spinal injuries, and those with an index spine injury may therefore benefit from standardized whole-spine imaging. Moreover, timing of surgical spinal surgery and outcome appear to depend on the severity of concomitant injuries and spinal injury localization. Future prospective studies are needed to identify trauma characteristics that are associated with improved outcome upon early or late spinal surgery.

Surgical load in major fractures - results of a survey on the optimal quantification and timing of surgery in polytraumatized patients.

PURPOSE: It is known that the magnitude of surgery and timing of surgical procedures represents a crucial step of care in polytraumatized patients. In contrast, it is not clear which specific factors are most critical when evaluating the surgical load (physiologic burden to the patient incurred by surgical procedures). Additionally, there is a dearth of evidence for which body region and surgical procedures are associated with high surgical burden. The aim of this study was to identify key factors and quantify the surgical load for different types of fracture fixation in multiple anatomic regions. METHODS: A standardized questionnaire was developed by experts from Société Internationale de Chirurgie Orthopédique et de Traumatologie (SICOT)-Trauma committee. Questions included relevance and composition of the surgical load, operational staging criteria, and stratification of operation procedures in different anatomic regions. Quantitative values according to a five-point Likert scale were chosen by the correspondents to determine the surgical load value based on their expertise. The surgical load for different surgical procedures in different body regions could be chosen in a range between "1," defined as the surgical load equivalent to external (monolateral) fixator application, and "5," defined as the maximal surgical load possible in that specific anatomic region. RESULTS: This questionnaire was completed online by 196 trauma surgeons from 61 countries in between Jun 26, 2022, and July 16, 2022 that are members of SICOT. The surgical load (SL) overall was considered very important by 77.0% of correspondents and important by 20.9% correspondents. Intraoperative blood loss (43.2%) and soft tissue damage (29.6%) were chosen as the most significant factors by participating surgeons. The decision for staged procedures was dictated by involved body region (56.1%), followed by bleeding risk (18.9%) and fracture complexity (9.2%). Percutaneous or intramedullary procedures as well as fractures in distal anatomic regions, such as hands, ankles, and feet, were consistently ranked lower in their surgical load. CONCLUSION: This study demonstrates a consensus in the trauma community about the crucial relevance of the surgical load in polytrauma care. The surgical load is ranked higher with increased intraoperative bleeding and greater soft tissue damage/extent of surgical approach and depends relevantly on the anatomic region and kind of operative procedure. The experts especially consider anatomic regions and the risk of intraoperative bleeding as well as fracture complexity to guide staging protocols. Specialized guidance and teaching is required to assess both the patient's physiological status and the estimated surgical load reliably in the preoperative decision-making and operative staging.

Developments in the understanding of staging a "major fracture" in polytrauma: results from an initiative by the polytrauma section of ESTES.

PURPOSE: Although the term "major fracture" is commonly used in the management of trauma patients, it is defined insufficiently to date. The polytrauma section of ESTES is trying to develop a more standardized use and a definition of the term. In this process, a standardized literature search was undertaken. We test the hypothesis that the understanding of "major fractures" has changed and is modified by a better understanding of patient physiology. METHODS: A systematic literature search of the Medline and EMBASE databases was conducted in March 2022. Original studies that investigated surgical treatment strategies in polytraumatized patients with fractures were included: This included timing, sequence and type of operative treatment. A qualitative synthesis regarding the prevalence of anatomic regions of interest and core factors determining decision-making was performed. Data were stratified by decades. RESULTS: 4278 articles were identified. Of these, 74 were included for qualitative evaluation: 50 articles focused on one anatomic region, 24 investigated the relevance of multiple anatomic regions. Femur fractures were investigated most frequently (62) followed by pelvic (22), spinal (15) and tibial (15) fractures. Only femur (40), pelvic (5) and spinal (5) fractures were investigated in articles with one anatomic region of interest. Before 2010, most articles focused on long bone injuries. After 2010, fractures of pelvis and spine were cited more frequently. Additional determining factors for decision-making were covered in 67 studies. These included chest injuries (42), TBI (26), hemorrhagic shock (25) and other injury-specific factors (23). Articles before 2000 almost exclusively focused on chest injury and TBI, while shock and injury-specific factors (e.g., soft tissues, spinal cord injury, and abdominal trauma) became more relevant after 2000. CONCLUSION: Over time, the way "major fractures" influenced surgical treatment strategies has changed notably. While femur fractures have long been the only focus, fixation of pelvic and spinal fractures have become more important over the last decade. In addition to the fracture location, associated conditions and injuries (chest trauma and head injuries) influence surgical decision-making as well. Hemodynamic stability and injury-specific factors (soft tissue injuries) have increased in importance over time.

