Specificity of postconcussion symptoms at 3 months after mild traumatic brain injury: results from a comparative cohort study.

OBJECTIVE: To assess the specificity of symptoms included in various symptom lists used to identify postconcussion syndrome (PCS), by using follow-up data comparing patients with mild traumatic brain injury (MTBI) and control patients during the month prior to injury and 3 months later. SETTING: The adult emergency department of a teaching hospital in Bordeaux, France. PARTICIPANTS: A cohort of patients with MTBI (n = 536) and a comparison group with nonhead injuries (n = 946). MAIN MEASURES: Postconcussion symptoms listed in the Rivermead Postconcussion Symptoms Questionnaire (RPQ), the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), and the 10th International Classification of Diseases (ICD-10). RESULTS: Analyses were performed comparing symptom occurrence in patients with MTBI and controls, before and 3 months after injury. Eight symptoms were identified as being specific to MTBI: headache, dizziness, intolerance of stress, forgetfulness, poor concentration, taking longer to think, blurred vision, and personality change. CONCLUSION: The relevance of symptoms proposed to constitute PCS should be reviewed. A more specific definition of PCS would make diagnosis easier and facilitate prevention as well as treatment of patients with MTBI.

Subclavian central venous catheter-related thrombosis in trauma patients: incidence, risk factors and influence of polyurethane type.

INTRODUCTION: The incidence of deep venous thrombosis (DVT) related to a central venous catheter varies considerably in ICUs depending on the population included. The aim of this study was to determine subclavian central venous catheter (SCVC)-related DVT risk factors in severely traumatized patients with regard to two kinds of polyurethane catheters. METHODS: Critically ill trauma patients needing a SCVC for their usual care were prospectively included in an observational study. Depending on the month of inclusion, patients received one of the two available products in the emergency unit: either an aromatic polyurethane SCVC or an aliphatic polyurethane SCVC. Patients were screened weekly by ultrasound for SCVC-related DVT. Potential risk factors were collected, including history-related, trauma-related and SCVC-related characteristics. RESULTS: A total of 186 patients were included with a median Injury Severity Sore of 30 and a high rate of severe brain injuries (21% of high intracranial pressure). Incidence of SCVC-related DVT was 37% (95% confidence interval: 26 to 40) in patients or 20/1,000 catheter-days. SCVC-related DVT occurred within 8 days in 65% of cases. There was no significant difference in DVT rates between the aromatic polyurethane and aliphatic polyurethane SCVC groups (38% vs. 36%). SCVC-related DVT independent risk factors were age>30 years, intracranial hypertension, massive transfusion (>10 packed red blood cell units), SCVC tip position in the internal jugular or in the innominate vein, and ipsilateral jugular catheter. CONCLUSION: SCVC-related DVT concerned one-third of these severely traumatized patients and was mostly clinically silent. Incidence did not depend on the type of polyurethane but was related to age>30 years, intracranial hypertension or misplacement of the SCVC. Further studies are needed to assess the cost-effectiveness of routine screening in these patients in whom thromboprophylaxis may be hazardous.

Assessment of white matter injury and outcome in severe brain trauma: a prospective multicenter cohort.

BACKGROUND: Existing methods to predict recovery after severe traumatic brain injury lack accuracy. The aim of this study is to determine the prognostic value of quantitative diffusion tensor imaging (DTI). METHODS: In a multicenter study, the authors prospectively enrolled 105 patients who remained comatose at least 7 days after traumatic brain injury. Patients underwent brain magnetic resonance imaging, including DTI in 20 preselected white matter tracts. Patients were evaluated at 1 yr with a modified Glasgow Outcome Scale. A composite DTI score was constructed for outcome prognostication on this training database and then validated on an independent database (n=38). DTI score was compared with the International Mission for Prognosis and Analysis of Clinical Trials Score. RESULTS: Using the DTI score for prediction of unfavorable outcome on the training database, the area under the receiver operating characteristic curve was 0.84 (95% CI: 0.75-0.91). The DTI score had a sensitivity of 64% and a specificity of 95% for the prediction of unfavorable outcome. On the validation-independent database, the area under the receiver operating characteristic curve was 0.80 (95% CI: 0.54-0.94). On the training database, reclassification methods showed significant improvement of classification accuracy (P < 0.05) compared with the International Mission for Prognosis and Analysis of Clinical Trials score. Similar results were observed on the validation database. CONCLUSIONS: White matter assessment with quantitative DTI increases the accuracy of long-term outcome prediction compared with the available clinical/radiographic prognostic score.

