This is a special edition EM Cases main episode podcast. In April 2022, I was honoured to be the guest professor for Calgary EM at their annual Hodsman Lecture day.The day was essentially a series of live podcasts highlighting some of the amazing work they do, capped off by a lecture on compassionate care dedicated to the memory of Dr. Barbara Tatham. We covered a wide range of topics: The challenges of posterior strokes with Dr. Katie Lin; improving your ED flow by having an Emergency Physician Lead on shift with Dr. Eddy Lang and Dr. Michael Betzner; when not to order a troponin and the HEAR score (this is not a typo; this is not HEART Score) with Dr. Andrew McRae; ketamine for suicidal ideation with Dr. Marshall Ross; EM Peer Support Workers for patients with substance use disorder with Dr. Stephanie VandenBerg, plus a closely related bonus cast on SREMI’s incredible ED Pathway to Peers program for youth with mental health issues with Dr. Bjug Borgundvaag and Christine Bradshaw…
Podcast production, sound design & editing by Anton Helman
Written Summary and blog post by Anton Helman, Katie Lin and Marshall Ross July 2022
Cite this podcast as: Helman, A. Lang, E. Betzner, M. McRae, A. Lin, K. VandenBerg, S. Ross, M. Borgundvaag, B. Bradshaw, C. Posterior Stroke, EP Lead, HEAR Score, Ketamine for Suicidal Ideation, Peer Support Workers- Highlights from Calgary EM Hodsman Lecture Day. Emergency Medicine Cases. July, 2022. https://emergencymedicinecases.com/posterior-stroke-ep-lead-hear-score-ketamine-for-suicidal-ideation-peer-support-highlights-from-calgary-em-hodsman-lecture-day. Accessed December 7, 2023
The challenges of posterior circulation stroke (PCIS)
Essential anatomy and corresponding deficits
Posterior circulation ischemic stroke (PCIS)/TIA involves the vertebrobasilar artery system (vertebral arteries arising from the subclavian arteries, three paired cerebellar arteries – AICA/PICA/SCA, the basilar artery, and the posterior cerebral arteries). Collectively, the posterior circulation supplies blood to the brainstem, cerebellum, occipital lobes, and thalami.
Crossed face vs body symptoms (one side of face and opposite site of body – motor/sensory/ataxia domains)
Walk test patients to assess for truncal ataxia/dysequilibrium; often in stroke, the vertigo will be milder compared to peripheral causes but the disequilibrium and ataxia may be more severe
Pearl: The vertigo in patients with a central cause tends to be less severe than that in peripheral causes of vertigo, while the ataxia in patients with a central cause of vertigo tends to be more severe than in patients with a peripheral cause.
Pitfall: While PCIS with isolated vertigo has been reported in the literature as a rare entity, it is incumbent upon the ED physician to perform a thorough history and physical looking for the “plus 1” features of PCIS. It may be that reported “isolated vertigo” is simply a reflection of poor history and physical exam assessments that have missed “plus 1” features, rather than truly isolated vertigo.
Locked in Syndrome – a unique presentation of posterior circulation ischemic stroke
Think about basilar stroke in patients who present with sudden collapse and persistent loss of consciousness with no clear alternative cause (ie. no signs of: significant head trauma, seizure, cardiac condition) – or “Locked in Syndrome“. Remember too that acute severe intracranial insult can be associated with hemodynamic instability and/or arrhythmias due to an overwhelming catecholamine surge. A key clinical clue to Locked in Syndrome from a basilar stroke is that the extra-ocular movements (EOMs) are spared, so be sure to open the patient’s eyelids and ask them to move their eyes; if they are able to move their eyes on command but lack all other motor function, consider Locked in Syndrome.
Pearl: A key clinical clue to Locked in Syndrome from a basilar stroke is that the EOMs are spared, so be sure to open the patient’s eyelids and ask them to move their eyes; if they are able to move their eyes but lack all other motor function, consider Locked in Syndrome.
Which ED assessment components are most helpful for stroke decision-making in patients with posterior circulation ischemic strokes?
Ensure the patient is stable enough to go for imaging. PCIS patients are at higher risk for nausea/vomiting (ie. soiled airway) and decreased LOC (may need airway protection).
