The value of pre-hospital trauma life support courses for medical personnel-a questionnaire study.

Background: The aim of the study was to determine the impact that PHTLS® course participation had on self-confidence of emergency personnel, regarding the pre-hospital treatment of patients who had suffered severe trauma. Furthermore, the goal was to determine the impact of specific medical profession, work experience and prior course participation had on the benefits of PHTLS® training. Methods: A structured questionnaire study was performed. Healthcare providers from local emergency services involved in pre-hospital care in the metropolitan area of Zurich (Switzerland, Europe) who completed a PHTLS® course were included. Altered self-confidence, communication, and routines in the treatment of severe trauma patients were examined. The impact of prior course participation, work experience and profession on course benefits were evaluated. Results: The response rate was 76%. A total of 6 transport paramedics (TPs), 66 emergency paramedics (EPs) and 15 emergency doctors (EDs) were included. Emergency paramedics had significantly more work experience compared with EDs (respectively 7.1 ± 5.7 yrs. vs. 4.5 ± 2.1 yrs., p = 0.004). 86% of the participants reported increased self-confidence in the pre-hospital management of severe trauma upon PHTLS® training completion. Moreover, according to 84% of respondents, extramural treatment of trauma changed upon course completion. PHTLS® course participants had improved communication in 93% of cases. This was significantly more frequent in EPs than TPs (p = 0.03). Multivariable analysis revealed emergency paramedics benefit the most from PHTLS® course participation. Conclusion: The current study shows that PHTLS® training is associated with improved self-confidence and enhanced communication, with regards to treatment of severe trauma patients in a pre-hospital setting, among medical emergency personnel. Additionally, emergency paramedics who took the PHTLS® course improved in overall self-confidence. These findings imply that all medical personal involved in the pre-hospital care of trauma patients, in a metropolitan area in Europe, do benefit from PHTLS® training. This was independent of the profession, previous working experience or prior alternative course participation.

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.

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.

Cellular activation status in femoral shaft fracture hematoma following different reaming techniques - A large animal model.

The local inflammatory impact of different reaming protocols in intramedullary nailing has been sparsely investigated. We examined the effect of different reaming protocols on fracture hematoma (FH) immunological characteristics in pigs. To do so, a standardized midshaft femur fracture was induced in adult male pigs. Fractures were treated with conventional reamed femoral nailing (group RFN, n = 6); unreamed femoral nailing (group UFN, n = 6); reaming with a Reamer Irrigator Aspirator device (group RIA, n = 12). Animals were observed for 6 h and FH was collected. FH-cell apoptosis and neutrophil receptor expression (Mac-1/CD11b and FcγRIII/CD16) were studied by flow cytometry and local temperature changes were analyzed. The study demonstrates that apoptosis-rates of FH-immune cells were significantly lower in group RIA (3.50 ± 0.53%) when compared with non-RIA groups: (group UFN 12.50 ± 5.22%, p = 0.028 UFN vs. RIA), (group RFN 13.30 ± 3.18%, p < 0.001, RFN vs. RIA). Further, RIA-FH showed lower neutrophil CD11b/CD16 expression when compared with RFN (mean difference of 43.0% median fluorescence intensity (MFI), p = 0.02; and mean difference of 35.3% MFI, p = 0.04, respectively). Finally, RIA induced a transient local hypothermia and hypothermia negatively correlated with both FH-immune cell apoptosis and neutrophil activation. In conclusion, immunologic changes observed in FH appear to be modified by certain reaming techniques. Irrigation during reaming was associated with transient local hypothermia, decreased apoptosis, and reduced neutrophil activation. Further study is warranted to examine whether the rinsing effect of RIA, specific tissue removal by reaming, or thermal effects predominantly determine local inflammatory changes during reaming.

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.

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.

Fracture fixation strategy and specific muscle tissue availability of neutrophilic granulocytes following mono- and polytrauma: intramedullary nailing vs. external fixation of femoral fractures.

