Search

Aim An increasing number of children undergo magnetic resonance imaging requiring anesthesia or sedation to ensure their immobility; however, magnetic resonance imaging may increase body temperature whereas sedation or anesthesia may decrease it. We investigated changes in body temperature in children who underwent sedation or anesthesia for magnetic resonance imaging. Methods Children aged 12 weeks-12 years undergoing anesthesia and magnetic resonance imaging were included in this prospective observational study. Tympanic body temperature was measured before and after magnetic resonance imaging, and the difference between measurements was calculated. Associations between the temperature difference and patient- or procedure-related factors were evaluated with linear and logistic regression analysis. Results A total of 74 children were included, of whom 5 (7%) had a temperature increase >= 0.5 degrees C. Mean temperature difference was -0.24 degrees C (SD 0.48) for the entire group and -0.28 degrees C for the youngest children (0-2 years). The temperature difference correlated positively with the duration of imaging (unadjusted coefficient 0.26, 95% confidence interval (CI), (0.01; 0.52)). Conclusion In this study of sedated or anesthetized children undergoing magnetic resonance imaging, clinically relevant increases in body temperature above 0.5 degrees C were only found in a few patients. However, longer imaging duration tended to be associated with increased body temperature.

Denmark has experienced an increase in the proportion of invasive vancomycin-resistant Enterococcus faecium (VRE) since 2002 (e.g.

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess effects of cognitive training interventions initiated during ICU or hospital stay versus no cognitive training on global cognitive function in adult patients after cessation of intensive care therapy.

Traumatic brain injury (TBI) contributes to almost one third of all trauma-related deaths, and those that survive often suffer from long-term physical and cognitive deficits. Ciclosporin (cyclosporine, cyclosporin A) has shown promising neuroprotective properties in pre-clinical TBI models. The Copenhagen Head Injury Ciclosporin (CHIC) study was initiated to establish the safety profile and pharmacokinetics of ciclosporin in patients with severe TBI, using a novel parenteral lipid emulsion formulation. Exploratory pharmacodynamic study measures included microdialysis in brain parenchyma and protein biomarkers of brain injury in the cerebrospinal fluid (CSF). Sixteen adult patients with severe TBI (Glasgow Coma Scale 4–8) were included, and all patients received an initial loading dose of 2.5 mg/kg followed by a continuous infusion for 5 days. The first 10 patients received an infusion dosage of 5 mg/kg/day whereas the subsequent 6 patients received 10 mg/kg/day. No mortality was registered within the study duration, and the distribution of adverse events was similar between the two treatment groups. Pharmacokinetic analysis of CSF confirmed dose-dependent brain exposure. Between- and within-patient variability in blood concentrations was limited, whereas CSF concentrations were more variable. The four biomarkers, glial fibrillary acidic protein, neurofilament light, tau, and ubiquitin carboxy-terminal hydrolase L1, showed consistent trends to decrease during the 5-day treatment period, whereas the samples taken on the days after the treatment period showed higher values in the majority of patients. In conclusion, ciclosporin, as administered in this study, is safe and well tolerated. The study confirmed that ciclosporin is able to pass the blood–brain barrier in a TBI population and provided an initial biomarker-based signal of efficacy.

Hypoxaemia is present in many critically ill patients, and may contribute to encephalopathy. Changes in the passage of large neutral amino acids (LNAAs) across the blood-brain barrier (BBB) with an increased cerebral influx of aromatic amino acids into the brain may concurrently be present and also contribute to encephalopathy, but it has not been established whether hypoxaemia

Background Delayed cerebral ischemia (DCI) is a serious and frequent complication following subarachnoid hemorrhage (SAH). The pathophysiology behind DCI remains poorly understood, but inflammation has been proposed to play a significant role. This study investigated the relationship between plasma levels of some of the most important inflammatory markers and DCI, cerebral vasospasm, and functional outcome in patients with SAH. Methods In 90 patients with SAH, interleukin-6, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, high sensitivity C-reactive protein (HsCRP), interleukin-8, interleukin-10, interferon gamma, and tumor necrosis factor alpha were measured in peripheral blood day 3 and day 8 after SAH. Any occurrence of DCI or infection was recorded, and computed tomography angiography was performed on day 8. Clinical outcome was assessed after 3 months. Results HsCRP on day 3 was higher in patients with angiographic vasospasm (P = 0.003), and HsCRP on day 8 was higher in patients with poor outcome (P = 0.014). No association with DCI, vasospasm, or outcome was found for any of the remaining analyzed substances. Conclusions High plasma levels of HsCRP were significantly associated with angiographic vasospasm and clinical outcome. Plasma levels of interleukin-6, vascular cell adhesion molecule-1, intercellular adhesion molecule-1, interleukin-8, interleukin-10, interferon gamma, and tumor necrosis factor alpha were not associated with DCI, angiographic vasospasm, or clinical outcome at 3 months.

Background Naloxone, an opioid receptor antagonist, is used as a pharmacological tool to detect tonic endogenous activation of opioid receptors in experimental pain models. We describe a pharmacokinetic model linking naloxone pharmacokinetics to its main metabolite after high-dose naloxone infusion. Methods Eight healthy volunteers received a three-stage stepwise high-dose i.v. naloxone infusion (total dose 3.25 mg kg−1). Naloxone and naloxone-3-glucuronide (N3G) plasma concentrations were sampled from infusion onset to 334 min after infusion discontinuation. Pharmacokinetic analysis was performed using non-linear mixed effect models (NONMEM). The predictive performances of Dowling's and Yassen's models were evaluated, and target-controlled infusion simulations were performed. Results Three- and two-compartment disposition models with linear elimination kinetics described the naloxone and N3G concentration time-courses, respectively. Two covariate models were developed: simple (weight proportional) and complex (with the shallow peripheral volume of distribution linearly increasing with body weight). The median prediction error (MDPE) and wobble for Dowling's model were –32.5% and 33.4%, respectively. For Yassen's model, the MDPE and wobble were 1.2% and 19.9%, respectively. Conclusions A parent–metabolite pharmacokinetic model was developed for naloxone and N3G after high-dose naloxone infusion. No saturable pharmacokinetics were observed. Whereas Dowling's model was inaccurate and over-predicted naloxone concentrations, Yassen's model accurately predicted naloxone pharmacokinetics. The newly developed covariate models may be used for high-dose TCI-naloxone for experimental and clinical practice. Clinical trials registration NCT01992146.

Introduction Delayed cerebral ischaemia (DCI) is one of the most frequent complications of aneurysmal subarachnoid haemorrhage (aSAH). The purpose of the present retrospective cohort study of patients with aSAH was to identify the association between DCI, functional outcome and 4-year mortality. Methods Patients admitted to the Neurointensive Care Unit at Rigshospitalet, Copenhagen, with aSAH from 1 January 2010, through 31 December 2013 were registered. Patients were categorized into 3 groups: (a) those with DCI, defined as either a decline in consciousness or focal neurological deficits lasting ≥1 hour without any other detectable cause, (b) those without DCI, or (c) those who were unassessable for DCI. Functional neurological outcome after 6 months, as measured by the modified Rankin Scale (mRS), was dichotomized into good (mRS 0-2) and poor (mRS 3-6). Kaplan-Meier survival curves were constructed, and incidence risk rates were calculated both to determine the association between DCI and mortality. Results Four hundred ninety-two cases of aSAH were recorded in the study period. DCI occurred in 23% of all patients, corresponding to 33% of assessable patients. Patients without DCI had the best functional outcome (mRS) compared to patients with DCI and patients who were unassessable; furthermore, the latter had worse outcomes than patients with DCI. Patients diagnosed with DCI had significantly higher mortality than those without DCI, even ignoring the first 14 days after admission. Conclusion DCI may be associated with both short- and long-term morbidity and mortality in patients with aSAH.