Remember PCIS-screening elements as part of your rapid neuro exam: facial droop, visual field deficit, eye movement abnormal/nystagmus, dysarthria (and other “Dangerous D’s”), gross motor/sensory screen, balance and limb ataxia (cerebellar symptoms)
Check for potential contraindications to thrombolysis: Last seen normal time, acute trauma/bleeding, anticoagulant/antiplatelet medications, significant PMHx (ie. cancer, recent surgery)
Additional helpful data points: Goals of care and baseline functional status (ie. would this reasonably benefit from treatment?)
Suggested criteria are for calling a code stroke for the patient that you suspect has just suffered a posterior stroke
*Note that these criteria are location-specific and may be different than your local criteria.
Disabling deficits presenting <6h since time of onset if during waking hours OR
<24h of last seen normal if new symptoms upon awakening from sleep (ie. “wake-up” stroke).
Evidence suggests most “wake-up” cases occur within 1-2h of patient awakening, likely due to diurnal cortisol and BP spike as your body prepares to wake up, so true “wake-up” patients may often be within a tissue treatment window.
Acute posterior ischemic stroke treatment
The literature on endovascular therapy (EVT) for posterior circulation ischemic stroke
The Basilar Artery Occlusion Endovascular Intervention Versus Standard Medical Treatment (BEST) was a multicenter randomized open-label trial with a blinded outcome assessment in patients presenting within 8 hours of VBAO at 28 centers in China between 2015 and 2017. The primary outcome was a modified Rankin Scale (mRS) score of ≤3 at 90 days, assessed on an intention-to-treat basis. The primary safety outcome was mortality at 90 days. While a sample size of 344 was originally calculated, only 131 (66 endovascular and 65 medical) patients were enrolled due to excessive crossovers and a progressive drop in per center recruitment. In the control group, 22% of the patients ended up receiving EVT, while 5% of the intervention group ended up receiving medical therapy only. The primary outcome was achieved in 42% of the patients in the EVT group and 32% in the medical care group, failing to reach statistical significance (adjusted odds ratio [aOR], 1.74; 95% confidence interval [CI], 0.81 to 3.74). The rates of symptomatic intracranial hemorrhage (sICH) and mortality did not differ between the groups.
The Basilar Artery International Cooperation Study (BASICS) trial was a multinational, multicenter RCT of 300 patients presenting within 6 hours of BAO stroke. Inclusion criteria were expanded mid-study to include patients aged >85 years, NIHSS score <10, and those with contraindications for intravenous thrombolysis. The primary outcome of a mRS score at 90 days was 44.2% vs 37.7%, not a significant difference. ICH and mortality rates were similar between groups.
Two further RCTs that applied specific patient selection criteria including baseline neurological severity and infarct volumes estimated by PC-ASPECTS and the pons midbrain index, have preliminary results (presented at the European Stroke Organization Conference as late-breaking research shortly following recording of this podcast segment):
Basilar Artery Occlusion Chinese Endovascular (BAOCHE) trial enrolled VBAO patients who presented between 6 and 24 hours after onset of stroke symptoms. An interim analysis of 212 of the originally planned 318 patients, showed improved rates of favourable functional outcomes at 90 days (modified Rankin Scale score) of 46.4% vs. 24.3%.
Endovascular Treatment for Acute Basilar Artery Occlusion (ATTENTION) is a prospective, open, blinded-endpoint RCT that has enrolled 342 BAO patients who presented within 12 hours of onset in 36 Chinese stroke centers. Successful reperfusion rates were as high as 93%, and favourable outcomes were 46% vs 22.8%.
Overall, the results of these studies are mixed and seem to depend heavily on several patient and neuroimaging variables. It appears that neurological severity, infarct volume, collateral circulation, and the time from onset-to-EVT are prognostic variables that future studies should address.
IV Thrombolysis (IVT) (tPA, possibly TNK currently being studied): <4.5h treatment time window as per guidelines. IV thrombolysis outside of that window is sometimes considered on a case-by-case basis depending on favourable neuroimaging and patient factors.
