Impact of enhanced recovery program implementation on postoperative outcomes after liver surgery: a monocentric retrospective study.

INTRODUCTION: It is still unclear whether enhanced recovery programs (ERPs) reduce postoperative morbidity after liver surgery. This study investigated the effect on liver surgery outcomes of labeling as a reference center for ERP. MATERIALS AND METHODS: Perioperative data from 75 consecutive patients who underwent hepatectomy in our institution after implementation and labeling of our ERP were retrospectively compared to 75 patients managed before ERP. Length of hospital stay, postoperative complications, and adherence to protocol were examined. RESULTS: Patient demographics, comorbidities, and intraoperative data were similar in the two groups. Our ERP resulted in shorter length of stay (3 days [1-6] vs. 4 days [2-7.5], p = 0.03) and fewer postoperative complications (24% vs. 45.3%, p = 0.0067). This reduction in postoperative morbidity can be attributed exclusively to a lower rate of minor complications (Clavien-dindo grade < IIIa), and in particular to a lower rate of postoperative ileus, after labeling. (5.3% vs. 25.3%, p = 0.0019). Other medical and surgical complications were not significantly reduced. Adherence to protocol improved after labeling (17 [16-18] vs. 14 [13-16] items, p < 0.001). CONCLUSIONS: The application of a labeled enhanced recovery program for liver surgery was associated with a significant shortening of hospital stay and a halving of postoperative morbidity, mainly ileus.

Changes in Intrinsic Connectivity Networks Topology Across Levels of Dexmedetomidine-Induced Alteration of Consciousness.

BACKGROUND: Human consciousness is generally thought to emerge from the activity of intrinsic connectivity networks (resting-state networks [RSNs]) of the brain, which have topological characteristics including, among others, graph strength and efficiency. So far, most functional brain imaging studies in anesthetized subjects have compared wakefulness and unresponsiveness, a state considered as corresponding to unconsciousness. Sedation and general anesthesia not only produce unconsciousness but also phenomenological states of preserved mental content and perception of the environment (connected consciousness), and preserved mental content but no perception of the environment (disconnected consciousness). Unresponsiveness may be seen during unconsciousness, but also during disconnectedness. Deep dexmedetomidine sedation is frequently a state of disconnected consciousness. In this study, we were interested in characterizing the RSN topology changes across 4 different and steady-state levels of dexmedetomidine-induced alteration of consciousness, namely baseline (Awake, drug-free state), Mild sedation (drowsy, still responding), Deep sedation (unresponsive), and Recovery, with a focus on changes occurring between a connected consciousness state and an unresponsiveness state. METHODS: A functional magnetic resonance imaging database acquired in 14 healthy volunteers receiving dexmedetomidine sedation was analyzed using a method combining independent component analysis and graph theory, specifically looking at changes in connectivity strength and efficiency occurring during the 4 above-mentioned dexmedetomidine-induced altered consciousness states. RESULTS: Dexmedetomidine sedation preserves RSN architecture. Unresponsiveness during dexmedetomidine sedation is mainly characterized by a between-networks graph strength alteration and within-network efficiency alteration of lower-order sensory RSNs, while graph strength and efficiency in higher-order RSNs are relatively preserved. CONCLUSIONS: The differential dexmedetomidine-induced RSN topological changes evidenced in this study may be the signature of inadequate processing of sensory information by lower-order RSNs, and of altered communication between lower-order and higher-order networks, while the latter remain functional. If replicated in an experimental paradigm distinguishing, in unresponsive subjects, disconnected consciousness from unconsciousness, such changes would sustain the hypothesis that disconnected consciousness arises from altered information handling by lower-order sensory networks and altered communication between lower-order and higher-order networks, while the preservation of higher-order networks functioning allows for an internally generated mental content (or dream).

Effect of left paratracheal pressure on left carotid blood flow.