Developing positron emission tomography (PET) radioligands for the detection of endogenous serotonin release will enable the investigation of serotonergic deficits in many neuropsychiatric disorders. The present study investigates how acute challenges that aim to increase or decrease cerebral serotonin levels affect binding of the serotonin 2A receptor (5-HT2AR) agonist radioligand [11C]Cimbi-36. In a randomized, double-blind, placebo-controlled, three-arm design, 23 healthy volunteers were PET scanned twice with [11C]Cimbi-36: at baseline and following double-blind assignment to one of three interventions (1) infusion of the selective serotonin reuptake inhibitor (SSRI) citalopram preceded by oral dosing of the 5-HT1AR antagonist pindolol, (n = 8) (2) acute tryptophan depletion (ATD) (n = 7) and (3) placebo (n = 8). Two-sample t-tests revealed no significant group differences in percent change of neocortical [11C]Cimbi-36 binding from baseline to intervention between placebo and citalopram/pindolol (p = 0.4) or between placebo and ATD (p = 0.5). Notably, there was a significantly larger within-group variation in 5-HT2AR binding after intervention with citalopram/pindolol, as compared with placebo (p = 0.007). These findings suggest that neither ATD nor a combination of citalopram and pindolol elicit acute unidirectional changes in serotonin levels sufficient to be detected with [11C]Cimbi-36 PET in neocortex. We suggest that the large interindividual variation in 5-HT2AR binding after citalopram/pindolol reflects that after an acute SSRI intervention, individuals respond substantially different in terms of their brain serotonin levels. Our observation has a potential impact for the understanding of patient responses to SSRI.

Delirium is common during sepsis, although under-recognized. We aimed to assess the value of continuous electroencephalography (cEEG) to aid in the diagnosis of delirium in septic patients. We prospectively evaluated 102 consecutive patients in a medical intensive care unit (ICU), who had sepsis or septic shock, without evidence of acute primary central nervous system disease. We initiated cEEG recording immediately after identification. The median cEEG time per patient was 44 h (interquartile range 21–99 h). A total of 6723 h of cEEG recordings were examined. The Confusion Assessment Method for the ICU (CAM-ICU) was administered six times daily to identify delirium. We analyzed the correlation between cEEG and delirium using 1252 two-minute EEG sequences recorded simultaneously with the CAM-ICU scorings. Of the 102 included patients, 66 (65%) had at least one delirium episode during their ICU stay, 30 (29%) remained delirium-free, and 6 (6%) were not assessable due to deep sedation or coma. The absence of delirium was independently associated with preserved high-frequency beta activity (> 13 Hz) (P

Objective. Invasively measured arterial blood pressure (ABP) is associated with complications, while non-invasively measured ABP is generally considered risk-free. This study aimed to investigate the reliability of non-invasive ABP measured using finger-cuff volume-clamp device compared to invasive ABP measured by an arterial catheter in patients with aneurysmal subarachnoid haemorrhage (SAH). Approach. In 30 patients admitted for neurointensive care with SAH, invasive and non-invasive ABP were recorded simultaneously. Reliability was assessed for mean, diastolic and systolic ABP separately using intraclass correlation coefficient (ICC) agreement for each full period and each 3 s average. Main results. A median of 3 (IQR: 2–3) periods were included for each participant. The full periods (n = 81) showed an ICC of 0.34 (95% CI: 0.14–0.52), 0.31 (95% CI: 0.10–0.49), and 0.20 (95% CI: 0.00–0.39) for mean, diastolic, and systolic ABP, respectively. Three-second averages (n = 33 786) for mean (ICC: 0.35; 95% CI: 0.33–0.36), diastolic (ICC: 0.25; 95% CI: 0.25–0.28), and systolic ABP (ICC: 0.26; 95% CI: 0.18–0.33) yielded similar findings. Pearson’s correlation coefficient showed an R 2 of 0.15 (p p p = 0.027) for mean, diastolic and systolic ABP, respectively. Significance. In patients with SAH, non-invasive measurement of ABP using the widely used Nano system from Finapres Medical Systems—a finger-cuff volume-clamp device (Finapres, Chennai, India) showed poor reliability and therefore cannot be used interchangeably with invasively measured ABP.

Background Mean flow index (Mxa) for evaluating dynamic cerebral autoregulation is derived using varying approaches for calculation, which may explain that the reliability ranges from poor to excellent. The comparability, repeatability, stability, and internal consistency of approaches have not previously been assessed. Methods We included 60 recordings from resting healthy volunteers and calculated Mxa using four different approaches: three without overlapping calculations, using intervals for averaging wave‐form data (blocks) of 3, 6, and 10 s, and correlation periods (epochs) of 60, 240, and 300 s (3–60–F, 6–240–F, and 10–300–F); and one using 10‐second blocks, 300 s epochs, and overlaps of 60 s (10–300–60). The comparability between the approaches was assessed using Student's t test, intraclass correlation coefficients (ICC), and Bland–Altman plot. Results Overall, 3–60–F resulted in a higher Mxa than the other indices (p, Mx has a low sensitivity to artifacts, but otherwise seems highly dependent on the approach, with a repeatability that is moderate at best. The varying accuracy and precision renders Mx unreliable for classifying impaired cerebral autoregulation using healthy adults for comparison.

Introduction Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease with great heterogeneity. Biological prognostic markers are needed for the patients to plan future supportive treatment, palliative treatment, and end-of-life decisions. In addition, prognostic markers are greatly needed for the randomization in clinical trials. Objective This study aimed to test the ALS Functional Rating Scale-Revised (ALSFRS-R) progression rate (ΔFS) as a prognostic marker of survival in a Danish ALS cohort. Methods The ALSFRS-R score at test date in association with duration of symptoms, from the onset of symptoms until test date, (defined as ΔFS’) was calculated for 90 Danish patients diagnosed with either probable or definite sporadic ALS. Median survival time was then estimated from the onset of symptoms until primary endpoint (either death or tracheostomy). ΔFS’ was subjected to survival analysis using Cox proportional hazards modelling, log-rank test, and Kaplan-Meier survival analysis. Results and conclusions Both ΔFS’ and age was found to be strong predictors of survival of the Danish ALS cohort. Both variables are easily obtained at the time of diagnosis and could be used by clinicians and ALS patients to plan future supportive and palliative treatment. Furthermore, ΔFS’, is a simple, prognostic marker that predicts survival in the early phase of disease as well as at later stages of the disease.

Anne-Lene Kjældgaard,1,2 Katrine Pilely,1 Karsten Skovgaard Olsen,2 Anne Øberg Lauritsen,2 Stephen Wørlich Pedersen,3 Kirsten Svenstrup,3,4 Merete Karlsborg,4 Helle Thagesen,5 Morten Blaabjerg,5 Ásta Theódórsdóttir,6 Elisabeth Gundtoft Elmo,3 Anette Torvin Møller,7 Niels Anker Pedersen,8 Niels Kirkegaard,8 Kirsten Møller,2,9 Peter Garred1,9 1Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Diagnostic Centre, Rigshospitalet, Copenhagen, Denmark; 2Department of Neuroanaesthesiology Neuroscience Centre, Rigshospitalet, Copenhagen, Denmark; 3Department of Neurology, Neuroscience Centre, Rigshospitalet, Copenhagen, Denmark; 4Department of Neurology, Bispebjerg Hospital, Copenhagen, Denmark; 5Department of Neurology, Roskilde University Hospital, Roskilde, Denmark; 6Department of Neurology, Odense University Hospital, Odense, Denmark; 7Department of Neurology, Aarhus Hospital, Copenhagen, Denmark; 8Department of Anaesthesiology, Private Hospital Gildhøj, Brondby, Denmark; 9Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, DenmarkCorrespondence: Anne-Lene KjældgaardLaboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Diagnostic Centre, Rigshospitalet, Ole Maaloesvej 26, Copenhagen, DK-2200, DenmarkTel +45 35457631Fax +45 35398766Email anne-lene.kjaeldgaard@regionh.dkBackground: The complement system has been suggested to be involved in the pathophysiology of amyotrophic lateral sclerosis (ALS), a progressive motor neuron disease. In the present study, we compared levels of selected complement markers to clinical outcome in ALS patients.Methods: This observational, explorative cohort study included 92 ALS patients, 61 neurological controls (NCs) admitted for suspected aneurysmal subarachnoid haemorrhage, and 96 neurologically healthy controls (NHCs). Peripheral blood and cerebrospinal fluid (CSF) were obtained for the measurement of ficolin-1, − 2, and − 3; collectin-11, MBL, MASP-3, MAP-1, C4, C3, PTX-3, and complement activation products C4c, C3bc, and sC5b-9. We recorded clinical outcomes of ALS patients for 24 to 48 months after inclusion in order to analyse the effects of the complement markers on survival time.Results: Compared with both control groups, ALS patients exhibited increased collectin-11, C4 and sC5b-9 in plasma, as well as increased ficolin-3 in CSF. Ficolin-2 was significantly decreased in plasma of the ALS patients compared with NHCs, but not with NCs. The concentration of collectin-11, C3 and C3bc correlated negatively with the revised ALS functional rating scale (ALSFRS-R). No association was found between levels of complement markers and survival as estimated by hazard ratios.Conclusion: ALS patients exhibit aberrant expression of selected mediators of the lectin complement pathway as well as increased activation of the terminal complement pathway, corroborating the notion that the complement system might be involved in the pathophysiology of ALS.Keywords: amyotrophic lateral sclerosis, innate immunity, complement, lectin pathway, cerebrospinal fluid, pathophysiology, observational cohort study

