April 11, 2019

The shiny new toy in stroke treatment is endovascular therapy.  There have now been 12 randomized controlled trials (RCTs) on endovascular stroke therapy (EST), with eight of the last nine showing positive results – stunningly positive.  This flood of positive trials has led to new guidelines from the American Heart Association (AHA) and American Stroke Association (ASA)that extend the treatment window potentially as far out as 24 hours after last known well, and has spawned a movement to completely overhaul how we deliver care for patients with acute ischemic stroke (AIS). With all of the enthusiasm for EST, it is important to review the evolution of this new approach, to review and critique the evidence, and to evaluate what this means in clinical practice.

April 1, 2019

Background: No matter which side of the debate you sit on in regard to systemic thrombolysis in acute ischemic stroke (AIS), there is one truth: systems have undergone major changes to ensure tPA is offered to patients in the ≤4.5-hour window.  The debate surrounding tPA in AIS lies in the equipoise surrounding benefits while there are very real harms.  Advocates of tPA in AIS hang on to two trials that have never been replicated (i.e. NINDS and ECASS-III), and both have major methodological issues. Skeptics of tPA in AIS appropriately argue that there are 11 other randomized clinical trials which have shown almost no benefit, but come at the cost of early increased early mortality and symptomatic intracranial hemorrhage (sICH) (Nice breakdown of individual trials of thrombolysis in stroke can be found at First10EM).  Now there is a push to extend the window of tPA out to 9 hours in AIS with newer imaging modalities such as MRI diffusion-weighted studies in patients with unknown onset of symptoms. The push for this stems from the fact that patients with a visible ischemic lesion on diffusion-weighted imaging, combined with the absence of a clearly visible hyperintense signal in the same region on fluid-attenuated inversion recovery (FLAIR) is predictive of symptom onset within 4.5 hours before imaging.

March 29, 2019

On the last day of the last SMACC conference, Dr. Ken Milne (The SGEM) and I had a cage match debating four critical care controversies. It was all done in good fun with both of us taking our opportunities to poke a little fun at each other. While we took a pro vs con approach to the presentation, our positions are much closer than the debate demonstrates. Although the literature is far from perfect, development of critical appraisal skills and application of evidence-based medicine to the literature is what we should be using to inform our care but not dictate our care. It is equally as important to incorporate clinical judgment and ask our patients what their values and preferences are before making decisions about care.

October 24, 2018

Background: Headache is a common presentation to the emergency department  (ED) accounting for 2% of all visits [1].  Of the patients that present with headache,1 – 3% will be due to a subarachnoid hemorrhage (SAH) [1]. SAH is a true diagnostic dilemma as delays in diagnosis can lead to significant morbidity and mortality. Further complicating matters, almost half of patients will be alert and neurologically intact at first presentation [3].  Non-Contrast Head CT (NCHCT) is very sensitive when performed soon after headache. However, we don’t want to order unnecessary NCHCTs as that increase cost and radiation exposure. Invasive testing such as lumbar puncture, which in itself can be a painful procedure, can also cause headache.  The Ottawa SAH Clinical Decision Rule was designed to help facilitate the identification of SAH in alert, neurologically intact adults presenting to the ED with acute, non-traumatic headache, while minimizing expensive and invasive over testing.  This post will serve as a review of the current literature in the derivation and validation of the Ottawa SAH Clinical Decision Rule.

September 24, 2018

Background: The assessment and management of the acute onset headache from the perspective of the emergency department is a point of contention and discussion commonly faced by emergency providers.  The Ottawa Subarachnoid Hemorrhage Rule is a clinical decision making instrument that was created to help identify patients who need further workup beyond a basic history and physical exam. It does not define the extent of workup required, specifically whether or not a CT versus CT and LP are required to rule out a subarachnoid hemorrhage. In a 2010, Perry et al (1) published results from a prospective cohort study which attempted to formulate a collection of sensitive, high risk characteristics that could identify patients who require workup for subarachnoid hemorrhage. The three separate collections of high-risk features were all found to be highly sensitive (100% sensitivity with 95% CI) and so further investigation was found to be warranted. An additional prospective cohort by Perry et al (2) was designed to further assess the sensitivity, specificity, and overall applicability of these 3 decision making rules to identify patients who require subarachnoid hemorrhage workup. The initial results of this study showed one of the clinical decision making instruments to have a superior sensitivity of 98.5% (95% CI, 94.6%-99.6%). The rule was then redefined to include “thunderclap” headache and limited neck flexion on exam, and then reassessed utilizing a recursive partitioning analysis in order to obtain 100% sensitivity. The Perry et al 2017 (3) study was designed to validate the collection of high-risk characteristics this group has identified as warranting possible workup for subarachnoid hemorrhage.