PCIS patients were included in existing RCT studies of IVT, but account for only 5% of patients in those studies
Systematic review and meta-analysis data suggests that IVT for PCIS as compared to ACIS has:
Better functional outcome with thrombolysis (OR 1.3-1.5)
Less frequent sICH (OR 0.32)
Likely due to smaller lesion sizes and more robust collateral blood flow in the posterior circulation
Bottom line for IV thrombolysis for posterior circulation ischemic stroke
IVT within 4.5h and in select “wake-up” stroke cases may improve functional outcomes based on preliminary data, and appears to be associated with slightly better outcomes and safety profile compared to anterior circulation ischemic stroke. This would be weighed carefully against risks, and generally would only be considered for disabling deficit cases with favourable imaging features (favourable imaging also carries a lower risk of hemorrhage after tPA).
Dornak T, Kral M, Sanak D, and Kanovsky P. Intravenous thrombolysis in posterior circulation stroke. 2019. Front in Neurol. 10:417.
Lee S, Han J, Jung I, Jung J. Do thrombolysis outcomes differ between anterior circulation stroke and posterior circulation stroke? A systematic review and meta-analysis. Int J of Stroke. 2020;15(8):849-57.
Hoyer C and Szabo K. Pitfalls in the Diagnosis of Posterior Circulation Stroke in the ED Setting. 2021. Front in Neuro. 12: open access article 82827.
Caplan LR, Wityk RJ, et al. New England Medical Center Posterior Circulation Registry. Ann Neurol. 2004;56:389-98.
Forster, A., Gass, A., Kern, R., Griebe, M., Hennerici, M. G., & Szabo, K. (2011). Thrombolysis in posterior circulation stroke: stroke subtypes and patterns, complications and outcome. Cerebrovasc Dis, 32(4), 349-353.
Kerber, K. A., Brown, D. L., Lisabeth, L. D., Smith, M. A., & Morgenstern, L. B. (2006). Stroke among patients with dizziness, vertigo, and imbalance in the emergency department: a population-based study. Stroke, 37(10), 2484-2487.
Kim, J. T., Park, M. S., Choi, K. H., Kim, B. J., Han, M. K., Park, T. H., . . . Cho, K. H. (2017). Clinical Outcomes of Posterior Versus Anterior Circulation Infarction With Low National Institutes of Health Stroke Scale Scores. Stroke, 48(1), 55-62.
Tei H, Uchiyama S, Usui T, and Ohara K. Posterior circulation ASPECTS on diffusion-weighted MRI can be a powerful marker for predicting functional outcome. J Neurol. 2010; 257(5):767-73.
Puetz V, Sylaja P, Coutts S, et al. Extent of hypoattenuation on CT angiography source images predicts functional outcome in aptients with basilar artery occlusion. Stroke. 2008; 39(9):2485-90.
Weber, R., Minnerup, J., Nordmeyer, H., Eyding, J., Krogias, C., Hadisurya, J., . . . investigators, R. (2019). Thrombectomy in posterior circulation stroke: differences in procedures and outcome compared to anterior circulation stroke in the prospective multicentre REVASK registry. Eur J Neurol, 26(2), 299-305.
Lee S, Han J, Jung I, Jung J. Do thrombolysis outcomes differ between anterior circulation stroke and posterior circulation stroke? A systematic review and meta-analysis. Int J of Stroke. 2020;15(8):849-57.
Liu X, Dai Q, Ye R, Zi W, Liu Y, Wang H, et al. Endovascular treatment versus standard medical treatment for vertebrobasilar artery occlusion (BEST): an open-label, randomised controlled trial. Lancet Neurol. 2020;19:115–122.
Langezaal L, van der Hoeven E, Mont’Alverne F, de Carvalho J, Lima FO, Dippel D, et al. Endovascular therapy for stroke due to basilar-artery occlusion. N Engl J Med. 2021;384:1910–1920.
Tao C, Li R, Zhu Y, Qun S, Xu P, Wang L, et al. Endovascular treatment for acute basilar artery occlusion: a multicenter randomized controlled trial (ATTENTION) Int J Stroke. 2022 Feb 22.
ATTENTION investigators Endovascular treatment for acute basilar artery occlusion. Oral presentation at European Stroke Organisation Conference; 2022 May 4-6; Lyon, FR.
Emergency Physician Lead to improve ED overcrowding, access block and job satisfaction?
