Acute Fluid Biomarkers for Diagnosis and Prognosis in Children with Mild Traumatic Brain Injury: A Systematic Review

BACKGROUND AND OBJECTIVE

Fluid biomarkers have the potential to improve the accuracy of diagnosis and prognosis in children with mild traumatic brain injury. Our primary objective was to assess the diagnostic and prognostic utility of acute blood and fluid biomarkers in children with mild traumatic brain injury.

METHODS

We performed a systematic review of the published literature in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. Fluid biomarker studies assessing pediatric mild traumatic brain injury diagnosis or prognosis were included if blood or fluids were sampled within 24 h of injury.

RESULTS

Thirty-two studies involving 4743 patients were included comprising 25 diagnostic studies and ten prognostic studies with three studies assessing both diagnosis and prognosis. Sixteen of the 25 diagnostic studies reported the area under the receiver operating characteristic curve (AUC) for predicting abnormal computed tomography scans of the head; S100 calcium binding protein B (S100B, N = 6 studies, AUC range 0.67-1.00), glial fibrillary acidic protein (N = 5, AUC range 0.41-0.85), ubiquitin C-terminal hydrolase (N = 3, AUC 0.59 and 0.83), neuron specific enolase (N = 1, AUC 0.99), total tau (N = 1, AUC 0.65), and interleukin-6 (N = 1, AUC 0.61). In four of the ten prognostic studies, increased acute serum S100B levels, tumor necrosis factor-α, or interleukin-8 were associated with post-concussive symptoms or fatigue from 3 to 12 months post-injury.

CONCLUSIONS

The largest amount of evidence supported the potential use of S100B, glial fibrillary acidic protein, and UCH-L1, but there was mixed accuracy for diagnosis and prognostication for all biomarkers in pediatric mTBI.

The World Organisation for Animal Health - current and potential roles in safe international trade of bees and other insects

The World Organisation for Animal Health (WOAH, founded as OIE) is the recognised intergovernmental standard-setting organisation for animal health and welfare. The WOAH mandate is to support its members in the prevention of the spread of animal diseases of concern, as listed in the Terrestrial Animal Health Code (Terrestrial Code). Once a disease, infection or infestation is listed, national Veterinary Authorities have the obligation regularly to notify WOAH of the presence or absence of the listed disease. In regard to insects, the scope of the Terrestrial Code limits its recommendations to preserving the health of bees (species of the genus Apis, extended to the genus Bombus and to the stingless bees for one disease). However, it does not include standards to mitigate the potential animal health risks associated with the international trade of other insects. A description of the standard-setting process and a review of the history of the standards for bee health highlight the resources and requirements to expand the scope of the Terrestrial Code to include recommendations for animal health risk mitigation measures for the safety of international trade in insects. Any initiative to develop guidance on insect trade should include WOAH in its role as the sole global standard-setting organisation on animal health and welfare matters. This aligns with the WOAH commitment to a One Health approach.

Blood-based traumatic brain injury biomarkers - Clinical utilities and regulatory pathways in the United States, Europe and Canada

INTRODUCTION

Traumatic brain injury (TBI) is a major global health issue, resulting in debilitating consequences to families, communities, and health-care systems. Prior research has found that biomarkers aid in the pathophysiological characterization and diagnosis of TBI. Significantly, the FDA has recently cleared both a bench-top assay and a rapid point-of-care assays of tandem biomarker (UCH-L1/GFAP)-based blood test to aid in the diagnosis mTBI patients. With the global necessity of TBI biomarkers research, several major consortium multicenter observational studies with biosample collection and biomarker analysis have been created in the USA, Europe, and Canada. As each geographical region regulates its data and findings, the International Initiative for Traumatic Brain Injury Research (InTBIR) was formed to facilitate data integration and dissemination across these consortia.

AREAS COVERED

This paper covers heavily investigated TBI biomarkers and emerging non-protein markers. Finally, we analyze the regulatory pathways for converting promising TBI biomarkers into approved in-vitro diagnostic tests in the United States, European Union, and Canada.

EXPERT OPINION

TBI biomarker research has significantly advanced in the last decade. The recent approval of an iSTAT point of care test to detect mild TBI has paved the way for future biomarker clearance and appropriate clinical use across the globe.

O-026 Advanced Glycation Endproducts: A new player in obesity related infertility

Globally, 39% of the adult population is overweight or obese, with the prevalence of obesity following an upward trajectory over the recent decades (WHO). Up to 30% of women of reproductive age in Western countries are obese before conception, and obese women experience higher rates of infertility and pregnancy complications than lean women; however, the mechanisms underpinning obesity-related infertility are poorly understood. Advanced Glycation Endproducts (AGEs) are a proinflammatory modification of proteins exposed to sugars, formed through the Maillard reaction. AGEs are elevated four-fold in the uterine fluid of obese, infertile women, compared to lean. AGEs equimolar to those in the obese microenvironment negatively impact the functions of endometrial epithelial and stromal cells, and adhesion and invasion of trophoblast cells, reducing the potential for successful maternal-fetal interactions (Antoniotti et al., 2018). This research further investigated preimplantation embryo development and endometrial cell functions in the presence of AGEs equimolar to those in obese uterine fluid.

Altered local environments in very early life can set offspring up for a lifetime of health or disease (DoHAD); thus, uterine AGEs may contribute to the prevalence of non-communicable disease in children of obese parents. Preimplantation mouse embryos were cultured in vitro with AGEs equimolar with uterine fluid concentrations from lean and obese women, and their development and implantation potential assessed. “Obese” AGEs did not impact the proportion of embryos reaching blastocyst stage by day 4, but significantly reduced the proportion of blastocysts hatching by day 5 (P < 0.01). AGEs equimolar with the obese uterine environment detrimentally impacted trophectoderm formation and function: reduced trophectoderm cell number (P < 0.01), reduced outgrowth on fibronectin (indicative of reduced implantation potential, (P < 0.01), but did not increase cell apoptosis (TUNEL assay). RAGE antagonism, but neither metformin nor antioxidants, improved trophectoderm cell number. Thus, obesity-associated AGEs link obesity and reduced fertility through poor placentation potential of embryos (Hutchison et al, 2020).

Endometrial epithelial cell function was examined in the presence of lean and obese concentrations of AGEs. Obese AGEs significantly reduced the rate of proliferation (xCelligence real time cell analysis) of the endometrial epithelial cell line ECC-1 versus lean AGEs (P = 0.04). Antioxidants successfully restored the rate of proliferation in the presence of obese AGEs (P = 0.7 versus lean AGEs). Subsequently, human endometrial epithelial organoid culture was utilised as a more physiologically relevant experimental paradigm. When cultured as organoids, primary endometrial epithelial cells were functionally responsive to obesity-associated AGEs, expressing both RAGE and TLR4. The morphology of organoids in culture was not impacted by the presence of obese AGEs versus lean; however, the proliferation of epithelial cells retrieved from organoid culture was altered by obese AGEs versus lean. Obese AGEs also increased the secretion of proinflammatory CXCL16 versus vehicle control (P = 0.04) while increased secretion of other proinflammatory cytokines and chemokines including TNFa approached significance in the presence of obese AGEs. As the inflammatory milieu is altered in the uterine fluid of infertile women, elevated AGEs may promote an infertile endometrial inflammatory environment.

AGEs link obesity and reduced fertility, being detrimental to preimplantation embryo development and endometrial cell function when present at concentrations equal to those in obese uterine fluid. Antioxidants and RAGE antagonism provide beneficial effects to cell function in the presence of obesity-associated AGEs. This research provides evidence supporting AGEs as a factor contributing to obesity related infertility, and as an emerging frontier for reproductive health. Clinically, reduction of uterine AGEs may improve fertility for obese couples wishing to conceive.

Antoniotti et al (2018). Hum Rep. 33(4), 654-665. PMID: 29471449

Hutchison et al (2020). RBMO. 41(5), 757-766. PMID: 32972872

Red blood cell transfusion in animal models of acute brain injuries: a systematic review protocol

BACKGROUND

Anemia is common in neurocritically ill patients. Considering the limited clinical evidence in this population, preclinical data may provide some understanding of the potential impact of anemia and of red blood cell transfusion in these patients. We aim to estimate the association between different transfusion strategies and neurobehavioral outcome in animal models.

