Sophie Hamada

Dexmedetomidine: new insights.

Dexmedetomidine is a potent alpha-2-adrenergic agonist, more selective than clonidine, with widespread actions on the mammalian brain that include sedation, anaesthetic-sparing, analgesia and sympatholytic properties. A large body of recent work supports its favourable profile in improving outcome and long-term brain function in the critically ill. The source of these benefits may lie in the neuroprotective properties that are seen in experimental models and in the clinical setting, in which it can attenuate delirium, preserve sleep architecture, preserve ventilatory drive and decrease sympathetic tone and inflammatory response. Dexmedetomidine may also be a valuable adjuvant when regional anaesthesia is used. Future research should aim at establishing the risk/benefit ratio when used at the bedside.

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.

Paris terrorist attack: Early lessons from the intensivists

During the night of 13–14 November, the city of Paris was exposed, within a few hours, to three bomb explosions, four shooting scenes, and one 3-hour hostage-taking of several hundred people causing at least 130 deaths and more than 250 injured victims. Most unstable patients were transferred to the six trauma centers of the Paris area, all members of the TRAUMABASE Group. A rapid adaptation of the organization of trauma patients’ admittance was required in all centers to face the particular needs of the situation. Everything went relatively well in all centers, with overall hospital mortality below 2 %. Nevertheless, most physicians nowadays agree that anticipation, teaching, and training are crucial to appropriately face such events. All of us have learned many additional issues from this experience. Following a meeting of the TRAUMABASE Group, the most relevant issues are detailed in the following.During the night of 13–14 November, the city of Paris was exposed, within a few hours, to three bomb explosions, four shooting scenes, and one 3-hour hostage-taking of several hundred people causing at least 130 deaths and more than 250 injured victims. Most unstable patients were transferred to the six trauma centers of the Paris area, all members of the TRAUMABASE Group. A rapid adaptation of the organization of trauma patients’ admittance was required in all centers to face the particular needs of the situation. Everything went relatively well in all centers, with overall hospital mortality below 2 %. Nevertheless, most physicians nowadays agree that anticipation, teaching, and training are crucial to appropriately face such events. All of us have learned many additional issues from this experience. Following a meeting of the TRAUMABASE Group, the most relevant issues are detailed in the following.

Effect of Rbc Transfusion on Sublingual Microcirculation in Hemorrhagic Shock Patients: A Pilot Study

Objectives: The effects of RBC transfusion on microvascular perfusion are not well documented. We investigated the effect of RBC transfusion on sublingual microcirculation in hemorrhagic shock patients. Design: Prospective, preliminary observational study. Settings: A 28-bed, surgical ICU in a university hospital. Patients: Fifteen hemorrhagic shock patients requiring RBC transfusion. Intervention: Transfusion of one unit of RBCs. Measurements and Main Results: The sublingual microcirculation was assessed with a Sidestream Dark Field imaging device before and after RBC transfusion. After transfusion of one unit of RBC, hemoglobin concentration increased from 8.5 g/dL (7.6–9.5 g/dL) to 9.6 g/dL (9.1–10.3 g/dL) g/dL (p = 0.02) but no effect on macrocirculatory parameters (arterial pressure, cardiac index, heart rate, and pulse pressure variations) was observed. Transfusion of RBC significantly increased microcirculatory flow index (from 2.3 [1.6–2.5] to 2.7 [2.6–2.9]; p < 0.003), the proportion of perfused vessels (from 79% [57–88%] to 92% [88–97%]; p < 0.004), and the functional capillary density (from 21 [19–22] to 24 [22–26] mm/mm2; p = 0.003). Transfusion of RBC significantly decreased the flow heterogeneity index (from 0.51 [0.34–0.62] to 0.16 [0.04–0.29]; p < 0.001). No correlations were observed between other macrovascular parameters and microvascular changes after transfusion. The change in microvascular perfusion after transfusion correlated negatively with baseline microvascular perfusion. Conclusions: RBC transfusion improves sublingual microcirculation independently of macrocirculation and the hemoglobin level in hemorrhagic shock patients. The change in microvascular perfusion after transfusion correlated negatively with baseline microvascular perfusion. Evaluation of microcirculation perfusion is critical for optimization of microvascular perfusion and to define which patients can benefit from RBC transfusion during cardiovascular resuscitation.

