Patrick Archambault

Predictive value of S-100β protein for prognosis in patients with moderate and severe traumatic brain injury: systematic review and meta-analysis

Objectives To determine the ability and accuracy of the S-100β protein in predicting prognosis after a moderate or severe traumatic brain injury. Design Systematic review and meta-analysis of randomised controlled trials and observational studies. Data sources Medline, Embase, Cochrane Central Register of Controlled Trials, BIOSIS (from their inception to April 2012), conference abstracts, bibliographies of eligible articles, and relevant narrative reviews. Study selection Two reviewers independently reviewed citations and selected eligible studies, defined as cohort studies or randomised control trials including patients with moderate or severe traumatic brain injury and evaluating the prognostic value of S-100β protein. Outcomes evaluated were mortality, score on the Glasgow outcome scale, or brain death. Data extraction Two independent reviewers extracted data using a standardised form and evaluated the methodological quality of included studies. Pooled results were presented with geometric means ratios and analysed with random effect models. Prespecified sensitivity analyses were performed to explain heterogeneity. Results The search strategy yielded 9228 citations. Two randomised controlled trials and 39 cohort studies were considered eligible (1862 patients). Most studies (n=23) considered Glasgow outcome score ≤3 as an unfavourable outcome. All studies reported at least one measurement of S-100β within 24 hours after traumatic brain injury. There was a significant positive association between S-100β protein concentrations and mortality (12 studies: geometric mean ratio 2.55, 95% confidence interval 2.02 to 3.21, I2=56%) and score ≤3 (18 studies: 2.62, 2.01 to 3.42, I2=79%). Sensitivity analysis based on sampling time, sampling type, blinding of outcome assessors, and timing of outcome assessment yielded similar results. Thresholds for serum S-100β protein values with 100% specificity ranged from 1.38 to 10.50 µg/L for mortality (six studies) and from 2.16 to 14.00 µg/L for unfavourable neurological prognosis as defined by the Glasgow outcome score. Conclusions After moderate or severe traumatic brain injury, serum S-100β protein concentrations are significantly associated with unfavourable prognosis in the short, mid, or long term. Optimal thresholds for discrimination remain unclear. Measuring the S-100β protein could be useful in evaluating the severity of traumatic brain injury and in the determination of long term prognosis in patients with moderate and severe injury.

Treatment for calcium channel blocker poisoning: A systematic review

Abstract Context. Calcium channel blocker poisoning is a common and sometimes life-threatening ingestion. Objective. To evaluate the reported effects of treatments for calcium channel blocker poisoning. The primary outcomes of interest were mortality and hemodynamic parameters. The secondary outcomes included length of stay in hospital, length of stay in intensive care unit, duration of vasopressor use, functional outcomes, and serum calcium channel blocker concentrations. Methods. Medline/Ovid, PubMed, EMBASE, Cochrane Library, TOXLINE, International pharmaceutical abstracts, Google Scholar, and the gray literature up to December 31, 2013 were searched without time restriction to identify all types of studies that examined effects of various treatments for calcium channel blocker poisoning for the outcomes of interest. The search strategy included the following Keywords: [calcium channel blockers OR calcium channel antagonist OR calcium channel blocking agent OR (amlodipine or bencyclane or bepridil or cinnarizine or felodipine or fendiline or flunarizine or gallopamil or isradipine or lidoflazine or mibefradil or nicardipine or nifedipine or nimodipine or nisoldipine or nitrendipine or prenylamine or verapamil or diltiazem)] AND [overdose OR medication errors OR poisoning OR intoxication OR toxicity OR adverse effect]. Two reviewers independently selected studies and a group of reviewers abstracted all relevant data using a pilot-tested form. A second group analyzed the risk of bias and overall quality using the STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) checklist and the Thomas tool for observational studies, the Institute of Health Economics tool for Quality of Case Series, the ARRIVE (Animal Research: Reporting In Vivo Experiments) guidelines, and the modified NRCNA (National Research Council for the National Academies) list for animal studies. Qualitative synthesis was used to summarize the evidence. Of 15,577 citations identified in the initial search, 216 were selected for analysis, including 117 case reports. The kappa on the quality analysis tools was greater than 0.80 for all study types. Results. The only observational study in humans examined high-dose insulin and extracorporeal life support. The risk of bias across studies was high for all interventions and moderate to high for extracorporeal life support. High-dose insulin. High-dose insulin (bolus of 1 unit/kg followed by an infusion of 0.5–2.0 units/kg/h) was associated with improved hemodynamic parameters and lower mortality, at the risks of hypoglycemia and hypokalemia (low quality of evidence). Extracorporeal life support. Extracorporeal life support was associated with improved survival in patients with severe shock or cardiac arrest at the cost of limb ischemia, thrombosis, and bleeding (low quality of evidence). Calcium, dopamine, and norepinephrine. These agents improved hemodynamic parameters and survival without documented severe side effects (very low quality of evidence). 4-Aminopyridine. Use of 4-aminopyridine was associated with improved hemodynamic parameters and survival in animal studies, at the risk of seizures. Lipid emulsion therapy. Lipid emulsion was associated with improved hemodynamic parameters and survival in animal models of intravenous verapamil poisoning, but not in models of oral verapamil poisoning. Other studies. Studies on decontamination, atropine, glucagon, pacemakers, levosimendan, and plasma exchange reported variable results, and the methodologies used limit their interpretation. No trial was documented in humans poisoned with calcium channel blockers for Bay K8644, CGP 28932, digoxin, cyclodextrin, liposomes, bicarbonate, carnitine, fructose 1,6-diphosphate, PK 11195, or triiodothyronine. Case reports were only found for charcoal hemoperfusion, dialysis, intra-aortic balloon pump, Impella device and methylene blue. Conclusions. The treatment for calcium channel blocker poisoning is supported by low-quality evidence drawn from a heterogeneous and heavily biased literature. High-dose insulin and extracorporeal life support were the interventions supported by the strongest evidence, although the evidence is of low quality.