Background Due to an expected surge of COVID-19 patients in need of mechanical ventilation, the intensive care capacity was doubled at Rigshospitalet, Copenhagen, in March 2020. This resulted in an urgent need for doctors with competence in working with critically ill COVID-19 patients. A training course and a theoretical test for non-intensivist doctors were developed. The aims of this study were to gather validity evidence for the theoretical test and explore the effects of the course. Methods The one-day course was comprised of theoretical sessions and hands-on training in ventilator use, haemodynamic monitoring, vascular access and use of personal protective equipment. Validity evidence was gathered for the test by comparing answers from novices and experts in intensive care. Doctors who participated in the course completed the test before (pre-test), after (post-test) and again within eight weeks following the course (retention-test). Results Fifty-four non-intensivist doctors from 15 different specialties with a wide range in clinical experience level completed the course. The test consisted of 23 questions and demonstrated a credible pass-fail standard at 16 points. Mean pre-test score was 11.9 (SD 3.0), mean post-test score 20.6 (1.8) and mean retention-test score 17.4 (2.2). All doctors passed the post-test. Conclusion Non-intensivist doctors, irrespective of experience level, can acquire relevant knowledge for working in the ICU through a focused one-day evidence-based course. This knowledge was largely retained as shown by a multiple-choice test supported by validity evidence. The test is available in appendix and online.

In this study, we derived and validated a composite EBI risk score. In addition to confirming the importance of EBI in determining long-term SAH recovery, the risk score could be used for patient selection or risk stratification in future clinical trials. The score was derived and validated in 2 independent cohorts, highlighting its ability to perform across separate patient populations. Future studies should focus on validating the application of EBI in clinical settings, examining other biomarkers in addition to sST2, and deepening our understanding of the pathophysiologic factors that lead to EBI and impact patient outcomes.

Introduction Intensive care for patients with severe acute brain injury aims both to treat the immediate consequences of the injury and to prevent and treat secondary brain injury to ensure a good functional outcome. Sedation may be used to facilitate mechanical ventilation, for treating agitation, and for controlling intracranial pressure. Ketamine is an N-methyl-D-aspartate receptor antagonist with sedative, analgesic, and potentially neuroprotective properties. We describe a protocol for a systematic review of randomised clinical trials assessing the beneficial and harmful effects of ketamine for patients with severe acute brain injury. Methods and analysis We will systematically search international databases for randomised clinical trials, including CENTRAL, MEDLINE, Embase, and trial registries. Two authors will independently review and select trials for inclusion, and extract data. We will compare ketamine by any regimen versus placebo, no intervention, or other sedatives or analgesics for patients with severe acute brain injury. The primary outcomes will be functional outcome at maximal follow up, quality of life, and serious adverse events. We will also assess secondary and exploratory outcomes. The extracted data will be analysed using Review Manager and Trials Sequential Analysis. Evidence certainty will be graded using GRADE. Ethics and dissemination The results of the systematic review will be disseminated through peer-reviewed publication. With the review, we hope to inform future randomised clinical trials and improve clinical practice. PROSPERO no CRD42021210447.

In patients with severe traumatic brain injury, there is limited evidence of the clinical effect of early orthostatic exercise, although such exercise may strengthen systemic or cerebral hemodynamic responses to head-up tilt, thereby minimizing orthostatic intolerance. We measured dynamic cerebral autoregulation (dCA) and the occurrence of orthostatic intolerance after four weeks of regular orthostatic exercise by head-up tilt using a tilt table with integrated stepping using the ERIGO® tilt-table and comparing it to standard care. Thirty-four patients with severe traumatic brain injury admitted to a neurocritical care unit were included in this randomized clinical trial. Middle cerebral artery blood flow velocity (MCAv), non-invasive mean arterial pressure, heart rate and PaCO2 were recorded; dCA was measured by the non-invasive mean flow index (nMxa). Transition from the supine position to head-up tilt triggered a 10–16% decrease in MCAv and increased nMxa in both groups at all time points (P < 0.05), with no differences between groups. There was no difference in the number of episodes with orthostatic intolerance (5 vs 3; 1 vs 2; 1 vs 0) at baseline, two weeks and four weeks, respectively, and no association between changes in PaCO2-adjusted nMxa and the occurrence of orthostatic reactions (P = 0.35). Early orthostatic exercise does not affect dynamic cerebral autoregulation and does not protect against orthostatic intolerance in patients with severe traumatic brain injury. Trial registration: ClinicalTrials.gov identifier: NCT02924649. Registered on 3rd October 2016.

Brain abscesses are often polymicrobial and of unclear primary origin. Here, we compare the use of next-generation sequencing (NGS) technology with classical microbiological diagnostics for identification of clinically relevant microorganisms and describe the microbiome profiling with respect to the primary source of brain abscess. Thirty-six samples from 36 patients, with primary brain abscesses, were subjected to both culture- and 16S/18S rRNA Sanger sequencing-based diagnostics (“standard methods”) and compared to a 16S/18S amplicon-based NGS, which were also subjected to a microbiome diversity analyses. Forty-seven species were identified with “standard methods” compared to 96 species with NGS, both confirming and adding to the number of species identified (p 0.05) between groups while beta diversity differed significantly (p = 0.003) comparing disseminated vs the other presumable origin of infection. Interesting, clustering was also detected between “dental” and “sinusitis,” although not significantly (p = 0.07). Microbiome-based diagnostics can increase sensitivity without losing specificity. The bacterial beta diversity differed between the presumably origin of the brain abscess and might help to clarify the primary source of infection.

Background Resuscitative endovascular balloon occlusion of the aorta (REBOA) reportedly elevates arterial blood pressure (ABP) during non-traumatic cardiac arrest. Objectives This randomized, blinded trial of cardiac arrest in pigs evaluated the effect of automated REBOA two minutes after balloon inflation on ABP (primary endpoint) as well as arterial blood gas values and markers of cerebral haemodynamics and metabolism. Methods Twenty anesthetized pigs were randomized to REBOA inflation or sham-inflation (n = 10 in each group) followed by insertion of invasive monitoring and a novel, automated REBOA catheter (NEURESCUE® Catheter & NEURESCUE® Assistant). Cardiac arrest was induced by ventricular pacing. Cardiopulmonary resuscitation was initiated three min after cardiac arrest, and the automated REBOA was inflated or sham-inflated (blinded to the investigators) five min after cardiac arrest. Results In the inflation compared to the sham group, mean ABP above the REBOA balloon after inflation was higher (inflation: 54 (95%CI: 43–65) mmHg; sham: 44 (33–55) mmHg; P = 0.06), and diastolic ABP was higher (inflation: 38 (29–47) mmHg; sham: 26 (20–33) mmHg; P = 0.02), and the arterial to jugular oxygen content difference was lower (P = 0.04). After return of spontaneous circulation, mean ABP (inflation: 111 (95%CI: 94–128) mmHg; sham: 94 (95%CI: 65–123) mmHg; P = 0.04), diastolic ABP (inflation: 95 (95%CI: 78−113) mmHg; sham: 78 (95%CI: 50−105) mmHg; P = 0.02), CPP (P = 0.01), and brain tissue oxygen tension (inflation: 315 (95%CI: 139−491)% of baseline; sham: 204 (95%CI: 75−333)%; P = 0.04) were higher in the inflation compared to the sham group. Conclusion Inflation of REBOA in a porcine model of non-traumatic cardiac arrest improves central diastolic arterial pressure as a surrogate marker of coronary artery pressure, and cerebral perfusion. Institutional protocol number 2017-15-0201-01371.