INTRODUCTION: Gautier et al. demonstrated that a compression in the left paratracheal region (left paratracheal pressure, LPP) can be used to seal the oesophagus. However, at this level, the left common carotid artery is very close to the carotid that could be affected during the manipulation. This study aimed to assess the hemodynamic effects of LPP on the carotid blood flow. METHODS: We prospectively included 47 healthy adult volunteers. We excluded pregnant women and people with anomalies of the carotid arteries. The common and internal carotid arteries were preliminarily studied with ultrasounds to exclude atheromatous plaques or vascular malformation. A planimetry of the common and internal carotid arteries was performed. Doppler echography served to measure the peak systolic (PSV) and end-diastolic velocities (EDV) in the common and internal carotid arteries. All measurements were repeated while applying LPP. RESULTS: Forty-seven participants were enrolled (32 women; mean [SD] age: 42 [13] years). The mean PSV difference [95% CI] in the left common carotid artery before and after LPP at the group level was -15.30 [-31.09 to 0.48] cm s-1 (p = .14). The mean surface difference [95% CI] in the left common carotid artery before and after LPP was 24.52 [6.11-42.92] mm2 (p = .11). Similarly, the same surface at the level of the left internal carotid artery changed by -18.89 [-51.59 to 13.80] mm2 after LPP (p = .58). CONCLUSIONS: Our results suggest that LPP does not have a significant effect on carotid blood flow in individuals without a carotid pathology. However, the safety of the manoeuvre should be evaluated in patients at risk of carotid anomalies.

Oral as compared to intravenous tranexamic acid to limit peri-operative blood loss associated with primary total hip arthroplasty: A randomised noninferiority trial.

BACKGROUND: Oral as compared to intravenous tranexamic acid (TXA) is an attractive option, in terms of cost and safety, to reduce blood loss and transfusion in total hip arthroplasty. Exclusion criteria applied in the most recent randomised trials may have limited the generalisability of oral tranexamic acid in this indication. Larger and more inclusive studies are needed to definitively establish oral administration as a credible alternative to intravenous administration. OBJECTIVES: To assess the noninferiority of oral to intravenous TXA at reducing intra-operative and postoperative total blood loss (TBL) in primary posterolateral approached total hip arthroplasty (PLTHA). DESIGN: Noninferiority, single centre, randomised, double-blind controlled study. SETTING: Patients scheduled for primary PLTHA. Data acquisition occurred between May 2021 and November 2022 at the University Hospital of Liège, Belgium. PATIENTS: Two hundred and twenty-eight patients, randomised in a 1 : 1 ratio from a computer-generated list, completed the trial. INTERVENTIONS: Administration of 2 g of oral TXA 2 h before total hip arthroplasty and 4 h after incision (Group oral) was compared to the intravenous administration of 1 g of TXA 30 min before surgery and 4 h after incision (Group i.v.). MAIN OUTCOME MEASURES: TBL (measured intra-operative and drainage blood loss up to 48 h after surgery, primary outcome), decrease in haemoglobin concentration, D-Dimer at day 1 and day 3, transfusion rate (secondary outcomes). RESULTS: Analyses were performed on 108 out of 114 participants (Group i.v.) and 104 out of 114 participants (Group oral). Group oral was noninferior to Group i.v. with regard to TBL, with a difference between medians (95% CI) of 35 ml (-103.77 to 33.77) within the noninferiority margins. Median [IQR] of estimated TBL was 480 ml [350 to 565] and 445 ml [323 to 558], respectively. No significant interaction between group and time was observed regarding the evolution of TBL and haemoglobin over time. CONCLUSIONS: TXA as an oral premedication before PLTHA is noninferior to its intravenous administration regarding peri-operative TBL. TRIAL REGISTRATION: European Clinical Trial Register under EudraCT-number 2020-004167-29 ( https://www.clinicaltrialsregister.eu/ctr-search/trial/2020-004167-29/BE ).

Binocular field configuration in owls: the role of foraging ecology.

The binocular field of vision differs widely in birds depending on ecological traits such as foraging. Owls (Strigiformes) have been considered to have a unique binocular field, but whether it is related to foraging has remained unknown. While taking into account allometry and phylogeny, we hypothesized that both daily activity cycle and diet determine the size and shape of the binocular field in owls. Here, we compared the binocular field configuration of 23 species of owls. While we found no effect of allometry and phylogeny, ecological traits strongly influence the binocular field shape and size. Binocular field shape of owls significantly differed from that of diurnal raptors. Among owls, binocular field shape was relatively conserved, but binocular field size differed among species depending on ecological traits, with larger binocular fields in species living in dense habitat and foraging on invertebrates. Our results suggest that (i) binocular field shape is associated with the time of foraging in the daily cycle (owls versus diurnal raptors) and (ii) that binocular field size differs between closely related owl species even though the general shape is conserved, possibly because the field of view is partially restricted by feathers, in a trade-off with auditory localization.