The use of higher platelet: RBC transfusion ratio in the acute phase of trauma resuscitation: a systematic review.

Objective:With the recognition of early coagulopathy, trauma resuscitation has shifted toward liberal platelet transfusions. The overall benefit of this strategy remains controversial. Our objective was to compare the effects of a liberal use of platelet (higher platelet:RBC ratios) with a conservative approach (lower ratios) in trauma resuscitation. Data Sources:We systematically searched Medline, Embase, Web of Science, Biosis, Cochrane Central, and Scopus. Study Selection:Two independent reviewers selected randomized controlled trials and observational studies comparing two or more platelet:RBC ratios in trauma resuscitation. We excluded studies investigating the use of whole blood or hemostatic products. Data Extraction:Two independent reviewers extracted data and assessed the risk of bias. Primary outcomes were early (in ICU or within 30 d) and late (in hospital or after 30 d) mortality. Secondary outcomes were multiple organ failure, lung injury, and sepsis. Data Synthesis:From 6,123 citations, no randomized controlled trials were identified. We included seven observational studies (4,230 patients) addressing confounders through multivariable regression or propensity scores. Heterogeneity of studies precluded meta-analysis. Among the five studies including exclusively patients requiring massive transfusions, four observed a lower mortality with higher ratios. Two studies considering nonmassively bleeding patients observed no benefit of using higher ratios. Two studies evaluated the implementation of a massive transfusion protocol; only one study observed a decrease in mortality with higher ratios. Of the two studies at low risk of survival bias, one study observed a survival benefit. Three studies assessed secondary outcomes. One study observed an increase in multiple organ failure with higher ratios, whereas no study demonstrated an increased risk in lung injury or sepsis. Conclusions:There is insufficient evidence to strongly support the use of a precise platelet:RBC ratio for trauma resuscitation, especially in nonmassively bleeding patients. Randomized controlled trials evaluating both the safety and efficacy of liberal platelet transfusions are warranted.

