Femoral blood gas analysis, another tool to assess hemorrhage severity following trauma: an exploratory prospective study.

BACKGROUND: Veno-arterial carbon dioxide tension difference (ΔPCO2) and mixed venous oxygen saturation (SvO2) have been shown to be markers of the adequacy between cardiac output and metabolic needs in critical care patients. However, they have hardly been assessed in trauma patients. We hypothesized that femoral ΔPCO2 (ΔPCO2 fem) and SvO2 (SvO2 fem) could predict the need for red blood cell (RBC) transfusion following severe trauma. METHODS: We conducted a prospective and observational study in a French level I trauma center. Patients admitted to the trauma room following severe trauma with an Injury Severity Score (ISS) > 15, who had arterial and venous femoral catheters inserted were included. ΔPCO2 fem, SvO2 fem and arterial blood lactate were measured over the first 24 h of admission. Their abilities to predict the transfusion of at least one pack of RBC (pRBCH6) or hemostatic procedure during the first six hours of admission were assessed using receiver operating characteristics curve. RESULTS: 59 trauma patients were included in the study. Median ISS was 26 (22-32). 28 patients (47%) received at least one pRBCH6 and 21 patients (35,6%) had a hemostatic procedure performed during the first six hours of admission. At admission, ΔPCO2 fem was 9.1 ± 6.0 mmHg, SvO2 fem 61.5 ± 21.6% and blood lactate was 2.7 ± 1.9 mmol/l. ΔPCO2 fem was significantly higher (11.6 ± 7.1 mmHg vs. 6.8 ± 3.7 mmHg, P = 0.003) and SvO2 fem was significantly lower (50 ± 23 mmHg vs. 71.8 ± 14.1 mmHg, P < 0.001) in patients who were transfused than in those who were not transfused. Best thresholds to predict pRBCH6 were 8.1 mmHg for ΔPCO2 fem and 63% for SvO2 fem. Best thresholds to predict the need for a hemostatic procedure were 5.9 mmHg for ΔPCO2 fem and 63% for SvO2 fem. Blood lactate was not predictive of pRBCH6 or the need for a hemostatic procedure. CONCLUSION: In severe trauma patients, ΔPCO2 fem and SvO2 fem at admission were predictive for the need of RBC transfusion and hemostatic procedures during the first six hours of management while admission lactate was not. ΔPCO2 fem and SvO2 fem appear thus to be more sensitive to blood loss than blood lactate in trauma patients, which might be of importance to early assess the adequation of tissue blood flow with metabolic needs.

Machine learning-based prediction of emergency neurosurgery within 24 h after moderate to severe traumatic brain injury.

BACKGROUND: Rapid referral of traumatic brain injury (TBI) patients requiring emergency neurosurgery to a specialized trauma center can significantly reduce morbidity and mortality. Currently, no model has been reported to predict the need for acute neurosurgery in severe to moderate TBI patients. This study aims to evaluate the performance of Machine Learning-based models to establish to predict the need for neurosurgery procedure within 24 h after moderate to severe TBI. METHODS: Retrospective multicenter cohort study using data from a national trauma registry (Traumabase®) from November 2011 to December 2020. Inclusion criteria correspond to patients over 18 years old with moderate or severe TBI (Glasgow coma score ≤ 12) during prehospital assessment. Patients who died within the first 24 h after hospital admission and secondary transfers were excluded. The population was divided into a train set (80% of patients) and a test set (20% of patients). Several approaches were used to define the best prognostic model (linear nearest neighbor or ensemble model). The Shapley Value was used to identify the most relevant pre-hospital variables for prediction. RESULTS: 2159 patients were included in the study. 914 patients (42%) required neurosurgical intervention within 24 h. The population was predominantly male (77%), young (median age 35 years [IQR 24-52]) with severe head injury (median GCS 6 [3-9]). Based on the evaluation of the predictive model on the test set, the logistic regression model had an AUC of 0.76. The best predictive model was obtained with the CatBoost technique (AUC 0.81). According to the Shapley values method, the most predictive variables in the CatBoost were a low initial Glasgow coma score, the regression of pupillary abnormality after osmotherapy, a high blood pressure and a low heart rate. CONCLUSION: Machine learning-based models could predict the need for emergency neurosurgery within 24 h after moderate and severe head injury. Potential clinical benefits of such models as a decision-making tool deserve further assessment. The performance in real-life setting and the impact on clinical decision-making of the model requires workflow integration and prospective assessment.