Depth of sedation with dexmedetomidine increases transcranial magnetic stimulation-evoked potential amplitude non-linearly.

BACKGROUND: Cortical excitability is higher in unconsciousness than in wakefulness, but it is unclear how this relates to anaesthesia. We investigated cortical excitability in response to dexmedetomidine, the effects of which are not fully known. METHODS: We recorded transcranial magnetic stimulation (TMS) and EEG in frontal and parietal cortex of 20 healthy subjects undergoing dexmedetomidine sedation in four conditions (baseline, light sedation, deep sedation, recovery). We used the first component (0-30 ms) of the TMS-evoked potential (TEP) to measure cortical excitability (amplitude), slope, and positive and negative peak latencies (collectively, TEP indices). We used generalised linear mixed models to test the effect of condition, brain region, and responsiveness on TEP indices. RESULTS: Compared with baseline, amplitude in the frontal cortex increased by 6.52 µV (P<0.001) in light sedation, 4.55 µV (P=0.003) in deep sedation, and 5.03 µV (P<0.001) in recovery. Amplitude did not change in the parietal cortex. Compared with baseline, slope increased in all conditions (P<0.02) in the frontal but not parietal cortex. The frontal cortex showed 5.73 µV higher amplitude (P<0.001), 0.63 µV ms-1 higher slope (P<0.001), and 2.2 ms shorter negative peak latency (P=0.001) than parietal areas. Interactions between dexmedetomidine and region had effects over amplitude (P=0.004) and slope (P=0.009), with both being higher in light sedation, deep sedation, and recovery compared with baseline. CONCLUSIONS: Transcranial magnetic stimulation-evoked potential amplitude changes non-linearly as a function of depth of sedation by dexmedetomidine, with a region-specific paradoxical increase. Future research should investigate other anaesthetics to elucidate the link between cortical excitability and depth of sedation.

Effects of remifentanil on brain responses to noxious stimuli during deep propofol sedation.

BACKGROUND: The safety of anaesthesia has improved as a result of better control of anaesthetic depth. However, conventional monitoring does not inform on the nature of nociceptive processes during unconsciousness. A means of inferring the quality of potentially painful experiences could derive from analysis of brain activity using neuroimaging. We have evaluated the dose effects of remifentanil on brain response to noxious stimuli during deep sedation and spontaneous breathing. METHODS: Optimal data were obtained in 26 healthy subjects. Pressure stimulation that proved to be moderately painful before the experiment was applied to the thumbnail. Functional MRI was acquired in 4-min periods at low (0.5 ng ml-1), medium (1 ng ml-1), and high (1.5 ng ml-1) target plasma concentrations of remifentanil at a stable background infusion of propofol adjusted to induce a state of light unconsciousness. RESULTS: At low remifentanil doses, we observed partial activation in brain areas processing sensory-discriminative and emotional-affective aspects of pain. At medium doses, relevant changes were identified in structures highly sensitive to general brain arousal, including the brainstem, cerebellum, thalamus, auditory and visual cortices, and the frontal lobe. At high doses, no significant activation was observed. CONCLUSIONS: The response to moderately intense focal pressure in pain-related brain networks is effectively eliminated with safe remifentanil doses. However, the safety margin in deep sedation-analgesia would be narrowed in minimising not only nociceptive responses, but also arousal-related biological stress.

Connected consciousness after tracheal intubation in young adults: an international multicentre cohort study.

BACKGROUND: Connected consciousness, assessed by response to command, occurs in at least 5% of general anaesthetic procedures and perhaps more often in young people. Our primary objective was to establish the incidence of connected consciousness after tracheal intubation in young people aged 18-40 yr. The secondary objectives were to assess the nature of these responses, identify relevant risk factors, and determine their relationship to postoperative outcomes. METHODS: This was an international, multicentre prospective cohort study using the isolated forearm technique to assess connected consciousness shortly after tracheal intubation. RESULTS: Of 344 enrolled subjects, 338 completed the study (mean age, 30 [standard deviation, 6.3] yr; 232 [69%] female). Responses after intubation occurred in 37/338 subjects (11%). Females (13%, 31/232) responded more often than males (6%, 6/106). In logistic regression, the risk of responsiveness was increased with female sex (odds ratio [ORadjusted]=2.7; 95% confidence interval [CI], 1.1-7.6; P=0.022) and was decreased with continuous anaesthesia before laryngoscopy (ORadjusted=0.43; 95% CI, 0.20-0.96; P=0.041). Responses were more likely to occur after a command to respond (and not to nonsense, 13 subjects) than after a nonsense statement (and not to command, four subjects, P=0.049). CONCLUSIONS: Connected consciousness occured after intubation in 11% of young adults, with females at increased risk. Continuous exposure to anaesthesia between induction of anaesthesia and tracheal intubation should be considered to reduce the incidence of connected consciousness. Further research is required to understand sex-related differences in the risk of connected consciousness.