Wikis and Collaborative Writing Applications in Health Care: A Scoping Review

Background Collaborative writing applications (eg, wikis and Google Documents) hold the potential to improve the use of evidence in both public health and health care. The rapid rise in their use has created the need for a systematic synthesis of the evidence of their impact as knowledge translation (KT) tools in the health care sector and for an inventory of the factors that affect their use. Objective Through the Levac six-stage methodology, a scoping review was undertaken to explore the depth and breadth of evidence about the effective, safe, and ethical use of wikis and collaborative writing applications (CWAs) in health care. Methods Multiple strategies were used to locate studies. Seven scientific databases and 6 grey literature sources were queried for articles on wikis and CWAs published between 2001 and September 16, 2011. In total, 4436 citations and 1921 grey literature items were screened. Two reviewers independently reviewed citations, selected eligible studies, and extracted data using a standardized form. We included any paper presenting qualitative or quantitative empirical evidence concerning health care and CWAs. We defined a CWA as any technology that enables the joint and simultaneous editing of a webpage or an online document by many end users. We performed qualitative content analysis to identify the factors that affect the use of CWAs using the Gagnon framework and their effects on health care using the Donabedian framework. Results Of the 111 studies included, 4 were experimental, 5 quasi-experimental, 5 observational, 52 case studies, 23 surveys about wiki use, and 22 descriptive studies about the quality of information in wikis. We classified them by theme: patterns of use of CWAs (n=26), quality of information in existing CWAs (n=25), and CWAs as KT tools (n=73). A high prevalence of CWA use (ie, more than 50%) is reported in 58% (7/12) of surveys conducted with health care professionals and students. However, we found only one longitudinal study showing that CWA use is increasing in health care. Moreover, contribution rates remain low and the quality of information contained in different CWAs needs improvement. We identified 48 barriers and 91 facilitators in 4 major themes (factors related to the CWA, users’ knowledge and attitude towards CWAs, human environment, and organizational environment). We also found 57 positive and 23 negative effects that we classified into processes and outcomes. Conclusions Although we found some experimental and quasi-experimental studies of the effectiveness and safety of CWAs as educational and KT interventions, the vast majority of included studies were observational case studies about CWAs being used by health professionals and patients. More primary research is needed to find ways to address the different barriers to their use and to make these applications more useful for different stakeholders.

WikiBuild: A New Application to Support Patient and Health Care Professional Involvement in the Development of Patient Support Tools

Active patient and public involvement as partners in their own health care and in the development of health services is key to achieving a health care system that is responsive to patients’ needs and values. It promotes better use of the health care system, and improves health outcomes, quality of life and patient satisfaction. By involving patients and health care professionals as partners in the creation and updating of patient health support tools, wikis—highly accessible, interactive vehicles of communication—have the potential to empower users to implement these support tools in daily life. Acknowledging the potential of wikis, and recognizing that they capitalize on the free and open access to information, scientists, opinion leaders and patient advocates have suggested that wikis could help decision-making constituencies improve the delivery of health care. They might also decrease its cost and improve access to knowledge within developing countries. However, little is known about the efficacy of wikis in helping to attain these goals. There is also a need to know more about the intention of patients and health care workers to use wikis, in what circumstances and what factors will influence their use of wikis. In this issue of the Journal of Medical Internet Research, Gupta et al describe how they developed and tested a new wiki-inspired application to improve asthma care. The researchers involved patients with asthma, primary care physicians, pulmonologists and certified asthma educators in the construction of an asthma action plan. Their paper—entitled “WikiBuild: a new online collaboration process for multistakeholder tool development and consensus building”—is the first description of a wiki-inspired technology built to involve patients and health care professionals in the development of a patient support tool. This innovative study has made important contributions toward how wikis could be generalized to involve multiple stakeholders in the development of other knowledge translation tools such as clinical practice guidelines or decision aids. More specifically, Gupta et al have uncovered potential action mechanisms toward increasing usage of these tools by patients and health care professionals. These are decreasing hierarchical influences, increasing usability and adapting a tool to local context. More research is now needed to determine if the use of the resulting wiki-developed plan will actually be higher than a plan developed using other methods. Furthermore, there is also a need to assess the intention of participants to continue using wiki-based processes on an ongoing basis. It is in this dynamic and continuous retroaction loop that the support tool users—both patients and health care professionals—can adapt and improve the product after its real-life shortcomings are revealed and as new evidence becomes available. As such, a wiki would be more than a simple patient support development tool, but could also become a dynamic and interactive repository and delivery tool that would facilitate ongoing and sustainable patient and professional engagement.

Health Care Professionals’ Beliefs About Using Wiki-Based Reminders to Promote Best Practices in Trauma Care