S100-B protein as a screening tool for the early assessment of minor head injury.

STUDY OBJECTIVE: A computed tomography (CT) scan has high sensitivity in detecting intracranial injury in patients with minor head injury but is costly, exposes patients to high radiation doses, and reveals clinically relevant lesions in less than 10% of cases. We evaluate S100-B protein measurement as a screening tool in a large population of patients with minor head injury. METHODS: We conducted a prospective observational study in the emergency department of a teaching hospital (Bordeaux, France). Patients with minor head injury (2,128) were consecutively included from December 2007 to February 2009. CT scans and plasma S100-B levels were compared for 1,560 patients. The main outcome was to evaluate the diagnostic value of the S100-B test, focusing on the negative predictive value and the negative likelihood ratio. RESULTS: CT scan revealed intracranial lesions in 111 (7%) participants, and their median S100-B protein plasma level was 0.46 µg/L (interquartile range [IQR] 0.27 to 0.72) versus 0.22 µg/L (IQR 0.14 to 0.36) in the other 1,449 patients. With a cutoff of 0.12 µg/L, traumatic brain injuries on CT were identified with a sensitivity of 99.1% (95% confidence interval [CI] 95.0% to 100%), a specificity of 19.7% (95% CI 17.7% to 21.9%), a negative predictive value of 99.7% (95% CI 98.1% to 100%), a positive likelihood ratio of 1.24 (95% CI 1.20 to 1.28), and a negative likelihood ratio of 0.04 (95% CI 0.006 to 0.32). CONCLUSION: Measurement of plasma S100-B on admission of patients with minor head injury is a promising screening tool that may be of help to support the clinician's decision not to perform CT imaging in certain cases of low-risk head injury.

Impact of norepinephrine on the relationship between pleth variability index and pulse pressure variations in ICU adult patients.

INTRODUCTION: Pleth Variability Index (PVI) is an automated and continuous calculation of respiratory variations in the perfusion index. PVI correlates well with respiratory variations in pulse pressure (ΔPP) and is able to predict fluid responsiveness in the operating room. ICU patients may receive vasopressive drugs, which modify vascular tone and could affect PVI assessment. We hypothesized that the correlation between PVI and ΔPP and the ability of PVI to identify patients with ΔPP > 13% is dependent on norepinephrine (NE) use. METHODS: 67 consecutive mechanically ventilated patients in the ICU were prospectively included. Three were excluded. The administration and dosage of NE, heart rate, mean arterial pressure, PVI and ΔPP were measured simultaneously. RESULTS: In all patients, the correlation between PVI and ΔPP was weak (r2 = 0.21; p = 0.001). 23 patients exhibited a ΔPP > 13%. A PVI > 11% was able to identify patients with a ΔPP > 13% with a sensitivity of 70% (95% confidence interval: 47%-87%) and a specificity of 71% (95% confidence interval: 54%-84%). The area under the curve was 0.80 ± 0.06. 35 patients (53%) received norepinephrine (NE(+)). In NE(+) patients, PVI and ΔPP were not correlated (r2 = 0.04, p > 0.05) and a PVI > 10% was able to identify patients with a ΔPP > 13% with a sensitivity of 58% (95% confidence interval: 28%-85%) and a specificity of 61% (95% confidence interval:39%-80%). The area under the ROC (receiver operating characteristics) curve was 0.69 ± 0.01. In contrast, NE(-) patients exhibited a correlation between PVI and ΔPP (r2 = 0.52; p < 0.001) and a PVI > 10% was able to identify patients with a ΔPP > 13% with a sensitivity of 100% (95% confidence interval: 71%-100%) and a specificity of 72% (95% confidence interval: 49%-90%). The area under the ROC curve was 0.93 ± 0.06 for NE(-) patients and was significantly higher than the area under the ROC curve for NE(+) patients (p = 0.02). CONCLUSIONS: Our results suggest that in mechanically ventilated adult patients, NE alters the correlation between PVI and ΔPP and the ability of PVI to predict ΔPP > 13% in ICU patients.