An EP Lead is a unique EM physician who’s role is to coordinate and lead clinical activities along with the charge nurse on shift in a flexible manner, with the goals of helping the other EM physicians be more efficient, reduce cognitive interruptions, improve job satisfaction and ultimately improve ED overcrowding and access block. Duties may include:
Trouble-shooting bottlenecks in flow
The main touchpoint for triage nurses and charge nurse
Adjudicating conflicts between admitting services
Communicating with admitting services to advocate for admitted patients to be transferred to the floor
Ordering directed tests and treatment for patients who are with EMS waiting to be placed in an ED stretcher, rather than only protocolled orders (which may reduce testing, testing costs, overdiagnosis, false positives etc)
Discharging patients who clearly do not require emergency care rather than them waiting hours to be seen via the usual process
Triage ECG review, protocol-driven lab test review
Taking phone calls from EMS, physicians referring patients into the ED, repatriation patients etc
While time-to-be-seen by a physician decreases with a dedicated triage physician, the data on ED length of stay, return ED visits and left without being seen rates are variable across studies.
In Calgary, their EP lead study in one hospital showed that EMS stays in the ED was reduced by an average of 20 minutes, and surveys of nurses and EM physicians suggested that the EP role improved their job satisfaction.
Rowe BH, Guo X, Villa-Roel C, Schull M, Holroyd B, Bullard M, Vandermeer B, Ospina M, Innes G. The role of triage liaison physicians on mitigating overcrowding in emergency departments: a systematic review. Acad Emerg Med. 2011 Feb;18(2):111-20.
Crowder, K., Domm, E., Lipp, R., Robinson, O., Vatanpour, S., Wang, D., & Lang, E. (2020). P117: A multicenter analysis of an emergency physician lead on department flow and the provider experience. CJEM, 22(S1), S107-S107.
Hosking I, Boyle A, Ahmed V, et al. What do emergency physicians in charge do? A qualitative observational study. Emergency Medicine Journal 2018;35:186-188.
When not to order a troponin – The HEAR Score
The problem: indiscriminately ordering troponin testing (especially high sensitivity troponins) in the ED on all adult patients with any symptom between the neck and waist is likely to result in false positives, more downstream testing (such as coronary angiograms which may be harmful), increased patient anxiety, prolonged length of ED stay contributing to overcrowding, more referrals and increased costs. High sensitivity troponin comes at the cost of poor specificity.
History, ECG, Age, Risk factor (HEAR Score) is a validated risk score that is the HEART score without the troponin. It is meant to help physicians evaluate the pretest probability of ACS and decide (in conjunction with shared decision making) which low risk patients may not require a troponin.
Source: modified from https://www.mdcalc.com/
A score <2 has a sensitivity of 98-98.5% for index visit and 30-day Major Cardiac Events (MACE), and in carefully selected patients may reduce the need for troponin testing and downstream cardiac testing.
In Canada, a study of the HEAR score in ED patients classified 20% of patients as low risk and not requiring troponin testing, with a sensitivity of 98.5% for ruling out MACE at index visit and at 30 days.
Is clinical gestalt + ECG as good as HEAR score?
Sensitivity of low-risk clinical gestalt combined with a non-ischemic ECG was about 95% sensitive for ruling out MI in a UK study.
Is there any incremental value of adding a troponin when HEAR score is <2?
Some of the studies validating the HEAR score investigated the incremental value of doing serial conventional troponins, and found that there was no incremental improvement in sensitivity for patients with a HEAR score <2 by adding troponin testing. The sensitivity for the 1 and 2-hour high sensitivity troponin algorithms also carry a 96-98% sensitivity, similar to the HEAR score.
Participating in active shared decision making with low risk patients when considering the HEAR score is important, so that both you and the patient are comfortable with the risks and benefits of not ordering a troponin.
O’Rielly CM, Andruchow JE, McRae AD. External validation of a low HEAR score to identify emergency department chest pain patients at very low risk of major adverse cardiac events without troponin testing. CJEM. 2022 Jan;24(1):68-74. doi: 10.1007/s43678-021-00159-y. Epub 2021 Jul 17.
Body R, Cook G, Burrows G, Carley S, Lewis PS. Can emergency physicians ‘rule in’ and ‘rule out’ acute myocardial infarction with clinical judgement? Emerg Med J. 2014 Nov;31(11):872-6.