Background Wikis are knowledge translation tools that could help health professionals implement best practices in acute care. Little is known about the factors influencing professionals’ use of wikis. Objectives To identify and compare the beliefs of emergency physicians (EPs) and allied health professionals (AHPs) about using a wiki-based reminder that promotes evidence-based care for traumatic brain injuries. Methods Drawing on the theory of planned behavior, we conducted semistructured interviews to elicit EPs’ and AHPs’ beliefs about using a wiki-based reminder. Previous studies suggested a sample of 25 EPs and 25 AHPs. We purposefully selected participants from three trauma centers in Quebec, Canada, to obtain a representative sample. Using univariate analyses, we assessed whether our participants’ gender, age, and level of experience were similar to those of all eligible individuals. Participants viewed a video showing a clinician using a wiki-based reminder, and we interviewed participants about their behavioral, control, and normative beliefs—that is, what they saw as advantages, disadvantages, barriers, and facilitators to their use of a reminder, and how they felt important referents would perceive their use of a reminder. Two reviewers independently analyzed the content of the interview transcripts. We considered the 75% most frequently mentioned beliefs as salient. We retained some less frequently mentioned beliefs as well. Results Of 66 eligible EPs and 444 eligible AHPs, we invited 55 EPs and 39 AHPs to participate, and 25 EPs and 25 AHPs (15 nurses, 7 respiratory therapists, and 3 pharmacists) accepted. Participating AHPs had more experience than eligible AHPs (mean 14 vs 11 years; P = .04). We noted no other significant differences. Among EPs, the most frequently reported advantage of using a wiki-based reminder was that it refreshes the memory (n = 14); among AHPs, it was that it provides rapid access to protocols (n = 16). Only 2 EPs mentioned a disadvantage (the wiki added stress). The most frequently reported favorable referent was nurses for EPs (n = 16) and EPs for AHPs (n = 19). The most frequently reported unfavorable referents were people resistant to standardized care for EPs (n = 8) and people less comfortable with computers for AHPs (n = 11). The most frequent facilitator for EPs was ease of use (n = 19); for AHPs, it was having a bedside computer (n = 20). EPs’ most frequently reported barrier was irregularly updated wiki-based reminders (n = 18); AHPs’ was undetermined legal responsibility (n = 10). Conclusions We identified EPs’ and AHPs’ salient beliefs about using a wiki-based reminder. We will draw on these beliefs to construct a questionnaire to measure the importance of these determinants to EPs’ and AHPs’ intention to use a wiki-based reminder promoting evidence-based care for traumatic brain injuries.

A descriptive study of access to services in a random sample of Canadian rural emergency departments

Objective To examine 24/7 access to services and consultants in a sample of Canadian rural emergency departments (EDs). Design Cross-sectional study—mixed methods (structured interview, survey and government data bases) with random sampling of hospitals. Setting Canadian rural EDs (rural small town (RST) definition—Statistics Canada). Participants 28% (95/336) of Canadian rural EDs providing 24/7 physician coverage located in hospitals with acute care hospitalisation beds. Main outcome measures General characteristics of the rural EDs, information about 24/7 access to consultants, equipment and services, and the proportion of rural hospitals more than 300 km from levels 1 and 2 trauma centres. Results Of the 336 rural EDs identified, 122 (36%) were randomly selected and contacted. Overall, 95 EDs participated in the study (participation rate, 78%). Hospitals had, on an average, 23 acute care beds, 7 ED stretchers and 13 500 annual ED visits. The proportion of rural hospitals with local access to the following 24/7 services was paediatrician, 5%; obstetrician, 10%; psychiatrist, 11%; internist, 12%; intensive care unit, 17%; CT scanner, 20%; surgeon, 26%; ultrasound, 28%; basic X-ray, 97% and laboratory services, 99%. Forty-four per cent and 54% of the RST EDs were more than 300 km from a level 1 and level 2 trauma centre, respectively. Conclusions This is the first study describing the services available in Canadian rural EDs. Apart from basic laboratory and X-ray services, most rural EDs have limited access to consultants, advanced imaging and critical care services. A detailed study is needed to evaluate the impact of these limited services on patient outcomes, costs and interfacility transport demands.

Invasive and Noninvasive Ventilation in the Emergency Department

This article reviews invasive and noninvasive ventilation for emergency physicians. It presents an overview of respiratory physiology principles that will help emergency physicians adapt their ventilation strategies to any clinical situation. The basic modes of ventilation are summarized. The advantages and limitations of certain novel modes of ventilation are presented. This review highlights a variety of ventilation strategies to be used for patients with normal lung mechanics and gas exchange, acute hypoxemic respiratory failure, decreased lung compliance, airflow obstruction, and weakness or restriction of the chest wall. This article will help clinicians prevent, recognize, and treat complications of mechanical ventilation.

Access to emergency care in rural Canada: should we be concerned?