The implementation of physicians assistant in a surgical ward improves continuity in daily clinical work and increases comprehensibility of nurses and physicians.

INTRODUCTION: Physician Assistant (PA) have been deployed to increase the capacity of a team, supporting continuity and medical cover. The goal of this study was to assess the implementation of PAs on continuity of surgical rounds, on the collaboration of nurses and physicians and on support of administrative work. METHODS: This cross-sectional survey was performed on nurses and physicians who work full-time at a surgical ward in a Swiss reference center. PAs were introduced in our institution in 2019. Participants answered a self-developed questionnaire 6 and 12 months after the implementation of PAs. Administrative work, teamwork, improvement of workflow, and training of physicians has been assessed. Participants answered questions on a 5-point Likert scale and were stratified according to profession (nurse, physician). RESULTS: Participants (n = 53) reported a positive effect on the regular conduct of rounds (2.9, SD 1.1 points after 6 weeks and 3.5, SD 1.1 points after 12 weeks, p = 0.05). A significant improvement of nurse-doctor collaboration has been reported (3.6, SD 1.0 and 4.2, SD 0.8, p = 0.05). Nurses (n = 28, 52.8%) reported the that PAs are integrated in the physicians team rather than the nurses team (4.0, SD 0.0 points and 4.4, SD 0.7 points, p = 0.266) and a significant beneficial effect on the surgical clinic (3.7, SD 1.0 points and 4.4, SD 0.8 points, p = 0.043). Improved overall management of surgical cases was reported by the physicians (n = 25, 47.2%) (4.8, SD 0.4 and 4.3, SD 0.6, p = 0.046). CONCLUSION: The implementation of PA has improved the collaboration of physicians and nurses substantially. Continuity of rounds has improved and the administrative workload for residents decreased substantially. Overall, the implementation of PA was reported to be beneficial for the surgical clinic.

Transition from a circular to a linear stapling protocol in laparoscopic Roux-en-Y gastric bypass surgery and its impact on quality of life: a 5-year outcome study.

PURPOSE: Surgical technique in bariatric surgery has been refined over the past decades. This study analysed the effect of changing the stapling protocol on the quality of life (QoL) at a midterm follow-up. METHODS: The retrospective cohort study included patients undergoing Roux-en-Y gastric bypass between June 2012 and March 2016. Patients were stratified into the circular stapling protocol (CSP, n = 117) or the linear stapling protocol (LSP, n = 118). QoL was quantified by the Moorehead score at 12, 24 and 60 months. Multivariate testing was used to identify confounders. RESULTS: The age was 42.8 ± 11.5 years and the body mass index (BMI) was 43.8 ± 6.2 kg/m2, with no baseline intergroup differences. Overall baseline Moorehead score was 0.42 ± 1.1 and improved in both groups after 12 months (1.97 ± 0.74, p < 0.001), 24 months (1.86 ± 0.79, p < 0.001) and 60 months (1.71 ± 0.9, p < 0.001). LSP was associated with improved Moorehead score after 60 months (odds ratio [OR] 1.251, 95% confidence interval [CI] 1.06-1.48, p = 0.010). Overall, a drop of mean BMI occurred and this effect lasted throughout the observation period (- 12.48 kg/m2, p < 0.001). More profound BMI reduction was further positively associated with Moorehead scores after 24 and after 60 months (OR 0.97, p = 0.028; OR 0.96, p = 0.007). Complications, rehospitalisations and reoperations were more frequent in the CSP group (50% vs 23.7%, p < 0.001; 39.7% vs 22.9%, p = 0.009; 37.1% vs 18.6%, p = 0.003). CONCLUSION: The CSP and LSP achieve a long-lasting increase in QoL, although the LSP is associated with fewer complications, persistent weight loss and improved Moorehead score. Therefore, the LSP might be considered the favourable protocol in Roux-en-Y gastric bypass.

Effects of Occult Hypoperfusion on Local Circulation and Inflammation - An Analysis in a Standardized Polytrauma Model.