The ability of pulse pressure variations obtained with CNAP™ device to predict fluid responsiveness in the operating room.

BACKGROUND: Respiratory-induced pulse pressure variations obtained with an arterial line (ΔPP(ART)) indicate fluid responsiveness in mechanically ventilated patients. The Infinity® CNAP™ SmartPod® (Dräger Medical AG & Co. KG, Lübeck, Germany) provides noninvasive continuous beat-to-beat arterial blood pressure measurements and a near real-time pressure waveform. We hypothesized that respiratory-induced pulse pressure variations obtained with the CNAP system (ΔPP(CNAP)) predict fluid responsiveness as well as ΔPP(ART) predicts fluid responsiveness in mechanically ventilated patients during general anesthesia. METHODS: Thirty-five patients undergoing vascular surgery were studied after induction of general anesthesia. Stroke volume (SV) measured with the Vigileo™/FloTrac™ (Edwards Lifesciences, Irvine, CA), ΔPP(ART), and ΔPP(CNAP) were recorded before and after intravascular volume expansion (VE) (500 mL of 6% hydroxyethyl starch 130/0.4). Subjects were defined as responders if SV increased by ≥15% after VE. RESULTS: Twenty patients responded to VE and 15 did not. The correlation coefficient between ΔPP(ART) and ΔPP(CNAP) before VE was r = 0.90 (95% confidence interval [CI] = 0.84-0.96; P < 0.0001). Before VE, ΔPP(ART) and ΔPP(CNAP) were significantly higher in responders than in nonresponders (P < 0.0001). The values of ΔPP(ART) and ΔPP(CNAP) before VE were significantly correlated with the percent increase in SV induced by VE (respectively, r(2) = 0.50; P < 0.0001 and r(2) = 0.57; P < 0.0001). Before VE, a ΔPP(ART) >10% discriminated between responders and nonresponders with a sensitivity of 90% (95% CI = 69%-99%) and a specificity of 87% (95% CI = 60%-98%). The area under the receiver operating characteristic (ROC) curve was 0.957 ± 0.035 for ΔPP(ART). Before VE, a ΔPP(CNAP) >11% discriminated between responders and nonresponders with a sensitivity of 85% (95% CI = 62%-97%) and a specificity of 100% (95% CI = 78%-100%). The area under the ROC curve was 0.942 ± 0.040 for ΔPP(CNAP). There was no significant difference between the area under the ROC curve for ΔPP(ART) and ΔPP(CNAP). CONCLUSIONS: A value of ΔPP(CNAP) >11% has a sensitivity of at least 62% in predicting preload-dependent responders to VE in mechanically ventilated patients during general anesthesia.

Facemask pressure-controlled ventilation in children: what is the pressure limit?