Time to source control and outcome in community-acquired intra-abdominal infections: The multicentre observational PERICOM study.

BACKGROUND: Optimal management of community-acquired intra-abdominal infections (IAI) requires timely surgical source control and adequate anti-infective treatment. OBJECTIVE: To describe the initial management of community-acquired IAI admitted to the emergency department and assess the association between the length of time to either diagnosis or therapeutic procedures and patient outcomes. DESIGN: A prospective, multicentre, observational study. SETTING: Thirteen teaching hospitals in France between April 2018 and February 2019. PATIENTS: Two hundred and five patients aged at least 18 years diagnosed with community-acquired IAI. MAIN OUTCOME MEASURES: The primary outcome was hospital length of stay. The secondary outcome was hospital mortality. RESULTS: Patients had a mean age of 56 (± 21) years and a median [interquartile] SAPS II of 26 [17 to 34]. Among the study cohort, 18% were postoperatively transferred to intensive care unit and 7% had died by day 28. Median [IQR] time to imaging, antibiotic therapy and surgery were 4 [2 to 6], 7.5 [4 to 12.5] and 9 [5.5 to 17] hours, respectively. The length of time to surgical source control [0.99, 95% confidence interval (CI), 0.98 to 0.99], SOFA greater than 2 [0.36 (95% CI, 0.26 to 0.651)], age greater than 60 years [0.65 (95% CI, 0.45 to 0.94)], generalized peritonitis [0.7 (95% CI, 0.56 to 0.89)] and laparotomy surgery [0.657 (95% CI, 0.42 to 0.78)] were associated with longer hospital length of stay. The duration of time to surgical source control [1.02 (95% CI, 1.01 to 1.04)], generalized peritonitis [2.41 (95% CI, 1.27 to 4.61)], and SOFA score greater than 2 [6.14 (95% CI, 1.40 to 26.88)] were identified as independent risk factors for 28-day mortality. CONCLUSION: This multicentre observational study revealed that the time to surgical source control, patient severity and generalized peritonitis were identified as independent risk factors for increased hospital LOS and mortality in community-acquired IAI. Organisational strategies to reduce the time to surgical management of intra-abdominal infections should be further evaluated. STUDY REGISTRATION: ClinicalTrials.gov on 1 April 2018, NCT03544203.

Clinical decision support for severe trauma patients: Machine learning based definition of a bundle of care for hemorrhagic shock and traumatic brain injury.

BACKGROUND: Deviation from guidelines is frequent in emergency situations, and this may lead to increased mortality. Probably because of time constraints, 55% is the greatest reported guidelines compliance rate in severe trauma patients. This study aimed to identify among all available recommendations a reasonable bundle of items that should be followed to optimize the outcome of hemorrhagic shocks (HSs) and severe traumatic brain injuries (TBIs). METHODS: We first estimated the compliance with French and European guidelines using the data from the French TraumaBase registry. Then, we used a machine learning procedure to reduce the number of recommendations into a minimal set of items to be followed to minimize 7-day mortality. We evaluated the bundles using an external validation cohort. RESULTS: This study included 5,924 trauma patients (1,414 HS and 4,955 TBI) between 2011 and August 2019 and studied compliance to 36 recommendation items. Overall compliance rate to recommendation items was 71.6% and 66.9% for HS and TBI, respectively. In HS, compliance was significantly associated with 7-day decreased mortality in univariate analysis but not in multivariate analysis (risk ratio [RR], 0.91; 95% confidence interval [CI], 0.90-1.17; p = 0.06). In TBI, compliance was significantly associated with decreased mortality in univariate and multivariate analysis (RR, 0.85; 95% CI, 0.75-0.92; p = 0.01). For HS, the bundle included 13 recommendation items. In the validation cohort, when this bundle was applied, patients were found to have a lower 7-day mortality rate (RR, 0.46; 95% CI, 0.27-0.63; p = 0.01). In TBI, the bundle included seven items. In the validation cohort, when this bundle was applied, patients had a lower 7-day mortality rate (RR, 0.55; 95% CI, 0.34-0.71; p = 0.02). DISCUSSION: Using a machine-learning procedure, we were able to identify a subset of recommendations that minimizes 7-day mortality following traumatic HS and TBI. These two bundles remain to be evaluated in a prospective manner. LEVEL OF EVIDENCE: Care Management, level II.

