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Acute Stroke: Current Evidence-based Recommendations for Prehospital Care

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Evidentiary Tables

Summary of the available and salient clinical research used to develop these evidence based recommendations.

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EVIDENTIARY TABLE

INTRODUCTION

Each year, 795,000 people experience a new or recurrent stroke causing significant mortality and neurologic disability.1 On average, every 40 seconds, someone in the United States has a stroke, accounting for one of every 18 deaths in the U.S.1 Emergency medical services (EMS) plays a pivotal role in recognizing acute strokes and providing timely transport to hospitals with specific stroke treatment capabilities. The optimal prehospital management and stroke system organization continue to evolve. EMS care varies widely across the U.S. The Institute of Medicine report, “Emergency Medical Services at the Crossroads,” notes that EMS needs more uniform high-quality care and specific standards for evaluating that care.2 One such standard is the prehospital protocol that EMS personnel follow while taking care of patients. Protocols vary widely between jurisdictions. We provide a summary of the evidence for the prehospital treatment of patients with suspected acute stroke and evaluate the consistency of California protocols.

METHODS

The state of California divides EMS care into 33 local EMS agencies (LEMSAs). One set of governmental medical control policies regulates first responders and ambulance transporters in each county-wide or region-wide system. Medical directors of those agencies, along with other interested EMS medical directors, make up the EMS Medical Directors Association of California (EMDAC). EMDAC supports and guides the various agencies and makes recommendations to the California EMS Authority about policy, legislation and scope of practice issues. In an effort to improve the quality of EMS care in our state, EMDAC has endeavored to create evidence-based recommendations for EMS protocols. Those recommendations and previous reviews are intended to assist medical directors of the various LEMSAs to develop high quality, evidence-based protocols.

A subcommittee of EMDAC developed this manuscript and chose by consensus the elements that should be included in any protocol for a patient with a suspected acute stroke. The subcommittee then created a narrative review of the existing evidence for prehospital treatment of a patient with a suspected acute stroke. Clinical questions regarding those interventions were developed in the population, intervention, control and outcome (PICO) format. Our population included those patients in the prehospital setting with a suspected acute stroke. The intervention varied by clinical question. The control consisted of patients who were not receiving the specific intervention, and outcomes were defined by accuracy of diagnosis and neurologic or imaging outcome after intervention.

We relied heavily on recommendations made by various organizations that have performed systematic reviews and meta-analyses regarding treatment interventions including the American Heart Association (AHA) and the International Liaison Committee on Resuscitation (ILCOR). We supplemented the recommendations from those organizations with additional literature searches through PubMed from 1966 to 2015 for each question. The primary literature review of PubMed searched for the term “Prehospital and Stroke.” That yielded 476 articles, 86 of which were published in English, not review articles, and pertinent to the topics identified by the EMDAC subcommittee. That search was supplemented with additional PubMed searches for specific topics.

CONCLUSION

Protocols for a patient with a suspected stroke vary widely across the State of California. The evidence-based recommendations that we present for the prehospital diagnosis and treatment of this condition may be useful for EMS medical directors tasked with creating and revising these protocols.

Level Recommendations

The process used for assigning levels of evidence (LOE) and grading our recommendations was taken from the American College of Emergency Physicians (ACEP) process of creating their clinical policies with slight modification to better fit our objectives. A committee of EMDAC reviewed studies and assigned LOE based on the study design, including features such as data collection methods, randomization, blinding, outcome measures and generalizability.3 A brief summary of the reviewed studies is available in an electronic appendix. LOE I consisted of randomized, controlled trials, prospective cohort studies, meta-analysis of randomized trials or prospective studies, or clinical guidelines/comprehensive review. LOE II consisted of nonrandomized trials and retrospective studies. LOE III consisted of case series, case reports, and expert consensus.


After assigning LOE to the studies, these were translated to clinical grades of our recommendations using the following standards:

Level A recommendations

Prehospital recommendations with a strong degree of certainty based on one or more LOE I studies or multiple LOE II studies.

Level B recommendations

Prehospital recommendations with a moderate degree of certainty based on one or more LOE II studies or multiple LOE III studies.

Level C recommendations

Prehospital recommendations that are based on only poor quality or minimal LOE III studies or based on consensus.

No recommendation

No recommendation will be given in those cases where only preliminary data or no published evidence exists and we have no expert consensus. We may also withhold recommendation when studies, no matter their LOE, currently show conflicting data.


After answering the clinical question and providing recommendations for diagnostic and treatment interventions, each current chest pain protocol for the 33 agencies were reviewed for consistency with the recommendations.