BACKGROUND: In this study, we sought to determine the level of inspiratory pressures allowing adequate and safe ventilation without any risk of gastric insufflation (GI) in children according to age. METHODS: One hundred children, aged 1 day to 16 years, ASA physical status I to II, scheduled for general anesthesia were studied prospectively. After induction of anesthesia, children's lungs were ventilated with pressure-controlled ventilation. The initial inspiratory pressure was 10 cm H(2)O and was increased by steps of 5 cm H(2)O, up to a maximum of 25 cm H(2)O. At each step, GI was detected by epigastric auscultation. The recorded data were age and weight. At each step, the inspiratory pressure, the respiratory rate, the expired tidal volume, the minute ventilation, and the occurrence of GI were also recorded. RESULTS: GI occurred in 78 children. GI occurred in 95% of children younger than 1 year, in 93% of children aged 1 to 5 years, and 56% of children older than 5 years (P = 0.001). The pressure threshold at which GI occurred increased with age: the younger the child, the lower the GI pressure threshold. Tidal volume increased with inspiratory pressure, but at >15 cm H(2)O, tidal volume did not change significantly. CONCLUSION: The inspiratory pressure threshold at which GI can occur depends on age. It is low in infants and increases with age. In most cases, proper ventilation without GI was obtained with an inspiratory pressure

Time course of mitochondrial metabolism alterations to repeated injections of bupivacaine in rat muscle.

PURPOSE: Bupivacaine-induced myotoxicity is associated with mitochondrial bioenergetic alterations. The impact of the duration of bupivacaine treatment on mitochondrial energy production remains undetermined. Here, we assessed, in vivo, the alteration of mitochondrial metabolism following different durations of bupivacaine exposure (40, 56, or 112 hr) that correspond to 5, 7, or 14 repeated injections of 0.25% bupivacaine, respectively. METHODS: Rats were divided randomly into seven different groups: one control group (no catheter); three groups with normal saline injections (1 mL x kg(-1)) every eight hours via a femoral nerve catheter for 40, 56, and 112 hr, respectively; and three groups with 0.25% bupivacaine injections (1 mL x kg(-1)) every eight hours via a femoral nerve catheter for 40, 56, and 112 hr. Psoas and gracilis muscle samples located within the bupivacaine infusion-diffusion space were investigated. To estimate mitochondrial respiratory capacity, the protein content of the mitochondrial respiratory chain apparatus was evaluated by measuring citrate synthase activity. To measure mitochondrial respiratory function, adenosine diphosphate-stimulated oxygen consumption was measured by polarography in saponin-skinned muscle fibres using glutamate-malate or succinate as energy substrates. RESULTS: In psoas and gracilis muscles, saline solution had no effect on the two mitochondrial parameters. Bupivacaine induced a significant decrease in the citrate synthase activity in psoas (r(2) = 0.74; P < 0.001) and gracilis muscle (r(2) = 0.52; P < 0.001), and there was a significant decrease in the adenosine diphosphate-stimulated oxygen consumption using glutamate or succinate as substrates in both muscles (P < 0.001). CONCLUSIONS: The severity of bupivacaine-induced myotoxicity is closely linked to the duration of bupivacaine exposure in the muscle fibres located close to the catheter tip.

Stress and lasting symptoms following injury: Results from a 4-month cohort of trauma patients recruited at the emergency department.

INTRODUCTION: Recent research suggests that up to 20% of minor trauma patients admitted to the emergency department (ED) will suffer from non-specific chronic conditions over the subsequent several months. Thus, the present study assessed the correlates of symptoms that persisted at 4 months after an ED visit and, in particular, evaluated the associations between these symptoms and self-reported stress levels at ED admission and discharge. METHOD: This study was a prospective observational investigation conducted in the ED of Bordeaux University Hospital that included patients admitted for minor trauma. All participants were contacted by phone 4 months after presentation at the ED to assess the occurrence of post-concussion-like symptoms (PCLS). RESULTS: A total of 193 patients completed the follow-up assessment at 4 months; 5.2% of the participants suffered from post-traumatic stress disorder (PTSD) and 24.5% suffered from PCLS. A multivariate analysis revealed an association between PCLS and stress level at discharge from the ED (odds ratios [OR]: 2.85, 95% confidence interval [CI]: 1.10-7.40). CONCLUSIONS: The risk of PCLS at 4 months after an ED visit for a minor injury increased in association with the level of stress at discharge from the ED. These results may improve the quality of life for the millions of patients who experience a stressful injury event every year.