Terror in Paris: Incidence and risk factors for infections related to high-energy ammunition injuries.

BACKGROUND: We aimed to assess the incidence and the risk factors for secondary wound infections associated to high-energy ammunition injuries (HEAI) in the cohort of civilian casualties from the 2015 terrorist attacks in Paris. METHODS: This retrospective multi-centric study included casualties presenting at least one HEAI who underwent surgery during the first 48 h following hospital admission. HEAI-associated infection was defined as a wound infection occurring within the initial 30 days following trauma. Risk factors were assessed using univariate and multivariate analysis. RESULTS: Among the 200 included victims, the rate of infected wounds was 11.5%. The median time between admission and the surgical revision for secondary wound infection was 11 days [IQR 9-20]. No patient died from an infectious cause. Infections were polymicrobial in 44% of the cases. The major risk factors for secondary wound infection were ISS (p < 0.001), SAPS II (p < 0.001), MGAP (p < 0.001), haemorrhagic shock (p = 0.003), use of vasopressors (p < 0.001), blood transfusion (p < 0.001), abdominal penetrating trauma (p = 0.003), open fracture (p = 0.01), vascular injury (p = 0.001), duration of surgery (p = 0.009), presence of surgical material (p = 0.01). In the multivariate analysis, the SAPS II score (OR 1.07 [1.014-1.182], p = 0.019) and the duration of surgery (OR 1.005 [1.000-1.012], p = 0.041) were the only risk factors identified. CONCLUSION: We report an 11.5% rate of secondary wound infection following high-energy ammunition injuries. Risk factors were an immediately severe condition and a prolonged surgery.

Mild increases in plasma creatinine after intermediate to high-risk abdominal surgery are associated with long-term renal injury.

BACKGROUND: The potential relationship between a mild acute kidney injury (AKI) observed in the immediate postoperative period after major surgery and its effect on long term renal function remains poorly defined. According to the "Kidney Disease: Improving Global Outcomes" (KDIGO) classification, a mild injury corresponds to a KIDIGO stage 1, characterized by an increase in creatinine of at least 0.3 mg/dl within a 48-h window or 1.5 to 1.9 times the baseline level within the first week post-surgery. We tested the hypothesis that patients who underwent intermediate-to high-risk abdominal surgery and developed mild AKI in the following days would be at an increased risk of long-term renal injury compared to patients with no postoperative AKI. METHODS: All consecutive adult patients with a plasma creatinine value ≤1.5 mg/dl who underwent intermediate-to high-risk abdominal surgery between 2014 and 2019 and who had at least three recorded creatinine measurements (before surgery, during the first seven postoperative days, and at long-term follow up [6 months-2 years]) were included. AKI was defined using a "modified" (without urine output criteria) KDIGO classification as mild (stage 1 characterised by an increase in creatinine of > 0.3 mg/dl within 48-h or 1.5-1.9 times baseline) or moderate-to-severe (stage 2-3 characterised by increase in creatinine 2 to 3 times baseline or to ≥4.0 mg/dl). The exposure (postoperative kidney injury) and outcome (long-term renal injury) were defined and staged according to the same KDIGO initiative criteria. Development of long-term renal injury was compared in patients with and without postoperative AKI. RESULTS: Among the 815 patients included, 109 (13%) had postoperative AKI (81 mild and 28 moderate-to-severe). The median long-term follow-up was 360, 354 and 353 days for the three groups respectively (P = 0.2). Patients who developed mild AKI had a higher risk of long-term renal injury than those who did not (odds ratio 3.1 [95%CI 1.7-5.5]; p < 0.001). In multivariable analysis, mild postoperative AKI was independently associated with an increased risk of developing long-term renal injury (adjusted odds ratio 4.5 [95%CI 1.8-11.4]; p = 0.002). CONCLUSIONS: Mild AKI after intermediate-to high-risk abdominal surgery is associated with a higher risk of long-term renal injury 1 y after surgery.

