Rural Stroke Care for Thank you for joining us! Prehospital - PDF document

Welcome Rural Stroke Care for � Thank you for joining us! Prehospital Providers � Format Chris Hogness, MD � Introductions Telehealth Training March 17 th , 2010 Northwest Regional Stroke Network What we will talk about today CASE � Evidence behind current stroke therapies � Previously healthy 48 yo man � Focus on intravenous thrombolysis � History of migraine HA, last episode 1 yr � Role of EMS in stroke systems of care: ago � Possible episodic hypertension remotely, � Activation of 911 normal blood pressure in recent visit to � Identification of stroke pt in the field PCP � Appropriate pre-hospital care � Low grade hemoglobin A1C elevation: 6.2 � Transport � Normal LDL cholesterol: 100 � System planning for improved care � No family history of vascular disease

CASE, continued CASE, continued � Experienced episode of weakness, fell at � Taken to local t-PA capable, critical home access hospital � Went back to bed � Head CT done: no acute change � Phone consultation with neurologist 2 hrs away � Awoke 1 hour later with speech difficulty � Time since last normal 4 ½ hrs and left hemiparesis � Recommendation for no TPA, not given � EMS activated: � Transferred to larger hospital � Delay in reaching rural location, paramedics chain up to get to his home Stroke kills and disables many CASE, continued � Further evaluation: � Most common cause of disability in the world � MRA brain: Acute stroke involving posterior division of R MCA � 1 person disabled every 45 seconds in US � MRA neck: Complete occlusion proximal R internal � Third leading cause of death in US carotid � F/U CT brain 4 days after event: Interval extension � 700,000 strokes/year in US of large R MCA infarct with surrounding edema � Washington state: � Specials: � 26,612 hosp and 3,167 (6.9%) deaths (2005) � TEE with bubble: no PFO � Hypercoagulable w/u negative

Pathophysiology of stroke Brain cells die quickly in stroke Angiographic and autopsy studies reveal � 1.9 million neurons lost per minute approximately 80% of strokes caused by � Initial ischemic penumbra, area of decreased occlusive arterial thrombus perfusion with neurologic dysfunction which may not be permanent if flow restored � Time window for clinical benefit of opening artery challengingly brief Recanalization (restoring flow) Opening the occluded artery rates by intervention � Intravenous thrombolytic � Spontaneous: 24.1% � Intra-arterial thrombolytic � Intravenous thrombolysis: 46.2% � Mechanical � Intra-arterial thrombolysis: 63.2% � Combined IV and IA thrombolysis: 67.5% � Mechanical: 83.6% � Rha et al: The impact of recanalization in ischemic stroke outcome: a meta-analysis. Stroke 2007: 38:967

Recanalization update, Recanalization (restoring flow) continued rates by intervention, update � 1,122 severe stroke patients at 13 academic centers between 2005 and 2009 � Treated with one or more of: � intra-arterial tPA � intracranial stenting � IV delivery of tPA in the arm � Merci Retriever for clot removal � Prenumbra aspiration catheter for clot removal � glycoprotein IIb/IIIa antagonists � angioplasty without stenting Most patient outcome data from Intravenous thrombolysis intravenous thrombolysis � Intra-arterial, mechanical not randomized � Multiple randomized controlled trials with iv thrombolysis: demonstrate reduced stroke disability � No RCT data comparing disability, death � Consensus guidelines recommend: � Improved flow may not correlate with improved outcome � American Heart Association depending on technique used (eg distal embolization) � American College of Chest Physicians � Exact niche for each modality not � Regulatory agencies approve: determined � FDA 1996 � Intra-arterial lower tPA volume, role in pts at increased risk of bleeding � Canada 1999 � Intra-arterial may be more effective for more proximal � European Union 2002 occlusions