Erythropoietin protects against local anesthetic myotoxicity during continuous regional analgesia.

BACKGROUND: Local anesthetics offer the benefits of extended analgesia with greater patient satisfaction and faster rehabilitation compared with intravenous morphine. These benefits, however, can be offset by adverse iatrogenic muscle pain caused by bupivacaine. Here, the authors describe the mechanisms of local anesthetic-induced myotoxicity and a partial protective effect of recombinant human erythropoietin (rhEPO). METHODS: The authors developed a rat analgesia model with femoral nerve catheter and a cell culture model of human skeletal muscle myoblasts to study local anesthetic effects. Rats were randomly assigned to four different groups: daily intraperitoneal injection with 5,000 U/kg rhEPO or saline coupled to a perineural catheter injection with 1 ml/kg bupivacaine, 0.25%, or saline. In psoas rat muscle, oxygen consumption rates were measured using a Clark-type electrode in saponin-skinned fibers. Mitochondrial adenosine triphosphate synthesis rates were determined by bioluminescence. Enzymatic activity of mitochondrial respiratory chain complexes was measured on tissue homogenates using spectrophotometric procedures, and mitochondrial morphology was analyzed by transmission electron microscopy. In addition, the interaction between bupivacaine and rhEPO was investigated on human skeletal muscle myoblasts by fluorescence microscopy using mitotracker green and using the lipophilic cation JC-1. RESULTS: Bupivacaine caused impairment of mitochondrial structure and bioenergetics in rats. Human myoblasts treated with bupivacaine showed a dose-dependent decrease in mitochondrial membrane potential associated with unusual morphologies. Impairment of mitochondrial bioenergetics was prevented partially by the use of rhEPO coadministered with bupivacaine. CONCLUSIONS: The authors demonstrated a dose- and time-dependent protective effect of rhEPO against bupivacaine-induced myotoxicity in regional analgesia.

The use of bispectral index to monitor barbiturate coma in severely brain-injured patients with refractory intracranial hypertension.

BACKGROUND: Barbiturate therapy in severely traumatic brain-injured (TBI) patients is usually monitored by an electroencephalogram (EEG) with burst-suppression pattern as a target. The Bispectral Index (BIS) is derived from EEG and considers cortical silence. We sought to determine whether a BIS range could predict a specific burst-suppression pattern. METHODS: Eleven TBI patients treated with barbiturate were included prospectively. EEG was recorded daily for 1 h. Every 5 min, the number of bursts and the suppression ratio (suppression ratio from EEG [SR(EEG)]: percentage of last 60 s in cortical silence) was calculated for 1 min on the raw EEG and compared to concomitant data from the BIS-XP (BIS and suppression ratio [SR(BIS)]). The optimal level of barbiturate coma was defined as 2-5 bursts/min in the EEG. A BIS range predictive of optimal level was determined from all data and its accuracy was studied for each examination. RESULTS: Agreement between SR(EEG) and SR(BIS) was high (interclass correlation coefficient 0.94 [95% confidence interval: 0.90-0.96]). There was a significant association between SR(EEG) and BIS. Significant disagreements were observed in some examinations. The best accuracy to predict optimal pattern was obtained with a BIS range from 6 to 15. CONCLUSION: The relationship between BIS and SR(EEG) was high in TBI patients treated with barbiturates. The rate of barbiturate infusion might be decreased if BIS is <6 or increased if BIS is >15. Correspondence between BIS and suppression pattern should periodically be checked by observation of the EEG analogical signal (as displayed by BIS-XP).

Forced vital capacity assessment for risk stratification of blunt chest trauma patients in emergency settings: A preliminary study.