Introduction: Occult hypoperfusion (OH) is defined as persistent lactic acidosis despite normalization of vital parameters following trauma. The aim of this study was to analyze the association of occult hypoperfusion with local circulation and inflammation of injured soft tissue in a porcine polytrauma model. Methods: This experimental study was performed with male landrace pigs who suffered a standardized polytrauma, including a femoral fracture, blunt chest trauma, liver laceration and a mean arterial pressure (MAP) controlled hemorrhagic shock. One hour after induction of trauma, the animals were resuscitated with retrograde femoral nailing, liver packing and volume replacement. Animals were stratified into Group Norm (normalizing lactate levels after resuscitation) and Group occult hypoperfusion (OH) (persistent lactate levels above 2 mmol/l with normalizing vital parameters after resuscitation). Local circulation (oxygen saturation, hemoglobin amount, blood flow) was measured with optical sensors at the subcutaneous soft tissue at the fractured extremity as well as at the stomach and colon. Local inflammatory parameters [interleukin (IL) 6, 8, 10, and heat shock protein (HSP)] were analyzed in the subcutaneous tissue of the fractured extremity. Results: Group Norm (n = 19) and Group OH (n = 5) were comparable in baseline vital and laboratory parameters. The shock severity and total amount of blood loss were comparable among Group Norm and Group OH. Following resuscitation Group OH had significantly lower local relative hemoglobin amount at the injured soft tissue of the fractured extremity when compared with Group Norm (39.4, SD 5.3 vs. 63.9, SD 27.6 A.U., p = 0.031). The local oxygenation was significantly lower in Group OH compared to Group Norm (60.4, SD 4.6 vs. 75.8, SD 12.8, p = 0.049). Local IL-6 in the fatty tissue was significantly higher in Group OH (318.3, SD 326.6 [pg/ml]) when compared with Group Norm (73.9,SD 96.3[pg/ml], p = 0.03). The local circulation at the abdominal organs was comparable in both groups. Conclusion: OH is associated with decreased local circulation and increased local inflammation at the injured soft tissue of the extremity in polytrauma. OH might reflect the severity of local soft tissue injuries, and guide treatment strategies.

Occult hypoperfusion and changes of systemic lipid levels after severe trauma: an analysis in a standardized porcine polytrauma model.

BACKGROUND: Occult hypoperfusion describes the absence of sufficient microcirculation despite normal vital signs. It is known to be associated with prolonged elevation of serum lactate and later complications in severely injured patients. We hypothesized that changes in circulating lipids are related to responsiveness to resuscitation. The purpose of this study is investigating the relation between responsiveness to resuscitation and lipidomic course after poly trauma. METHODS: Twenty-five male pigs were exposed a combined injury of blunt chest trauma, liver laceration, controlled haemorrhagic shock, and femoral shaft fracture. After 1 h, animals received resuscitation and fracture stabilization. Venous blood was taken regularly and 233 specific lipids were analysed. Animals were divided into two groups based on serum lactate level at the end point as an indicator of responsiveness to resuscitation (<2 mmol/L: responder group (R group), ≧2 mmol/L: occult hypoperfusion group (OH group)). RESULTS: Eighteen animals met criteria for the R group, four animals for the OH group, and three animals died. Acylcarnitines showed a significant increase at 1 h compared to baseline in both groups. Six lipid subgroups showed a significant increase only in R group at 2 h. There was no significant change at other time points. CONCLUSIONS: Six lipid groups increased significantly only in the R group at 2 h, which may support the idea that they could serve as potential biomarkers to help us to detect the presence of occult hypoperfusion and insufficient resuscitation. We feel that further study is required to confirm the role and mechanism of lipid changes after trauma.

Shift of Neutrophils From Blood to Bone Marrow Upon Extensive Experimental Trauma Surgery.

