Kai Sprengel

Whole-body CT-based imaging algorithm for multiple trauma patients: radiation dose and time to diagnosis

OBJECTIVE To determine the number of imaging examinations, radiation dose and the time to complete trauma-related imaging in multiple trauma patients before and after introduction of whole-body CT (WBCT) into early trauma care. METHODS 120 consecutive patients before and 120 patients after introduction of WBCT into the trauma algorithm of the University Hospital Zurich were compared regarding the number and type of CT, radiography, focused assessment with sonography for trauma (FAST), additional CT examinations (defined as CT of the same body regions after radiography and/or FAST) and the time to complete trauma-related imaging. RESULTS In the WBCT cohort, significantly more patients underwent CT of the head, neck, chest and abdomen (p < 0.001) than in the non-WBCT cohort, whereas the number of radiographic examinations of the cervical spine, chest and pelvis and of FAST examinations were significantly lower (p < 0.001). There were no significant differences between cohorts regarding the number of radiographic examinations of the upper (p = 0.56) and lower extremities (p = 0.30). We found significantly higher effective doses in the WBCT (29.5 mSv) than in the non-WBCT cohort (15.9 mSv; p < 0.001), but fewer additional CT examinations for completing the work-up were needed in the WBCT cohort (p < 0.001). The time to complete trauma-related imaging was significantly shorter in the WBCT (12 min) than in the non-WBCT cohort (75 min; p < 0.001). CONCLUSION Including WBCT in the initial work-up of trauma patients results in higher radiation doses, but fewer additional CT examinations are needed, and the time for completing trauma-related imaging is shorter. ADVANCES IN KNOWLEDGE WBCT in trauma patients is associated with a high radiation dose of 29.5 mSv.

Effect of elevated serum alcohol level on the outcome of severely injured patients.

Background The influence of high blood alcohol level (BAL) on the outcome of severely injured patients and the corresponding pathophysiological changes is a controversial issue. Objective To carry out a prognostic study to compare the physiological values and short-term outcome of severely injured patients depending on their serum alcohol level. Methods A total of 383 severely injured patients with an Injury Severity Score (ISS) ≥17 were admitted to the trauma division between October 2008 and December 2009 and enrolled into this study. Patients were grouped according to their BAL (>0.5‰,‘BAL positive’ vs <0.5‰,‘BAL negative’). Trauma mechanism, pattern of injury and its treatment, and a course of intensive care treatment, physiological parameters and outcome with respect to mortality were analysed. Results Both groups had similar ISS. In comparison with the BAL-negative group, patients in the BAL-positive group had a significantly lower Glasgow Coma Scale score (9.64 vs 12 points; p=0.005) and, although not significant, a trend towards higher values of the Abbreviated Injury Score for the head (3.29 vs 2.81 points; p=0.146). Furthermore, significantly higher lactate (3.11 mmol/L vs 2.02 mmol/L; p<0.001) levels and lower median arterial pressure values (87.9 mm Hg vs 99.4 mm Hg; p=0.006) were seen in the BAL-positive group at day of admission. However, the overall in-hospital mortality was comparable to that in BAL-negative patients (19.6% vs 21.5%). Similarly, hospital stay (15.29 vs 17.55 days) and duration of intensive care unit treatment (8.53 vs 8.36 days) were not significantly affected by a high BAL upon admission. Conclusions Severely injured patients with a raised BAL have a higher incidence of severe traumatic brain injury and worse initial physiological parameters. However, the survival rate and in-hospital stay is not influenced. This supports the theory of a neuroprotective role of alcohol.

Change of transfusion and treatment paradigm in major trauma patients

Trauma promotes trauma‐induced coagulopathy, which requires urgent treatment with fixed‐ratio transfusions of red blood cells, fresh frozen plasma and platelet concentrates, or goal‐directed administration of coagulation factors based on viscoelastic testing. This retrospective observational study compared two time periods before (2005–2007) and after (2012–2014) the implementation of changes in trauma management protocols which included: use of goal‐directed coagulation management; admission of patients to designated trauma centres; whole‐body computed tomography scanning on admission; damage control surgery; permissive hypotension; restrictive fluid resuscitation; and administration of tranexamic acid. The incidence of massive transfusion (≥ 10 units of red blood cells from emergency department arrival until intensive care unit admission) was compared with the predicted incidence according to the trauma associated severe haemorrhage score. All adult (≥ 16 years) trauma patients primarily admitted to the University Hospital Zürich with an injury severity score ≥ 16 were included. In 2005–2007, the observed and trauma associated severe haemorrhage score that predicted the incidence of massive transfusion were identical, whereas in 2012–2014 the observed incidence was less than half that predicted (3.7% vs. 7.5%). Compared to 2005–2007, the proportion of patients transfused with red blood cells and fresh frozen plasma was significantly lower in 2012–2014 in both the emergency department (43% vs. 17%; 31% vs. 6%, respectively), and after 24 h (53% vs. 27%; 37% vs. 16%, respectively). The use of tranexamic acid and coagulation factor XIII also increased significantly in the 2012–2014 time period. Implementation of a revised trauma management strategy, which included goal‐directed coagulation management, was associated with a reduced incidence of massive transfusion and a reduction in the transfusion of red blood cells and fresh frozen plasma.