Development and Validation of a Prediction Score for Low-Cardiac-Output Syndrome After Adult Cardiac Surgery.

OBJECTIVES: The authors aimed to develop a simple prediction score to help identify patients at high risk of low-cardiac-output syndrome after adult cardiac surgery. DESIGN: A single-center, retrospective, observational study. SETTING: At a tertiary hospital. PARTICIPANTS: Adult patients who underwent on-pump cardiac surgery between April 2016 and March 2021. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: Among the 2,806 patients retained for final analyses, 355 (12.7%) developed low-cardiac-output syndrome. Using a stepwise backward variable selection procedure applied to a multivariate logistic regression, a prediction model, including 8 risk factors, could be identified-preoperative left ventricular ejection fraction, glomerular filtration rate <60 mL/min according to the Cockcroft formula or preoperative dialysis, combined surgery, nonelective surgery, mitral valve surgery for mitral valve regurgitation, history of extracardiac arteriopathy, preoperative hemoglobin <13 g/dL, and New York Heart Association functional class III or IV. A clinical prediction score was derived from the regression coefficients. The model had a good discriminative ability, with an area under the receiver operating characteristics curve of 0.8 (95% CI: 077-0.84). Using a threshold value of 5, the score had a 68% sensitivity, 79% specificity, a positive-predictive value of 33%, and a negative-predictive value of 94%. These results were validated on a validation sample using the bootstrap resampling technique. CONCLUSIONS: The authors developed a clinical score to facilitate the prediction of low- cardiac-output syndrome after adult cardiac surgery. This could help tailor patient management by contributing to the early identification of those at high risk of postoperative low cardiac output.

On-table Extubation After Minimally Invasive Cardiac Surgery: A Retrospective Observational Pilot Study.

OBJECTIVE: To assess the safety of "on-table" extubation after minimally-invasive heart valve surgery. DESIGN: A single-center retrospective observational study. SETTING: At a tertiary referral academic hospital. PARTICIPANTS: Patients who underwent nonemergent isolated heart valve surgery through a minithoracotomy approach between January 2016 and August 2021. INTERVENTION: All patients were treated by 1 of the 6 cardiac anesthesiologists of the hospital. Only some of them practiced "on-table" extubation, and the outcome of patients extubated "on-table" was compared to those extubated in the intensive care unit (ICU). MEASUREMENT AND MAIN RESULTS: The primary outcome was the occurrence of any postoperative respiratory complication during the entire hospital stay. Secondary outcomes included the use of inotropes and vasopressors, de novo atrial fibrillation, and lengths of stay in the ICU and the hospital. A total of 294 patients met inclusion criteria, of whom 186 (63%) were extubated "on-table." Cardiopulmonary bypass duration was significantly longer, and moderate intraoperative hypothermia was significantly more frequent in patients extubated in the ICU. After adjustment for these confounders and for the European System for Cardiac Operative Risk Evaluation (EuroSCORE) II using a multivariate logistic model, no association was found between the extubation strategy and postoperative pulmonary complications (adjusted odds ratio = 0.84; 95% CI = 0.40-1.77; p = 0.64). "On-table" extubation was associated with a lower risk of postoperative pneumonia and fewer vasopressors requirements. CONCLUSION: "On-table" extubation was not associated with an increased incidence of respiratory complications. A randomized controlled trial is warranted to confirm these results and determine whether "on-table" extubation offers additional benefits.

Comparison between supra-inguinal fascia iliaca and pericapsular nerve group blocks on postoperative pain and functional recovery after total hip arthroplasty: A noninferiority randomised clinical trial.