BACKGROUND: In the stabilization of femoral fractures in mono- and polytrauma, clinical practice has shown better care through intramedullary nailing. However, the reason why this is the case is not fully understood. In addition to concomitant injuries, the immunological aspect is increasingly coming to the fore. Neutrophil granulocytes (PMNL), in particular next to other immunological cell types, seem to be associated with the fracture healing processes. For this reason, the early phase after fracture (up to 72 h after trauma) near the fracture zone in muscle tissue was investigated in a pig model. MATERIAL AND METHODS: A mono- and polytrauma pig model (sole femur fracture or blunt thoracic trauma, hemorrhagic shock, liver laceration, and femur fracture) was used to demonstrate the immunological situation through muscle biopsies and their analysis by histology and qRT-PCR during a 72 h follow-up phase. Two stabilization methods were used (intramedullary nail vs. external fixator) and compared with a nontraumatized sham group. RESULTS: Monotrauma shows higher PMNL numbers in muscle tissue compared with polytrauma (15.52 ± 5.39 mono vs. 8.23 ± 3.36 poly; p = 0.013), regardless of the treatment strategy. In contrast, polytrauma shows a longer lasting invasion of PMNL (24 h vs. 72 h). At 24 h in the case of monotrauma, the fracture treated with external fixation shows more PMNL than the fracture treated with intramedullary nailing (p = 0.026). This difference cannot be determined in polytrauma probably caused by a generalized immune response. Both monotrauma and polytrauma show a delayed PMNL increase in the muscle tissue of the uninjured side. The use of intramedullary nailing in monotrauma resulted in a significant increase in IL-6 (2 h after trauma) and IL-8 (24 and 48 h after trauma) transcription. CONCLUSION: The reduction of PMNL invasion into the nearby muscle tissue of a monotrauma femur fracture stabilized by intramedullary nailing supports the advantages found in everyday clinical practice and therefore underlines the usage of nailing. For the polytrauma situation, the fixation seems to play a minor role, possibly due to a generalized immune reaction.

The impact of intramedullary nailing on the characteristics of the pulmonary neutrophil pool in rodents.

PURPOSE: Dysregulation of polymorphonuclear neutrophil (PMN) biology is associated with the development of inflammatory complications after trauma, such as acute respiratory distress syndrome (ARDS). It has been demonstrated that intramedullary nailing is both associated with altered pulmonary neutrophil deposition and the occurrence of ARDS. This standardized study aimed to characterize the long-term remote neutrophil response in the lungs in case of a femur fracture and intramedullary nailing. METHODS: A standardized rat model including intramedullary nailing and a femur fracture was utilized. Groups were terminated after observation times of three, seven and 14 days. Neutrophils were isolated from lung parenchyma and broncho-alveolar lavage fluid (BALF) and analyzed by flow cytometry. Absolute neutrophil numbers as well as membrane expression levels of CD11b, CD62L, and CD11a were compared. RESULTS: Pulmonary neutrophil numbers were increased 3 days after intervention. Membrane expression levels of CD11b (P < 0.01), CD62L (P < 0.01), and CD11a (P = 0.06) on parenchymal PMNs increased as well after 3 days. Thereafter, values restored gradually to physiological levels. Furthermore, neutrophil activation status patterns between parenchymal and BALF neutrophil pools did not correlate. CONCLUSIONS: The current study demonstrates that IMN and a femur fracture are associated with transient increased pulmonary PMN deposition, as well as a specific pattern of activation characterized by temporary increased selectin and integrin receptor expression on pulmonary neutrophils. This phenomenon might play an important role in the pathomechanism of ARDS after IMN. Moreover, we found striking differences between parenchymal and BALF-neutrophil populations, demonstrating the limited readout potential of BALF analysis to investigate the entire pulmonary neutrophil pool.

Effect of neurokinin-1-receptor blockage on fracture healing in rats.