Introduction: Extensive trauma surgery evokes an immediate cellular immune response including altered circulatory neutrophil numbers. The concurrent bone marrow (BM) response however is currently unclear. We hypothesize that these BM changes include (1) a relative reduction of the bone marrow neutrophil fraction and (2) increasing heterogeneity of the bone marrow neutrophil pool due to (3) the appearance of aged/returning neutrophils from circulation into the BM-compartment. Materials and Methods: Eight pigs were included in a standardized extensive trauma surgery model. Blood and bone marrow samples were collected at baseline and after 3 hours of ongoing trauma surgery. Leukocyte and subtype counts and cell surface receptor expression levels were studied by flow cytometry. Results: All animals survived the interventions. A significant drop in circulating neutrophil counts from 9.3 to 3.2x106 cells/ml (P=0.001) occurred after intervention, whereas circulatory neutrophil cell surface expression of CD11b increased. The concurrent bone marrow response included an increase of the BM neutrophil fraction from 63 ± 3 to 71 ± 3 percent (P<0.05). Simultaneously, the BM neutrophil pool became increasingly mature with a relative increase of a CXCR4high-neutrophil subtype that was virtually absent at baseline. Conclusion: The current study shows a shift in composition of the BM neutrophil pool during extensive trauma surgery that was associated with a relatively circulatory neutropenia. More specifically, under these conditions BM neutrophils were more mature than under homeostatic conditions and a CXCR4high-neutrophil subset became overrepresented possibly reflecting remigration of aged neutrophils to the BM. These findings may contribute to the development of novel interventions aimed to modify the trauma-induced immune response in the BM.

Improved Clinical and Financial Outcomes in Proximal Gastric Bypass Surgery Following the Transition from a Conventional Circular Stapling to an Augmented Linear Stapling Protocol.

Bariatric techniques for bypass surgery evolve constantly. Switching from one well-established protocol to another in a running surgical teaching program is challenging. We analyzed clinical and financial outcomes at a single bariatric center transitioning from circular to an augmented linear bypass protocol. MATERIALS AND METHODS: Between 2011 and 2018, 454 patients were included in this retrospective study. The circular bypass protocol (CIRC; n = 177) was used between 2011 and 2012. Between 2013 and 2015 the transition occurred. Thereafter, the augmented linear protocol (aLIN; n = 277) was primarily utilized. RESULTS: Overall, the mean preoperative BMI dropped from 42.2 to 29.6 kg/m2 after 5 years with no difference between groups. Operation times were significantly shorter in the aLIN vs. CIRC group at 108 (± 32) vs. 120 (± 34) min (P < 0.001), respectively. The reoperation rate was significantly higher in the CIRC vs. aLIN group at n = 65 (36%) vs. n = 35 (13%; P < 0.001), respectively. Specifically, revision due to internal hernia occurred much more frequently in the CIRC-group, n = 36 (20%) vs. n = 12 (4%; P < 0.001). Moreover, reoperation rates for gastrojejunostomy leakage and endoscopic dilatations for anastomotic stenosis were higher in the CIRC vs. aLIN group (P < 0.001). Adjusted overall mean cost per case was lower in aLIN-patients at 15,403 (± 7848) vs. CIRC-patients at 18,525 (± 7850) Swiss francs (P < 0.001). Overall profit was 2555 ± 4768 vs. 1455 ± 5638 Swiss francs in the aLIN vs. CIRC-group, respectively (P = 0.026). CONCLUSION: This study shows improved clinical and financial outcomes after a gradual transition from a circular stapling protocol to an augmented linear stapling protocol in proximal gastric bypass surgery.

Standardized porcine unilateral femoral nailing is associated with changes in PMN activation status, rather than aberrant systemic PMN prevalence.

PURPOSE: Intramedullary nailing (IMN) of fractures is associated with increased rates of inflammatory complications. The pathological mechanism underlying this phenomenon is unclear. However, polymorphonuclear granulocytes (PMNs) seem to play an important role. We hypothesized that a femur fracture and standardized IMN in pigs is associated with altered appearance of PMNs in circulation and enhanced activation status of these cells. METHODS: A porcine model including a femur fracture and IMN was utilized. Animals were randomized for control [anesthesia + mechanical ventilation only (A/MV)] and intervention [A/MV and unilateral femur fracture (FF) + IMN] conditions. PMN numbers and responsiveness, integrin (CD11b), L-selectin (CD62L) and Fcγ-receptor (CD16 and CD32)-expression levels were measured by flowcytometry of blood samples. Animals were observed for 72 h. RESULTS: Circulatory PMN numbers did not differ between groups. Early PMN-responsiveness was retained after insult. PMN-CD11b expression increased significantly upon insult and peaked after 24 h, whereas CD11b in control animals remained unaltered (P = 0.016). PMN-CD16 expression levels in the FF + IMN-group rose gradually over time and were significantly higher compared with control animals, after 48 h (P = 0.016) and 72 h (P = 0.032). PMN-CD62L and CD32 expression did not differ significantly between conditions. CONCLUSION: This study reveals that a femur fracture and subsequent IMN in a controlled setting in pigs is associated with enhanced activation status of circulatory PMNs, preserved PMN-responsiveness and unaltered circulatory PMN-presence. Indicating that monotrauma plus IMN is a specific and substantial stimulus for the cellular immune system. Early alterations of circulatory PMN receptor expression dynamics may be predictive for the intensity of the post traumatic response.