METHODS

We will conduct a systematic review of comparative studies of red blood cell transfusion strategies using animal models of traumatic brain injury, ischemic stroke or cerebral hemorrhage. We will search MEDLINE, EMBASE, and Web of Science databases for eligible studies from inception onwards. Two independent reviewers will perform study selection and data extraction. We will report our results in a descriptive synthesis focusing on characteristics of included studies, reported outcomes, risk of bias, and construct validity. Our primary outcome is the neurological function (neurobehavioral performance) and our secondary outcomes include mortality, infarct size, intracranial pressure, cerebral perfusion pressure, cerebral blood flow, and brain tissue oxygen tension. If appropriate, we will also perform a quantitative synthesis and pool results using random-effect models. Heterogeneity will be expressed with I² statistics. Subgroup analyses are planned according to animal model characteristics, co-interventions, and risks of bias.

DISCUSSION

Our study is aligned with the efforts to better understand the level of evidence on the impact of red blood cell transfusion strategies from preclinical studies in animal models of acute brain injury and the potential translation of information from the preclinical to the clinical research field.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018086662 .

Interleukin-8 Predicts Fatigue at 12 Months Post-Injury in Children with Traumatic Brain Injury

Despite many children experiencing fatigue after childhood brain injury, little is known about the predictors of this complaint. To date, traditional indices of traumatic brain injury (TBI) severity have not predicted reliably persisting fatigue (up to three years post-injury). This study aimed to establish whether persisting fatigue is predicted by serum biomarker concentrations in child TBI. We examined whether acute serum biomarker expression would improve prediction models of 12-month fatigue based on injury severity. Blood samples were collected from 87 children (1-17 years at injury) sustaining mild to severe TBI (Glasgow Coma Scale [GCS] range 3-15; mean 12.43; classified as mild TBI [n = 50, 57%] vs. moderate/severe TBI [n = 37, 43%]), and presenting to the emergency departments (ED) and pediatric intensive care units (PICU) at one of three tertiary pediatric hospitals (Royal Children's Hospital (RCH); Hospital for Sick Children (HSC), Toronto; St Justine Children's Hospital (SJH), Montreal). Six serum biomarker concentrations were measured within 24 h of injury (interleukin-6, interleukin-8 [IL-8], soluble vascular cell adhesion molecule [SVCAM], S100 calcium binding protein B [S100B], neuron specific enolase [NSE], and soluble neural cell adhesion molecule [sNCAM]). Fatigue at 12 months post-injury was measured using the Pediatric Quality of Life Inventory Multidimensional Fatigue Scale (parent report), classified as present/absent using previously derived cut-points. At 12 months post-injury, 22% of participants experienced fatigue. A model including IL-8 was the best serum biomarker for estimating the probability of children experiencing fatigue at 12 months post-injury. The IL-8 also significantly improved predictive models of fatigue based on severity.

96 Validation of the candidate mutation responsible for embryonic lethality in Holstein haplotype 2 carriers

Holstein haplotype 2 (HH2) is embryonic lethal and carried by 1.21% of the US Holstein population. Using next-generation sequencing, we identified a high-impact frameshift mutation in intraflagellar protein 80 (IFT80) as the putative causal mutation. In bovine embryos, IFT80 expression begins at the 8-cell stage and decreases by the blastocyst stage. We hypothesised that the loss of function of IFT80 early in development causes the lethal phenotype. The aim of this study was to mimic the mutation observed invivo using a CRISPR-Cas9 approach to determine its effect on embryo development. Two guide RNAs (gRNAs) were designed to disrupt exon 11 (Ex11), one before and one after the known IFT80 mutation site, creating a 317-nucleotide (nt) cut to facilitate genotyping. Then, gRNAs annealed to a tracr-Cas9mRNA complex were delivered to 1-cell embryos by microinjection. Each replicate contained control embryos injected with only Cas9mRNA and treated embryos injected with gRNAs targeting IFT80. Embryos from each group were collected at the 8-cell stage for genotyping and gene expression analysis (n=47), or on Day 8 to validate genotypes of embryos left to develop (n=50). DNA sequences containing gRNA target sequences were amplified and visualised on an agarose gel. IFT80 expression was determined in biallelic embryos (n=13) using quantitative PCR and normalized to GAPDH. Primers were designed for the transcript regions before and after gRNAs target sequences, exons 9 and 12, respectively. Expression data were analysed using SAS software (v. 9.4; SAS Institute Inc.) using PROC GLM and LSMEANS to determine expression differences. Biallelic samples (n=9) were Sanger-sequenced (SS) and aligned with the reference sequence to determine exact cut sites. Protein amino acid (AA) sequences were predicted using SS data. Protein models were constructed using the I-Tasser platform, and then aligned and visualised using PyMol 2.4. Biallelic edits showed a significant decrease in exon 12 expression (P<0.05), and no difference in exon 9 compared with controls (P>0.05), indicating that the transcript was severely affected downstream of the edited sites. The reference protein model contained 777 AA, whereas the biallelic sample with the most accurate cut sites yielded a 385-AA protein, indicating that the mutation severely altered protein conformation and possible function. Embryos injected with CRISPR-Cas9 targeting Ex11 arrested at the 8-cell stage and failed to form blastocysts. Day 8 embryos were genotyped (n=24) and 58% were biallelic, 21% were monoallelic, and 21% appeared wild-type. Given the high rate of edits, the observed embryonic arrest is likely due to disruption of IFT80, and wild-type embryos may contain small edits not visible by gel. In conclusion, generation of CRISPR-Cas9 IFT80 knockouts demonstrated that the frameshift mutation in Ex11 results in a seemingly nonfunctional protein that is responsible for the embryonic lethality seen in HH2 carriers. Future research is needed to determine how IFT80 regulates embryonic development. This research was supported by USDA-NIFA National Needs Fellowship, USDA-NIFA AFRI Grant No. 2019-67015-28998.

Agitated behavior scale in pediatric traumatic brain injury

Agitation following TBI commonly occurs during the acute recovery phase. The ABS is a valid measure of agitation in adults following TBI. The objective of the study was to determine if ABS scores accurately measure acute agitation in pediatric patients recovering from TBI. The ABS was completed twice daily for 4 days and mean ABS scores were calculated. Physicians assessed patients' agitation daily using a VAS. In addition, interventions for agitation were recorded. The association between ABS and VAS scores was assessed using Spearman's correlation. The relationship between the number of medication classes taken for agitation (0, 1-2, or ≥3) and ABS scores was assessed using one-way analysis of variance. Finally, the association between the use of hand restraints and ABS scores was examined using an unpaired two-sample t-test. Twenty-six pediatric patients with acute TBI were included. ABS scores significantly associated with VAS scores. Patients that required interventions for agitation (hand restraints or ≥3 medication classes) had higher ABS scores than patients that did not receive any intervention. The study supports the use of ABS scoring to measure agitation in pediatric patients with TBI. However, additional studies are warranted to further support the validity of this scale. Abbreviations: TBI: Traumatic brain injury; ABS: Agitated Behaviour Scale; VAS: visual analog scale; PCCU: Pediatric Critical Care Unit.

Comparison of crystalloid resuscitation fluids for treatment of acute brain injury: a clinical and pre-clinical systematic review and network meta-analysis protocol

BACKGROUND

Current guidelines identify the choice of fluid resuscitation as important in minimizing the incidence of secondary brain injury from cerebral edema. It is widely accepted that isotonic crystalloid resuscitation fluids, specifically normal saline (NS), are optimal for resuscitation and that other relatively hypotonic fluids, such as Ringer's lactate (RL), should be avoided in this patient population. The aim of this review is to systematically compare the use of relatively hypotonic versus isotonic crystalloid resuscitation fluids in clinical and pre-clinical models of acute brain injury and their effect on outcomes. In recognition of the potential need for a network meta-analysis (NMA), we have also included all other relevant crystalloid resuscitation fluids as interventions of relevance to potentially inform indirect comparisons.

METHODS

Systematic searches of MEDLINE, Embase, and Web of Science BIOSIS Previews® will be used to identify eligible clinical and pre-clinical studies, which included studies examining acute brain injury (human and in vivo animal brain injury models) within the first 7 days of therapy. The intervention of interest is the intravenous use of relatively hypotonic crystalloid resuscitation fluids (e.g., Ringer's lactate, Hartmann's or Plasma Lyte® fluids). The main comparator of interest is an isotonic crystalloid resuscitation fluid, specifically normal saline (0.9%). Other crystalloid resuscitation fluids (e.g., hypertonic saline (3-23.4%)) will also be included as an additional intervention of interest. The primary outcome measures of interest are intracranial pressure (ICP) and cerebral perfusion pressure (CPP). Secondary outcomes include the effect of resuscitation on cerebral edema, brain and serum osmolarity, and electrolyte concentrations and clinical outcomes including modified Rankin Scale (mRS), (extended) Glasgow Outcome Scale (GOS/eGOS), and mortality. Separate meta-analyses will be conducted to quantify the effects of the different fluid resuscitation on acute brain injury outcomes in clinical and pre-clinical populations. Network meta-analyses to compare interventions will also be performed to compare the effects of different interventions.