OBJECTIVE: The aim of this study was to assess the performance of Forced Vital Capacity (FVC) for prediction of secondary respiratory complications in blunt chest trauma patients. METHODS: During a 15-month period, all consecutive blunt chest trauma patients admitted in our emergency intensive care unit with more than 3 rib fractures were eligible, unless they required mechanical ventilation in the prehospital or emergency settings. FVC was measured at admission and at emergency discharge after therapeutic interventions. The main outcome was the occurrence of secondary respiratory complications defined by hospital-acquired pulmonary infection, secondary admission in the intensive care unit or mechanical ventilation for respiratory failure or death. The performance of FVC for prediction of secondary respiratory complications was assessed by receiver operating characteristic (ROC) curve and multivariate analysis after logistic regression. RESULTS: Sixty-two consecutive patients were included and 13 (21%) presented secondary respiratory complications. Only FVC measured at emergency discharge - not FCV at admission - was significantly lower in patients who developed secondary respiratory complications (44±15 vs. 61±20%, P=0.002). The area under the ROC curves for FCV in predicting secondary pulmonary complications was 0.79 [95% CI: 0.66-0.88], P=0.0001. An FVC at discharge≤50% was independently associated with the occurrence of secondary complications with an OR at 7.9 [1.9-42.1], P=0.004. CONCLUSION: The non-improvement of FVC≤50% at emergency discharge is associated with secondary respiratory complications and should prevent the under-triage of patients with no sign of respiratory failure at admission.

Association between augmented renal clearance and clinical failure of antibiotic treatment in brain-injured patients with ventilator-acquired pneumonia: A preliminary study.

OBJECTIVES: This preliminary study aimed to determine whether augmented renal clearance (ARC) impacts negatively on the clinical outcome in traumatic brain-injured patients (TBI) treated for a first episode of ventilator-acquired pneumonia (VAP). METHODS: During a 5-year period, all TBI patients who had developed VAP were retrospectively reviewed to assess variables associated with clinical failure in multivariate analysis. Clinical failure was defined as an impaired clinical response with a need for escalating antibiotics during treatment and/or within 15 days after the end-of-treatment. Recurrence was considered if at least one of the initial causative bacterial strains was growing at a significant concentration from a second sample. Augmented renal clearance (ARC) was defined by an enhanced creatinine clearance exceeding 130mL/min/1.73m2 calculated from a urinary sample during the first three days of antimicrobial therapy. MAIN RESULTS: During the study period, 223 TBI patients with VAP were included and 59 (26%) presented a clinical failure. Factors statistically associated with clinical failure were GSC≤7 (OR=2.2 [1.1-4.4], P=0.03), early VAP (OR=3.9 [1.9-7.8], P=0.0001), bacteraemia (OR=11 [2.2-54], P=0.003) and antimicrobial therapy≤7 days (OR=3.7 [1.8-7.4], P=0.0003). ARC was statistically associated with recurrent infections with an OR of 4.4 [1.2-16], P=0.03. CONCLUSION: ARC was associated with recurrent infection after a first episode of VAP in TBI patients. The optimal administration and dosing of the antimicrobial agents in this context remain to be determined.

Emergency room intervention to prevent post concussion-like symptoms and post-traumatic stress disorder. A pilot randomized controlled study of a brief eye movement desensitization and reprocessing intervention versus reassurance or usual care.

Up to 20% of patients presenting at an emergency room (ER) after a stressful event will for several months suffer from very diverse long-lasting symptoms and a potentially significant decline in quality of life, often described as post concussion-like symptoms (PCLS). The objectives of our randomized open-label single-center study were to assess the feasibility of psychologist-led interventions in the context of the ER and to compare the effect of eye movement desensitization and reprocessing (EMDR) with reassurance and usual care. Conducted in the ER of Bordeaux University Hospital, the study included patients with a high risk of PCLS randomized in three groups: a 15-min reassurance session, a 60-min session of EMDR, and usual care. Main outcomes were the proportion of interventions that could be carried out and the prevalence of PCSL and post-traumatic stress disorder (PTSD) three months after the ER visit. One hundred and thirty patients with a high risk of PCLS were randomized. No logistic problem or patient refusal was observed. In the EMDR, reassurance and control groups, proportions of patients with PCLS at three months were 18%, 37% and 65% and those with PTSD were 3%, 16% and 19% respectively. The risk ratio for PCLS adjusted for the type of event (injury, non-injury) for the comparison between EMDR and control was 0.36 [95% CI 0.20-0.66]. This is the first randomized controlled trial that shows that a short EMDR intervention is feasible and potentially effective in the context of the ER. The study was registered at ClinicalTrials.gov (NCT03194386).

