Rural Stroke Care for Prehospital Providers

1. Rural Stroke Care for Prehospital Providers Chris Hogness, MD Telehealth Training March 17th, 2010 Northwest Regional Stroke Network

2. Welcome Thank you for joining us! Format Introductions

3. What we will talk about today • Evidence behind current stroke therapies • Focus on intravenous thrombolysis • Role of EMS in stroke systems of care: • Activation of 911 • Identification of stroke pt in the field • Appropriate pre-hospital care • Transport • System planning for improved care

4. CASE • Previously healthy 48 yo man • History of migraine HA, last episode 1 yr ago • Possible episodic hypertension remotely, normal blood pressure in recent visit to PCP • Low grade hemoglobin A1C elevation: 6.2 • Normal LDL cholesterol: 100 • No family history of vascular disease

5. CASE, continued • Experienced episode of weakness, fell at home • Went back to bed • Awoke 1 hour later with speech difficulty and left hemiparesis • EMS activated: • Delay in reaching rural location, paramedics chain up to get to his home

6. CASE, continued • Taken to local t-PA capable, critical access hospital • Head CT done: no acute change • Phone consultation with neurologist 2 hrs away • Time since last normal 4 ½ hrs • Recommendation for no TPA, not given • Transferred to larger hospital

7. CASE, continued • Further evaluation: • MRA brain: Acute stroke involving posterior division of R MCA • MRA neck: Complete occlusion proximal R internal carotid • F/U CT brain 4 days after event: Interval extension of large R MCA infarct with surrounding edema • Specials: • TEE with bubble: no PFO • Hypercoagulable w/u negative

8. Stroke kills and disables many • Most common cause of disability in the world • 1 person disabled every 45 seconds in US • Third leading cause of death in US • 700,000 strokes/year in US • Washington state: • 26,612 hosp and 3,167 (6.9%) deaths (2005)

9. Pathophysiology of stroke Angiographic and autopsy studies reveal approximately 80% of strokes caused by occlusive arterial thrombus

10. Brain cells die quickly in stroke • 1.9 million neurons lost per minute • Initial ischemic penumbra, area of decreased perfusion with neurologic dysfunction which may not be permanent if flow restored • Time window for clinical benefit of opening artery challengingly brief

11. Opening the occluded artery • Intravenous thrombolytic • Intra-arterial thrombolytic • Mechanical

12. Recanalization (restoring flow) rates by intervention • Spontaneous: 24.1% • Intravenous thrombolysis: 46.2% • 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

13. Recanalization (restoring flow) 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

14. Recanalization update, continued • Patients treated with mechanical agents and drugs (n=584) compared to those treated only with mechanical therapy (n=274) or only drug therapy (n=264). • Successful recanalization in 68% of all patients • Recanalization rate for multimodal therapy patients 74%, no higher incidence of hemorrhage. • Stenting and IA TPA only independent predictors of vessel recanalization during endovascular treatment. ASA International Stroke Conference Feb 2010

15. Most patient outcome data from intravenous thrombolysis • Intra-arterial, mechanical not randomized with iv thrombolysis: • No RCT data comparing disability, death • Improved flow may not correlate with improved outcome depending on technique used (eg distal embolization) • Exact niche for each modality not determined • Intra-arterial lower tPA volume, role in pts at increased risk of bleeding • Intra-arterial may be more effective for more proximal occlusions

16. Intravenous thrombolysis • Multiple randomized controlled trials demonstrate reduced stroke disability • Consensus guidelines recommend: • American Heart Association • American College of Chest Physicians • Regulatory agencies approve: • FDA 1996 • Canada 1999 • European Union 2002

17. National Institute of Neurologic Disorders and Stroke (NINDS): NEJM 1995 • 624 pts with acute ischemic stroke, treated within 3 hrs of symptoms onset • Randomized to TPA vs placebo • Complete/near complete recovery at 90 days: • 31-50% TPA vs 20-35% placebo • Mortality not significantly different • 17% TPA vs 21% placebo • 10 fold increase in brain hemorrhage • 6.4% TPA vs 0.5% placebo

18. Stroke disability scores used in NINDS trial and others • Modified Rankin scale: functional score • 0 = no symptoms; 5 = severe disability • Barthel index: activities of daily living • 0-100; 100 = complete independence • Glasgow outcome scale: function • 1 = good recovery; 5 = death • NIH Stroke Scale (NIHSS) • 42 point scale measure of neurologic deficit

19. NINDS favorable disability outcomes • Modified Rankin scale of 0-1: • 39% tPA vs 26 % placebo • Barthel index of 95-100: • 50% tPA vs 38% placebo • Glasgow Outcome Scale of 1: • 44% tPA vs 32% placebo • NIHSS 0-1: • 31% tPA vs 20% placebo

20. Pooled analysis of 6 tPA trials • 2775 patients • NINDS parts 1&2 (3 hr window) • ECASS I and II (6 hr window) • ATLANTIS A (6 hr window) and B (5 hr) • Findings: • Benefit dependent on time from onset of symptoms to treatment • Hemorrhage 5.9% tPA vs 1.1% placebo • Lancet 2004: 363:768-774