Association of Prehospital Time to In-Hospital Trauma Mortality in a Physician-Staffed Emergency Medicine System.

Importance: The association between total prehospital time and mortality in physician-staffed trauma systems remains uncertain. Objective: To describe the association of total prehospital time and in-hospital mortality in prehospital, physician-staffed trauma systems in France, with the hypothesis that total prehospital time is associated with increased mortality. Design, Setting, and Participants: This cohort study was conducted from January 2009 to December 2016. Data for this study were derived from 2 distinct regional trauma registries in France (1 urban and 1 rural) that both have a physician-staffed emergency medical service. Consecutive adult trauma patients admitted to either of the regional trauma referral centers during the study period were included. Data analysis took place from March 2018 to September 2018. Main Outcomes and Measures: The association between death and prehospital time was assessed with a multivariable model adjusted with confounders. Total prehospital time was the primary exposure variable, recorded as the time from the arrival of the physician-led prehospital care team on scene to the arrival at the hospital. The main outcome of interest was all-cause in-hospital mortality. Results: A total of 10 216 patients were included (mean [SD] age, 41 [18] years; 7937 men [78.3%]) affected by predominantly nonpenetrating injuries (9265 [91.5%]), with a mean (SD) Injury Severity Score of 17 (14) points. Of the patients, 6737 (66.5%) had at least 1 body region with an Abbreviated Injury Scale score of 3 or more. A total of 1259 patients (12.4%) presented in shock (with systolic pressure <90 mm Hg) and 2724 (26.9%) with severe head injury (Abbreviated Injury Scale score ≥3 points). On unadjusted analysis, increasing prehospital times (in 30-minute categories) were associated with a markedly and constant increase in the risk of in-hospital death. The odds of death increased by 9% for each 10-minute increase in prehospital time (odds ratio, 1.09 [95% CI, 1.07-1.11]) and after adjustment by 4% (odds ratio, 1.04 [95% CI, 1.01-1.07]). Conclusions and Relevance: In this study, an increase in total prehospital time was associated with increasing in-hospital all-cause mortality in trauma patients at a physician-staffed emergency medical system, after adjustment for case complexity. Prehospital time is a management objective in analogy to physiological targets. These findings plead for a further streamlining of prehospital trauma care and the need to define the optimal intervention-to-time ratio.

Strategic proposal for a national trauma system in France.

In this road map for trauma in France, we focus on the main challenges for system implementation, surgical and radiology training and upon innovative training techniques. Regarding system organisation: procedures for triage, designation and certification of trauma centres are mandatory to implement trauma networks on a national scale. Data collection with registries must be created, with a core dataset defined and applied through all registries. Regarding surgical and radiology training, diagnostic-imaging processes should be standardised and the role of the interventional radiologist within the trauma team and the trauma network should be clearly defined. Education in surgery for trauma is crucial and recent changes in medical training in France will promote trauma surgery as a specific sub-specialty. Innovative training techniques should be implemented and be based on common objectives, scenarios and evaluation, so as to improve individual and team performances. The group formulated 14 proposals that should help to structure and improve major trauma management in France over the next 10 years.

Early management of severe pelvic injury (first 24 hours).

OBJECTIVE: Pelvic fractures represent 5% of all traumatic fractures and 30% are isolated pelvic fractures. Pelvic fractures are found in 10 to 20% of severe trauma patients and their presence is highly correlated to increasing trauma severity scores. The high mortality of pelvic trauma, about 8 to 15%, is related to actively bleeding pelvic injuries and/or associated injuries to the head, abdomen or chest. Regardless of the severity of pelvic trauma, diagnosis and treatment must proceed according to a strategy that does not delay the management of the most severely injured patients. To date, in France, there are no guidelines issued by healthcare authorities or professional societies that address this subject. DESIGN: A consensus committee of 22 experts from the French Society of Anaesthesia and Intensive Care Medicine (Société Française d'Anesthésie et de Réanimation; SFAR) and the French Society of Emergency Medicine (Société Française de Médecine d'Urgence; SFMU) in collaboration with the French Society of Radiology (Société Française de Radiologie; SFR), French Defence Health Service (Service de Santé des Armées; SSA), French Society of Urology (Association Française d'Urologie; AFU), the French Society of Orthopaedic and Trauma Surgery (Société Française de Chirurgie Orthopédique et Traumatologique; SOCFCOT), and the French Society of Digestive Surgery (Société Française de Chirurgie digestive; SFCD) was convened. A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independently from any industry funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasised. METHODS: Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. The analysis of the literature and the recommendations were then conducted according to the GRADE® methodology. RESULTS: The SFAR Guideline panel provided 22 statements on prehospital and hospital management of the unstable patient with pelvic fracture. After three rounds of discussion and various amendments, a strong agreement was reached for 100% of recommendations. Of these recommendations, 11 have a high level of evidence (Grade 1 ± ), 11 have a low level of evidence (Grade 2 ± ). CONCLUSIONS: Substantial agreement exists among experts regarding many strong recommendations for management of the unstable patient with pelvic fracture.