Approximately 20% of Canadians live in rural areas. Compared to their urban counterparts, rural citizens are in poorer health and are at greater risk for trauma and trauma death. There are great challenges providing and accessing rural emergency care in Canada due to inherent greater distances and limited resources. However, few studies have described the level of resources available in rural emergency departments (EDs) in Canada and the challenge this represents for providing safe patient care. There is minimal information on ED use in Canada, and comparison between provinces is limited by differences in the types of data collected. We present the situation in a rural ED in Nelson, British Columbia, after major service cuts took place. The issue of reasonable access to emergency services is discussed in the context of the Canada Health Act (CHA). We argue that with budgetary constraints and rising costs, service attribution may not be evidence based and outcomes will not be compared to established benchmarks. Considerable variability in access to timely patient care may result; further research is required to determine the impact of service cuts prior to their implementation. In 2001, health care services to BC rural populations were reduced. In the region served by Kootenay Lake Hospital in Nelson, services were centralized in a community 74 km away. The intensive care unit, general surgical service, and inpatient mental health ward were closed, and laboratory and radiography services were reduced. As a result, over 1,500 patients per year required transfer for workups, consultations, or a higher level of care, frequently on an emergency basis. This transfer process resulted in delays in obtaining definitive care. A recent report also suggested that the service cuts coincided with worse outcomes. Using data from the Discharge Abstract Database and the Canadian Institute for Health Information, the Fraser Institute published its British Columbia hospital report card in 2011. For example, residents in Nelson fell from fourth place (4 of 47 municipalities in 2001–2002, prior to health cuts) to last in the province in 2008–2009 with respect to ‘‘failure to rescue,’’ which is considered among the most important health quality indicators and describes mortality from complications that arose while a patient was hospitalized. For many, Canada’s universal health care system is a defining feature of this country. Rural citizens may be tempted to look toward the CHA as a safeguard because one of the central components of the CHA is ‘‘reasonable access’’ to care. The ‘‘intent of accessibility criterion’’ of the CHA is set to ensure that Canadians ‘‘have reasonable access to insured hospital, medical and surgical-dental services on uniform terms and conditions, unprecluded or unimpeded, either directly or indirectly, by charges (user charges or extra-billing) or other means (e.g., discrimination on the basis of age, health status or financial circumstances).’’ Yet reasonable access in terms of physical availability of medical services has been interpreted under the CHA using the ‘‘where and as available’’ rule. Thus, residents of a province or territory are entitled to have access to insured health services at the facility where the services are provided and as the services are available in that setting. Moreover, Canadian emergency medical service systems are not part of the CHA; emergency transportation times and direct costs to patients to where services are available will demonstrate great variation across the country. Hence, the ‘‘where and as available’’ nuance confers significant powers to provinces with respect to service

Clinical outcomes, predictors, and prevalence of anterior pituitary disorders following traumatic brain injury: a systematic review.

Objectives:To assess the clinical outcomes, predictors, and prevalence of anterior pituitary disorders following traumatic brain injury. Data Sources:We searched Medline, Embase, Cochrane Registry, BIOSIS, and Trip Database up to February 2012 and consulted bibliographies of narrative reviews and selected articles. Study Selection:We included cohort, case-control, cross-sectional studies and randomized trials enrolling at least five adults with blunt traumatic brain injury in whom at least one anterior pituitary axis was assessed. We excluded case series and studies in which other neurological conditions were indistinguishable from traumatic brain injury. Data Extraction:Two independent reviewers selected citations, extracted data, and assessed the risk of bias using a standardized form. Data Synthesis:We performed meta-analyses using random effect models and assessed heterogeneity using the I2 index. Results:We included 66 studies (5,386 patients) evaluating prevalence, 14 evaluating clinical outcomes, and 27 evaluating predictors. Thirty studies were at low risk of bias. Anterior pituitary disorders were associated with a trend toward increased ICU mortality (risk ratio, 1.79; 95% CI, 0.99–3.21; four studies) and no difference in Glasgow Outcome Scale score (mean difference, –0.45; 95% CI, –1.10 to 0.20; three studies). Age (mean difference, 3.19; 95% CI, 0.31–6.08; 19 studies), traumatic brain injury severity (risk ratio, 2.15; 95% CI, 1.20–3.86 for patients with severe vs nonsevere traumatic brain injury; seven studies), and skull fractures (risk ratio, 1.73; 95% CI, 1.03–2.91; six studies) predicted anterior pituitary disorders. Over the long term, 31.6% (95% CI, 23.6–40.1%; 27 studies) of patients had at least one anterior pituitary disorder. We observed significant heterogeneity that was not solely explained by the risk of bias or traumatic brain injury severity. Conclusions:Approximately one third of traumatic brain injury patients have persistent anterior pituitary disorder. Older age, traumatic brain injury severity, and skull fractures predict anterior pituitary disorders, which in turn may be associated with higher ICU mortality. Further high-quality studies are warranted to better define the burden of anterior pituitary disorders and to identify high-risk patients.