21. Favorable outcome at 3 months by time of treatment: pooled data IV rtPA vs Placebo Time (min) Odds Ratio 95% CI 090 2.8 1.84.5 91180 1.5 1.12.1 181270 1.4 1.11.9 271360 1.2 0.91.5

22. 3 hours Pooled tPA data: benefit vs time Pooled analysis of ATLANTIS, ECASS, and NINDS rt-PA stroke trials. Lancet. 2004;363:768

23. 3 TO 4 ½ HOURS:ECASS III: NEJM 2008 • 821 pts 18 to 80 yrs old with acute ischemic stroke for whom treatment could be administered 3 to 4 ½ hrs from stroke onset, randomized to tPA vs placebo • 52% no disability with tPA vs 45% placebo • No mortality difference (7.7% tPA vs 8.4%) • Symptomatic hemorrhage 7.9% tPA vs 3.5% • NEJM 2008;359:1317-29

24. IV thrombolysis is underutilized • Currently, estimated 4% of patients with ischemic stroke receive thrombolysis with rt-PA • Very short time window • Patients arrive late • Hospitals may be slow to respond

25. How long does it take pts to get to the 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

26. How long does it take to begin rtPA after pt arrives at hospital?

27. Goal treatment timeline for door-to-needle Evaluation by physician: 10 min Stroke expertise contacted:15 min Head CT or MRI performed: 25 min Interpretation of CT/MRI: 45 min Start of treatment: 60 min

28. Why do patients delay seeking care for acute ischemic stroke? • Painless • Unlike myocardial infarction • Cognition may be impaired by the event • Not calling 911 • 1st call to physician associated with delay • 911 dispatch may fail to recognize sx or not understand pt due to stroke

29. True/False: EMS response times to suspected stroke should be equal to response times for suspected MI

30. AHA recommended goals for EMS response time in stroke Dispatch time < 1 minute Turnout time < 1 minute Travel time equivalent to trauma or MI calls

31. What is the maximum on scene time recommended for EMS personnel prior to transport of the patient with stroke?

32. Minimize on-scene time • Least is best • No more than 10 minutes in assessment • Some parts may be done in transit • Goal <15 minutes total on-scene time

33. True / False: EMS personnel should use a validated screening tool in assessing pts for stroke

34. EMS stroke assessment tools Cincinnati Prehospital Stroke Scale Los Angeles Prehospital Stroke Screen F.A.S.T.

35. F.A.S.T. Face Arm Speech Time last normal If one component abnormal, 72% probability CVA

36. Name several conditions that can mimic stroke

37. Conditions mimicking stroke: Hypoglycemia Seizure with post-ictal period Complex migraine Conversion disorder Drug ingestion

38. Over-triage Err on the side of over-identification rather than under-identification AHA: “Initially, EMSS should establish a goal of over-triage of 30% for the prehospital assessment of acute stroke” Lessons from trauma: if over-triage is not present, under-triage will result

39. What routine pieces of history should be obtained? TIME LAST NORMAL Hx diabetes? Use of insulin? Hypertension? Medications used? Hx seizure disorder?

40. What piece of history is often not included in prehospital assessments?

41. Time last normal EMS personnel often only medical providers with access to all witnesses Transporting family/witnesses with patient may help with treatment decisions at the hospital

42. Prehospital treatment of stroke • True/False: • __First address ABCs • __Run glucose containing solutions IV • __Correct hypovolemia with IV saline • __Correct hypoglylcemia when present • __Administer aspirin • __Administer oxygen in the non-hypoxic patient • __Keep pt NPO

43. Prehospital treatment of stroke • True/False: • T__First address ABCs • F__Run glucose containing solutions IV • T__Correct hypovolemia with IV saline • T__Correct hypoglylcemia when present • F__Administer aspirin • F__Administer oxygen in the non-hypoxic patient • T__Keep pt NPO

44. Transport • Determine appropriate facility • Closest TPA capable if < 2 hrs from time last normal • Assumes door-to-needle will be <60 min • Primary stroke center / Comprehensive stroke center • State guidelines pending regarding appropriate level of stroke center based on time last normal

45. Transport, cont. • Early hospital notification • Confirm availability of CT • Specify F.A.S.T findings • Consider air transport in remote areas • EMS responders simultaneously call for air transport and prenotify ED at receiving stroke center in some systems

47. Management en route • Lay patient flat unless airway compromise • Don’t elevate head greater than 20 degrees • IV access • 16 or 18 gage if possible • Avoid glucose containing solutions • 2nd exam/neuro reassess • Perform TPA check list

48. What labs need to be sent on stroke TPA treatment candidates? CBC including platelets Cardiac enzymes Electrolytes, BUN, creatinine, glucose PT/INR PTT

49. Name as many contraindications to tPA as you can

50. Contraindications to TPA: clinical Symptoms/signs only minor or rapidly improving Seizure at onset of stroke (not absolute) Symptoms suggestive of subarachnoid hemorrhage Persistent blood pressure elevation >185/110 Active bleeding or acute trauma (fx)