BACKGROUND: Pain after a posterolateral approach for total hip arthroplasty (THA) may affect early functional recovery. Supra-inguinal fascia iliaca (SFIB) and pericapsular nerve group (PENG) blocks have been proposed as promising analgesia techniques. OBJECTIVES: This trial was conducted to compare a PENG with a SFIB for controlling postoperative pain and for providing functional recovery. DESIGN: Noninferiority monocentric randomised controlled study. SETTING: One hundred and two patients scheduled for a total hip arthroplasty via the posterolateral approach under spinal anaesthesia were prospectively allocated to two groups. Data acquisition occurred between October 2021 and July 2022 at the University Hospital of Liege. PATIENTS: One hundred and two patients completed the trial. INTERVENTIONS: Group SFIB received supra-inguinal fascia iliaca block (SFIB) (40 ml ropivacaine 0.375%), whereas group PENG received a PENG block (20 ml ropivacaine 0.75%). MAIN OUTCOME MEASURES: Rest and mobilisation pain on a 0 to 10 numeric rating scale at fixed time points: 1 and 6 h after surgery, on day-1 and day-2 at 8 a.m.,1 p.m. and 6 p.m. On day-1 and day-2, evolution of quality-of-recovery-15 score was assessed, and timed-up-and-go, 2 and 6 min-walking tests. The noninferiority margin was set as 1 numeric rating scale point 6 h after surgery. RESULTS: Six hours after surgery, pain scores in group PENG were noninferior to those of group SFIB, with a difference between medians at 0 (95% CI -0.93 to 0.93). There were no significant differences between the groups regarding rest and dynamic pain trajectories during the first 48 postoperative hours, with no significant effects of group (rest P  = 0.800; dynamic P  = 0.708) or interaction between group and time (rest P  = 0.803; dynamic P  = 0.187). Similarly, no significant differences were observed regarding motor and functional recovery as assessed by timed-up-and-go ( P  = 0.197), 2 min ( P  = 0.364), and 6 min walking ( P  = 0.347) tests and quality-of-recovery-15 ( P  = 0.417) score. CONCLUSION: Following a total hip arthroplasty via the posterolateral approach, a PENG block is noninferior to SFIB regarding postoperative pain control 6 h after surgery, and functional recovery. TRIAL REGISTRATION: European Clinical Trial Register under EudraCT-number 2020-005126-28 ( https://www.clinicaltrialsregister.eu/ctr-search/trial/2020-005126-28/BE ).

Intra-operative electroencephalogram frontal alpha-band spectral analysis and postoperative delirium in cardiac surgery: A prospective cohort study.

BACKGROUND: Postoperative delirium (POD) remains a frequent complication after cardiac surgery, with pre-operative cognitive status being one of the main predisposing factors. However, performing complete pre-operative neuropsychological testing is challenging. The magnitude of frontal electroencephalographic (EEG) α oscillations during general anaesthesia has been related to pre-operative cognition and could constitute a functional marker for brain vulnerability. OBJECTIVE: We hypothesised that features of intra-operative α-band activity could predict the occurrence of POD. DESIGN: Single-centre prospective observational study. SETTING: University hospital, from 15 May 2019 to 15 December 2021. PATIENTS: Adult patients undergoing elective cardiac surgery. MAIN OUTCOME MEASURES: Pre-operative cognitive status was assessed by neuropsychological tests and scored as a global z score. A 5-min EEG recording was obtained 30 min after induction of anaesthesia. Anaesthesia was maintained with sevoflurane. Power and peak frequency in the α-band were extracted from the frequency spectra. POD was assessed using the Confusion Assessment Method for Intensive Care Unit, the Confusion Assessment Method and a chart review. RESULTS: Sixty-five (29.5%) of 220 patients developed POD. Delirious patients were significantly older with median [IQR] ages of 74 [64 to 79] years vs. 67 [59 to 74] years; P  < 0.001) and had lower pre-operative cognitive z scores (-0.52 ±â€Š1.14 vs. 0.21 ±â€Š0.84; P  < 0.001). Mean α power (-14.03 ±â€Š4.61 dB vs. -11.59 ±â€Š3.37 dB; P  < 0.001) and maximum α power (-11.36 ±â€Š5.28 dB vs. -8.85 ±â€Š3.90 dB; P  < 0.001) were significantly lower in delirious patients. Intra-operative mean α power was significantly associated with the probability of developing POD (adjusted odds ratio, 0.88; 95% confidence interval (CI), 0.81 to 0.96; P  = 0.007), independently of age and only whenever cognitive status was not considered. CONCLUSION: A lower intra-operative frontal α-band power is associated with a higher incidence of POD after cardiac surgery. Intra-operative measures of α power could constitute a means of identifying patients at risk of this complication. TRIAL REGISTRATION: NCT03706989.