DISCUSSION

This systematic review will comprehensively summarize the difference in treatment efficacy of various crystalloid resuscitation fluids in acute brain injury. This review is essential to underscore the evidence, or lack thereof, present in the literature to date to support current preference-driven practice and to direct future study.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO #CRD42016042960.

Time to Epinephrine Administration and Survival From Nonshockable Out-of-Hospital Cardiac Arrest Among Children and Adults

BACKGROUND

Previous studies have demonstrated that earlier epinephrine administration is associated with improved survival from out-of-hospital cardiac arrest (OHCA) with shockable initial rhythms. However, the effect of epinephrine timing on patients with nonshockable initial rhythms is unclear. The objective of this study was to measure the association between time to epinephrine administration and survival in adults and children with emergency medical services (EMS)-treated OHCA with nonshockable initial rhythms.

METHODS

We performed a secondary analysis of OHCAs prospectively identified by the Resuscitation Outcomes Consortium network from June 4, 2011, to June 30, 2015. We included patients of all ages with an EMS-treated OHCA and an initial nonshockable rhythm. We excluded those with return of spontaneous circulation in <10 minutes. We conducted a subgroup analysis involving patients <18 years of age. The primary exposure was time (minutes) from arrival of the first EMS agency to the first dose of epinephrine. Secondary exposure was time to epinephrine dichotomized as early (<10 minutes) or late (≥10 minutes). The primary outcome was survival to hospital discharge. We adjusted for Utstein covariates and Resuscitation Outcomes Consortium study site.

RESULTS

From 55 568 EMS-treated OHCAs, 32 101 patients with initial nonshockable rhythms were included. There were 12 238 in the early group, 14 517 in the late group, and 5346 not treated with epinephrine. After adjusting for potential confounders, each minute from EMS arrival to epinephrine administration was associated with a 4% decrease in odds of survival for adults, odds ratio=0.96 (95% confidence interval, 0.95-0.98). A subgroup analysis (n=13 290) examining neurological outcomes showed a similar association (adjusted odds ratio, 0.94 per minute; 95% confidence interval, 0.89-0.98). When epinephrine was given late in comparison with early, odds of survival were 18% lower (odds ratio, 0.82; 95% confidence interval, 0.68-0.98). In a pediatric analysis (n=595), odds of survival were 9% lower (odds ratio, 0.91; 95% confidence interval, 0.81-1.01) for each minute delay in epinephrine.

CONCLUSIONS

Among OHCAs with nonshockable initial rhythms, the majority of patients were administered epinephrine >10 minutes after EMS arrival. Each minute delay in epinephrine administration was associated with decreased survival and unfavorable neurological outcomes. EMS agencies should consider strategies to reduce epinephrine administration times in patients with initial nonshockable rhythms.

The changing case-mix of hip fractures in Scotland - evidence from the Scottish Hip Fracture Audit

Until discontinued in 2008, the Scottish Hip Fracture Audit collected and reported on data relating to the quality of care of hip fracture patients in Scotland. In 2013, the audit was recommenced under the umbrella of the MSK Audit group, which audits high volume orthopaedic pathways across Scotland. Our aim is to report on the changes in the demographics of hip fracture patients in Scotland between 2003 and 2013. There was an increase in the proportion of male patients from 2003 to 2013 (22.4% to 29.5%; p < 0.0001). An increased percentage of hip fracture patients were admitted from their own home (63.9% to 73.1%; p < 0.0001). Both these factors have deleterious effects on the outcome, and use of necessary resources, following hip fracture. There was also an increase in the percentage of patients who were American Society of Anesthesiologists Grade 3 (52.9% to 56.4%). Over the last decade, there has been a shift in the demographics of Scotland's hip fracture patients. If hip fracture incidence increases as predicted, this potentially more-challenging case-mix will likely impact on multiple health resources.

Performance Monitoring in Children Following Traumatic Brain Injury Compared to Typically Developing Children

Children with traumatic brain injury are reported to have deficits in performance monitoring, but the mechanisms underlying these deficits are not well understood. Four performance monitoring hypotheses were explored by comparing how 28 children with traumatic brain injury and 28 typically developing controls (matched by age and sex) performed on the stop-signal task. Control children slowed significantly more following incorrect than correct stop-signal trials, fitting the error monitoring hypothesis. In contrast, the traumatic brain injury group showed no performance monitoring difference with trial types, but significant group differences did not emerge, suggesting that children with traumatic brain injury may not perform the same way as controls.

Brain biomarkers and pre-injury cognition are associated with long-term cognitive outcome in children with traumatic brain injury

Background

Children with traumatic brain injury (TBI) are frequently at risk of long-term impairments of attention and executive functioning but these problems are difficult to predict. Although deficits have been reported to vary with injury severity, age at injury and sex, prognostication of outcome remains imperfect at a patient-specific level. The objective of this proof of principle study was to evaluate a variety of patient variables, along with six brain-specific and inflammatory serum protein biomarkers, as predictors of long-term cognitive outcome following paediatric TBI.

Method

Outcome was assessed in 23 patients via parent-rated questionnaires related to attention deficit hyperactivity disorder (ADHD) and executive functioning, using the Conners 3rd Edition Rating Scales (Conners-3) and Behaviour Rating Inventory of Executive Function (BRIEF) at a mean time since injury of 3.1 years. Partial least squares (PLS) analyses were performed to identify factors measured at the time of injury that were most closely associated with outcome on (1) the Conners-3 and (2) the Behavioural Regulation Index (BRI) and (3) Metacognition Index (MI) of the BRIEF.

Results

Higher levels of neuron specific enolase (NSE) and lower levels of soluble neuron cell adhesion molecule (sNCAM) were associated with higher scores on the inattention, hyperactivity/impulsivity and executive functioning scales of the Conners-3, as well as working memory and initiate scales of the MI from the BRIEF. Higher levels of NSE only were associated with higher scores on the inhibit scale of the BRI.

Conclusions

NSE and sNCAM show promise as reliable, early predictors of long-term attention-related and executive functioning problems following paediatric TBI.

Health professionals' experiences of behavioural family therapy for adults with intellectual disabilities: a thematic analysis

WHAT IS KNOWN ON THE SUBJECT?: Behavioural Family Therapy (BFT) has been shown to help people with some severe mental health conditions, such as schizophrenia, by reducing relapse rates and stress within families. It can be difficult to put family interventions, like BFT, into clinical practice. Families where someone has an intellectual disability can experience more stress compared to those who do not, but we know very little about using BFT with families where a member has an intellectual disability. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: We interviewed nine Community Learning Disability Nurses and Allied Health Professionals about their experiences delivering BFT to families where one member has an intellectual disability. We found that therapists' experiences of delivering BFT were broadly positive, although they found some aspects of their service frustrating. EXPLAIN THE IMPORTANCE OF THE PAPER'S FINDINGS FOR A NON-SPECIALIST AUDIENCE: The study identifies the perceived benefits of BFT as a model to work with families, where a member has an intellectual disability. The study highlights some of the challenges experienced by practitioners, notably issues with engagement and some issues specific to working with adults with an intellectual disability. The findings suggest that it needs to be clear which families would benefit most from BFT, that interventions need to be adapted for people with intellectual disabilities and that Community Learning Disability Nurses and Allied Health Professionals should have support from management to deliver these interventions.

ABSTRACT

Introduction Studies have found family interventions (FIs) to be effective in reducing stress and relapse rates for a variety of mental health conditions. However, implementing FIs into clinical practice is challenging. Studies have suggested that levels of stress within some families of people with intellectual disabilities can be high. However, there is little reported about the use and implementation of FIs, such as Behavioural Family Therapy (BFT), in adult intellectual disability services. Purpose of study To explore the experiences of practitioners delivering BFT to adults with intellectual disabilities. Method A qualitative methodology was employed, using semi-structured individual interviews with BFT therapists from a health professional background (n = 9). Data were analysed thematically. Results Two overarching themes were identified: positivity and frustration. Discussion Implementation of therapy was identified as being broadly successful but with some underlying challenges, notably wider organizational issues and some issues specific to working with adults with intellectual disabilities. Implications for practice The broadly positive experiences reported provide encouragement for the delivery of FIs, such as BFT, to adults with intellectual disabilities, by professions outwith psychology. However, there is a need to provide clarity on referral processes, adapt materials accordingly for this client group and ensure that supportive management and supervision is available to therapists.