Early myocardial damage (EMD) and valvular dysfunction after femur fracture in pigs.

Musculoskeletal injuries are the most common reason for surgery in severely injured patients. In addition to direct cardiac damage after physical trauma, there is rising evidence that trauma induces secondary cardiac structural and functional damage. Previous research associates hip fractures with the appearance of coronary heart disease: As 25% of elderly patients developed a major adverse cardiac event after hip fracture. 20 male pigs underwent femur fracture with operative stabilization via nailing (unreamed, reamed, RIA I and a new RIA II; each group n = 5). Blood samples were collected 6 h after trauma and the concentration of troponin I and heart-type fatty acid binding protein (HFABP) as biomarkers for EMD were measured. At baseline and 6 h after trauma, transesophageal ECHO (TOE) was performed; and invasive arterial and left ventricular blood pressure were measured to evaluate the cardiac function after femur fracture. A systemic elevation of troponin I and HFABP indicate an early myocardial damage after femur fracture in pigs. Furthermore, various changes in systolic (ejection fraction and cardiac output) and diastolic (left ventricular end-diastolic pressure, mitral valve deceleration time and E/A ratio) parameters illustrate the functional impairment of the heart. These findings were accompanied by the development of valvular dysfunction (pulmonary and tricuspid valve). To the best of our knowledge, we described for the first time the development of functional impairment of the heart in the context of EMD after long bone fracture in pigs. Next to troponin and HFABP elevation, alterations in the systolic and diastolic function occurred and were accompanied by pulmonary and tricuspid valvular insufficiency. Regarding EMD, none of the fracture stabilization techniques (unreamed nailing, reaming, RIA I and RIA II) was superior.

Simultaneous Casualty Admissions-Do they Affect Treatment in the Receiving Trauma Center?

BACKGROUND: Simultaneous trauma admissions expose medical professionals to increased workload. The impact of simultaneous trauma admissions on hospital allocation, therapy, and outcome is currently unclear. We hypothesized that multiple admission-scenarios impact the diagnostic pathway and outcome. METHODS: The TraumaRegister DGU® was utilized. Patients admitted between 2002-2015 with an ISS ≥ 9, treated with ATLS®- algorithms were included. Group ´IND´ included individual admissions, two individuals that were admitted within 60 min of each other were selected for group ´MULT´. Patients admitted within 10 min were considered as simultaneous (´SIM´) admissions. We compared patient and trauma characteristics, treatment, and outcomes between both groups. RESULTS: 132,382 admissions were included, and 4,462/3.4% MULTiple admissions were found. The SIM-group contained 1,686/1.3% patients. The overall median injury severity score was 17 and a mean age of 48 years was found. MULT patients were more frequently admitted to level-one trauma centers (68%) than individual trauma admissions were (58%, p < 0.001). Mean time to CT-scanning (24 vs. 26/28 min) was longer in MULT / SIM patients compared to individual admissions. No differences in utilization of damage control principles were seen. Moreover, mortality rates did not differ between the groups (13.1% in regular admissions and 11.4%/10,6% in MULT/SIM patients). CONCLUSION: This study demonstrates that simultaneous treatment of injured patients is rare. Individuals treated in parallel with other patients were more often admitted to level-one trauma centers compared with individual patients. Although diagnostics take longer, treatment principles and mortality are equal in individual admissions and simultaneously admitted patients. More studies are required to optimize health care under these conditions.

Splenectomy is associated with altered leukocyte kinetics after severe trauma.