Neurologic injury and selective blockage of sensory nerve endings is associated with impaired fracture healing, however, the role of specific neurotransmitters has not been sufficiently investigated. Our aim was to investigate the impact of specific Substance P-receptor blockage on fracture healing, since the neuropeptide Substance P has both neurogenic and osteogenic activity. After intramedullary stabilization, an isolated femur fracture was induced in 72 Sprague-Dawley rats. In the NK1-R group, the neurokinin-1-tachykinin receptor for substance P was blocked by a specific antagonist (SR140333) for the first two weeks after fracture induction. The control group only received vehicle. Gene-expression, histology, micro-computed tomography, and biomechanical tests were performed. NK1-receptor blocking suppressed osteocalcin expression at one week, collagen 1A2 expression at one and two weeks and collagen 2A1 expression at 2 weeks after fracture induction. Biomechanical testing revealed a significant reduction in maximal load to failure in the NK1-R group at 6 weeks (69.78 vs. 155.45 N, p = 0.029) and at 3 months (72.50 vs.176.33 N, p = 0.01) of fracture healing. Blocking the NK1-receptor suppresses gene expression in and reduces biomechanical strength of healing bone. Therefore, we assume a potential therapeutic relevance of Substance P in cases of disturbed fracture healing.

Safety of selective nonoperative management for blunt splenic trauma: the impact of concomitant injuries.

BACKGROUND: Nonoperative management for blunt splenic injury is the preferred treatment. To improve the outcome of selective nonoperative therapy, the current challenge is to identify factors that predict failure. Little is known about the impact of concomitant injury on outcome. Our study has two goals. First, to determine whether concomitant injury affects the safety of selective nonoperative treatment. Secondly we aimed to identify factors that can predict failure. METHODS: From our prospective trauma registry we selected all nonoperatively treated adult patients with blunt splenic trauma admitted between 01.01.2000 and 12.21.2013. All concurrent injuries with an AIS ≥ 2 were scored. We grouped and compared patients sustaining solitary splenic injuries and patients with concomitant injuries. To identify specific factors that predict failure we used a multivariable regression analysis. RESULTS: A total of 79 patients were included. Failure of nonoperative therapy (n = 11) and complications only occurred in patients sustaining concomitant injury. Furthermore, ICU-stay as well as hospitalization time were significantly prolonged in the presence of associated injury (4 versus 13 days,p < 0.05). Mortality was not seen. Multivariable analysis revealed the presence of a femur fracture and higher age as predictors of failure. CONCLUSIONS: Nonoperative management for hemodynamically normal patients with blunt splenic injury is feasible and safe, even in the presence of concurrent (non-hollow organ) injuries or a contrast blush on CT. However, associated injuries are related to prolonged intensive care unit- and hospital stay, complications, and failure of nonoperative management. Specifically, higher age and the presence of a femur fracture are predictors of failure.

Non-operative management for penetrating splenic trauma: how far can we go to save splenic function?

BACKGROUND: Selective non-operative management (NOM) for the treatment of blunt splenic trauma is safe. Currently, the feasibility of selective NOM for penetrating splenic injury (PSI) is unclear. Unfortunately, little is known about the success rate of spleen-preserving surgical procedures. The aim of this study was to investigate the outcome of selective NOM for penetrating splenic injuries. METHODS: A dual-centre study is performed in two level-one trauma centres. All identified patients treated for PSI were identified. Patients were grouped based on the treatment they received. Group one consisted of splenectomised patients, the second group included patients treated by a spleen-preserving surgical intervention, and group three included those patients who were treated by NOM. RESULTS: A total of 118 patients with a median age of 27 and a median ISS of 25 (interquartile range (IQR) 16-34) were included. Ninety-six patients required operative intervention, of whom 45 underwent a total splenectomy and 51 underwent spleen-preserving surgical procedures. Furthermore, 22 patients (12 stab wounds and 10 gunshot wounds) were treated by NOM. There were several anticipated significant differences in the baseline encountered. The median hospitalization time was 8 (5-12) days, with no significant differences between the groups. The splenectomy group had significantly more intensive care unit (ICU) days (2(0-6) vs. 0(0-1)) and ventilation days (1(0-3) vs. 0(0-0)) compared to the NOM group. Mortality was only noted in the splenectomy group. CONCLUSIONS: Spleen-preserving surgical therapy for PSI is a feasible treatment modality and is not associated with increased mortality. Moreover, a select group of patients can be treated without any surgical intervention at all.