Development and validation of a pre-hospital "Red Flag" alert for activation of intra-hospital haemorrhage control response in blunt trauma.

BACKGROUND: Haemorrhagic shock is the leading cause of early preventable death in severe trauma. Delayed treatment is a recognized prognostic factor that can be prevented by efficient organization of care. This study aimed to develop and validate Red Flag, a binary alert identifying blunt trauma patients with high risk of severe haemorrhage (SH), to be used by the pre-hospital trauma team in order to trigger an adequate intra-hospital standardized haemorrhage control response: massive transfusion protocol and/or immediate haemostatic procedures. METHODS: A multicentre retrospective study of prospectively collected data from a trauma registry (Traumabase®) was performed. SH was defined as: packed red blood cell (RBC) transfusion in the trauma room, or transfusion ≥ 4 RBC in the first 6 h, or lactate ≥ 5 mmol/L, or immediate haemostatic surgery, or interventional radiology and/or death of haemorrhagic shock. Pre-hospital characteristics were selected using a multiple logistic regression model in a derivation cohort to develop a Red Flag binary alert whose performances were confirmed in a validation cohort. RESULTS: Among the 3675 patients of the derivation cohort, 672 (18%) had SH. The final prediction model included five pre-hospital variables: Shock Index ≥ 1, mean arterial blood pressure ≤ 70 mmHg, point of care haemoglobin ≤ 13 g/dl, unstable pelvis and pre-hospital intubation. The Red Flag alert was triggered by the presence of any combination of at least two criteria. Its predictive performances were sensitivity 75% (72-79%), specificity 79% (77-80%) and area under the receiver operating characteristic curve 0.83 (0.81-0.84) in the derivation cohort, and were not significantly different in the independent validation cohort of 2999 patients. CONCLUSION: The Red Flag alert developed and validated in this study has high performance to accurately predict or exclude SH.

Tranexamic acid in severe trauma patients managed in a mature trauma care system.

BACKGROUND: Tranexamic acid (TXA) use in severe trauma remains controversial notably because of concerns of the applicability of the CRASH-2 study findings in mature trauma systems. The aim of our study was to evaluate the outcomes of TXA administration in severely injured trauma patients managed in a mature trauma care system. METHODS: We performed a retrospective study of data prospectively collected in the TraumaBase registry (a regional registry collecting the prehospital and hospital data of trauma patients admitted in six Level I trauma centers in Paris Area, France). In hospital mortality was compared between patients having received TXA or not in the early phase of resuscitation among those presenting an unstable hemodynamic state. Propensity score for TXA administration was calculated and results were adjusted for this score. Hemodynamic instability was defined by the need of packed red blood cells (pRBC) transfusion and/or vasopressor administration in the emergency room (ER). RESULTS: Among patients meeting inclusion criteria (n = 1,476), the propensity score could be calculated in 797, and survival analysis could be achieved in 684 of 797. Four hundred seventy (59%) received TXA, and 327 (41%) did not. The overall hospital mortality rate was 25.7%. There was no effect of TXA use in the whole population but mortality was lowered by the use of TXA in patients requiring pRBC transfusion in the ER (hazard ratio, 0.3; 95% confidence interval, 0.3-0.6). CONCLUSION: The use of TXA in the management of severely injured trauma patients, in a mature trauma care system, was not associated with reduction in the hospital mortality. An independent association with a better survival was found in a selected population of patients requiring pRBC transfusion in the ER. LEVEL OF EVIDENCE: Therapeutic study, level III.