Objectives Knowledge regarding delirium prevention in patients with acute brain injury remains limited. We tested the hypothesis that an intervention bundle which targeted sedation, sleep, pain, and mobilisation would reduce delirium in patients with acute brain injury. Design A prospective before-after intervention study: a five-month phase of standard care was followed by a six-month intervention phase. Setting The neuro-intensive care unit, University Hospital of Copenhagen, Denmark. Main outcome measures The Intensive Care Delirium Screening Checklist was used to detect delirium. Primary outcome was delirium duration; secondary outcomes were delirium prevalence, ICU length of stay and one year mortality. Results Forty-four patients were included during the standard care phase, and 50 during the intervention phase. Delirium was present in 90% of patients in the standard care group and 88% in the intervention group (p = 1.0), and time with delirium was 4 days vs 3.5 days (p = 0.26), respectively. Also, ICU length of stay (13 vs. 10.5 days (p = 0.4)) and the one year mortality (21% vs 12% (p = 0.38))) were similar between groups. Conclusion We found a high prevalence of delirium in patients with acute brain injury. The intervention bundle did not significantly reduce prevalence or duration of delirium, ICU length of stay or one year mortality.

IntroductionAmyotrophic lateral sclerosis (ALS) is a devastating, progressive disease that causes degeneration of the motor neurons leading to paresis of the bulbar and the skeletal musculature. The pathogenesis of ALS remains unknown. We will test the hypothesis that the complement system is involved in the pathophysiology of ALS. This protocol article describes our efforts to establish a national Danish ALS biobank. The primary aim is to obtain biological material from patients with ALS for the current study as well as for future studies.Methods and analysisWe intend to establish an observational ALS biobank; some of the material from this biobank will be used for a prospective, observational case–control study. The participants are patients with ALS, neurologically healthy controls and non-ALS neurological controls. Each participant consents to be interviewed and to donate blood and cerebrospinal fluid to the biobank. Analysis of the complement system will be carried out on the three groups of patients and compared.Ethics and disseminationThe project has been approved by the Committees on Health Research Ethics in the Capital Region of Denmark (Approval number H-16017145) and the Danish Data Protection Agency (file number 2012-58-0004). All results will be published in peer-reviewed, medical journals and presented at scientific conferences.Trial registration numberNCT02869048

Neurovascular-based imaging techniques such as functional MRI (fMRI) may reveal signs of consciousness in clinically unresponsive patients but are often subject to logistical challenges in the intensive care unit (ICU). Near-infrared spectroscopy (NIRS) is another neurovascular imaging technique but low cost, can be performed serially at the bedside, and may be combined with electroencephalography (EEG), which are important advantages compared to fMRI. Combined NIRS-EEG, however, has never been evaluated for the assessment of neurovascular coupling and consciousness in acute brain injury.We explored resting-state oscillations in eight-channel NIRS oxyhemoglobin and eight-channel EEG band-power signals to assess neurovascular coupling, the prerequisite for neurovascular-based imaging detection of consciousness, in patients with acute brain injury in the ICU (n = 9). Conscious neurological patients from step-down units and wards served as controls (n = 14). Unsupervised adaptive mixture-independent component analysis (AMICA) was used to correlate NIRS-EEG data with levels of consciousness and clinical outcome.Neurovascular coupling between NIRS oxyhemoglobin (0.07-0.13 Hz) and EEG band-power (1-12 Hz) signals at frontal areas was sensitive and prognostic to changing consciousness levels. AMICA revealed a mixture of five models from EEG data, with the relative probabilities of these models reflecting levels of consciousness over multiple days, although the accuracy was less than 85%. However, when combined with two channels of bilateral frontal neurovascular coupling, weighted k-nearest neighbor classification of AMICA probabilities distinguished unresponsive patients from conscious controls with 90% accuracy (positive predictive value 93%, false discovery rate 7%) and, additionally, identified patients who subsequently failed to recover consciousness with 99% accuracy.We suggest that NIRS-EEG for monitoring of acute brain injury in the ICU is worthy of further exploration. Normalization of neurovascular coupling may herald recovery of consciousness after acute brain injury.

New findings What is the central question of this study? Can the change in haemoglobin's affinity for oxygen in the human cerebral circulation be modelled in vivo? What is the main finding and its importance? We provide a novel method for modelling the oxyhaemoglobin dissociation curve at the cerebral capillary level in humans, so that the cerebral capillary and mitochondrial oxygen tensions can reliably be estimated. This may be useful in future human-experimental studies on cerebral oxygen transport. Abstract We provide a method for modelling the oxyhaemoglobin dissociation curve (ODC) in the cerebral capillary in humans. In contrast to most previous approaches, our method involves the construction of an averaged ODC based on paired arterial-jugular venous blood gas values, which enables the estimation of oxygen parameters in cerebral capillary blood. The method was used to determine the mean cerebral capillary oxygen saturation and tension from data previously collected from 30 healthy volunteers. The averaged ODC provided systematically higher capillary oxygen tensions than when assuming a 'fixed' standard arterial ODC. When the averaged and measured arterial ODC were used for constructing the capillary ODC, similar values were obtained during resting breathing, but not when the arterial ODC was modulated by hypocapnia. The findings suggest that our method for modelling the cerebral capillary ODC provides robust and physiologically reliable estimates of the cerebral capillary oxygen tension, which may be of use in future studies of cerebral oxygen transport in humans.

Hypozincaemia may develop in critically ill patients, including those with acute brain injury in the early phase after hospital admission. The aim of this study was to investigate the prevalence of hypozincaemia after aneurysmal subarachnoid haemorrhage (aSAH) and its association with delayed cerebral ischemia and functional outcome. We retrospectively analysed a cohort of 384 patients with SAH admitted to the Neurointensive Care Unit at Rigshospitalet, Copenhagen, Denmark, in whom at least one measurement of plasma zinc concentration was done during the hospital stay. Hypozincaemia was defined as at least one measurement of plasma zinc below 10 μmol/L. Potential associations between hypozincaemia, demographic variables and functional outcome after aSAH were analysed in multivariable logistic regression models. Hypozincaemia was observed in 67% (n = 257) of all patients and occurred within 7 days in more than 95% of all hypozincaemic patients. In a multivariable model, severe SAH (WFNS 3–5; OR 4.2, CI 2.21–8.32, p

Background: Cognitive impairment and reduced health-related quality of life (HRQoL) are well-established sequelae of critical illness. Studies on survivors of critical illness have found delirium to be a predictor of these conditions, but evidence regarding survivors of acute brain injury is sparse. We aimed to explore if delirium duration was associated with 1-year cognitive impairment and reduced HRQoL in patients with acute brain injury. Method: Intensive care unit (ICU) delirium was assessed using the Intensive Care Delirium Screening Checklist. Cognitive status was assessed using the Repeatable Battery for Neuropsychological Status (RBANS) and HRQoL using the European Quality of Life 5-dimension questionnaire (EQ-5D). We used a multiple linear regression for testing the association of delirium duration with cognitive impairment and quality of life, respectively. Results: Forty-seven survivors of acute brain injury participated in follow-up and 35 completed RBANS. Delirium was present in 39 of 47 (83%) with a median duration of 4 days. Delirium duration did not predict cognitive impairment (95% CI −4.1 to 0.5) or lower HRQoL (95% CI −1.4 to 2.7). Moderate-to-severe cognitive impairment was present in 17 of 35 (49%) participants, and they had a mean EQ-5D health visual analogue scale of 70.9 vs 81.6 for the Danish age-matched norm. Conclusions: Our sample did not demonstrate an association between delirium and 1-year cognitive impairment or reduced HRQoL. Still, a large proportion of the participants were cognitively impaired, and their quality of life was lower compared to norm. Larger studies are necessary to explore these associations further.