The clinical protocols were reviewed during the month of July 2015. Institutional review board approval was deemed to not be necessary for this review of publicly available research and clinical protocols.

USE OF A STROKE SCALE

Clinical Question

Does the use of a prehospital stroke scale help identify strokes in patients found with acute neurological deficits, and which stroke scale is most effective?

Current Prehospital Treatment Recommendation

Level A Recommendations

A stroke scale should be used in the prehospital setting for any patient with an acute neurological deficit to rapidly assess and triage patients with possible stroke.

There is currently no practical prehospital scale that accurately detects strokes outside of the middle cerebral artery distribution.

CPSS and LAPSS are the most validated and most frequently used scales.

Level B Recommendations

None given.

Level C Recommendations

In the future, scales such as CPSSS, NIHSS and KPSS may be added to gauge stroke severity and direct transport to a higher level of care, e.g. comprehensive rather than basic stroke receiving center.

No Recommendation

N/A

Summary of Current Evidence

Timely recognition is the most critical step in the prehospital care of a patient with an acute stroke. Sepsis, hypo- or hyperglycemia, seizure, tumor, intracranial hemorrhage, migraine, and syncope can all cause acute neurological deficits. If a stroke is correctly identified, the patient can be appropriately transported to a designated stroke center that can provide timely care, including tissue plasminogen activator (tPA) or endovascular therapy when appropriate. The misdiagnosis of stroke may lead to delayed care or inappropriate treatment. When not recognized in the field, the initial triage process frequently misses the stroke.4 When EMS providers do not document a stroke scale, they are more likely to miss the diagnosis.5,6

There are many scoring systems to screen for an acute ischemic stroke in the field. EMS groups most commonly use Face Arm Speech Test (FAST), Cincinnati Prehospital Stroke Scale (CPSS) (most commonly used in California), or Los Angeles Prehospital Stroke Screen (LAPSS). Many of the more commonly used stroke scales are not designed to identify posterior circulation strokes.

FAST includes facial droop, arm weakness, speech difficulties, and time to seek medical help. FAST is simple to use and has shown reproducibility between physicians and paramedics.7 It had a sensitivity of 79-85% and specificity of 68%.8,9 However, FAST did not detect 38% of posterior cerebral circulation strokes.7

The CPSS includes three components – pronator drift, speech difficulties, and facial droop. Many studies have shown the reproducibility and validity of this scale between physicians and prehospital providers.10 Sensitivity ranged from 44-95% and specificity was 23-96%.5,6,8,10-16 With a score of two, it predicted patients receiving thrombolytic therapy with a 96% sensitivity and 65% specificity, although that has been studied less.17 The CPSS, like the FAST, is limited in that it was designed to identify middle cerebral artery strokes.

Recently, the Cincinnati Prehospital Stroke Severity Scale (CPSSS) was developed to predict severe anterior ischemic strokes and large vessel occlusions (LVO).18 Unlike the CPSS, the CPSSS grades the severity of the stroke. The scale gives two points for conjugate gaze deviation and one point for incorrectly answering at least one of two level of consciousness questions (age or current month).18 The scale further gives one point for not following at least one of two commands (close eyes, open and close hand) and one point for not holding an arm up for 10 seconds.18 CPSSS greater than or equal to two was 89% sensitive and 73% specific for National Institute of Health Stroke Scale (NIHSS) greater than or equal to 15, which predicts LVO.18 The recognition of LVOs may become more important as stroke systems develop and as advanced therapies show more efficacy.

The LAPSS is only used for patients over 45 years of age with an absence of history of seizure disorder, symptom duration less than 24 hours, and a blood glucose range of 60-400mg/dL.19 It detects unilateral weakness in facial grimace, handgrip and arm strength.19 With those criteria, LAPSS was designed to decrease the false positive rate of CPSS. Paramedics using LAPSS demonstrated a sensitivity of 74-98%, with a specificity of 44-97%, PPV 86%, and NPV 98%.8,11,12,19,20

Los Angeles Motor Scale (LAMS) assigns values to the points on the LAPSS to assess severity, giving a score of zero through 10 with bilateral weakness or zero through five with unilateral weakness.8,21,22 LAMS quickly and effectively assesses for LVO. LAMS demonstrated a sensitivity of 81%, specificity of 89%, and accuracy of 85% for LVO if the LAMS score was four or higher.21 LAMS correlated closely with NIHSS and predicted three-month outcome.22