Unchanged pediatric out-of-hospital cardiac arrest incidence and survival rates with regional variation in North America

AIM

Outcomes for pediatric out-of-hospital cardiac arrest (OHCA) are poor. Our objective was to determine temporal trends in incidence and mortality for pediatric OHCA.

METHODS

Adjusted incidence and hospital mortality rates of pediatric non-traumatic OHCA patients from 2007-2012 were analyzed using the 9 region Resuscitation Outcomes Consortium-Epidemiological Registry (ROC-Epistry) database. Children were divided into 4 age groups: perinatal (<3 days), infants (3days-1year), children (1-11 years), and adolescents (12-19 years). ROC regions were analyzed post-hoc.

RESULTS

We studied 1738 children with OHCA. The age- and sex-adjusted incidence rate of OHCA was 8.3 per 100,000 person-years (75.3 for infants vs. 3.7 for children and 6.3 for adolescents, per 100,000 person-years, p<0.001). Incidence rates differed by year (p<0.001) without overall linear trend. Annual survival rates ranged from 6.7-10.2%. Survival was highest in the perinatal (25%) and adolescent (17.3%) groups. Stratified by age group, survival rates over time were unchanged (all p>0.05) but there was a non-significant linear trend (1.3% increase) in infants. In the multivariable logistic regression analysis, infants, unwitnessed event, initial rhythm of asystole, and region were associated with worse survival, all p<0.001. Survival by region ranged from 2.6-14.7%. Regions with the highest survival had more cases of EMS-witnessed OHCA, bystander CPR, and increased EMS-defibrillation (all p<0.05).

CONCLUSIONS

Overall incidence and survival of children with OHCA in ROC regions did not significantly change over a recent 5year period. Regional variation represents an opportunity for further study to improve outcomes.

The influence of corticosteroid treatment on the outcome of influenza A(H1N1pdm09)-related critical illness

Background

Patients with 2009 pandemic influenza A(H1N1pdm09)-related critical illness were frequently treated with systemic corticosteroids. While observational studies have reported significant corticosteroid-associated mortality after adjusting for baseline differences in patients treated with corticosteroids or not, corticosteroids have remained a common treatment in subsequent influenza outbreaks, including avian influenza A(H7N9). Our objective was to describe the use of corticosteroids in these patients and investigate predictors of steroid prescription and clinical outcomes, adjusting for both baseline and time-dependent factors.

Methods

In an observational cohort study of adults with H1N1pdm09-related critical illness from 51 Canadian ICUs, we investigated predictors of steroid administration and outcomes of patients who received and those who did not receive corticosteroids. We adjusted for potential baseline confounding using multivariate logistic regression and propensity score analysis and adjusted for potential time-dependent confounding using marginal structural models.

Results

Among 607 patients, corticosteroids were administered to 280 patients (46.1 %) at a median daily dose of 227 (interquartile range, 154–443) mg of hydrocortisone equivalents for a median of 7.0 (4.0–13.0) days. Compared with patients who did not receive corticosteroids, patients who received corticosteroids had higher hospital crude mortality (25.5 % vs 16.4 %, p = 0.007) and fewer ventilator-free days at 28 days (12.5 ± 10.7 vs 15.7 ± 10.1, p < 0.001). The odds ratio association between corticosteroid use and hospital mortality decreased from 1.85 (95 % confidence interval 1.12–3.04, p = 0.02) with multivariate logistic regression, to 1.71 (1.05–2.78, p = 0.03) after adjustment for propensity score to receive corticosteroids, to 1.52 (0.90–2.58, p = 0.12) after case-matching on propensity score, and to 0.96 (0.28–3.28, p = 0.95) using marginal structural modeling to adjust for time-dependent between-group differences.

Conclusions

Corticosteroids were commonly prescribed for H1N1pdm09-related critical illness. Adjusting for only baseline between-group differences suggested a significant increased risk of death associated with corticosteroids. However, after adjusting for time-dependent differences, we found no significant association between corticosteroids and mortality. These findings highlight the challenges and importance in adjusting for baseline and time-dependent confounders when estimating clinical effects of treatments using observational studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1230-8) contains supplementary material, which is available to authorized users.

A quantitative analysis of out-of-hospital pediatric and adolescent resuscitation quality--A report from the ROC epistry-cardiac arrest

AIM

High-quality cardiopulmonary resuscitation (CPR) may improve survival. The quality of CPR performed during pediatric out-of-hospital cardiac arrest (p-OHCA) is largely unknown. The main objective of this study was to describe the quality of CPR performed during p-OHCA resuscitation attempts.

METHODS

Prospective observational multi-center cohort study of p-OHCA patients ≥ 1 and < 19 years of age registered in the Resuscitation Outcomes Consortium (ROC) Epistry database. The primary outcome was an a priori composite variable of compliance with American Heart Association (AHA) guidelines for both chest compression (CC) rate and CC fraction (CCF). Event compliance was defined as a case with 60% or more of its minute epochs compliant with AHA targets (rate 100-120 min(-1); depth ≥ 38 mm; and CCF ≥ 0.80). In a secondary analysis, multivariable logistic regression was used to evaluate the association between guideline compliance and return of spontaneous circulation (ROSC).

RESULTS

Between December 2005 and December 2012, 2564 pediatric events were treated by EMS providers, 390 of which were included in the final cohort. Of these events, 22% achieved AHA compliance for both rate and CCF, 36% for rate alone, 53% for CCF alone, and 58% for depth alone. Over time, there was a significant increase in CCF (p < 0.001) and depth (p = 0.03). After controlling for potential confounders, there was no significant association between AHA guideline compliance and ROSC.

CONCLUSIONS

In this multi-center study, we have established that there are opportunities for professional rescuers to improve prehospital CPR quality. Encouragingly, CCF and depth both increased significantly over time.

Coherent coupling of molecular resonators with a microcavity mode

The optical hybridization of the electronic states in strongly coupled molecule–cavity systems have revealed unique properties, such as lasing, room temperature polariton condensation and the modification of excited electronic landscapes involved in molecular isomerization. Here we show that molecular vibrational modes of the electronic ground state can also be coherently coupled with a microcavity mode at room temperature, given the low vibrational thermal occupation factors associated with molecular vibrations, and the collective coupling of a large ensemble of molecules immersed within the cavity-mode volume. This enables the enhancement of the collective Rabi-exchange rate with respect to the single-oscillator coupling strength. The possibility of inducing large shifts in the vibrational frequency of selected molecular bonds should have immediate consequences for chemistry.

Coherent coupling of light with electronic transitions has led to phenomena such as polariton lasing and superfluidity. Shalabney et al. now couple the optical modes of micro-cavity to the vibrational modes of a molecule at room temperature and thereby alter the chemical behaviour of the molecule.

Children's psychological and behavioral responses following pediatric intensive care unit hospitalization: the caring intensively study

BACKGROUND

Pediatric intensive care unit (PICU) hospitalization places children at increased risk of persistent psychological and behavioral difficulties following discharge. Despite tremendous advances in medical technology and treatment regimes, approximately 25% of children demonstrate negative psychological and behavioral outcomes within the first year post-discharge. It is imperative that a broader array of risk factors and outcome indicators be explored in examining long-term psychological morbidity to identify areas for future health promotion and clinical intervention. This study aims to examine psychological and behavioral responses in children aged 3 to 12 years over a three year period following PICU hospitalization, and compare them to children who have undergone ear, nose and/or throat (ENT) day surgery.

METHODS/DESIGN

This mixed-methods prospective cohort study will enrol 220 children aged 3 to 12 years during PICU hospitalization (study group, n = 110) and ENT day surgery hospitalization (comparison group, n = 110). Participants will be recruited from 3 Canadian pediatric hospitals, and followed for 3 years with data collection points at 6 weeks, 6 months, 1 year, 2 years and 3 years post-discharge. Psychological and behavioral characteristics of the child, and parent anxiety and parenting stress, will be assessed prior to hospital discharge, and again at each of the 5 subsequent time points, using standardized measures. Psychological and behavioral response scores for both groups will be compared at each follow-up time point. Multivariate regression analysis will be used to adjust for demographic and clinical variables at baseline. To explore baseline factors predictive of poor psychological and behavioral scores at 3 years among PICU patients, correlation analysis and multivariate linear regression will be used. A subgroup of 40 parents of study group children will be interviewed at years 1 and 3 post-discharge to explore their perceptions of the impact of PICU hospitalization on their children and enhance our understanding of findings generated from standardized measures in the larger cohort study. An interpretive descriptive approach will guide qualitative data collection and analysis.