Background Although used extensively worldwide, the effects of general anaesthesia on the human brain remain largely elusive. Moreover, general anaesthesia may contribute to serious conditions or adverse events such as postoperative cognitive dysfunction and delirium. To understand the basic mechanisms of general anaesthesia, this project aims to study and compare possible de novo neuroplastic changes induced by two commonly used types of general anaesthesia, i.e. inhalation anaesthesia by sevoflurane and intravenously administered anaesthesia by propofol. In addition, we wish to to explore possible associations between neuroplastic changes, neuropsychological adverse effects and subjective changes in fatigue and well-being. Methods This is a randomised, participant- and assessor-blinded, cross-over clinical trial. Thirty healthy volunteers (male:female ratio 1:1) will be randomised to general anaesthesia by either sevoflurane or propofol. Multimodal magnetic resonance imaging (MRI) of the brain will be performed before and after general anaesthesia and repeated after 1 and 8 days. Each magnetic resonance imaging session will be accompanied by cognitive testing and questionnaires on fatigue and well-being. After a wash-out period of 4 weeks, the volunteers will receive the other type of anaesthetic (sevoflurane or propofol), followed by the same series of tests. Primary outcomes: changes in T1-weighted 3D anatomy and diffusion tensor imaging. Secondary outcomes: changes in resting-state functional magnetic resonance imaging, fatigue, well-being, cognitive function, correlations between magnetic resonance imaging findings and the clinical outcomes (questionnaires and cognitive function). Exploratory outcomes: changes in cerebral perfusion and oxygen metabolism, lactate, and response to visual stimuli. Discussion To the best of our knowledge, this is the most extensive and advanced series of studies with head-to-head comparison of two widely used methods for general anaesthesia. Recruitment was initiated in September 2019. Trial registration Approved by the Research Ethics Committee in the Capital Region of Denmark, ref. H-18028925 (6 September 2018). EudraCT and Danish Medicines Agency: 2018-001252-35 (23 March 2018). www.clinicaltrials.gov, ID: NCT04125121. Retrospectively registered on 10 October 2019.

BACKGROUND: Delirium is underinvestigated in the neuro-critically ill, although the harmful effect of delirium is well established in patients in medical and surgical intensive care units (ICU).To detect delirium, a valid tool is needed. We hypothesized that delirium screening would be feasible in patients with acute brain injury and we aimed to validate and compare the Confusion Assessment Method for the ICU and the Intensive Care Delirium Screening Checklist against clinical International Classification of Diseases-10 criteria as reference.METHODS: Nurses assessed delirium using the Confusion Assessment Method for the ICU and Intensive Care Delirium Screening Checklist in adult patients with acute brain injury admitted to the Neurointensive care unit (Neuro-ICU), Copenhagen University Hospital, if their Richmond agitation-sedation scale score was -2 or above. As the reference, a team of psychiatrist assessed patients using the International Classification of Diseases-10 criteria.RESULTS: We enrolled 74 patients, of whom 25 (34%) were deemed unable to assess by the psychiatrists, leaving 49 (66%) for final analysis. Sensitivity and specificity for the Confusion Assessment Method for the ICU was 59% (95% CI: 41-75) and 56% (95% CI: 32-78), respectively, and 85% (95% CI: 70-94) and 75% (95% CI: 51-92), respectively, for the Intensive Care Delirium Screening Checklist.CONCLUSIONS: Our findings suggest that the Intensive Care Delirium Screening Checklist may be a valid tool and the Confusion Assessment Method for the ICU is less suitable for delirium detection for patients in the Neuro-ICU. In the neuro-critically ill, delirium screening is challenged by limited feasibility.

Amyotrophic lateral sclerosis (ALS) is a devastating, neurodegenerative motor neuron disease. The aetiology of ALS remains an enigma which hinders the design of an effective treatment to prevent, postpone, or reverse the pathophysiological changes occurring during the aggressive progression of this disease. During the last decade, basic research within the innate immune system, and in particular the complement system, has revealed new, important roles of the innate immune system during development, homeostasis, and ageing within as well as outside the central nervous system. Several lines of evidence indicate that aberrant activation of the complement system locally in the central nervous system as well as systemically may be involved in the pathophysiology of ALS. This exciting new knowledge could point towards the innate immune system as a potential target of medical intervention in ALS. Recently, the historic perception of ALS as a central neurodegenerative disease has been challenged due to the significant amount of evidence of a dying-back mechanism causing the selective destruction of the motor neurons, indicating that disease onset occurs outside the borders of the blood-brain-barrier. This review addresses the function of the innate immune system during ALS. We emphasize the role of the complement system and specifically suggest the involvement of ficolin-3 from the lectin pathway in the pathophysiology of ALS.

The systemic inflammatory response triggered by lipopolysaccharide (LPS) is associated with cerebral vasoconstriction, but the underlying mechanisms are unknown. We therefore examined whether a 4-hour intravenous LPS infusion (0.3 ng·kg−1) induces any changes in the transcerebral net exchange of the vasoactive peptides endothelin-1 (ET-1) and calcitonin-gene related peptide (CGRP) and catecholamines in human volunteers. Cerebral blood flow was measured by the Kety–Schmidt technique, and paired arterial-to-jugular venous blood samples were obtained for estimating the transcerebral exchange of ET-1, CGRP, and catecholamines by the Fick principle in 12 volunteers before and after LPS infusion. The cerebrovascular release of ET-1 was enhanced, whereas the transcerebral net exchange of CGRP and catecholamines was unaffected. Our findings thus point towards locally produced ET-1 within the cerebrovasculature as a contributor to cerebral vasoconstriction after LPS infusion.

Background: Early mobilisation on a tilt table with stepping versus standard care may be beneficial for patients with severe brain injury, but data from randomised clinical trials are lacking. Methods: This statistical analysis plan describes the analyses of data collected in a randomised clinical feasibility trial for early mobilisation by head-up tilt with stepping versus standard care after severe traumatic brain injury. Primary feasibility outcomes are the proportion of included participants who were randomised out of all screened patients; the proportion of participants allocated to the experimental intervention who received at least 60% of the planned exercise sessions; and safety outcomes such as severe adverse events and reactions and adverse events and reactions. Exploratory clinical outcomes are suspected unexpected severe adverse reactions; and functional outcomes as assessed by Coma Recovery Scale – Revised at four weeks; Early Functional Ability Scale, and Functional Independence Measure at three months. Exploratory physiological outcomes are electrocardiographic data; mean arterial pressure; and middle cerebral artery blood flow velocity, all obtained during the head-up tilt test. From the first head-up tilt test and five days onwards, a heart rate was measured by continuous electrocardiography. The detailed description includes the statistical analysis including use of multiple imputation and Trial Sequential Analysis. Conclusions: The present statistical analysis plan serves to minimise potential trial reporting bias and selective P hacking and to improve transparency. This feasibility trial will inform design and eventual launching of a larger multicentre randomised clinical trial. Trial registration: ClinicalTrials.gov identifier: NCT02924649. Registered on 3 October 2016.

This work describes a fully-integrated portable microfluidic analysis system for real-time monitoring of dynamic changes in glucose and lactate occurring in the brain as a result of cardiac arrest and resuscitation. Brain metabolites are sampled using FDA-approved microdialysis probes and coupled to a high-temporal resolution 3D printed microfluidic chip housing glucose and lactate biosensors. The microfluidic biosensors are integrated with a wireless 2-channel potentiostat forming a compact analysis system that is ideal for use in a crowded operating theatre. Data are transmitted to a custom-written app running on a tablet for real-time visualisation of metabolic trends. In a proof-of-concept porcine model of cardiac arrest, the integrated analysis system proved reliable in a challenging environment resembling a clinical setting; noise levels were found to be comparable with those seen in the lab and were not affected by major clinical interventions such as defibrillation of the heart. Using this system, we were able, for the first time, to measure changes in brain glucose and lactate levels caused by cardiac arrest and resuscitation; the system was sensitive to clinical interventions such as infusion of adrenaline. Trends suggest that cardiopulmonary resuscitation alone does not meet the high energy demands of the brain as metabolite levels only return to their values preceding cardiac arrest upon return of spontaneous circulation.