Oliver G, Reynard C, Morris N, Body R. Can Emergency Physician Gestalt “Rule In” or “Rule Out” Acute Coronary Syndrome: Validation in a Multicenter Prospective Diagnostic Cohort Study. Acad Emerg Med. 2020 Jan;27(1):24-30.
Smith LM et al. Identification of very low-risk acute chest pain patients without troponin testing. Emerg Med J 2020.
Mahler SA et al. The HEART Pathway Randomized Trial: Identifying Emergency Department Patients with Acute Chest Pain for Early Discharge. Circ Cardiovasc Qual Outcomes 2015.
Otsuka Y, Takeda S. Validation study of the modified HEART and HEAR scores in patients with chest pain who visit the emergency department. Acute Med Surg. 2020 Nov 7;7(1):e591.
Ketamine to relieve suicidal ideation and reduce acute risk
Biological plausibility of ketamine for suicidal ideation
Ketamine is an NMDA receptor antagonist. Little is understood about its biological plausibility for its effects on depression and suicidality. The most compelling theories revolve around the concept of neuroplasticity that appear to occur hours to days after dosing, rather than its immediate neurotransmitter effects. Animal studies suggest that pre-frontal cortex dendritic atrophy that occurs with chronic stress is partially reversed by ketamine, whose effects last for about one week.
Ketamine for depression
The interest in ketamine for depression started when a number of war veterans receiving ketamine for surgery seemed to recover from surgery with less pain and less depression. A recent systematic review of >2900 patients in 36 trials that looked at ketamine and esketamine for depression concluded that ketamine was safe and effective for treating depression. The Canadian Network for Mood and Anxiety Treatments (CANMAT) Task Force Recommendations endorsed ketamine for treatment resistant depression as a level 1 recommendation. The antidepressant effects of ketamine are thought to start around 2 hours and last about 7 days. In patients who have resolution of suicidality after ketamine, 89% of them remain free of suicidal ideation at 7 days.
Psychiatry literature on ketamine for suicidal ideation
The most compelling evidence for treating suicidality with ketamine is from the psychiatry literature. A 2021 systematic review identified 15 studies including 9 RCT looking at esketamine and ketamine for suicidal ideation in both inpatient and outpatient psychiatry settings. The most common dose of ketamine was 0.5mg/kg IV infusion over 40min. They concluded that IV ketamine showed a rapid decrease in suicidal ideation but that the effects were short lived.
Emergency Medicine literature on ketamine for suicidal ideation
There is a paucity of EM literature for ketamine and suicidal ideation. There are only 3 prospective trials with large confidence intervals and suboptimal trial design enrolling and treating a total of 77 patients. The largest study by Kashani excluded patients with substance use disorder, and all of these trials used only 0.2mg/kg IV, a significantly lower dose than the one that has been established in the psychiatric literature of 0.5mg/kg IV over 40 minus. Keeping these caveats in mind, these studies did show significant improvements in suicidal ideation as measured by standardized psychometrics. Data from the smaller trial showed significant improvements compared to the control group at 90 min but that difference became non-significant at 230min. It appears that patients receiving ketamine improved faster, but over time they eventually caught up as their suicidal ideation resolved on its own.
Is there potential for ketamine to relieve suffering from suicidal ideation, decrease admission rates and bridge patients to ongoing care?
Currently, the EM literature points to a trend in acutely reducing suicidal ideation in patients without substance use disorder based on tiny poorly designed studies. Based on some of the psychiatry literature suggesting ketamine’s anti-suicidal ideation effects up to 7 days, it is plausible that carefully selected patients with suicidal ideation who receive ketamine in the ED may not require admission if they are ensured followup within 7 days. Larger, well designed ED RCTs are required before we consider incorporating ketamine for suicidal ideation into our practices.
P A Zunszain. Ketamine: synaptogenesis, immunomodulation and glycogen synthase kinase-3 as underlying mechanisms of its antidepressant properties. Molecular Psychiatry volume 18, pages1236–1241 (2013).
Anees Bahji, Carlos A. Zarate & Gustavo H. Vazquez (2022) Efficacy and safety of racemic ketamine and esketamine for depression: a systematic review and meta-analysis, Expert Opinion on Drug Safety.
Swainson J, et al. The Canadian Network for Mood and Anxiety Treatments (CANMAT) Task Force Recommendations for the Use of Racemic Ketamine in Adults with Major Depressive Disorder:. Can J Psychiatry. 2021 Feb;66(2):113-125.