DISCUSSION

This study aims to generate new information regarding the magnitude and duration of psychological and behavioral disturbances among children admitted to PICUs, potentially leading to remedial or preventive interventions.

A double-blind, placebo-controlled intervention trial of 3 and 10 mg sublingual melatonin for post-concussion syndrome in youths (PLAYGAME): study protocol for a randomized controlled trial

Background

By the age of sixteen, one in five children will sustain a mild traumatic brain injury also known as concussion. Our research found that one in seven school children with mild traumatic brain injury suffer post-concussion syndrome symptoms for three months or longer. Post-concussion syndrome is associated with significant disability in the child and his/her family and yet there are no evidence-based medical treatments available. Melatonin has several potential mechanisms of action that could be useful following mild traumatic brain injury, including neuroprotective effects. The aim of this study is to determine if treatment with melatonin improves post-concussion syndrome in youths following mild traumatic brain injury. Our hypothesis is that treatment of post-concussion syndrome following mild traumatic brain injury with 3 or 10 mg of sublingual melatonin for 28 days will result in a decrease in post-concussion syndrome symptoms compared with placebo.

Methods/Design

Ninety-nine youths with mild traumatic brain injury, aged between 13 and 18 years, who are symptomatic at 30 days post-injury will be recruited. This study will be conducted as a randomized, double blind, placebo-controlled superiority trial of melatonin. Three parallel treatment groups will be examined with a 1:1:1 allocation: sublingual melatonin 3 mg, sublingual melatonin 10 mg, and sublingual placebo. Participants will receive treatment for 28 days. The primary outcome is a change on the Post-Concussion Symptom Inventory (Parent and Youth). The secondary outcomes will include neurobehavioral function, health-related quality of life and sleep. Neurophysiological and structural markers of change, using magnetic resonance imaging techniques and transcranial magnetic stimulation, will also be investigated.

Discussion

Melatonin is a safe and well-tolerated agent that has many biological properties that may be useful following a traumatic brain injury. This study will determine whether it is a useful treatment for children with post-concussion syndrome. Recruitment commenced on 4 December 2014.

Trial registration

This trial was registered on 6 June 2013 at ClinicalTrials.gov. Registration number: NCT01874847.

Critically ill patients with 2009 influenza A(H1N1) infection in Canada

CONTEXT

Between March and July 2009, the largest number of confirmed cases of 2009 influenza A(H1N1) infection occurred in North America.

OBJECTIVE

To describe characteristics, treatment, and outcomes of critically ill patients in Canada with 2009 influenza A(H1N1) infection.

DESIGN, SETTING, AND PATIENTS

A prospective observational study of 168 critically ill patients with 2009 influenza A(H1N1) infection in 38 adult and pediatric intensive care units (ICUs) in Canada between April 16 and August 12, 2009.

MAIN OUTCOME MEASURES

The primary outcome measures were 28-day and 90-day mortality. Secondary outcomes included frequency and duration of mechanical ventilation and duration of ICU stay.

RESULTS

Critical illness occurred in 215 patients with confirmed (n = 162), probable (n = 6), or suspected (n = 47) community-acquired 2009 influenza A(H1N1) infection. Among the 168 patients with confirmed or probable 2009 influenza A(H1N1), the mean (SD) age was 32.3 (21.4) years; 113 were female (67.3%) and 50 were children (29.8%). Overall mortality among critically ill patients at 28 days was 14.3% (95% confidence interval, 9.5%-20.7%). There were 43 patients who were aboriginal Canadians (25.6%). The median time from symptom onset to hospital admission was 4 days (interquartile range [IQR], 2-7 days) and from hospitalization to ICU admission was 1 day (IQR, 0-2 days). Shock and nonpulmonary acute organ dysfunction was common (Sequential Organ Failure Assessment mean [SD] score of 6.8 [3.6] on day 1). Neuraminidase inhibitors were administered to 152 patients (90.5%). All patients were severely hypoxemic (mean [SD] ratio of Pao(2) to fraction of inspired oxygen [Fio(2)] of 147 [128] mm Hg) at ICU admission. Mechanical ventilation was received by 136 patients (81.0%). The median duration of ventilation was 12 days (IQR, 6-20 days) and ICU stay was 12 days (IQR, 5-20 days). Lung rescue therapies included neuromuscular blockade (28% of patients), inhaled nitric oxide (13.7%), high-frequency oscillatory ventilation (11.9%), extracorporeal membrane oxygenation (4.2%), and prone positioning ventilation (3.0%). Overall mortality among critically ill patients at 90 days was 17.3% (95% confidence interval, 12.0%-24.0%; n = 29).

CONCLUSION

Critical illness due to 2009 influenza A(H1N1) in Canada occurred rapidly after hospital admission, often in young adults, and was associated with severe hypoxemia, multisystem organ failure, a requirement for prolonged mechanical ventilation, and the frequent use of rescue therapies.

A pilot open label, single dose trial of fenobam in adults with fragile X syndrome

Objective:

A pilot open label, single dose trial of fenobam, an mGluR5 antagonist, was conducted to provide an initial evaluation of safety and pharmacokinetics in adult males and females with fragile X syndrome (FXS).

Methods:

Twelve subjects, recruited from two fragile X clinics, received a single oral dose of 50–150 mg of fenobam. Blood for pharmacokinetic testing, vital signs and side effect screening was obtained at baseline and numerous time points for 6 h after dosing. Outcome measures included prepulse inhibition (PPI) and a continuous performance test (CPT) obtained before and after dosing to explore the effects of fenobam on core phenotypic measures of sensory gating, attention and inhibition.

Results:

There were no significant adverse reactions to fenobam administration. Pharmacokinetic analysis showed that fenobam concentrations were dose dependent but variable, with mean (SEM) peak values of 39.7 (18.4) ng/ml at 180 min after the 150 mg dose. PPI met a response criterion of an improvement of at least 20% over baseline in 6 of 12 individuals (4/6 males and 2/6 females). The CPT did not display improvement with treatment due to ceiling effects.

Conclusions:

Clinically significant adverse effects were not identified in this study of single dose fenobam across the range of dosages utilised. The positive effects seen in animal models of FXS treated with fenobam or other mGluR5 antagonists, the apparent lack of clinically significant adverse effects, and the potential beneficial clinical effects seen in this pilot trial support further study of the compound in adults with FXS.

X-linked inhibitor of apoptosis protein expression after ischemic injury in the human and rat developing brain

X-linked inhibitor of apoptosis protein (XIAP) is a potent suppressor of neuronal death. The aim of this study was to investigate the expression of XIAP after ischemia in the human and rat developing brain. Autopsy specimens from 19 children with neuropathologic diagnosis of focal cerebral ischemic infarct were processed immunohistochemically for XIAP expression. XIAP positive cells were compared in pathologically classified acute (1-4 d), subacute (5-30 d), and chronic (months) strokes vs. age-matched controls with normal brain histology. For the animal studies, ischemia was induced in 1-wk-old rats by unilateral carotid artery occlusion and transient hypoxia. XIAP expression was quantified at four time points after ischemia in the infarct core and peri-infarct area. Neuronal XIAP expression was higher in the penumbra of subacute human infarcts compared with controls (p < 0.05). XIAP expression in the peri-infarct of rat pup was highest at 7 d postischemic injury (p < 0.05). The increase in XIAP expression was associated with a reduction in activated caspase-3 in ischemic neonatal rat brain. Our results demonstrate that XIAP expression postischemic injury is delayed in both species and may continue for several days. Therefore, potentiation of XIAP expression may be neuroprotective in the developing brain.

A systematic review of the clinical effectiveness and cost-effectiveness and economic modelling of minimal incision total hip replacement approaches in the management of arthritic disease of the hip

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of minimal incision approaches to total hip replacement (THR) for arthritis of the hip.

DATA SOURCES

Major electronic databases were searched from 1966 to 2007. Relevant websites were also examined and experts in the field were consulted.