Influence of metal ions on human lymphocytes and the generation of titanium-specific T-lymphocytes

Background There is mounting evidence to suggest the involvement of the immune system by means of activation by metal ions released via biocorrosion, in the pathophysiologic mechanisms of aseptic loosening of orthopedic implants. However, the detailed mechanisms of how metal ions become antigenic and are presented to T-lymphocytes, in addition to how the local inflammatory response is driven, remain to be investigated. Methods Human T-lymphocytes were cultured in the presence of a variety of metal ions before investigating functional and phenotypic changes using flow cytometric analysis. Additionally, human monocyte-derived dendritic cells (mDC) loaded with metal ions were used as antigen-presenting cells and incubated with naive T-lymphocytes with the aim of generating titanium-specific T-lymphocytes. Results Using an autologous in vitro model, with mDC treated with Titanium (IV), we were able to induce Titanium (IV)-specific T-lymphocytes. These T-lymphocytes responded in a dose-related manner to Titanium (IV), while they did not cross-react with Titanium (III) or other metal ions, indicating that the new antigenic peptide complexes formed by Titanium (IV) are highly specific. Conclusion This study showed that mDC exposed to Titanium (IV) are able to induce the generation of Titanium (IV)-specific T-lymphocytes, demonstrating the strong and specific antigenicity of Titanium (IV) ions released by biocorrosion.

An Integrated Clinico-transcriptomic Approach Identifies a Central Role of the Heme Degradation Pathway for Septic Complications after Trauma.

Objective: The present study was aimed to identify mechanisms linked to complicated courses and adverse events after severe trauma by a systems biology approach. Summary Background Data: In severe trauma, overwhelming systemic inflammation can result in additional damage and the development of complications, including sepsis. Methods: In a prospective, longitudinal single-center study, RNA samples from circulating leukocytes from patients with multiple injury (injury severity score ≥17 points; n = 81) were analyzed for dynamic changes in gene expression over a period of 21 days by whole-genome screening (discovery set; n = 10 patients; 90 samples) and quantitative RT-PCR (validation set; n = 71 patients, 517 samples). Multivariate correlational analysis of transcripts and clinical parameters was used to identify mechanisms related to sepsis. Results: Transcriptome profiling of the discovery set revealed the strongest changes between patients with either systemic inflammation or sepsis in gene expression of the heme degradation pathway. Using quantitative RT-PCR analyses (validation set), the key components haptoglobin (HP), cluster of differentiation (CD) 163, heme oxygenase-1 (HMOX1), and biliverdin reductase A (BLVRA) showed robust changes following trauma. Upregulation of HP was associated with the severity of systemic inflammation and the development of sepsis. Patients who received allogeneic blood transfusions had a higher incidence of nosocomial infections and sepsis, and the amount of blood transfusion as source of free heme correlated with the expression pattern of HP. Conclusions: These findings indicate that the heme degradation pathway is associated with increased susceptibility to septic complications after trauma, which is indicated by HP expression in particular.

Fresh frozen plasma is permissive for systemic inflammatory response syndrome, infection, and sepsis in multiple-injured patients

BACKGROUND The correction of coagulopathy with fresh frozen plasma (FFP) is one of the main issues in the treatment of multiple-injured patients. Infectious and septic complications contribute to an adverse outcome in multiple-injured patients. Here, we investigated the role of FFP in the development of inflammatory complications given within the first 48 hours. METHODS A total of 2033 patients with multiple injuries and an Injury Severity Score greater than 16 points and aged 16 years or older were included. The population was subdivided into 2 groups: those who received FFP and those who did not. The data were analyzed using SPSS version 22.0. Associations between the data were tested using Pearson correlation. Independent predictivity was analyzed by binary logistic regression and multivariate regression. Data were considered as significant if P<.05. RESULTS The prothrombin time at admission was significantly lower (68.5%±23.3% vs 81.8%±21.0% normal; P<.001) in the group receiving FFP. The application of FFP led to a more severe systemic inflammatory response syndrome (SIRS) grade (3.0±1.2 vs 2.2±1.4; P<.001), to a higher infection rate (48% vs 28%; P<.001), and to a higher sepsis rate (29% vs 13%; P<.001) in the patients receiving FFP. The correlations between SIRS and the incidence of infections and sepsis increased with the amount of FFP applied (P<.001). CONCLUSIONS Treatment with FFP of bleeding patients with multiple injuries enhances the risk of SIRS, infection, and sepsis; however, a multifactorial genesis has to be postulated.