Preoperative continuation of aspirin before isolated heart valve surgery and postoperative bleeding and transfusion: a single-center retrospective study.

BACKGROUND: The risks and benefits of preoperative aspirin continuation in patients undergoing isolated heart valve replacement surgery are unclear. We investigated the effect of aspirin continuation on the risk of bleeding and transfusion in these patients. METHODS: In this single center, retrospective study, among 474 adult patients who underwent isolated heart valve surgery between April 2013 and June 2018, 269 continued aspirin within 5 days before surgery (aspirin group) and 205 patients did not take or stopped aspirin no later than 5 days before surgery (non-aspirin group). The chi-square test, the Mann-Whitney U-test, and the Student's T-test were used to compare data between the groups. Univariate and Multivariate logistic regressions were used to assess crude and adjusted relationships between outcome and exposure. RESULTS: The primary outcome, red blood cell (RBC) transfusion, occurred in 59 patients (22%) of the aspirin group and in 24 patients (12%) of the non-aspirin group (p = 0.004). After adjustment for confounding factors, continuation of aspirin was no longer associated with RBC transfusion (aOR1.8;95%CI,0.98-3.2;p = 0.06). The amount of allogenic blood products, the incidence of surgical re-exploration for bleeding, the volume of re-transfused cell-saved blood, and the cumulative chest tube drainage during the first 24 postoperative hours were similar between groups. CONCLUSION: Preoperative continuation of aspirin in patients undergoing isolated heart valve surgery is neither associated with a higher incidence of RBC transfusion, nor with larger perioperative blood loss, or more frequent surgical revision for bleeding. TRIAL REGISTRATION: Clinicaltrials.gov (NCT05151796).

[Fibromyalgia, where are we in 2023 ?] / Fibromyalgie, où en est-on en 2023 ?

Fibromyalgia remains a nebulous clinical entity for many practitioners. Actually, this pathology associates diffuse chronic pain with a host of somatic complaints, which may be variable from one patient to another. The difficulty resides also in establishing the diagnosis, which remains essentially clinical, in the absence of anatomical lesions, as well as biological or anatomopathological anomalies. Patients are usually confronted to a therapeutic wandering phase, of variable duration, before being recognized in their pathology. Management of fibromyalgia has to be multimodal, including physiotherapy, a cognitive-behavioural approach, and an individually tailored medical support.

La fibromyalgie reste une entité clinique nébuleuse dans l'esprit de nombreux praticiens. En effet, cette pathologie associe douleurs chroniques diffuses à une multitude de symptômes tels que des troubles du sommeil, des troubles cognitifs, ainsi que de nombreuses plaintes somatiques variables d'un patient à l'autre. La difficulté réside également dans l'établissement du diagnostic. Celui-ci reste avant tout clinique, en l'absence de lésions anatomiques, d'anomalies biologiques ou anatomo-pathologiques. Les patients passent, généralement, par une phase plus ou moins longue d'errance thérapeutique avant d'avoir une reconnaissance de leur pathologie. La prise en charge doit être multimodale, incluant une revalidation en kinésithérapie, une thérapie cognitivo-comportementale, et un accompagnement médical adapté au cas par cas.

[Plasma biomarkers in traumatic brain injury : current status]. / Biomarqueurs plasmatiques dans le traumatisme crânien : état des lieux.

Traumatic Brain Injury (TBI) is a common trauma and a worldwide major cause of mortality or disability in both civilian and military populations. TBI is not a pathological entity in its own, but rather a pattern of heterogeneous traumas with diverse and varied mechanisms and clinical expressions. Therefore, no universal medical response can be settled to it. Instead, medical management must be tailored to each individual's specific needs. If the current identification and prognosis of TBI is basically based on neurological examination and computerized tomography, specific biomarkers could represent a valuable aid in this diagnostic and therapeutic challenge. The potential implications of these markers are broad, encompassing among others the detection of unsuspected TBI, the monitoring of trauma severity, short-, intermediate- and long-term prognosis and apprehension of the extent of the sequelae. This topic has received broad and growing interest over the past decade, and the current literature is extensive. This short narrative review summarizes the latest advances in the field of plasma biomarkers in TBI patients.