REVIEW METHODS

Studies of minimal (one or two) incision THR compared with standard THR were assessed for inclusion in the review of clinical effectiveness. A systematic review of economic evaluations comparing a minimal incision approach to standard THR was also performed and the estimates from the systematic review of clinical effectiveness were incorporated into an economic model. Utilities data were sourced to estimate quality-adjusted life-years (QALYs). Due to lack of data, no economic analysis was conducted for the two mini-incision surgical method.

RESULTS

Nine randomised controlled trials (RCTs), 17 non-randomised comparative studies, six case series and one registry were found to be useful for the comparison of single mini-incision THR with standard THR. One RCT compared two mini-incision THR with standard THR, and two RCTs, five non-randomised comparative studies and two case series compared two mini-incision with single mini-incision THR. The RCTs were of moderate quality. Most had fewer than 200 patients and had a follow-up period of less than 1 year. The single mini-incision THR may have some perioperative advantages, e.g. blood loss [weighted mean difference (WMD) -57.71 ml, p<0.01] and shorter operative time, of uncertain practical significance. It may also offer a shorter recovery period and greater patient satisfaction. Evidence on long-term outcomes (especially revision) is too limited to be useful. Lack of data prevented subgroup analysis. With respect to the two-incision approach, data were suggestive of shorter recovery compared with single-incision THR, but conclusions must be treated with caution. The costs to the health service, per patient, of single mini-incision THR depend upon assumptions made, but are similar at one year (7060 pounds sterling vs 7350 pounds sterling for standard THR). For a 40-year time horizon the costs were 11,618 pounds sterling for mini-incision and 11,899 pounds sterling for standard THR. Two existing economic evaluations were identified, but they added little, if any, value to the current evidence base owing to their limited quality. In the economic model, mini-incision THR was less costly and provided slightly more QALYs in both the 1- and 40-year analyses. The mean QALYs at 1 year were 0.677 for standard THR and 0.695 for mini-incision THR. At 40 years, the mean QALYs were 8.463 for standard THR and 8.480 for mini-incision. At 1 year the probabilistic sensitivity analyses indicate that mini-incision THR has a 95% probability of being cost-effective if society's willingness to pay for a QALY were up to 50,000 pounds sterling. This is reduced to approximately 55% for the 40-year analysis. The results were driven by the assumption of a 1-month earlier return to usual activities and a decreased hospital length of stay and operation duration following mini-incision THR. If mini-incision THR actually required more intensive use of resources it would become approximately 200 pounds sterling more expensive and would only be cost-effective (cost per QALY>30,000 pounds sterling) if recovery was 1.5 weeks faster. A threshold analysis around risk of revision showed, using the same cost per QALY threshold, mini-incision THR would have to have no more than a 7.5% increase in revisions compared with standard THR for it to be no longer considered cost-effective (one more revision for every 200 procedures performed). Further sensitivity analysis involved relaxing assumptions of equal long-term outcomes where possible. and broadly similar results to the base-case analysis were found in this and further sensitivity analyses.

CONCLUSIONS

Compared with standard THR, minimal incision THR has small perioperative advantages in terms of blood loss and operation time. It may offer a shorter hospital stay and quicker recovery. It appears to have a similar procedure cost to standard THR, but evidence on its longer term performance is very limited. Further long-term follow-up data on costs and outcomes including analysis of subgroups of interest to the NHS would strengthen the current economic evaluation.

Femoral head viability after Birmingham resurfacing hip arthroplasty: assessment with use of [18F] fluoride positron emission tomography

BACKGROUND

Total hip resurfacing has become increasingly popular over the last decade. There remains concern about the effect of the surgical approach on femoral head viability and the role of resurfacing in the management of established osteonecrosis. In view of these concerns, we examined femoral head viability following resurfacing through a modified anterolateral approach.

METHODS

The viability of the femoral heads of ten patients who had undergone successful unilateral Birmingham hip resurfacing was assessed with use of positron emission tomography in conjunction with the injection of fluorine at a mean of twenty months after surgery. For each patient, in both the hip that had undergone resurfacing and the contralateral nonresurfaced hip, activity was measured in four regions of interest: the lateral aspect of the femoral head, the medial aspect of the femoral head, the lateral aspect of the femoral neck, and the proximal aspect of the femur. The uptake of fluorine in each area was converted to standard uptake volumes.

RESULTS

No areas of osteonecrosis were seen in the femoral head of any patient. There were no significant differences in the standard uptake volumes as measured in the four regions of the nonresurfaced hips, whereas the median values were higher in all four regions of the resurfaced hips. The difference between the values in the resurfaced hips compared with those in the nonresurfaced hips was only significant (p < 0.05) in the lateral aspect of the femoral head.

CONCLUSIONS

This study establishes positron emission tomography in conjunction with injection of fluorine as a possible modality for the assessment of femoral head viability after hip resurfacing. Viability following successful Birmingham hip resurfacing performed through a modified anterolateral approach has also been demonstrated. The increase in bone activity that was seen in the resurfaced hips in our study group may be related to bone remodeling or reperfusion of small areas of osteonecrosis. This technique offers the potential to study femoral head perfusion and viability following all types of resurfacing.

LEVEL OF EVIDENCE

Diagnostic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Hypothermia pediatric head injury trial: the value of a pretrial clinical evaluation phase

BACKGROUND

The utility of a pretrial clinical evaluation or run-in phase prior to conducting trials of complex interventions such as hypothermia therapy following severe traumatic brain injury in children and adolescents has not been established.

METHODS

The primary objective of this study was to prospectively evaluate the ability of investigators to adhere to the clinical protocols of care including the cooling and rewarming procedures as well as management guidelines in patients with severe traumatic brain injury (Glasgow Coma Scale<or=8) treated with 24 h of hypothermia therapy. A secondary objective was to evaluate the ability of study research assistants to complete the study case report form using a procedures manual. The study was conducted at 18 sites in Canada, the United Kingdom and France prior to proceeding to a randomized controlled trial (RCT). After 2 patients were enrolled at each center, an independent clinical evaluation committee examined the process of care and the completeness of data collection. Centers were permitted to enroll patients in the RCT once they met pre-established adherence criteria.

RESULTS

Seventeen of the 18 centers completed the pretrial clinical evaluation phase demonstrating compliance with study procedures and proceeded to an RCT of hypothermia therapy. One center enrolled only 1 patient in the pretrial clinical evaluation phase due to small numbers of patients with traumatic brain injury, and therefore, did not proceed to the RCT. Three centers were required to enroll more than 2 patients in the pretrial clinical evaluation phase prior to proceeding to the RCT because of problems with adherence to the clinical protocols at two centers and the training of new study personnel at another center. Of the 39 patients enrolled during the pretrial clinical evaluation phase, 8 (20.5%) died and 22 (62.9%) had a good outcome defined as normal, mild or moderate disability assessed using the Pediatric Cerebral Performance Category score at 6 months following injury.

DISCUSSION

The pretrial clinical evaluation phase was useful to ensure compliance with complex hypothermia therapy and consensus-based clinical management guidelines of care successfully implemented across 17 of 18 centers. This study maneuver allowed us to complete a subsequent RCT in 225 children following severe traumatic brain injury.

Clinically important venous thromboembolism in pediatric critical care: a Canadian survey

PURPOSE

Pediatric venous thromboembolism (VTE) is becoming an increasingly recognized morbidity associated with critical illness. The objective of this survey is to identify the patient factors and radiological features that pediatric intensivists consider more or less likely to make a venous thrombosis (VTE) clinically important in their patients.

MATERIALS AND METHODS

Our definition of clinically important VTE was a VTE likely to result in short- or long-term morbidity or mortality if left untreated. We asked respondents to rate the likelihood that patient factors and radiological features make a venous thrombosis clinically important using a 5-point scale (1 = much less likely to 5 = much more likely).

RESULTS

The 38 (58.5%) of 65 pediatric intensivists responding rated 4 patient factors as most likely to make a VTE clinically important: clinical suspicion of pulmonary embolism (mean score, 4.8), symptoms (mean, 4.5), detection by physical exam (mean, 4.4), and the presence of an acute or chronic cardiopulmonary comorbidity that might limit a patient's ability to tolerate pulmonary embolism (mean, 4.3). Of the radiological features, the 2 considered most important were VTE involving the vena cava extending into the right atrium (mean, 5) and central veins (mean, 4.5).

CONCLUSIONS

When labeling a VTE as clinically important, pediatric intensivists rely on several specific patient factors and thrombus characteristics.