Intestinal microcirculation and mucosal oxygenation during hemorrhagic shock and resuscitation at different inspired oxygen concentrations.

BACKGROUND: Hypotensive resuscitation is the standard of care of hemorrhagic shock resuscitation. The optimal level of arterial pressure is debated and there is a lack of data on relationships between arterial pressure, microcirculation and tissue oxygenation. We investigated the relationship between mean arterial pressure, intestinal microcirculation and mucosal oxygen tension during hemorrhagic shock and resuscitation at different inspired oxygen fraction concentration. METHODS: The study was divided into two phases: 32 mice were progressively exsanguinated and then transfused in mean arterial pressure (MAP)-titrated steps of 10 mm Hg. Mice were randomized to four experimental groups: a control group in which sham mice underwent a laparotomy and three interventional groups with a common phase of exsanguination followed by progressive resuscitation at three different inspired oxygen concentrations (FIO2) (15%, 30%, and 100%). Intestinal mucosal oxygenation (intestinal PO2) and microcirculatory parameters were recorded at each 10 mm Hg MAP step. RESULTS: During exsanguination, intestinal PO2 decreased linearly with MAP levels. Microcirculatory parameters decreased nonlinearly with MAP levels while they had a linear relationship with intestinal PO2. Intestinal mucosal hypoxia (PO2 ≤ 20 mm Hg) began at a MAP of 60 mm Hg and MAP < 60 mm Hg was associated with a high percentage of animal with intestinal hypoxia (≥32%). Combination of MAP and microcirculatory parameters was superior to MAP alone at predicting mucosal oxygenation. Inversely, during resuscitation with FIO2 = 30%, the microcirculatory parameters increased linearly with MAP levels while they had a nonlinear relationship with intestinal PO2. Hypoxia (FIO2 = 15%) was poorly tolerated. In hyperoxic group (FIO2 = 100%) intestinal PO2 became significantly higher than baseline values as soon as 50 mm Hg MAP. CONCLUSION: During hemorrhagic shock, intestinal PO2 decreased linearly with MAP levels and microcirculatory parameters. Associating MAP and microcirculatory parameters allowed a better prediction of intestinal PO2 than MAP alone. A MAP < 60 mm Hg was associated with a high percentage of animal with intestinal hypoxia. Normoxic resuscitation (FIO2 = 30%) was sufficient to restore intestinal PO2.

Evaluation of the performance of French physician-staffed emergency medical service in the triage of major trauma patients.

BACKGROUND: Proper prehospital triage of trauma patients is a cornerstone for the process of care of trauma patients. In France, emergency physicians perform this process according to a national triage algorithm called Vittel Triage Criteria (VTC), introduced in 2002 to help the triage decision-making process. The aim of this two-center study was to evaluate the performance of the triage process based on the VTC to identify major trauma patients in the Paris area. METHODS: This was a retrospective analysis of two cohorts. The first cohort consisted of all patients admitted between January 2011 and September 2012 in two trauma referral centers in the region of Paris (Ile de France) and allowed estimation of overtriage. Undertriage was assessed in a second cohort made up of all prehospital trauma interventions from one emergency medicine sector during the same period. Adequate triage was defined by a direct admission of patients with an Injury Severity Score (ISS) greater than 15 into one of the regional trauma centers, and undertriage was defined as an initial nonadmission to a trauma center. Overtriage was defined by an admission of patients with an ISS of 15 or lower to a trauma center. The performance of the VTC was evaluated according to a strict to-the-letter application of the VTC and termed as theoretical triage. Logistic regression was performed to identify VTC criteria able to predict major trauma. RESULTS: Among 998 admitted patients of the first cohort, 173 patients (17%) were excluded because they were not directly admitted in the first 24 hours. In the first cohort (n = 825), adequate triage was 58% and overtriage was 42%. In the second cohort (n = 190), adequate triage was 40%, overtriage was 60%, and undertriage was less than 1%. Theoretical triage generated a nonsignificantly lower overtriage and a higher undertriage compared with observed triage. The most powerful predictors of major trauma were paralysis (odds ratio [OR,] 0.09; 95% confidence interval [CI], 0.03-0.22), flail chest (OR, 0.1; 95% CI, 0.01-0.03), and Glasgow Coma Scale (GCS) score of less than 13 (OR, 0.28; 95% CI, 0.17-0.45), whereas global assessments of speed and mechanism alone were poor predictors (positive likelihood ratio, 0.92-1.4). CONCLUSION: In the Paris area, the French physician-based prehospital triage system for patients with suspicion of major trauma showed a high rate of overtriage and a low rate of undertriage. Criteria of global assessment of speed and mechanism alone were poor predictors of major trauma.