Background: Early mobilisation on a tilt table with stepping versus standard care may be beneficial for patients with severe brain injury, but data from randomised clinical trials are lacking. Methods: This statistical analysis plan describes the analyses of the data collected in the randomised clinical feasibility trial for early mobilisation by head-up tilt with stepping versus standard care after severe traumatic brain injury. The primary feasibility outcomes are the proportion of included participants who were randomised compared with all screened patients; the proportion of participants allocated to the experimental intervention who received at least 60% of the planned exercise sessions; and safety outcomes such as severe adverse events and reactions and adverse events and reactions. Exploratory clinical outcomes are suspected unexpected severe adverse reactions, the coma recovery scale – revised, the early functional ability scale, and the functional independence measure. Explorative physiological outcomes are electrocardiography, mean arterial pressure, middle cerebral artery blood flow velocity all obtained during the head-up tilt test. From the first head-up tilt test and five days onwards, a continuous electrocardiographic heart rate was measured. The detailed description includes the statistical analysis including use of multiple imputation and Trial Sequential Analysis. Conclusions: The present statistical analysis plan serves to minimise potential trial reporting bias and selective P hacking and to improve transparency. This feasibility trial will be used for deciding to launch and designing a larger multicentre randomised clinical trial. Trial registration: ClinicalTrials.gov identifier: NCT02924649. Registered on 3 October 2016.

OBJECTIVE: To investigate whether soluble growth stimulation expressed gene 2 (sST2), a prognostic marker in cardiovascular and inflammatory disorders, is associated with neurological injury after aneurysmal subarachnoid hemorrhage (SAH).METHODS: We studied SAH patients from 2 independent cohorts. Outcome assessments included functional status at 90 days using the modified Rankin Scale (mRS), mortality, and delayed cerebral ischemia (DCI). The relationships between sST2 plasma level and outcome measures were assessed in both cross-sectional and longitudinal analysis. Primary blood mononuclear cells from SAH patients and elective aneurysm controls were analyzed by multiparameter flow cytometry.RESULTS: In the discovery cohort, sST2 predicted 90-day mRS 3-6 (C index = 0.724, p INTERPRETATION: Plasma sST2 predicts DCI, functional outcome, and mortality after SAH, independent of clinical and radiographic markers. Elevated sST2 is also associated with changes in CD14+ CD16+ monocytes. ANN NEUROL 2019;86:384-394.

Introduction: Aneurysmal subarachnoid hemorrhage (SAH) has a lower incidence than ischemic stroke but affects younger individuals with a high mortality and a high frequency of complications in survivors. The underlying pathways that contribute to poor functional outcome are poorly understood. Hypothesis: MicroRNA (miRNA) changes in cerebrospinal fluid (CSF) are associated with the occurrence of delayed cerebral ischemia and poor functional outcome after SAH. Methods: Using real-time polymerase quantification chain reaction (RT-qPCR), 43 selected miRNAs were measured in daily CSF samples from a discovery cohort of SAH patients admitted to Rigshospitalet, Copenhagen, Denmark, and compared to neurologically healthy patients. Findings were validated in CSF from a replication cohort of SAH patients admitted to Massachusetts General Hospital, Boston, Massachusetts. Outcome measures were delayed cerebral ischemia (DCI), as well as functional outcome three months after ictus measured by the modified Rankin Scale score. Results: MiRNAs were quantified and passed RT-qPCR quality control in 427 CSF samples from 63 SAH patients in the discovery cohort, in 104 CSF samples from 63 SAH patients in the replication cohort and in 11 CSF samples from 11 neurologically healthy patients. Elevated miR-9-3p was associated with a poor functional outcome in both the discovery cohort (p < 0.0001) after correction for multiple testing (q < 0.01) and in the replication cohort (p < 0.01). Furthermore, elevated miR-9-5p was associated with a poor functional outcome in the discovery cohort (p < 0.01) after correction for multiple testing (q < 0.05). No miRNA was associated with DCI in both cohorts. Conclusions: Mir-9-3p is elevated in the CSF following SAH and this elevation is associated with a poor functional outcome.

123I-CLINDE is a radiotracer developed for SPECT and targets the 18-kDa translocator protein (TSPO). TSPO is upregulated in glial cells and used as a measure of neuroinflammation in a variety of central nervous system diseases. The aim of this study was to examine the test-retest variability of 123I-CLINDE binding in healthy subjects. Methods: SPECT scans were acquired over 90 min in 16 healthy controls (9 women, 8 mixed-affinity binders [MABs] and 8 high-affinity binders [HABs] twice with an interval of 35 ± 15 d). Arterial input functions were based on individual blood measurements in 8 subjects and a population-based approach in combination with individual whole-blood time-activity curves in the other 8 subjects. Seven brain volumes of interest were extracted and quantified by SUVs and by 2-tissue-compartment modeling for calculation of distribution volumes (VT). Test-retest variability was measured by percentage difference (PD), the absolute PD, intraclass correlation coefficient (ICC), and coefficient of variation. Results: The absolute PD of brain SUV and the VT had similar values. The ICC values were higher for VTs than for brain SUVs, which were both moderate to high; however, lower ICC values were observed when calculated separately for HABs and MABs. Test-retest reproducibility was higher in subjects with immediate centrifugation of blood samples. The population-based method efficiently recovered data with delayed centrifugation. The VT of a 49-y-old male HAB was 7.5 ± 1.4 mL/cm3 compared with 4.6 ± 1.4 mL/cm3 of a sex- and age-matched MAB. The SUVs of a 49-y-old male HAB and MAB were 1.03 ± 0.14 and 0.88 ± 0.15 g/mL, respectively. Conclusion: The test-retest reproducibility of 123I-CLINDE is comparable or better than that reported for commonly used PET TSPO tracers. Because of the binding of 123I-CLINDE to blood cells and peripheral tissues, SUV is not a sufficient surrogate of VT from 2-tissue-compartment modeling. The population-adjusted method has the potential to reduce the complexity of blood analyses of TSPO tracers.

Observational clinical studies suggest the initial phase of sepsis may involve impaired cellular immunity. In the present study, we investigated temporal changes in T-cell subsets and T-cell cytokine production during human endotoxemia. Endotoxin ( Escherichia coli lipopolysaccharide 4 ng/kg) was administered intravenously in 15 healthy volunteers. Peripheral blood and bronchoalveolar lavage fluid (BALF) were collected at baseline and after 2, 4, 6, 8, and 24 hours for flow cytometry. CD4+CD25+CD127lowFoxp3+regulatory T cells (Tregs), CD4+CD161+cells, and activated Human leukocyte antigen, HLA-DR+CD38+T cells were determined. Ex vivo whole-blood cytokine production and Toll-like receptor (TLR)-4 expression on Tregs were measured. Absolute number of CD3+CD4+( P = .026), CD3+CD8+( P = .046), Tregs ( P = .023), and CD4+CD161+cells ( P = .042) decreased after endotoxin administration. The frequency of anti-inflammatory Tregs increased ( P = .033), whereas the frequency of proinflammatory CD4+CD161+cells decreased ( P = .034). Endotoxemia was associated with impaired whole-blood production of tumor necrosis factor-α, interleukin-10, IL-6, IL-17, IL-2, and interferon-γ in response to phytohaemagglutinin but did not affect TLR4 expression on Tregs. No changes in the absolute count or frequency of BALF T cells were observed. Systemic inflammation is associated with lymphopenia, a relative increase in the frequency of anti-inflammatory Tregs, and a functional impairment of T-cell cytokine production.