Le traumatisme crânien (TC) est une pathologie courante et une cause majeure de mortalité ou d'invalidité dans le monde, tant chez les civils que chez les militaires. Le TC ne constitue pas une entité pathologique à part entière, mais plutôt un ensemble de lésions hétérogènes dont les mécanismes et les expressions cliniques sont divers et variés. Par conséquent, aucune prise en charge universelle ne peut être établie et les traitements médicaux doivent être adaptés et ajustés à l'individu. Si, actuellement, l'identification et le pronostic des TC reposent essentiellement sur l'examen clinique neurologique et la tomodensitométrie, des biomarqueurs spécifiques pourraient représenter une aide précieuse dans ce défi diagnostique et thérapeutique. L'implication potentielle de ces marqueurs est vaste, avec un rôle à jouer, entre autres, dans la détection de la présence d'un TC insoupçonné, le suivi de la sévérité du traumatisme, le pronostic de morbi-mortalité à court, moyen et long termes, et la prédiction de la gravité et de l'étendue des séquelles. Ce sujet a suscité un intérêt large et croissant au cours de la dernière décennie, et la littérature actuelle est abondante. Cette brève revue narrative résume les dernières avancées dans le domaine des biomarqueurs plasmatiques lors d'un TC.

Perturbations in dynamical models of whole-brain activity dissociate between the level and stability of consciousness.

Consciousness transiently fades away during deep sleep, more stably under anesthesia, and sometimes permanently due to brain injury. The development of an index to quantify the level of consciousness across these different states is regarded as a key problem both in basic and clinical neuroscience. We argue that this problem is ill-defined since such an index would not exhaust all the relevant information about a given state of consciousness. While the level of consciousness can be taken to describe the actual brain state, a complete characterization should also include its potential behavior against external perturbations. We developed and analyzed whole-brain computational models to show that the stability of conscious states provides information complementary to their similarity to conscious wakefulness. Our work leads to a novel methodological framework to sort out different brain states by their stability and reversibility, and illustrates its usefulness to dissociate between physiological (sleep), pathological (brain-injured patients), and pharmacologically-induced (anesthesia) loss of consciousness.

How hot is the hot zone? Computational modelling clarifies the role of parietal and frontoparietal connectivity during anaesthetic-induced loss of consciousness.

In recent years, specific cortical networks have been proposed to be crucial for sustaining consciousness, including the posterior hot zone and frontoparietal resting state networks (RSN). Here, we computationally evaluate the relative contributions of three RSNs - the default mode network (DMN), the salience network (SAL), and the central executive network (CEN) - to consciousness and its loss during propofol anaesthesia. Specifically, we use dynamic causal modelling (DCM) of 10 min of high-density EEG recordings (N = 10, 4 males) obtained during behavioural responsiveness, unconsciousness and post-anaesthetic recovery to characterise differences in effective connectivity within frontal areas, the posterior 'hot zone', frontoparietal connections, and between-RSN connections. We estimate - for the first time - a large DCM model (LAR) of resting EEG, combining the three RSNs into a rich club of interconnectivity. Consistent with the hot zone theory, our findings demonstrate reductions in inter-RSN connectivity in the parietal cortex. Within the DMN itself, the strongest reductions are in feed-forward frontoparietal and parietal connections at the precuneus node. Within the SAL and CEN, loss of consciousness generates small increases in bidirectional connectivity. Using novel DCM leave-one-out cross-validation, we show that the most consistent out-of-sample predictions of the state of consciousness come from a key set of frontoparietal connections. This finding also generalises to unseen data collected during post-anaesthetic recovery. Our findings provide new, computational evidence for the importance of the posterior hot zone in explaining the loss of consciousness, highlighting also the distinct role of frontoparietal connectivity in underpinning conscious responsiveness, and consequently, suggest a dissociation between the mechanisms most prominently associated with explaining the contrast between conscious awareness and unconsciousness, and those maintaining consciousness.

Influence of Levobupivacaine Regional Scalp Block on Hemodynamic Stability, Intra- and Postoperative Opioid Consumption in Supratentorial Craniotomies: A Randomized Controlled Trial.