Contrast-enhanced ultrasound: a new vision of microcirculation in the intensive care unit.

To gain new insights into renal perfusion and pathogenesis of acute kidney injury in intensive care unit (ICU) patients, we need new techniques to evaluate renal microcirculation. In addition, a bedside technique applicable in the ICU could be extremely useful for physicians to adjust the optimal therapeutic/preventive modalities for kidney perfusion in each patient. Contrast-enhanced ultrasound (CEUS) has been validated to assess and quantify the microcirculation up to capillary perfusion in several organs. In a recent issue, Schneider and colleagues suggest that CEUS is feasible, well tolerated and able to quantify cortical renal microcirculation in patients undergoing cardiac surgery. In addition, CEUS derived-parameters suggest a decrease in renal perfusion occurring within 24 hours of surgery in patients at risk of acute kidney injury. This study opens up new possibilities for the assessment of cortical renal microcirculation in ICU patients.

Interleukin 10 antioxidant effect decreases leukocytes/endothelial interaction induced by tumor necrosis factor α.

Little is known about the endothelial mechanisms involved in the anti-inflammatory effects of interleukin 10 (IL-10). The goal of this study was to evaluate the effects of IL-10 on endothelial oxidative stress and endothelial inflammation induced by tumor necrosis factor α (TNF-α). Production of reactive oxygen species (ROS) in perfused human umbilical vein endothelial cells (HUVECs) was studied by fluorescent microscopy using dichlorodihydrofluorescein diacetate. Tumor necrosis factor α (1 ng/mL) was added to the perfusion medium in the absence and presence of IL-10 (1 ng/mL). The role of phosphatidylinositol 3-kinase (PI3-kinase) was assessed using wortmannin and LY 2940002 (inhibitors of PI3-kinase). Specific inhibition of p110 α and p110 γ/δ PI3-kinase subunits was studied using A66 and TG100-115. As well, levels of ceramide and intercellular adhesion molecule 1 (ICAM-1) expression were measured. Finally, the effect of IL-10 on TNF-α-induced leukocyte/endothelium interaction was examined using an ex vivo perfused vessel model. Interleukin 10 significantly reduced dichlorodihydrofluorescein diacetate fluorescence induced by TNF-α in HUVECs (12.5% ± 3.2% vs. 111.7% ± 21.6% at 60 min). Pretreatment by LY2940002 or wortmannin restored ROS production induced by TNF-α in the presence of IL-10. In HUVECs treated by TNF-α + IL-10, inhibition of p110 α PI3-kinase subunit significantly increased ROS production, whereas p110 γ/δ inhibition did not have a significant effect. Pretreatment with IL-10 significantly decreased TNF-α-induced increased levels of ceramide (TNF-α vs. TNF-α + IL-10: 6,278 ± 1,013 vs. 1,440 ± 130 pmol/mg prot), as well as ICAM-1 expression and leukocyte adhesion (TNF-α vs. TNF-α + IL-10: 26.8 ± 2.6 vs. 6.7 ± 0.4 adherent leukocytes/field at 15 min). Interleukin 10 decreases the level of inflammation induced by TNF-α in endothelial cells by reducing the TNF-α-induced ROS production, ICAM-1 expression, and leukocyte adhesion to the endothelium. The antioxidant effect of IL-10 is mediated through PI3-kinase and is paralleled by a decrease in ceramide synthesis induced by TNF-α.

Renal resistive index better predicts the occurrence of acute kidney injury than cystatin C.