Long-term prognosis after out-of-hospital resuscitation of cardiac arrest in trauma patients: prehospital trauma-associated cardiac arrest

Background Although prehospital cardiac arrest (CA) remains associated with poor long-term outcome, recent studies show an improvement in the survival rate after prehospital trauma associated CA (TCA). However, data on the long-term neurological outcome of TCA, particularly from physician-staffed Emergency Medical Service (EMS), are scarce, and results reported have been inconsistent. The objective of this pilot study was to evaluate the long-term outcome of patients admitted to several trauma centres after a TCA. Methods This study is a retrospective database review of all patients from a multicentre prospective registry that experienced a TCA and had undergone successful cardiopulmonary resuscitation (CPR) prior their admission at the trauma centre. The primary end point was neurological outcome at 6 months among patients who survived to hospital discharge. Results 88 victims of TCA underwent successful CPR and were admitted to the hospital, 90% of whom were victims of blunt trauma. Of these 88 patients, 10 patients (11%; CI 95% 6% to 19%) survived to discharge: on discharge, 9 patients displayed a GCS of 15 and Cerebral Performance Categories (CPC) 1–2 and one patient had a GCS 7 and CPC of 3. Hypoxia was the most frequent cause of CA among survivors. 6-month follow-up was achieved for 9 patients of the 10 surviving patients. The 9 patients with a good outcome on hospital discharge had a CPC of 1 or 2 6 months post discharge. All returned to their premorbid family and social settings. Conclusions Among patients admitted to hospital after successful CPR from TCA, hypoxia as the likely aetiology of arrest carried a more favourable prognosis. Most of the patients successfully resuscitated from TCA and surviving to hospital discharge had a good neurological outcome, suggesting that prehospital resuscitation may not be futile.

Fluid resuscitation and vasopressors in severe trauma patients.

Purpose of reviewTo discuss the fluid resuscitation and the vasopressor support in severe trauma patients. Recent findingsA critical point is to prevent a potential increase in bleeding by an overly aggressive resuscitative strategy. Indeed, large-volume fluid replacement may promote coagulopathy by diluting coagulation factors. Moreover, an excessive level of mean arterial pressure may induce bleeding by preventing clot formation. SummaryFluid resuscitation is the first-line therapy to restore intravascular volume and to prevent cardiac arrest. Thus, fluid resuscitation before bleeding control must be limited to the bare minimum to maintain arterial pressure to minimize dilution of coagulation factors and complications of over fluid resuscitation. However, a strategy of low fluid resuscitation needs to be handled in a flexible way and to be balanced considering the severity of the hemorrhage and the transport time. A target systolic arterial pressure of 80–90 mmHg is recommended until the control of hemorrhage in trauma patients without brain injury. In addition to fluid resuscitation, early vasopressor support may be required to restore arterial pressure and prevent excessive fluid resuscitation. It is crucial to find the best alchemy between fluid resuscitation and vasopressors, to consider hemodynamic monitoring and to establish trauma resuscitative protocols.

Comparison of the Prognostic Significance of Initial Blood Lactate and Base Deficit in Trauma Patients.

Background: Initial blood lactate and base deficit have been shown to be prognostic biomarkers in trauma, but their respective performances have not been compared. Methods: Blood lactate levels and base deficit were measured at admission in trauma patients in three level 1 trauma centers. This was a retrospective analysis of prospectively acquired data. The association of initial blood lactate and base deficit with mortality was tested using receiver operating characteristics curve, logistic regression using triage scores (Revised Trauma Score and Mechanism Glasgow scale and Arterial Pressure score), and Trauma Related Injury Severity Score as a reference standard. The authors also used a reclassification method. Results: The authors evaluated 1,075 trauma patients (mean age, 39 ± 18 yr, with 90% blunt and 10% penetrating injuries and a mortality of 13%). At admission, blood lactate was elevated in 425 (39%) patients and base deficit was elevated in 725 (67%) patients. Blood lactate was correlated with base deficit (R2 = 0.54; P < 0.001). Using logistic regression, blood lactate was a better predictor of death than base deficit when considering its additional predictive value to triage scores and Trauma Related Injury Severity Score. This result was confirmed using a reclassification method but only in the subgroup of normotensive patients (n = 745). Conclusions: Initial blood lactate should be preferred to base deficit as a biologic variable in scoring systems built to assess the initial severity of trauma patients.

The initial management of severe trauma patients at hospital admission

The initial management of trauma patient is a critical period aiming at: stabilizing the vital functions; following a rigorous injury assessment; defining a therapeutic strategy. This management has to be organized to minimize loss of time that would be deleterious for the patients outcome. Thus, before patient arrival, the trauma team alert should lead to the initiation of care procedures adapted to the announced severity of the patient. Moreover, each individual should know its role in advance and the team should be managed by only one individual (the trauma leader) to avoid conflicts of decision. A rapid trauma injury assessment aims not only at guiding resuscitation (chest drainage, pelvic contention, to define the mean arterial pressure goal) but also to decide a critical intervention in case of hemodynamic instability (laparotomy, thoracotomy, arterial embolisation). This initial assessment includes a chest and a pelvic X-ray, abdominal ultrasound (extended to the lung) and transcranial Doppler (TCD). The whole body scanner with administration of intravenous contrast material is the cornerstone of the injury assessment but can be done for patients stabilized after the initial resuscitation.