The Melbourne Ambulance Stroke Screen (MASS) includes speech difficulties plus the components of the LAPSS. In contrast with LAPSS, blood glucose range begins at 50mg/dL.8,11,14 Age must be greater than 45 years, and there must be no history of seizure or epilepsy. Patient must be ambulatory at baseline. Sensitivity was found to be as high as 83-98% with a specificity of 44-86% and 100% sensitivity for ischemic strokes eligible for thrombolytic therapy.8,11,14

If the patient does not have a history of seizures, symptom duration greater than 25 hours, or blood glucose outside 60-400mg/dL, the Medic Prehospital Assessment for Code Stroke (Med PACS) can rule in a stroke. Under those circumstances, it evaluates facial droop, gaze, arm and leg weakness and speech.8 Sensitivity ranged from 44-74% with specificity 32-98%.8,16

The Recognition of Stroke in the Emergency Room (ROSIER) score assesses facial, arm, or leg weakness, speech, and visual field deficits. Blood glucose must be >62mg/dL. Scores range from -2 to 5, with a score less than or equal to zero indicating a low likelihood of stroke. Seizure or syncope are scored as -1.8,13,23 It demonstrated a sensitivity of 80-89% and a specificity of 79-83%.8,13 Physicians confirmed 64% of strokes and 78% of non-strokes identified by ambulance clinicians with ROSIER.23

The most common scale used in the hospital setting is the NIHSS. For prehospital assessment, the shortened version was developed, including assessment of gaze, visual field, motor function of the right and left leg, language, level of consciousness, facial paresis, and dysarthria.8,24 It attempts to predict stroke severity but is more complicated than some of the other stroke scales. With its complexity, it can evaluate strokes outside of the middle cerebral artery distribution.

The Kurashiki Prehospital Stroke Scale (KPSS) is applied after a stroke is recognized by another stroke scale, such as the CPSS. It awards 13 points assessing consciousness, motor weakness, and speech.8,25-29 When used for recognition, sensitivity ranged from 83-86% and specificity ranged from 60-69% for detecting stroke.8 A KPSS score of 3-9 predicts candidates for tPA with a sensitivity of 84% and specificity of 93%.26 It is a simpler scale than the full NIHSS but showed good correlation with the NIHSS when used by emergency medical technicians and can predict long-term outcome.25,28,29

The Maria Prehospital Stroke Scale Score (MPSS) can be used both to identify strokes and to determine stroke severity. It grades facial droop, arm drift and speech disturbances, and the score predicts tPA use.30 The Rapid Arterial Occlusion Evaluation (RACE) scale is also based on the NIHSS to evaluate LVO via assessment of facial palsy, arm motor function, leg motor function, gaze, and aphasia or agnosia.31 The scale showed strong correlation with the NIHSS, sensitivity of 85%, and specificity of 68%.31

With the development of endovascular capable centers, the recognition of LVO may become more important, and the use of scales such as CPSSS, NIHSS, and KPSS may be useful in grading stroke severity and making destination decisions.


LEMSA Use of a Stroke Scale Type of stroke scale Emergent large vessel occlusion scale
Alameda County Yes Cincinnati prehospital stroke scale No
Central California No N/A No
San Francisco Yes Cincinnati prehospital stroke scale No
Coastal Valleys Yes Cincinnati prehospital stroke scale No
Contra Costa County Yes Cincinnati prehospital stroke scale No
El Dorado County Yes Cincinnati prehospital stroke scale No
Imperial County Yes LAPSS  
Inland Counties Yes Modified LAPSS  
Kern County Yes Cincinnati prehospital stroke scale No
Los Angeles County Yes mLAPSS No
Marin County Yes Cincinnati prehospital stroke scale No
Merced County No N/A No
Monterey County Yes BEFAST No
Mountain Valley Yes Cincinnati prehospital stroke scale No
Napa County Yes Cincinnati prehospital stroke scale No
Northern California Yes Cincinnati prehospital stroke scale No
North Coast No Motor weakness, paralysis, speech distrubances, aphasia, headache, visual problems altered mental status  
Orange County No No seizure prior to or during arrival, last seen normal within seven hours, GCS 10 or greater, and pronator drift or facial paresis No
Riverside County Yes Cincinnati prehospital stroke scale No
Sacramento County Yes Cincinnati prehospital stroke scale No
San Benito County Yes If <6 hours, Cincinnati prehospital stroke scale No
San Diego County Yes Cincinnati prehospital stroke scale No
San Joaquin County Yes Cincinnati prehospital stroke scale No
San Luis Obispo County Yes FAST No
San Mateo County Yes Cincinnati prehospital stroke scale No
Santa Barbara County Yes Cincinnati prehospital stroke scale No
Santa Clara County Yes Santa Clara County stroke scale - balance problems, diplopia, facial droop, arm drift, speech abnormalities, time last seen normal <6 hours  
Santa Cruz County Yes Cincinnati prehospital stroke scale No
Sierra-Sacramento Yes Cincinnati prehospital stroke scale No
Solano County Yes Cincinnati prehospital stroke scale No
Tuolumne County No Weakness or paralysis on one side of the body/face, slurred speech, speech difficulty, difficulty with balance, inability to understand, difficulty in naming objects, confusion, difficulty swallowing, headache, visual disturbances (double vision, blindness, paralysis of extra-ocular muscles) No
Ventura County Yes Cincinnati prehospital stroke scale No
Yolo County Yes Cincinnati prehospital stroke scale No
  85%    
TABLE 1 | LEMSA, local EMS agencies; LAPSS, Los Angeles Prehospital Stroke Screen; EMS, emergency medical services; mLAPSS, modified Los Angeles prehospital stroke screen; BEFAST, balance eyes face arm speech time; GCS, glasgow coma scale; FAST, face arm speech time
Blood Glucose Evaluation