BACKGROUND: Inadequate activation of the innate immune system after trauma can lead to severe complications such as Acute Respiratory Distress Syndrome and Multiple Organ Dysfunction Syndrome. The spleen is thought to modulate the cellular immune system. Furthermore, splenectomy is associated with improved outcome in severely injured trauma patients. We hypothesized that a splenectomy alters the cellular immune response in polytrauma. METHODS: All adult patients with an ISS ≥ 16 and suffering from splenic or hepatic injuries were selected from our prospective trauma database. Absolute leukocyte numbers in peripheral blood were measured. White blood cell kinetics during the first 14 days were compared between splenectomized patients, patients treated surgically for liver trauma and nonoperatively treated individuals. RESULTS: A total of 129 patients with a mean ISS of 29 were included. Admission characteristics and leukocyte numbers were similar in all groups, except for slightly impaired hemodynamic status in patients with operatively treated liver injuries. On admission, leukocytosis occurred in all groups. During the first 24 h, leukopenia developed gradually, although significantly faster in the operatively treated patients. Thereafter, leukocyte levels normalized in all nonoperatively treated cases whereas leukocytosis persisted in operatively treated patients. This effect was significantly more prominent in splenectomized patients than all other conditions. CONCLUSIONS: This study demonstrates that surgery for intra-abdominal injuries is associated with an early drop in leucocyte numbers in peripheral blood. Moreover, splenectomy in severely injured patients is associated with an altered cellular immune response reflected by a persistent state of prominent leukocytosis after trauma.

Pre-hospital trauma care in Switzerland and Germany: do they speak the same language?

PURPOSE: Swiss and German (pre-)hospital systems, distribution and organization of trauma centres differ from each other. It is unclear if outcome in trauma patients differs as well. Therefore, this study aims to determine differences in characteristics, therapy and outcome of trauma patients between both German-speaking countries. METHODS: The TraumaRegister DGU® (TR-DGU) was used. Patients with Injury Severity Score ≥ 9 admitted to a level 1 trauma centre between 01/2009 and 12/2017 were included if they required ICU care or died. Trauma pattern, pre-hospital procedures and outcome were compared between Swiss (CH, n = 4768) and German (DE, n = 66,908) groups. RESULTS: Swiss patients were older than German patients (53 vs. 50 years). ISS did not differ between groups (CH 23.8 vs. DE 23.0 points). There were more low falls < 3 m (34% vs. 21%) at the expense of less traffic accidents (37% vs. 52%) in the Swiss population. In Switzerland 30% of allocations were done without physician involvement, whereas this occurred in 4% of German cases. Despite a comparable number of patients with a GCS ≤ 8 (CH 29.6%; DE 26.4%), differences in pre-hospital intubation rates occurred (CH 31% vs. DE 40%). Severe traumatic brain injuries were diagnosed most frequently in Switzerland (CH 62% vs. DE 49%). Admission vital signs were similar, and standardized mortality ratios were close to one in both countries. CONCLUSION: This study demonstrates that patients' age, trauma patterns and pre-hospital care differ between Germany and Switzerland. However, adjusted mortality was almost similar. Further benchmarking studies are indicated to optimize trauma care in both German-speaking countries.

Instant intra-operative neutropenia despite the emergence of banded (CD16dim/CD62Lbright) neutrophils in peripheral blood - An observational study during extensive trauma-surgery in pigs.

INTRODUCTION: Deregulation of polymorphonuclear neutrophils (PMNs) is an essential step in the development of inflammatory complications upon trauma. Different neutrophil subtypes have been identified recently, however, the role of neutrophil subtypes in immunoregulation upon trauma is unclear. We hypothesize that extensive trauma surgery causes instant progressive heterogeneity of the blood neutrophil pool, and increased appearance of young (CD16dim/CD62Lbright) neutrophils in peripheral blood. MATERIAL AND METHODS: A standardized extensive thoraco-abdominal porcine trauma surgery model was utilized, and 12 animals were included. Blood was collected at defined timepoints and neutrophil numbers and subtypes were studied by flowcytometry. Neutrophil subtypes were identified by differences in cell surface expression levels of CD16 (FcγRIII) and CD62L (L-selectin). Porcine neutrophil subtypes were further characterized after flow sorting. RESULTS: Eleven animals survived the 3-hour surgical protocol. Neutrophil numbers dropped significantly from a mean of 8,6 ± 3,5 × 106 to 2,4 ± 1,8 × 106 cells/ml during 180 min, (p<0.001). Simultaneously, the blood PMN population became increasingly heterogeneous due to the appearance of new neutrophil subtypes. Cell sorting experiments and cytological analysis revealed that these porcine subtypes had specific morphological characteristics, mimicking their human counterparts. At baseline, 88% ± 1 percent of circulatory PMNs comprised of mature (CD16bright/CD62Lbright) PMNs, while at 3 h the blood PMN pool consisted of 59% ± 2 percent of mature subtypes (p<0.001). Despite a marked drop in neutrophil levels during surgery, absolute and relative numbers of banded (CD16dim/CD62Lbright) neutrophils continued to rise throughout surgery. CONCLUSION: Standardized extensive trauma surgery was associated with instant progressive neutropenia and increased heterogeneity of the blood neutrophil pool. Furthermore, three different neutrophil subsets in peripheral porcine blood were identified over the course of surgery. Further studies should clarify their precise role in the development of early organ failure upon extensive trauma surgery. This for the first time exemplifies experimentally the time constraints and impact of damage control surgery after severe trauma.