BACKGROUND: The anesthetic management of supratentorial craniotomy (CR) necessitates tight intraoperative hemodynamic control. This type of surgery may also be associated with substantial postoperative pain. We aimed at evaluating the influence of regional scalp block (SB) on hemodynamic stability during the noxious events of supratentorial craniotomies and total intravenous anesthesia, its influence on intraoperative anesthetic agents' consumption, and its effect on postoperative pain control. METHODS: Sixty patients scheduled for elective CR were prospectively enrolled. Patient, anesthesiologist, and neurosurgeon were blind to the random performance of SB with either levobupivacaine 0.33% (intervention group [group SB], n = 30) or the same volume of saline (control group [group CO], placebo group, n = 30). General anesthesia was induced and maintained using target-controlled infusions of remifentanil and propofol that were adjusted according to hemodynamic parameters and state entropy of the electroencephalogram (SE), respectively. Mean arterial blood pressure (MAP), heart rate (HR), SE, and propofol and remifentanil effect-site concentrations (Ce) were recorded at the time of scalp block performance (Baseline), and 0, 1, 3, and 5 minutes after skull-pin fixation (SP), skin incision (SI), CR, and dura-mater incision (DM). Morphine consumption and postoperative pain intensity (0-10 visual analog scale [VAS]) were recorded 1, 3, 6, 24, and 48 hours after surgery. Propofol and remifentanil overall infusion rates were also recorded. Data were analyzed using 2-tailed Student unpaired t tests, 2-way mixed-design analysis of variance (ANOVA), and Tukey's honestly significant difference (HSD) tests for post hoc comparisons as appropriate. RESULTS: Demographics and length of anesthetic procedure of group CO and SB were comparable. SP, SI, and CR were associated with a significantly higher MAP in group CO than in group SB, at least at one of the time points of recording surrounding those noxious events. This was not the case at DM. Similarly, HR was significantly higher in group CO than in group SB during SP and SI, at least at 1 of the points of recording, but not during CR and DM. Propofol and remifentanil Ce and overall infusion rates were significantly higher in group CO than in group SB, except for propofol Ce during SP. Postoperative pain VAS and cumulative morphine consumption were significantly higher in group CO than in group SB. CONCLUSIONS: In supratentorial craniotomies, SB improves hemodynamic control during noxious events and provides adequate and prolonged postoperative pain control as compared to placebo.

Unconsciousness reconfigures modular brain network dynamics.

The dynamic core hypothesis posits that consciousness is correlated with simultaneously integrated and differentiated assemblies of transiently synchronized brain regions. We represented time-dependent functional interactions using dynamic brain networks and assessed the integrity of the dynamic core by means of the size and flexibility of the largest multilayer module. As a first step, we constrained parameter selection using a newly developed benchmark for module detection in heterogeneous temporal networks. Next, we applied a multilayer modularity maximization algorithm to dynamic brain networks computed from functional magnetic resonance imaging (fMRI) data acquired during deep sleep and under propofol anesthesia. We found that unconsciousness reconfigured network flexibility and reduced the size of the largest spatiotemporal module, which we identified with the dynamic core. Our results represent a first characterization of modular brain network dynamics during states of unconsciousness measured with fMRI, adding support to the dynamic core hypothesis of human consciousness.

Potential adaptive divergence between subspecies and populations of snapdragon plants inferred from QST -FST comparisons.

Phenotypic divergence among natural populations can be explained by natural selection or by neutral processes such as drift. Many examples in the literature compare putatively neutral (FST ) and quantitative genetic (QST ) differentiation in multiple populations to assess their evolutionary signature and identify candidate traits involved with local adaptation. Investigating these signatures in closely related or recently diversified species has the potential to shed light on the divergence processes acting at the interspecific level. Here, we conducted this comparison in two subspecies of snapdragon plants (eight populations of Antirrhinum majus pseudomajus and five populations of A. m. striatum) in a common garden experiment. We also tested whether altitude was involved with population phenotypic divergence. Our results identified candidate phenological and morphological traits involved with local adaptation. Most of these traits were identified in one subspecies but not the other. Phenotypic divergence increased with altitude for a few biomass-related traits, but only in A. m. striatum. These traits therefore potentially reflect A. m. striatum adaptation to altitude. Our findings imply that adaptive processes potentially differ at the scale of A. majus subspecies.