Ficolins serve as soluble recognition molecules in the lectin pathway of complement. They are known to participate in the systemic host-response to infection but their role in local pulmonary defence is still incompletely understood. The purpose of this study was to clarify whether acute lung and systemic inflammation induce recruitment of lectins in humans.Fifteen healthy volunteers received LPS intravenously (IV) or in a lung subsegment on two different occasions. Volunteers were evaluated by consecutive blood samples and by bronchoalveolar lavage 2, 4, 6, 8, or 24h after LPS (n=3 in all groups), and gene expression patterns and protein levels of mannose-binding lectin (MBL) and ficolins were determined.Endobronchial LPS was associated with an increase in alveolar ficolin-3 and MBL levels (p0.04 and p0.001, respectively). IV LPS elicited a pronounced acute phase response with an increase in CRP (p0.001) and plasma ficolin-1 protein levels (p0.001), whereas no changes were observed in ficolin-1 gene expression patterns (p=0.11) or plasma protein levels of MBL, ficolin-2, or ficolin-3.LPS induces a tissue-specific recruitment of ficolin-3 and ficolin-1 in the lung and systemic compartment, respectively, suggesting an important role of distinct lectin complement pathway initiators in the local pulmonary and systemic host defence.

Introduction [11C]Cimbi-36 is a recently developed serotonin 2A (5-HT2A) receptor agonist positron emission tomography (PET) radioligand that has been successfully applied for human neuroimaging. Here, we investigate the test–retest variability of cerebral [11C]Cimbi-36 PET and compare [11C]Cimbi-36 and the 5-HT2A receptor antagonist [18F]altanserin. Methods Sixteen healthy volunteers (mean age 23.9 ± 6.4 years, 6 males) were scanned twice with a high resolution research tomography PET scanner. All subjects were scanned after a bolus of [11C]Cimbi-36; eight were scanned twice to determine test–retest variability in [11C]Cimbi-36 binding measures, and another eight were scanned after a bolus plus constant infusion with [18F]altanserin. Regional differences in the brain distribution of [11C]Cimbi-36 and [18F]altanserin were assessed with a correlation of regional binding measures and with voxel-based analysis. Results Test–retest variability of [11C]Cimbi-36 non-displaceable binding potential (BPND) was consistently

Objective In the present hypothesis-generating study, we investigated whether spontaneous blood pressure oscillations are suppressed to lower frequencies, and whether abolished oscillations are associated with an adverse outcome in mechanically ventilated patients with sepsis. Methods We retrospectively subjected invasive steady-state blood pressure recordings from 65 mechanically ventilated patients with sepsis to spectral analysis. Modified spectral bands were visually identified by plotting spectral power against frequency. Results Modified middle-frequency and low-frequency (MF' and LF') oscillations were absent in 9% and 22% of the patients, respectively. In patients in whom spontaneous blood pressure oscillations were preserved, the MF' oscillations occurred at 0.021 Hz (median, interquartile range 0.013-0.030), whereas the LF' oscillations occurred at 0.009 Hz (median, interquartile range 0.006-0.010). The absence of LF' oscillations was associated with a higher 30-day mortality [50 vs. 18%, hazard ratio, 3.6 (95% confidence interval: 1.4-9.8), P=0.01]. Conclusion Spontaneous blood pressure oscillations in mechanically ventilated septic patients may be suppressed to lower frequencies than previously reported for spontaneously breathing, healthy humans. Patients in whom the resultant changes in blood pressure (MF' and LF' oscillations) are abolished may have a higher risk of an adverse outcome. This may reflect suppression of the pressor area in the brainstem with subsequent sympathetic dysfunction.

Bed rest and physical inactivity are the consequences of hospital admission for many patients. Physical inactivity induces changes in glucose metabolism, but its effect on the incretin effect, which is reduced in, e.g., Type 2 diabetes, is unknown. To investigate how 8 days of strict bed rest affects the incretin effect, 10 healthy nonobese male volunteers underwent 8 days of strict bed rest. Before and after the intervention, all volunteers underwent an oral glucose tolerance test (OGTT) followed by an intravenous glucose infusion (IVGI) on the following day to mimic the blood glucose profile from the OGTT. Blood glucose, serum insulin, serum C-peptide, plasma incretin hormones [glucagon-like peptide (GLP-1) and glucose-dependent insulinotropic peptide (GIP)], and serum glucagon were measured serially during both the OGTT and the IVGI. The incretin effect is calculated as the relative difference between the area under the curve for the insulin response during the OGTT and that of the corresponding IVGI, respectively. Concentrations of glucose, insulin, C-peptide, and GIP measured during the OGTT were higher after the bed rest intervention (all P < 0.05), whereas there was no difference in the levels of GLP-1 and Glucagon. Bed rest led to a mean loss of 2.4 kg of fat-free mass, and induced insulin resistance evaluated by the Matsuda index, but did not affect the incretin effect ( P = 0.6). In conclusion, 8 days of bed rest induces insulin resistance, but we did not see evidence of an associated change in the incretin effect.

Background There is increasing focus on earlier rehabilitation in patients with traumatic or hypoxic brain injury or stroke. This systematic review evaluates the benefits and harms of early head-up mobilisation versus standard care in patients with severe acquired brain injury. Methods We searched Medline, CENTRAL, EMBASE, four other databases and 13 selected clinical trial registries until April 2020. Eligible randomised clinical trials compared early head-up mobilisation versus standard care in patients with severe acquired brain injury and were analysed conducting random- and fixed-effects meta-analyses and Trial Sequential Analysis (TSA). Certainty of evidence was assessed by GRADE. Main results We identified four randomised clinical trials (total n = 385 patients) with severe acquired brain injury (stroke 86% and traumatic brain injury 13%). Two trials were at low risk and two at high risk of bias. We found no evidence of a difference between early mobilisation vs. standard care on mortality or poor functional outcome at end of the intervention (relative risk (RR) 1.19, 95% CI 0.93 to 1.53; I2 0%; very low certainty) or at maximal follow-up (RR 1.03, 95% CI 0.89 to 1.21; I2 0%; very low certainty). We found evidence against an effect on quality of life at maximal follow-up. The proportion of patients with at least one serious adverse event did not differ at end of intervention or at maximal follow-up. For most comparisons, TSA suggested that further trials are needed. Conclusions We found no evidence of a difference between early mobilisation versus standard care for patients with severe acquired brain injury. Early mobilisation appeared not to exert a major impact on quality of life. This systematic review highlights the insufficient evidence in patients with severe brain injury, and no firm conclusions can be drawn from these data. Trial registration Protocol uploaded to PROSPERO: April 2018 (revised October 2018, CRD42018088790).

Background Because osmotic fluid shifts may occur over the blood-brain barrier, patients with acute brain injury are theoretically at risk of surges in intracranial pressure (ICP) during hemodialysis. However, this remains poorly investigated. We studied changes in ICP during hemodialysis in such patients. Methods We performed a retrospective study of patients with acute brain injury admitted to Rigshospitalet (Copenhagen, Denmark) from 2012 to 2016 who received intermittent hemodialysis (IHD) or continuous renal replacement therapy (CRRT) while undergoing ICP monitoring. Data from each patient's first dialysis session were collected. Area under the curve divided by time (AUC/t) for ICP was calculated separately before and during dialysis. Results Thirteen patients were included. During dialysis, ICP increased from a baseline of 11.9 mm Hg (median; interquartile range 6.3-14.7) to a maximum of 21 mm Hg (18-27) (P = 0.0024), and AUC/t for ICP was greater during dialysis (15.2 (13.4-18.8) vs 11.7 mm Hg (6.4-15.1), P = 0.042). The maximum ICP increase was independent of dialysis modality, but peak values were reached earlier in patients treated with IHD (N = 4) compared to CRRT (N = 9) (75 [30-90] vs 375 min [180-420] after start of treatment, P = 0.0095). The maximum ICP increase correlated positively to the baseline plasma urea concentration (Spearman's r = 0.69, P = 0.017). Conclusion Hemodialysis is associated with increased ICP in neurocritically ill patients, and the magnitude of the increase may be related to initial plasma urea levels.