Kashani P, Yousefian S, Amini A, Heidari K, Younesian S, Hatamabadi HR. The effect of intravenous ketamine in suicidal ideation of emergency department patients. Emerg (Tehran). 2014;2(1):36–9.
Burger J, Capobianco M, Lovern R, et al. A double-blinded, randomized, placebo- controlled sub-dissociative dose ketamine pilot study in the treatment of acute de- pression and Suicidality in a military emergency department setting. Mil Med. 2016; 181(10):1195–9.
Domany Y, Shelton RC, McCullumsmith CB. Ketamine for acute suicidal ideation. An emergency department intervention: a randomized, double-blind, placebo- controlled, proof-of-concept trial. Depress Anxiety. 2020;37(3):224–33.
Peer support workers for ED patients with mental health issues and substance use disorder
Peer support programs engage trained people with lived experience of mental health and/or substance use issues in supporting patients who present to the ED with similar issues. Their role may include helping connect patients with resources in the community, frequent check-in phone calls after discharge, helping to relieve the anxiety of the current crisis that brought them to the ED and being a soundboard to help the patient feel that they have been heard during their ED visit.
ED peer support programs in North America have been shown to improve both system level and patient-centered outcomes:
Decreased substance use
Decreased self-reported anxiety and depression
Decrease ED visits and hospitalizations
Increased housing stability
Decrease interactions with the criminal justice system
Increases likelihood of attending followup addiction clinic or community service appointments
Improves the wellbeing of the peer support workers
For advice on how to develop and implement a peer support worker program in your ED please email Dr. Borgundvaag and Christine Bradshaw at Bjug.Borgundvaag@sinaihealth.ca and Christine.Bradshaw@sinaihealth.ca
McGuire AB, Powell KG, Treitler PC, Wagner KD, Smith KP, Cooperman N, Robinson L, Carter J, Ray B, Watson DP. Emergency department-based peer support for opioid use disorder: Emergent functions and forms. J Subst Abuse Treat. 2020 Jan;108:82-87.
Ashford, R. D., Meeks, M., Curtis, B., & Brown, A. M. (2018, November 29). Utilization of PeerBased Substance Use Disorder and Recovery Interventions in Rural Emergency Departments: Patient Characteristics and Exploratory Analysis. Journal of Rural Mental Health. Advance online publication.
Kaur M, Melville RH Jr. Emergency Department Peer Support Specialist Program. Psychiatr Serv. 2021 Feb 1;72(2):230.
Glowacki, K., Whyte, M., Weinstein, J. et al. Exploring how to enhance care and pathways between the emergency department and integrated youth services for young people with mental health and substance use concerns. BMC Health Serv Res 22, 615 (2022).
Crisanti, A.S.; Earheart, J.; Deissinger, M.; Lowerre, K.; Salvador, J.G. Implementation Challenges and Recommendations for Employing Peer Support Workers in Emergency Departments to Support Patients Presenting after an Opioid-Related Overdose. Int. J. Environ. Res. Public Health 2022, 19, 5276.
Chinman M, George P, Dougherty RH, Daniels AS, Ghose SS, Swift A, Delphin-Rittmon ME. Peer support services for individuals with serious mental illnesses: assessing the evidence. Psychiatr Serv. 2014 Apr 1;65(4):429-41.
Sledge WH, Lawless M, Sells D, Wieland M, O’Connell MJ, Davidson L. Effectiveness of peer support in reducing readmissions of persons with multiple psychiatric hospitalizations. Psychiatr Serv. 2011 May;62(5):541-4.
Drs. Lin, Betzner, Lang, McRae and VandenBerg and Christine Bradshaw have no conflicts of interest to declare. Dr. Marshall works in a private clinic for patients with mental health issues and substance use disorder where they prescribe ketamine. Drs. Helman and Borgundvaag are supported by SREMI, the non-profit research and education institute that also supports the Pathway to Peers Program.
Dr. Anton Helman is an Emergency Physician at North York General in Toronto. He is an Assistant Professor at the University of Toronto, Division of Emergency Medicine and the Education Innovation Lead at the Schwartz-Reisman Emergency Medicine Instititute. He is the founder, editor-in-chief and host of Emergency Medicine Cases.