Cortical layer-specific critical dynamics triggering perception.

Perceptual experiences may arise from neuronal activity patterns in mammalian neocortex. We probed mouse neocortex during visual discrimination using a red-shifted channelrhodopsin (ChRmine, discovered through structure-guided genome mining) alongside multiplexed multiphoton-holography (MultiSLM), achieving control of individually specified neurons spanning large cortical volumes with millisecond precision. Stimulating a critical number of stimulus-orientation-selective neurons drove widespread recruitment of functionally related neurons, a process enhanced by (but not requiring) orientation-discrimination task learning.

Qualitative Analysis of the Lived Experience of First-Time Nurse Responders in Disaster.

The study purpose was to examine the reflections of the lived experiences of nurses in shelters or temporary community medical clinics responding for the first time to a civilian disaster. The disaster-nursing literature echoes the need for development of disaster content in the nursing curriculum. However, little thematic analysis-supporting curriculum from the lived experience of first-time responders exists in the literature.

Compliance with the Canadian Association of Emergency Physicians' asthma clinical practice guidelines at a tertiary care emergency department.

Introduction: Although evidence-based clinical practice guidelines (CPGs) exist, emergency department (ED) asthma management remains highly variable. Our objective was to compare asthma management at a tertiary care ED with that advised by the Canadian Association of Emergency Physicians' (CAEP) asthma CPG and current best practice.

Methods: This medical record study enrolled patients between the ages of 19 and 60 years with a previous diagnosis of asthma who were seen for an acute asthma exacerbation at the Vancouver General Hospital ED in 2008.

A prospective cluster-randomized trial to implement the Canadian CT Head Rule in emergency departments.

Background: The Canadian CT Head Rule was developed to allow physicians to be more selective when ordering computed tomography (CT) imaging for patients with minor head injury. We sought to evaluate the effectiveness of implementing this validated decision rule at multiple emergency departments.

Methods: We conducted a matched-pair cluster-randomized trial that compared the outcomes of 4531 patients with minor head injury during two 12-month periods (before and after) at hospital emergency departments in Canada, six of which were randomly allocated as intervention sites and six as control sites.

Implementation of the Canadian C-Spine Rule: prospective 12 centre cluster randomised trial.

Objective: To evaluate the effectiveness of an active strategy to implement the validated Canadian C-Spine Rule into multiple emergency departments.

Design: Matched pair cluster randomised trial.

Setting: University and community emergency departments in Canada.

Aminophylline in bradyasystolic cardiac arrest: a randomised placebo-controlled trial.

Background: Endogenous adenosine might cause or perpetuate bradyasystole. Our aim was to determine whether aminophylline, an adenosine antagonist, increases the rate of return of spontaneous circulation (ROSC) after out-of-hospital cardiac arrest.

Methods: In a double-blind trial, we randomly assigned 971 patients older than 16 years with asystole or pulseless electrical activity at fewer than 60 beats per minute, and who were unresponsive to initial treatment with epinephrine and atropine, to receive intravenous aminophylline (250 mg, and an additional 250 mg if necessary) (n=486) or placebo (n=485).

A clinical prediction rule for early discharge of patients with chest pain.

Study Objective: Current risk stratification tools do not identify very-low-risk patients who can be safely discharged without prolonged emergency department (ED) observation, expensive rule-out protocols, or provocative testing. We seek to develop a clinical prediction rule applicable within 2 hours of ED arrival that would miss fewer than 2% of acute coronary syndrome patients and allow discharge within 2 to 3 hours for at least 30% of patients without acute coronary syndrome.

Methods: This prospective, cohort study enrolled consenting eligible subjects at least 25 years old at a single site.

Comparison of the Canadian CT Head Rule and the New Orleans Criteria in patients with minor head injury.

Context: Current use of cranial computed tomography (CT) for minor head injury is increasing rapidly, highly variable, and inefficient. The Canadian CT Head Rule (CCHR) and New Orleans Criteria (NOC) are previously developed clinical decision rules to guide CT use for patients with minor head injury and with Glasgow Coma Scale (GCS) scores of 13 to 15 for the CCHR and a score of 15 for the NOC. However, uncertainty about the clinical performance of these rules exists.

Safety and efficiency of emergency department assessment of chest discomfort.

Background: Most Canadian emergency departments use an unstructured, individualized approach to patients with chest pain, without data to support the safety and efficiency of this practice. We sought to determine the proportions of patients with chest discomfort in emergency departments who either had acute coronary syndrome (ACS) and were inappropriately discharged from the emergency department or did not have ACS and were held for investigation.

Methods: Consecutive consenting patients aged 25 years or older presenting with chest discomfort to 2 urban tertiary care emergency departments between June 2000 and April 2001 were prospectively enrolled unless they had a terminal illness, an obvious traumatic cause, a radiographically identifiable cause, severe communication problems or no fixed address in British Columbia or they would not be available for follow-up by telephone.

Retrospective application of the NEXUS low-risk criteria for cervical spine radiography in Canadian emergency departments.

Study Objective: We evaluate the accuracy, reliability, and potential impact of the National Emergency X-Radiography Utilization Study (NEXUS) low-risk criteria for cervical spine radiography, when applied in Canadian emergency departments (EDs).

Methods: The Canadian C-Spine Rule derivation study was a prospective cohort study conducted in 10 Canadian EDs that recruited alert and stable adult trauma patients. Physicians completed a 20-item data form for each patient and performed interobserver assessments when feasible.

The Canadian C-spine rule versus the NEXUS low-risk criteria in patients with trauma.

Background: The Canadian C-Spine (cervical-spine) Rule (CCR) and the National Emergency X-Radiography Utilization Study (NEXUS) Low-Risk Criteria (NLC) are decision rules to guide the use of cervical-spine radiography in patients with trauma. It is unclear how the two decision rules compare in terms of clinical performance.

Methods: We conducted a prospective cohort study in nine Canadian emergency departments comparing the CCR and NLC as applied to alert patients with trauma who were in stable condition.

The Canadian C-spine rule performs better than unstructured physician judgment.

Study Objectives: We compare the predictive accuracy of emergency physicians' unstructured clinical judgment to the Canadian C-Spine rule.

Methods: This prospective multicenter cohort study was conducted at 10 Canadian urban academic emergency departments. Included in the study were alert, stable, adult patients with a Glasgow Coma Scale score of 15 and trauma to the head or neck.

Tissue plasminogen activator in cardiac arrest with pulseless electrical activity.

Background: Coronary thrombosis and pulmonary thromboembolism are common causes of cardiac arrest. We assessed whether the administration of tissue plasminogen activator (t-PA) during cardiopulmonary resuscitation would benefit patients with cardiac arrest and pulseless electrical activity of unknown or presumed cardiovascular cause.

Methods: Patients who were older than 16 years of age and who had more than one minute of pulseless electrical activity that was unresponsive to initial therapy outside the hospital or in the emergency department were eligible.