Peri-acetabular radiolucent lines: inter- and intra-observer agreement on post-operative radiographs

Peri-acetabular radiolucent lines (RLLs) seen on "early" post-operative radiographs have been identified as a potential predictor of long-term implant performance. This study examines the inter- and intra-observer variation encountered when assessing such radiographs. Four consultant orthopaedic surgeons assessed the presence, extent and width of RLLs in 220 radiographs performed on 50 patients taken one to two weeks, six weeks, six months and one year following surgery. Inter-observer agreement was fair at 7-14 days but improved to moderate to good in films at six and 12 months. Intra-observer agreement was moderate to good at 7-10 days but again improved to good at 6 and 12 months. When only the presence or absence of RLLs was considered, both inter-observer and intra-observer agreement improved for both the six-month and one-year radiographs. This experiment shows that caution must be used for the interpretation of RLLs on hip radiographs taken during the very early post-operative period. We recommend that films taken at least six weeks to six months following surgery should be used for assessment to reduce observer variation. For optimum results, a single experienced observer should do the assessment with a simple classification.

Early dialysis in a neonate with intrauterine lisinopril exposure

In general, angiotensin converting enzyme (ACE) inhibitors should be discontinued in pregnancy, as they can induce an ACE fetopathy. For the treatment of the latter, early peritoneal dialysis is recommended for in utero exposure to captopril and enalapril, although the outcome is poor. Early peritoneal dialysis has not previously been reported for lisinopril induced multiorgan failure. A case is reported in which treatment was given on postnatal day 3. The patient recovered from oligoanuria to almost normal renal function, and heart, brain, and musculoskeletal injury was reversible. This is despite relatively poor clearance of the drug through peritoneal dialysis. Analysis of the pharmacokinetic data suggests that haemodialysis or haemofiltration would be more efficacious for removal of the drug, and these treatments should be performed if available.

Transcranial Doppler during suspected brain death in children: Potential limitation in patients with cardiac "shunt"

OBJECTIVES: We report a potential limitation of transcranial Doppler for assessing cerebral circulation during suspected brain death in children. DESIGN: Review of two case series identified during our clinical practice. PATIENTS: Eight children with suspected brain death and seven with intact-brain and cardiovascular anomalies. MEASUREMENTS AND MAIN RESULTS: Brain-death criteria included lack of cerebral-brainstem reactivity, electrocortical silence and absent blood flow by brain scintigraphy ((99m)Tc-hexamethylpropylenamine oxime). Five intracranial Doppler patterns were found in eight cases of suspected brain death: A) orthograde continuous flow; B) reduced systolic flow velocity with absence of diastolic flow; C) reduced systolic flow velocity with retrograde diastolic flow, sometimes with antegrade late diastolic flow; D) systolic spikes of very low flow velocity; and E) absence of Doppler signals. Only patterns "C," "D," and "E" were associated with the absence of supra- and infratentorial brain perfusion. The most common Doppler alterations in patients with intact-brain and cardiovascular anomalies were the absence of diastolic flow (pattern "B") or the presence of retrograde flow during diastole (pattern "C"). CONCLUSION: Transcranial Doppler monitoring of pediatric patients may have value in identifying patients who have severe cerebral compromise, who may progress to brain death. However, key Doppler alterations, such as absent or retrograde flow during diastole, are not uniquely associated with the diagnosis of brain death, particularly in the setting of congential heart disease. The use of conventional methodology for the diagnosis of brain death in infants and children remains the "gold standard."

Indomethacin and cyclosporin a inhibit in vitro ischemia-induced expression of ICAM-1 and chemokines in human brain endothelial cells

Brain inflammation has been implicated in the development of brain edema and secondary brain damage in ischemia and trauma. Mechanisms involved in leukocyte infiltration across the blood-brain barrier are still unknown. In this study, we show that human cere-bromicrovascular endothelial cells (HCEC) subjected to a 4 h in vitro ischemia (hypoxia + glucose deprivation) followed by a 4-24 h recovery express elevated levels of ICAM-1, IL-8, and MCP-1 mRNAs (semi-quantitative RT-PCR) and secrete increased amounts of the immunoreactive chemokines IL-8 and MCP-1 (ELISA). The ischemia-induced expression of ICAM-1 in HCEC, and the expression/release of IL-8 and MCP-1 in HCEC were abolished by the non-steroid anti-inflammatory drug, indomethacin (100-300 microM). The immunosuppressant cyclosporin A (50 microM) partially reduced the ischemia-stimulated IL-8 and MCP-1 secretion by HCEC. Both indomethacin and cyclosporin A also inhibited the ischemia-induced neutrophil chemotaxis elicited by HCEC media. The study indicates that in vitro ischemia augments the expression of adhesion molecules and leukocyte chemoattractants at the site of the BBB. This ischemic pro-inflammatory activation of HCEC may constitute a key event in initiating post-ischemic inflammation, and it can be suppressed by the anti-inflammatory drugs, indomethacin and cyclosporin A.

A role for platelets and endothelial selectins in tumor necrosis factor-alpha-induced leukocyte recruitment in the brain microvasculature

The mechanisms mediating leukocyte recruitment into the cerebral nervous system during inflammation are still poorly understood. The objective of this study was to investigate the leukocyte recruitment in the brain microcirculation by intravital microscopy. Superfusion of the brain with artificial cerebrospinal fluid did not induce leukocyte rolling or adhesion. However, intraperitoneal tumor necrosis factor-alpha (TNF-alpha) caused marked leukocyte rolling and adhesion in the brain microcirculation. Histology revealed that the recruitment was primarily of neutrophils. Both E- and P-selectin were required for TNF-alpha-induced leukocyte recruitment, as rolling was reduced after treatment with either anti-E- or anti-P-selectin antibody and eliminated in E- or P-selectin-deficient mice. A significant increase in brain P- and E-selectin expression was seen after TNF-alpha treatment, but both were an order of magnitude less than in any other tissue. We observed significant platelet paving of TNF-alpha-stimulated endothelium and found that anti-platelet antibody reduced leukocyte rolling and adhesion, as did acetylsalicylic acid (aspirin). However, depletion of platelets did not reduce cerebral P-selectin expression. Moreover, chimeric mice lacking P-selectin on endothelium but not platelets had significantly decreased P-selectin expression and reduced leukocyte recruitment in the brain. This suggests a role for endothelial P-selectin in cerebral leukocyte recruitment. In conclusion, TNF-alpha-induced neutrophil recruitment into the brain requires both endothelial E-selectin and P-selectin as well as platelets, but platelet P-selectin was not a major contributor to this process.

Mycoplasma pulmonis genital disease: effect of rat strain on pregnancy outcome

BACKGROUND AND PURPOSE

Mycoplasma pulmonis is a natural pathogen of the respiratory and genital tracts of rats. Differential susceptibility and severity of the respiratory form of the disease, known as murine respiratory mycoplasmosis (MRM), exist between rat strains. We now report that specific rat strains vary in susceptibility to genital tract infection and pregnancy outcome.

METHODS

Specific-pathogen-free (SPF) female F344, LEW, Wistar (WIS) and Sprague Dawley (SD) rats were intravaginally inoculated with 3 x 10(7) colony-forming units (CFU) of M. pulmonis strain X1048 or sterile diluent, and allowed to breed at 10 days after inoculation. Pregnant dams and pups were necropsied within 24 hours of parturition. At necropsy, culture for M. pulmonis was performed on dam and pups, and adverse effects on pregnancy outcome were assessed by determination of the incidence of infertility, fetal resorption, stillbirths, changes in litter size, and pup birth weight. Blood from dams was collected prior to inoculation and at time of necropsy for measurement of IgM and IgG antibodies to M. pulmonis.

RESULTS

At time of necropsy, WIS (50%) and SD (60%) dams had a higher frequency of M. pulmonis culture positivity in the genital tract than did LEW (22.2%) and F344 (17.6%) dams. Dams that were still infected with M. pulmonis at time of necropsy had various complications. The SD rats had the greatest degree of adverse effects on pregnancy outcome, which were: infertility, decreased litter size (P < or = 0.01), decreased pup birth weight (P < or = 0.01), increased frequency of resorptions, stillbirths (P < or = 0.05), and the highest rate of pup pulmonary infection (23.1%) (P < or = 0.001). Despite a 50% colonization rate, WIS dams were the least adversely affected. The WIS pups born from M. pulmonis. infected dams had slight decrease in birth weight, and only 6% had pulmonary infections. The LEW infected dams developed infertility and lower numbers of liveborn pups without evidence of vertical transmission. The F344 infected dams had lower numbers of liveborn pups that were smaller than their control counterparts, and none had pulmonary infections. None of the animals had detectable IgM and IgG antibodies to M. pulmonis before inoculation. At time of necropsy, all animals inoculated with M. pulmonis developed significantly (P < or = 0.001) higher amounts of M. pulmonis IgG and IgM antibodies, with SD rats developing the highest amounts (P < or = 0.005).