The objective of this study was to determine the predictive value of the renal resistive index (RI) and cystatin C values in serum (SCys) and urine (UCys) in the development of acute kidney injury (AKI) in critically ill patients with severe sepsis or polytrauma. This was a prospective, double-center, descriptive study. There were 58 patients with severe sepsis (n= 28) or polytrauma (n = 30). Renal resistive index, SCys, and UCys were measured within 12 h following admission (day 1 [D1]) to the intensive care unit. Renal function was assessed using the AKI network classification: On day 3 (D3), 40 patients were at stage 0 or 1, and 18 were at stage 2 or 3. Patients with AKI stage 2 or 3 had significantly higher RI (0.80 vs. 0.66, P < 0.0001), SCys (1.23 vs. 0.68 mg/L, P = 0.0002), and UCys (3.32 vs. 0.09 mg/L, P = 0.0008). They also had higher Simplified Acute Physiology Score II, arterial lactate level, and intensive care unit mortality. In multivariate analysis, an RI of greater than 0.707 on D1 was the only parameter predictive of the development of AKI stage 2 or 3 on D3 (P = 0.0004). In the subgroup of patients with AKI stage 2 or 3 on D1, RI remained the only parameter associated with persistent AKI on D3 (P = 0.016). In multivariate analysis comparing the predictive value of RI, SCys, and UCys, RI was the only parameter predictive of AKI stage 2 or 3 on D3. Renal resistive index seems to be a promising tool to assess the risk of AKI.

Postresuscitation syndrome: potential role of hydroxyl radical-induced endothelial cell damage.

OBJECTIVE: After out of hospital cardiac arrest, it has been reported that endothelium dysfunction may occur during the postresuscitation syndrome. However, the consequences of the reperfusion phase on endothelial reactive oxygen species production and redox homeostasis have not been explored in out of hospital cardiac arrest patients. DESIGN: Prospective, observational study. SETTING: Medical intensive care unit in a university hospital. PATIENTS: Twenty successfully resuscitated out of hospital cardiac arrest patients, seven septic shock patients, and ten healthy volunteers. INTERVENTION: Plasma was collected from patients at admission and 12, 24, 36, 48, and 72 hrs after cardiac arrest. We studied the production of reactive oxygen species and cell survival during plasma perfusion using perfused endothelial cells (human umbilical vein endothelial cells) as a model. Cell antioxidant response was studied by measuring superoxide dismutase, glutathione peroxidase, and glutathione reductase activities and reduced and oxidized glutathione levels. Mitochondrial respiratory chain activity was assessed by measuring complex I, II, III, and IV activities and anaerobic glycolysis by measuring glucose-6-phosphate dehydrogenase activity. MEASUREMENTS AND MAIN RESULTS: Using perfused endothelial cells as a model, we demonstrate that plasma from out of hospital cardiac arrest patients induced on naive human umbilical vein endothelial cells a significant and massive cell death compared to plasma from septic shock patients and healthy volunteers. An increase of reactive oxygen species production with a decrease in antioxidant defenses (superoxide dismutase, glutathione peroxidase, and glutathione reductase activities, reduced and oxidized glutathione levels) was observed. The metabolic consequence of plasma exposure showed that mitochondrial respiratory chain activity was significantly impaired and anaerobic glycolysis was significantly increased. Inhibiting hydroxyl radical production significantly decreased cell death, suggesting that plasma from out of hospital cardiac arrest induced significant cell death by triggering the Fenton reaction. CONCLUSION: Plasma from out of hospital cardiac arrest induces major endothelial toxicity with an acute pro-oxidant state in the cells and impairment of mitochondrial respiratory chain activity. This toxicity could be due to hydroxyl radical production by activation of the Fenton reaction.

[Hemorrhagic shock]. / Choc hémorragique.

Hemorrhagic shock generates a prolonged alteration of organ perfusion due to the decrease in oxygen delivery. Hemorrhagic shock is mainly due to three etiologies: traumatology, gastrointestinal bleeding and high risk surgery. If intensive cares are not rapidly performed, severe complications occur, as organ failure with a high mortality rate. Primary cares aim at restoring a perfusion pressure to prevent tissue hypoperfusion while waiting for the radical therapy of bleeding. Priority during initial treatment is to restore tissue perfusion and achieve haemostasis in vital functions. Fluid resuscitation and transfusion are common to every case of hemorrhagic shock but the strategy to localise the hemorrhage and stop the bleeding differs between the situations. Key factors in the management of hemorrhagic shock are the communication between surgical, anaesthetic, and critical care teams and the application of pathology.