The mechanism of the angiotensin-converting enzyme inhibitor quinapril is not related to bradykinin level in heart tissue.

In order to examine the effect of the angiotensin-converting enzyme inhibitor (ACEi) quinapril, we performed a sensitive and specific radioimmunoassay (RIA) to quantify bradykinin, BK-(1-9), in heart and kidney tissues. The BK-(1-9) level was unaffected in the heart of sham and water-deprived rats treated for 2h with quinapril (10mg/kg), but was significantly higher in the kidneys in the two groups. In these conditions, circulating and tissue angiotensin II (Ang II) levels were significantly decreased by quinapril. Moreover, our results indicated that acute treatment with this dose of quinapril induced kinin-mediated effects which were not related to its action on bradykinin degradation in rat hearts.

Association of symptoms following mild traumatic brain injury with posttraumatic stress disorder vs. postconcussion syndrome.

IMPORTANCE: A proportion of patients experience long-lasting symptoms following mild traumatic brain injury (MTBI). The postconcussion syndrome (PCS), included in the DSM-IV, has been proposed to describe this condition. Because these symptoms are subjective and common to other conditions, there is controversy whether PCS deserves to be identified as a diagnostic syndrome. OBJECTIVE: To assess whether persistent symptoms 3 months following head injury are specific to MTBI or whether they are better described as part of posttraumatic stress disorder (PTSD). DESIGN, SETTING, AND PARTICIPANTS: We conducted a prospective cohort study of injured patients recruited at the adult emergency department of the University Hospital of Bordeaux from December 4, 2007, to February 25, 2009. MAIN OUTCOMES AND MEASURES: At 3-month follow-up, we compared the prevalence and risk factors for PCS and PTSD. Multiple correspondence analyses were used to assess clustering of symptoms and their associations with the type of injury. RESULTS: We included 534 patients with head injury and 827 control patients with other nonhead injuries. Three months following the trauma, 21.2% of head-injured and 16.3% of nonhead-injured patients fulfilled the DSM-IV diagnosis of PCS; 8.8% of head-injured patients fulfilled the diagnostic criteria for PTSD compared with 2.2% of control patients. In multivariate analysis, MTBI was a predictor of PTSD (odds ratio, 4.47; 95% CI, 2.38-8.40) but not of PCS (odds ratio, 1.13; 95% CI, 0.82-1.55). Correspondence analysis suggested that symptoms considered part of PCS behave similarly to PTSD symptoms in the hyperarousal dimension. None of these 22 symptoms showed any pattern of clustering, and no clear proximity with head or nonhead injury status could be found. CONCLUSIONS AND RELEVANCE: Persistent subjective symptoms frequently reported 3 months after MTBI are not specific enough to be identified as a unique PCS and should be considered part of the hyperarousal dimension of PTSD.

Mind wandering and driving: responsibility case-control study.

OBJECTIVE: To assess the association between mind wandering (thinking unrelated to the task at hand) and the risk of being responsible for a motor vehicle crash. DESIGN: Responsibility case-control study. SETTING: Adult emergency department of a university hospital in France, April 2010 to August 2011. PARTICIPANTS: 955 drivers injured in a motor vehicle crash. MAIN OUTCOME MEASURES: Responsibility for the crash, mind wandering, external distraction, negative affect, alcohol use, psychotropic drug use, and sleep deprivation. Potential confounders were sociodemographic and crash characteristics. RESULTS: Intense mind wandering (highly disrupting/distracting content) was associated with responsibility for a traffic crash (17% (78 of 453 crashes in which the driver was thought to be responsible) v 9% (43 of 502 crashes in which the driver was not thought to be responsible); adjusted odds ratio 2.12, 95% confidence interval 1.37 to 3.28). CONCLUSIONS: Mind wandering while driving, by decoupling attention from visual and auditory perceptions, can jeopardise the ability of the driver to incorporate information from the environment, thereby threatening safety on the roads.