CONCLUSIONS

Both F344 and LEW rats are more resistant to vaginal inoculation with M. pulmonis than are WIS and SD rats. However, only SD dams suffered severe adverse effects on pregnancy outcome. The SD dams also had the greatest IgM and IgG antibody response to M. pulmonis. Our studies clearly indicate differences among rat strains in their susceptibility to vaginal inoculation with M. pulmonis and in secondary complications associated with infection. This system may be a useful model for determining host-specific factors that influence the outcome of natural mycoplasmal infections of the genital tract.

A bench-top method for evaluating modular total hip component combinations

A modular total hip prosthesis allows the surgeon to vary head size, neck length, and acetabular coverage. Different combinations, however, may increase the risk of impingement of the prosthesis neck on the acetabular liner, leading to dislocation. We developed a bench-top model to test different modular component combinations to determine how far the femoral component could travel within the acetabular liner before impingement led to dislocation. We tested two hip systems, each from a different manufacturer. Certain components increased the risk of impingement and dislocation: skirted necks, smaller heads, and lipped liners. While the contribution of each component was small, the risk was additive, so that the combination of a small head with a skirted neck in a lipped liner actually reduced the available range of motion by 18 degrees, from 146 degrees to 128 degrees, in the first system, and by 13 degrees, from 156 degrees to 143 degrees in the other. This method could be adapted to test a wide range of component configurations, from a number of manufacturers. These findings may be useful in avoiding potentially unstable configurations when given a choice of modular components.

Increased expression of bioactive chemokines in human cerebromicrovascular endothelial cells and astrocytes subjected to simulated ischemia in vitro

Leukocyte infiltration into the brain has been implicated in the development of ischemic brain damage. In this study, simulated in vitro ischemia/reperfusion and IL-1beta were found to up-regulate both the expression of intercellular adhesion molecule- (ICAM-1) in cultured human cerebromicrovascular endothelial cells (HCEC) and the adhesion of allogenic neutrophils to HCEC. Both HCEC and human fetal astrocytes (FHAS) also responded to IL-1beta and to in vitro ischemia/reperfusion by a pronounced up-regulation of IL-8 and MCP-1 mRNA and by increased release of IL-8 and MCP-1 in cell culture media. FHAS were found to release 30-times higher levels of MCP-1 than HCEC under both basal and ischemic conditions. However, 100 u/ml IL-1beta induced greater stimulation of both IL-8 and MCP-1 secretion in HCEC (50 and 20 times above controls, respectively) than in FHAS (three and two times above controls, respectively). IL-8 was the principal neutrophil chemoattractant released from IL-1beta-treated HCEC, since IL-8 antibody completely inhibited neutrophil chemotaxis enticed by HCEC media. However, the IL-8 antibody neutralized only 50% of IL-1beta-stimulated neutrophil chemoattractants released from FHAS, and 40%-60% of ischemia-stimulated chemotactic activity released by either HCEC or FHAS. These results suggest that simulated in vitro ischemia, in addition to IL-8 and MCP-1, stimulates secretion of other bioactive chemokines from HCEC and FHAS.

The induction of ICAM-1 in human cerebromicrovascular endothelial cells (HCEC) by ischemia-like conditions promotes enhanced neutrophil/HCEC adhesion

Ischemic brain injury is exacerbated by leukocyte infiltration and formation of vasogenic edema. In this study we demonstrate that intercellular adhesion molecule-1 (ICAM-1) is dramatically (3 to 15-fold) up-regulated in human cerebromicrovascular endothelial cells (HCEC) by a 16 h exposure to the cytokine, IL-1 beta (50-200 u/ml), the phorbol ester, TPA (1-100 nM), or by simulated in vitro ischemia/reperfusion. These treatments also significantly increased the adhesion of allogeneic neutrophils to HCEC monolayers. Both IL-1 beta- and TPA-induced expression of ICAM-1 and increased neutrophil adhesion to HCEC were inhibited by the transcriptional inhibitor, actinomycin D (AcD; 1-10 micrograms/ml), and by an anti-ICAM-1 antibody (ICAM-1 Ab). By contrast, ischemia-induced neutrophil adhesion was only slightly affected by AcD and ICAM-1 Ab alone, but it was abolished by the combination of anti-ICAM-1 and anti-CD18 antibodies. The increase in surface expression of ICAM-1 and neutrophil adhesion by IL-1 beta, TPA and ischemia were significantly reduced by the cyclo-oxygenase (COX) inhibitors, indomethacin (100-300 microM) and dexamethasone (10-50 microM). These results indicate that ICAM-1 expression in HCEC can lead to enhanced neutrophil adhesion and that COX activation in HCEC likely plays a role in the processes by which leukocyte adhesion and recruitment take place in the brain during inflammation and ischemia in vivo.

Lower anion gap increases sensitivity in predicting elevated lactate

OBJECTIVE

The normal reference range for the anion gap (AG) has recently been questioned by several authors. Lowering the upper limit of normal of the AG has been found to be more sensitive in predicting elevated lactate in critically ill adults. The objectives of this study are i) to define a new upper limit of normal of the AG in a study population of healthy adult volunteers, ii) to determine the sensitivity, specificity, the positive predictive value and the negative predictive value of the new upper limit for AG in detecting elevated lactate in critically ill children and to compare these results to the old upper limit of normal of AG (16 mmol/l), iii) to construct a receiver-operating-characteristic (ROC) curve for anion gap as a predictor of elevated lactate, iv) to determine the relationship between anion gap and serum lactate levels in critically ill patients.

DESIGN

A prospective, cohort study.

SETTING

Paediatric Intensive Care Unit of a University Hospital.

SUBJECTS

Part I: Convenience sample of healthy adult volunteers to provide a reference range for anion gap calculation. Part II: Consecutive children admitted to the Paediatric Intensive Care Unit who had lactate levels measured for clinical reasons.

MEASUREMENTS

Part I: Electrolytes and blood gases were measured from blood samples drawn from 25 adult volunteers. The reference range for AG was calculated using the equation, AG = Na - (Cl + HCO3). The upper limit of normal was calculated as mean + 2 SD. Part II: Eligible ICU patients were included in this study if they had lactate, electrolytes and blood gases obtained simultaneously. The AG was calculated as above. The new upper limit of normal AG was compared to an AG of 16 for diagnosing an elevated plasma lactate.

RESULTS

The mean anion gap in the normal population was 9.4 +/- 1 mmol/l with 11 mmol/l being used as the new upper limit of normal. Thirty-six ICU patients had 189 arterial blood samples from which lactate, electrolytes and blood gas were measured simultaneously. The sensitivity, specificity, positive predictive value and negative predictive value of using an AG of 11 mmol/l as the upper limit of normal were 86%, 40%, 65% and 69% respectively, compared to 49%, 84%, 80% and 55% respectively using the upper limit of normal of AG of 16 mmol/l. The ROC curve supported lowering the upper limit of normal for the anion gap to predict an elevated lactate. There was a linear relationship between anion gap and serum lactate levels.

CONCLUSIONS

An AG of 11 mmol/l as the upper limit of normal has a higher sensitivity and higher negative predictive value but lower specificity and lower positive predictive value for detecting elevated lactate in critically ill children.

Cellular aspects of corpus luteum function in the primate

The primate corpus luteum produces progesterone for a period of 14-16 days, at which time, in non-fertile cycles, steroidogenesis ceases and the tissue regresses. Studies completed in this laboratory have established that while luteinizing hormone (LH) is necessary to maintain luteal steroidogenesis, changes in LH secretion are not causal to luteolysis. The studies presented here demonstrate that luteal cell synthetic capacity, as reflected in steady-state levels of messenger ribonucleic acid (mRNA) encoding steroidogenic enzymes, is maximal shortly after ovulation and steadily declines thereafter, independently of progesterone and LH secretion. In addition, the loss of luteal mRNA expression for steroidogenic enzymes following LH withdrawal occurs 24 h after the decline in progesterone levels. Finally, the detection of mRNA encoding vascular endothelial growth factor within the corpus luteum throughout the luteal phase in the subhuman primate may provide the first identification of a potential secreted, non-steroidal factor responsible for the vast degree of angiogenesis that occurs within the corpus luteum.