Fibrinogen on Admission in Trauma score: Early prediction of low plasma fibrinogen concentrations in trauma patients

BACKGROUND Early recognition of low fibrinogen concentrations in trauma patients is crucial for timely haemostatic treatment and laboratory testing is too slow to inform decision-making. OBJECTIVE To develop a simple clinical tool to predict low fibrinogen concentrations in trauma patients on arrival. DESIGN Retrospective cohort study. SETTING Three designated level 1 trauma centres in the Paris Region, from January 2011 to December 2013. PATIENTS Patients admitted in accordance with national triage guidelines for major trauma and plasma fibrinogen concentration testing on admission. INTERVENTION Construction of a clinical score [Fibrinogen on Admission in Trauma (FibAT) score] in a derivation cohort to predict fibrinogen plasma concentration 1.5 g l−1 or less after multiple regressions. One point was given for each predictive factor. The score was the sum of all. Validation was performed in a separate validation cohort. MAIN OUTCOME MEASURE Predictive accuracy of FibAT score. RESULTS In total, 2936 patients were included, 2124 in the derivation cohort and 812 in the validation cohort. In the derivation cohort, a multivariate logistic model identified the following predictive factors for plasma fibrinogen concentrations 1.5 g l−1 or less: age less than 33 years, prehospital heart rate more than 100 beats per minute, prehospital SBP less than 100 mmHg, blood lactate concentration on admission more than 2.5 mmol l−1, free intraabdominal fluid on sonography, decrease in haemoglobin concentration from prehospital to admission of more than 2 g dl−1, capillary haemoglobin concentration on admission less than 12 g dl−1 and temperature on admission less than 36°C. The FibAT score had an area under the receiver operating characteristic curve of 0.87 [95% confidence interval (0.86 to 0.91)] in the derivation cohort and of 0.82 (95% confidence interval (0.86 to 0.91)] in the validation cohort to predict a low plasma fibrinogen. CONCLUSION The FibAT score accurately predicts plasma fibrinogen levels 1.5 g l−1 or less on admission in trauma patients. This easy-to-use score could allow early, goal-directed therapy to trauma patients.

Femoral arterial and central venous catheters in the trauma resuscitation room

BACKGROUND Arterial and central venous femoral catheters (fAC-CVC) use during the initial management of severe trauma patients is not a standard technique in most trauma centers. Arguments in favor of their use are: continuous monitoring of blood pressure, safe drug administration, easy blood sampling and potentially large bore venous access. The lack of evidence makes the practice heterogeneous. The aim of the present study was to describe the use and complications of fAC-CVC in the trauma bay in two centers where they are routinely used. METHODS This was a retrospective analysis of routine fAC-CVC use from two French trauma centers. All patients admitted directly to the trauma resuscitation room were included. Demographic, clinical and biological data were collected from the scene to discharge to describe the use of catheters during initial trauma management including infectious, mechanical and thrombotic complications. RESULTS 243 pairs of femoral catheters were inserted among 692 patients admitted in both trauma centers. Femoral AC-CVC use was more frequent in critically ill patients with higher ISS 26 [17; 41] vs 13 [8; 24], p < 0.001(median [quartile 1-3]), severe traumatic brain injury (AIS head 1[0-4] vs 0[0-3], p < 0.001), lower systolic blood pressure, 92 (37) vs 113 (28) mmHg, p < 0.001 mean (standard deviation), lower haemoglobin on arrival, 10.9 (3) vs 13.3 (2.1) g/dL (p < 0.001), and higher blood lactate concentration, 4.0 (3.9) vs 2.1 (1.8) mmol/L (p < 0.001). In patients with fAC-CVC use time in the trauma room was longer, 46 [40;60] vs 30 [20;40] minutes (p < 0.05). In total 52 colonizations and 3 bloodstream infections were noted in 1000 catheter days. An incidence of 12% of mechanical complications and of 42% deep venous thromboses were observed. Of the latter none was associated with confirmed pulmonary embolism. CONCLUSION Femoral AC-CVC appeared to be deployed more often in critically ill patients, presenting with shock and/or traumatic brain injury in particular. The observed rate of complications in this sample seems to be low compared to reported rates.