Stroke disability scores used in National Institute of Neurologic Disorders and Stroke (NINDS): NEJM 1995 NINDS trial and others � Modified Rankin scale: functional score • 624 pts with acute ischemic stroke, treated within 3 hrs of symptoms onset � 0 = no symptoms; 5 = severe disability � Barthel index: activities of daily living • Randomized to TPA vs placebo � 0-100; 100 = complete independence • Complete/near complete recovery at 90 days: � Glasgow outcome scale: function •31-50% TPA vs 20-35% placebo � 1 = good recovery; 5 = death � NIH Stroke Scale (NIHSS) •Mortality not significantly different � 42 point scale measure of neurologic deficit •17% TPA vs 21% placebo •10 fold increase in brain hemorrhage •6.4% TPA vs 0.5% placebo NINDS favorable disability Pooled analysis of 6 tPA trials outcomes � 2775 patients � Modified Rankin scale of 0-1: � NINDS parts 1&2 (3 hr window) � 39% tPA vs 26 % placebo � ECASS I and II (6 hr window) � Barthel index of 95-100: � ATLANTIS A (6 hr window) and B (5 hr) � 50% tPA vs 38% placebo � Findings: � Glasgow Outcome Scale of 1: � Benefit dependent on time from onset of symptoms to treatment � 44% tPA vs 32% placebo � Hemorrhage 5.9% tPA vs 1.1% placebo � NIHSS 0-1: � Lancet 2004: 363:768-774 � 31% tPA vs 20% placebo

Pooled tPA data: benefit vs time Favorable outcome at 3 months by time of treatment: pooled data IV rtPA vs Placebo Time (min) Odds Ratio 95% CI 3 hours 0 − 90 2.8 1.8 − 4.5 91 − 180 1.5 1.1 − 2.1 181 − 270 1.1 − 1.9 1.4 271 − 360 0.9 − 1.5 1.2 Pooled analysis of ATLANTIS, ECASS, and NINDS rt-PA stroke trials. Lancet . 2004;363:768 3 TO 4 ½ HOURS: IV thrombolysis is underutilized ECASS III: NEJM 2008 � 821 pts 18 to 80 yrs old with acute ischemic stroke for � Currently, estimated 4% of patients with whom treatment could be administered 3 to 4 ½ hrs from ischemic stroke receive thrombolysis with stroke onset, randomized to tPA vs placebo rt-PA � 52% no disability with tPA vs 45% placebo � Very short time window � No mortality difference (7.7% tPA vs 8.4%) � Symptomatic hemorrhage 7.9% tPA vs 3.5% � Patients arrive late � Hospitals may be slow to respond � NEJM 2008;359:1317-29

How long does it take pts to get to How long does it take to begin the hospital? rtPA after pt arrives at hospital? � 106,924 pts treated over 4 year period at • 905 “Get-With-the-Guidelines” hospitals for whom time of onset of stroke available � 28.3% arrived within 60 minutes � 31.7% 1-3 hours � 40.1% > 3 hours � Jeff Saver, Feb 18, 2009, ASA International Stroke Conference Why do patients delay seeking Goal treatment timeline for door- care for acute ischemic stroke? to-needle � Evaluation by physician: 10 min � Painless � Stroke expertise contacted:15 min � Unlike myocardial infarction � Cognition may be impaired by the event � Head CT or MRI performed: 25 min � Not calling 911 � Interpretation of CT/MRI: 45 min � 1 st call to physician associated with delay � Start of treatment: 60 min � 911 dispatch may fail to recognize sx or not understand pt due to stroke

AHA recommended goals for EMS response time in stroke � Dispatch time < 1 minute True/False: EMS response times � Turnout time < 1 minute to suspected stroke should be � Travel time equivalent to trauma or MI equal to response times for calls suspected MI Minimize on-scene time � Least is best What is the maximum on scene � No more than 10 minutes in assessment time recommended for EMS � Some parts may be done in transit personnel prior to transport of the � Goal <15 minutes total on-scene time patient with stroke?

EMS stroke assessment tools True / False: EMS personnel � Cincinnati Prehospital Stroke Scale � Los Angeles Prehospital Stroke Screen should use a validated screening � F.A.S.T. tool in assessing pts for stroke F.A.S.T. � Face Name several conditions that can � Arm mimic stroke � Speech � Time last normal � If one component abnormal, 72% probability CVA

Conditions mimicking stroke: Over-triage � Hypoglycemia � Err on the side of over-identification rather than under-identification � Seizure with post-ictal period � AHA: “Initially, EMSS should establish a � Complex migraine goal of over-triage of 30% for the � Conversion disorder prehospital assessment of acute stroke” � Drug ingestion � Lessons from trauma: if over-triage is not present, under-triage will result What routine pieces of history should be obtained? � TIME LAST NORMAL What piece of history is often not � Hx diabetes? Use of insulin? included in prehospital � Hypertension? Medications used? assessments? � Hx seizure disorder?