Paradigm shifts in diagnostics and treatment of multiply injured patients – How does it affect visceral injuries?

EAC 0.62 TRISS 0.717 ISS 0.777 NISS 0.849 APACHE II 0880 TTS 0.917 RISC 0.939 RISC II 0.953 Abdominal injuries in polytraumatized patients [1] can be life threatening and require careful assessment. They may alter the way of management in the polytrauma patient and can dominate the clinical course. There have been several changes in the philosophy of management over the last 50 years [2]. These were associated with changes in the type of injury, caused by improved injury prevention and passive car safety. Changes in the management of nonsurgical bleeding, intensive care options and perioperative care were also relevant. All these initiated the development of multiple changes in treatment.

Assessment of polytraumatized patients according to the Berlin Definition: Does the addition of physiological data really improve interobserver reliability?

Background Several new definitions for categorizing the severely injured as the Berlin Definition have been developed. Here, severely injured patients are selected by additive physiological parameters and by the general Abbreviated Injury Scale (AIS)-based assessment. However, all definitions should conform to an AIS severity coding applied by an expert. We examined the dependence of individual coding on defining injury severity in general and in identifying polytrauma according to several definitions. A precise definition of polytrauma is important for quality management. Methods We investigated the interobserver reliability (IR) between several polytrauma definitions for identifying polytrauma using several cut-off levels (ISS ≥16, ≥18, ≥20, ≥25 points, and the Berlin Definition). One hundred and eighty-seven patients were included for analyzing IR of the polytrauma definitions. IR for polytrauma definitions was assessed by Cohen’s kappa. Results IR for identifying polytrauma according to the relevant definitions showed moderate agreement (<0.60) in the ISS cutoff categories (ISS ≥16, ≥18, and ≥20 points), while ISS ≥25 points just reached substantial agreement (0.62) and the Berlin Definition demonstrated a correlation of 0.77 which is nearly perfect agreement (>0.80). Conclusion Compared with the ISS-based definitions of polytrauma, the Berlin Definition proved less dependent on the individual rater. This underlines the need to redefine the selection of severely injured patients. Using the Berlin Definition for identifying polytrauma could improve the comparability of patient data across studies, in trauma center benchmarking, and in quality assurance.

Abbreviated Surgery: Orthopaedic Surgery

The stepwise approach to the orthopaedic stabilization of the severely injured patient foresees manoeuvres to support resuscitation. This is achieved by i.v. infusions, coagulatory support, vasopressors if required and providing temporary stabilization and by minimizing the load of surgery. The idea behind it is that the biological reserve of the patient is maintained, and the pathogenetic changes induced by trauma are not exaggerated through inadequate surgeries. It is along the concept of the adage primum non nocere or “do no further harm”.

Reimbursement of care for severe trauma under SwissDRG

QUESTIONS Treatment of patients with severe injuries is costly, with best results achieved in specialised care centres. However, diagnosis-related group (DRG)-based prospective payment systems have difficulties in depicting treatment costs for specialised care. We analysed reimbursement of care for severe trauma in the first 3 years after the introduction of the Swiss DRG reimbursement system (2012-2014). MATERIAL/METHODS The study included all patients with solely basic insurance, hospital admission after 01.01.2011 and discharge in 2011 or 2012, who were admitted to the resuscitation room of the University Hospital of Zurich, aged ≥16 years and with an injury severity score (ISS) ≥16 (n = 364). Clinical, financial and administrative data were extracted from the electronic medical records. All cases were grouped into DRGs according to different SwissDRG versions. We considered results to be significant if p ≤0.002. RESULTS The mean deficit decreased from 12 065 CHF under SwissDRG 1.0 (2012) to 2 902 CHF under SwissDRG 3.0 (2014). The main reason for the reduction of average deficits was a refinement of the DRG algorithm with a regrouping of 23 cases with an ISS ≥16 from MDC 01 to DRGs within MDC21A. Predictors of an increased total loss per case could be identified: for example, high total number of surgical interventions, surgeries on multiple anatomical regions or operations on the pelvis (p ≤0.002). Psychiatric diagnoses in general were also significant predictors of deficit per case (p<0.001). CONCLUSION The reimbursement for care of severely injured patients needs further improvement. Cost neutral treatment was not possible under the first three versions of SwissDRG.