Background Intensive rehabilitation of patients with severe traumatic brain injury is generally applied in the subacute stages of the hospital stay. Few studies have assessed the association between early and intensive physical rehabilitation and functional outcomes. The aim of this trial is to assess the feasibility of an intensive physical rehabilitation intervention focusing on mobilisation to the upright position, starting as early as clinically possible versus standard care in the intensive care unit. The feasibility study is intended to inform a subsequent randomised clinical trial that will investigate benefits and harms of the intervention. Methods This randomised clinical feasibility trial with a follow-up period of 1 year will use blinded outcome assessors for the Coma Recovery Scale–Revised. A maximum of 60 patients admitted to the neurointensive care unit at Rigshospitalet, Denmark, with traumatic brain injury (age of at least 18 years), a low level of consciousness, and stable intracranial pressure will be included in the trial. Patients will be randomly assigned to experimental intervention versus standard care (1:1) stratified according to their Glasgow Coma Score. The intervention group will receive daily mobilisation in a tilt table with an integrated stepping device (ERIGO®). Feasibility is declared if more than 60% (the lower 95% confidence interval of the proportion) of eligible patients are included in the trial and more than 52% (the lower 95% confidence interval of the proportion) of patients in the intervention group receive more than 60% of the planned interventions. Safety is assessed by the occurrence of adverse events and adverse reactions. Exploratory clinical outcomes consist of cerebral haemodynamics (blood flow velocity and pressure autoregulation) and baroreceptor sensitivity in the early phase as well as functional outcomes (Coma Recovery Scale–Revised, Early Functional Ability scale, and Functional Independence Measure). Discussion Our findings will inform a future, larger-scale randomised clinical trial on early mobilisation using a tilt table early after severe traumatic brain injury. Trial registration ClinicalTrials.gov identifier: NCT02924649. Registered on 3 October 2016. Electronic supplementary material The online version of this article (10.1186/s13063-018-3004-x) contains supplementary material, which is available to authorized users.

BACKGROUND: Animal models of serious infection suggest that 24 h of induced hypothermia improves circulatory and respiratory function and reduces mortality. We tested the hypothesis that a reduction of core temperature to 32-34°C attenuates organ dysfunction and reduces mortality in ventilator-dependent patients with septic shock.METHODS: In this randomised, controlled, open-label trial, we recruited patients from ten intensive care units (ICUs) in three countries in Europe and North America. Inclusion criteria for patients with severe sepsis or septic shock were a mean arterial pressure of less than 70 mm Hg, mechanical ventilation in an ICU, age at least 50 years, predicted length of stay in the ICU at least 24 h, and recruitment into the study within 6 h of fulfilling inclusion criteria. Exclusion criteria were uncontrolled bleeding, clinically important bleeding disorder, recent open surgery, pregnancy or breastfeeding, or involuntary psychiatric admission. We randomly allocated patients 1:1 (with variable block sizes ranging from four to eight; stratified by predictors of mortality, age, Acute Physiology and Chronic Health Evaluation II score, and study site) to routine thermal management or 24 h of induced hypothermia (target 32-34°C) followed by 48 h of normothermia (36-38°C). The primary endpoint was 30 day all-cause mortality in the modified intention-to-treat population (all randomly allocated patients except those for whom consent was withdrawn or who were discovered to meet an exclusion criterion after randomisation but before receiving the trial intervention). Patients and health-care professionals giving the intervention were not masked to treatment allocation, but assessors of the primary outcome were. This trial is registered with ClinicalTrials.gov, number NCT01455116.FINDINGS: Between Nov 1, 2011, and Nov 4, 2016, we screened 5695 patients. After recruitment of 436 of the planned 560 participants, the trial was terminated for futility (220 [50%] randomly allocated to hypothermia and 216 [50%] to routine thermal management). In the hypothermia group, 96 (44·2%) of 217 died within 30 days versus 77 (35·8%) of 215 in the routine thermal management group (difference 8·4% [95% CI -0·8 to 17·6]; relative risk 1·2 [1·0-1·6]; p=0·07]).INTERPRETATION: Among patients with septic shock and ventilator-dependent respiratory failure, induced hypothermia does not reduce mortality. Induced hypothermia should not be used in patients with septic shock.FUNDING: Trygfonden, Lundbeckfonden, and the Danish National Research Foundation.

Background: Aneurysmal subarachnoid hemorrhage (SAH) has a lower incidence than ischemic stroke but affects younger individuals with a high mortality and a high frequency of complications in survivors. The underlying pathways that contribute to poor functional outcome are poorly understood. This study evaluated microRNA (miRNA) changes in cerebrospinal fluid (CSF) and their association with the occurrence of delayed cerebral ischemia (DCI) and poor functional outcome after SAH. Methods: Using real-time quantification polymerase chain reaction, 43 selected miRNAs were measured in daily CSF samples from a discovery cohort of SAH patients admitted to Rigshospitalet, Copenhagen, Denmark, and compared to neurologically healthy patients. Findings were validated in CSF from a replication cohort of SAH patients admitted to Massachusetts General Hospital, Boston, Massachusetts. The CSF levels of miRNA over time were compared to the occurrence DCI, and functional outcome three months after ictus measured by the modified Rankin Scale (mRS) score. Findings: MiRNAs were quantified in 427 CSF samples from 63 SAH patients in the discovery cohort, in 104 CSF samples from 63 SAH patients in the replication cohort and in 11 CSF samples from 11 neurologically healthy patients. The miRNA profile changed remarkably immediately after SAH. Elevated miR-9-3p was associated with a poor functional outcome in the discovery cohort (p < 0·0001) after correction for multiple testing (q < 0·01) and in the replication cohort (p < 0·01). Furthermore, elevated miR-9-5p was associated with a poor functional outcome in the discovery cohort (p < 0·01) after correction for multiple testing (q < 0·05). No miRNA was associated with DCI in both cohorts. Interpretation: MiR-9-3p is elevated in the CSF following SAH and this elevation is associated with a poor functional outcome. Clinical Registration Number: clinicaltrials.gov (file # NCT02320539 & NCT01791257). Funding Statement: S.B. was salaried by grants from the Research Board at Rigshospitalet, Copenhagen, Denmark and The Lundbeck Foundation. Reagents for miRNA profiling were funded by Grosserer Jakob Ehrenreich & Hustru Grete Ehrenreichs Fond, Brodrene Hartmanns Fond, Torben & Alice Frimodts Fond, Grosserer L.F.Foghts Fond and Aase & Ejnar Danielsens Fond. Declaration of Interest: The authors have no conflict of interest. Ethical Approval Statement: The first two protocols were approved by the Danish Scientific Ethics Committee of the Capital Region (file # H-3-2013-009 & H-6-2014-073) and the Danish Data Protection Agency (file # RH-2013-30-0935 & RH-2013- 30-1386). The protocol for the replication cohort was approved by the Massachusetts General Hospital Institutional Review Board (file # 2010P002749). According to Danish and U.S. law, informed consent was obtained from either the patient or by their next of kin and general practitioner

Vasopressor support is used widely for maintaining vital organ perfusion pressure in septic shock, with implications for dynamic cerebral autoregulation (dCA). This study investigated whether a noradrenaline-induced steady state increase in mean arterial blood pressure (MAP) would enhance dCA following lipopolysaccharide (LPS) infusion, a human-experimental model of the systemic inflammatory response during early sepsis. The dCA in eight healthy males was examined prior to and during an intended noradrenaline-induced MAP increase of approximately 30 mmHg. This was performed at baseline and repeated after a 4-h intravenous LPS infusion. The assessments of dCA were based on transfer function analysis of spontaneous oscillations between MAP and middle cerebral artery blood flow velocity measured by transcranial Doppler ultrasound in the low frequency range (0.07-0.20 Hz). Prior to LPS, noradrenaline administration was associated with a decrease in gain (1.18 (1.12-1.35) vs 0.93 (0.87-0.97) cm/mmHg per s; P < 0.05) with no effect on phase (0.71 (0.93-0.66) vs 0.94 (0.81-1.10) radians; P = 0.58). After LPS, noradrenaline administration changed neither gain (0.91 (0.85-1.01) vs 0.87 (0.81-0.97) cm/mmHg per s; P = 0.46) nor phase (1.10 (1.04-1.30) vs 1.37 (1.23-1.51) radians; P = 0.64). The improvement of dCA to a steady state increase in MAP is attenuated during an LPS-induced systemic inflammatory response. This may suggest that vasopressor treatment with noradrenaline offers no additional neuroprotective effect by enhancing dCA in patients with early sepsis.