Etomidate increases susceptibility to pneumonia in trauma patients.

PURPOSE: To investigate the impact of etomidate on the rate of hospital-acquired pneumonia (HAP) in trauma patients and the effects of hydrocortisone in etomidate-treated patients. METHODS: This was a sub-study of the HYPOLYTE multi-centre, randomized, double-blind, placebo-controlled trial of hydrocortisone in trauma patients (NCT00563303). Inclusion criterion was trauma patient with mechanical ventilation (MV) of ≥48 h. The use of etomidate was prospectively collected. Endpoints were the results of the cosyntropin test and rate of HAP on day 28 of follow-up. RESULTS: Of the 149 patients enrolled in the study, 95 (64 %) received etomidate within 36 h prior to inclusion. 79 (83 %) of 95 patients receiving etomidate and 34 of the 54 (63 %) not receiving etomidate had corticosteroid insufficiency (p = 0.006). The administration of etomidate did not alter basal cortisolemia (p = 0.73), but it did decrease the delta of cortisolemia at 60 min (p = 0.007). There was a correlation between time from etomidate injection to inclusion in the study and sensitivity to corticotropin (R (2) = 0.19; p = 0.001). Forty-nine (51.6 %) patients with etomidate and 16 (29.6 %) patients without etomidate developed HAP by day 28 (p = 0.009). Etomidate was associated with HAP on day 28 in the multivariate analysis (hazard ratio 2.48; 95 % confidence interval 1.19-5.18; p = 0.016). Duration of MV with or without etomidate was not significantly different (p = 0.278). Among etomidate-exposed patients, 18 (40 %) treated with hydrocortisone developed HAP compared with 31 (62 %) treated with placebo (p = 0.032). Etomidate-exposed patients treated with hydrocortisone had fewer ventilator days (p < 0.001). CONCLUSIONS: Among the patients enrolled in the study, etomidate did not alter basal cortisolemia, but it did decrease reactivity to corticotropin. We suggest that in trauma patients, etomidate is an independent risk factor for HAP and that the administration of hydrocortisone should be considered after etomidate use.

Comparison of effects of equiosmolar doses of mannitol and hypertonic saline on cerebral blood flow and metabolism in traumatic brain injury.

The potential superiority of hypertonic saline (HTS) over mannitol (MTL) for control of intracranial pressure (ICP) following traumatic brain injury (TBI) is still debated. Forty-seven severe TBI patients with increased ICP were prospectively recruited in two university hospitals and randomly treated with equiosmolar infusions of either MTL 20% (4 mL/kg; n=25 patients) or HTS 7.5% (2 mL/kg; n=22 patients). Serum sodium, hematocrit, ICP, arterial blood pressure, cerebral perfusion pressure (CPP), shear rate, global indices of cerebral blood flow (CBF) and metabolism were measured before, and 30 and 120 min following each infusion during the course of illness. Outcome was assessed at 6 months. Both HTS and MTL effectively and equally reduced ICP levels with subsequent elevation of CPP and CBF, although this effect was significantly stronger and of longer duration after HTS and correlated with improved rheological blood properties induced by HTS. Further, effect of HTS on ICP appeared to be more robust in patients with diffuse brain injury. In contrast, oxygen and glucose metabolic rates were left equally unaffected by both solutions. Accordingly, there was no significant difference in neurological outcome between the two groups. In conclusion, MTL was as effective as HTS in decreasing ICP in TBI patients although both solutions failed to improved cerebral metabolism. HTS showed an additional and stronger effect on cerebral perfusion of potential benefit in the presence of cerebral ischemia. Treatment selection should therefore be individually based on sodium level and cerebral hemodynamics.