Protective effects of new femoral reaming techniques (Reamer irrigator aspirator, RIA I and II) on pulmonary function and posttraumatic contusion (CT morphology) - results from a standardized large animal model.

INTRODUCTION: The effects of reaming for preparation of intramedullary fixation in long bone fractures have been widely studied. We compared pulmonary and systemic effects between conventional reaming with reamer irrigator aspirator and unreamed nailing in an acute porcine trauma model with a standardized femur fracture. MATERIALS AND METHODS: In a standardized porcine model, (moderate blunt chest trauma, abdominal injury and femoral shaft fracture), the femur was submitted to intramedullary nailing after resuscitation and normalization of pulmonary function. The treatment groups included 3 reamer types (Group RFN: conventional reaming with Synream; group RIA1; reamer irrigator aspirator, version 2005; group RIA 2; reamer irrigator aspirator, version 2019) and were compared to unreamed femoral nailing (Group UFN). Pulmonary function measurements included arterial partial carbon-dioxide pressure (paCO2 [kPa]) (baseline, post reaming, 2,4,6 h) and volumetric measures of contusion in chest computer tomography (CT) (at 6 hrs.). Systemic inflammatory response was measured at baseline and every second hour until six hours after trauma. RESULTS: This study included 24 male animals, mean weight 50.76 ± 4.1 kg n = 6 per group). Group RFN developed a significantly higher partial CO2 (pCO2) at one hour after reaming when compared with all other groups (7.4 ± 0.4 kPa versus 5.4 ± 0.6 RIA 1, 5.6 ± 0.4 RIA 2, and 5.5 ± 0.5 UFN, p < 0.001), along with a had lower pO2 (12.3 ± 1.3 kPa versus 17.2 ± 1.9 RIA 1, 17.4 ± 1.6 RIA 2, and 16.4 ± 0.7 UFN, p < 0.001) and the degree of pulmonary hyperdense changes in the CT analysis was higher in RFN (485.2 ± 98.5 cm3 versus 344.4 ± 74.4 cm3 RIA 1 and 335.2 ± 58.1 cm3 RIA 2, p < 0.01). The inflammatory reaction was lowest in both RIA groups when compared with group RFN or UFN (p < 0.001). CONCLUSION: Both RIA 1 and RIA 2 protect the lung from reaming induced dysfunction and have no systemic inflammatory effects, while the negative effects were more sustained after reamed or unreamed nailing. Both RIA 1 and RIA II appear to be of value in terms of a Safe Definitive Surgery (SDS) strategy.

Lessons learned from the mechanisms of posttraumatic inflammation extrapolated to the inflammatory response in COVID-19: a review.

Up to 20% of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) patients develop severe inflammatory complications with diffuse pulmonary inflammation, reflecting acute respiratory distress syndrome (ARDS). A similar clinical profile occurs in severe trauma cases. This review compares pathophysiological and therapeutic principles of severely injured trauma patients and severe coronavirus disease 2019 (COVID-19). The development of sequential organ failure in trauma parallels deterioration seen in severe COVID-19. Based on established pathophysiological models in the field of trauma, two complementary pathways of disease progression into severe COVID-19 have been identified. Furthermore, the transition from local contained disease into systemic and remote inflammation has been addressed. More specifically, the traumatology concept of sequential insults ('hits') resulting in immune dysregulation, is applied to COVID-19 disease progression modelling. Finally, similarities in post-insult humoral and cellular immune responses to severe trauma and severe COVID-19 are described. To minimize additional 'hits' to COVID-19 patients, we suggest postponing all elective surgery in endemic areas. Based on traumatology experience, we propose that immunoprotective protocols including lung protective ventilation, optimal thrombosis prophylaxis, secondary infection prevention and calculated antibiotic therapy are likely also beneficial in the treatment of SARS-CoV-2 infections. Finally, rising SARS-CoV-2 infection and mortality rates mandate exploration of out-of-the box treatment concepts, including experimental therapies designed for trauma care.