Clinical Question

Should paramedics measure glucose and administer dextrose in hypoglycemic patients in cases of suspected stroke?

Summary of Current Evidence

Hypo- and hyperglycemia both mimic stroke.33 It is critical to measure glucose levels when there is concern for a possible stroke. This will differentiate between stroke and hypoglycemia. Symptoms such as hemiparesis, hemiplegia, speech or visual disturbances, confusion, and poor coordination can all present in patients with hypoglycemia and can be corrected with administration of dextrose.33-35 While symptoms such as tremulousness and altered behavior may occur with milder degrees of hypoglycemia, focal stroke-like neurological symptoms, such as hemiplegia, typically do not manifest until glucose levels are less than 45mg/dL.33-38 There is a clear benefit to giving dextrose to those patients with glucose below 45mg/dL. That treatment will differentiate between those having stroke-like symptoms from hypoglycemia and those truly having a stroke.

However, it is less clear if dextrose should be routinely given to patients with mild coincidental hypoglycemia. A bolus administration of dextrose typically results in an acute, transient (less than one hour) elevation in serum glucose into a hyperglycemic range.39-41 The utility and safety of dextrose administration in patients with large focal neurological deficits but mild, possibly non-contributory hypoglycemia may need to be evaluated in the future. Hyperglycemia can also present as a stroke mimic, and elevated blood glucose on admission correlates with worse outcomes after stroke, specifically infarct expansion,42-48 and with intracranial hemorrhage after tPA.49, 50

Current Prehospital Treatment Recommendation

Level A Recommendations

Blood glucose should be checked in every patient with suspected stroke.

Patients with hypoglycemia (glucose below 45mg/dL) should be treated with dextrose.

Level B Recommendations

None given.

Level C Recommendations

None given.

No Recommendation

N/A


LEMSA Advise routine evaluation of BS Advise titrated dose Titration dose Dextrose 10% Notes
Alameda County Yes No N/A Yes  
Central California Yes Yes 80mg/dL with persistent AMS Yes (25g IV)  
San Francisco Yes Yes 60mg/dL No If BS <60 or known diabetic, dextrose 50%
Coastal Valleys Yes Yes 60-80mg/dL Yes (150mL IV of D10) Glucagon 1mg IM if no IV access; recheck BS if symptoms not resolved; repeat additional dextrose 10% 100mL IV if glucose 60-80 or less; Dextrose 50% 25g IV if glucose 60-80 after 250mL Dextrose 10%. If Dextrose 50% unavailable, repeat Dextrose 10%.
Contra Costa County Yes Yes 60mg/dL Yes Check and treat if indicated
El Dorado County Yes Yes 60mg/dL No 25gm of 50% dextrose, if no IV then 1gm glucagon
Imperial County Yes Yes 60mg/dL No Dextrose 50% 25gm IV or glucagon 1mg IM if no IV
Inland Counties Yes No N/A No  
Kern County Yes Yes 60-80mg/dL Yes Use appropriate protocol to rule out narcosis/hypoglycemia then re-enter CVA protocol if indicated
Los Angeles County Yes Yes 60mg/dL No Oral glucose if awake and alert, 50% 50mL, glucagon if no IV 1mg IM; if BS remains <60, repeat dextrose 50, repeat glucagon Q20min x2
Marin County Yes No N/A No  
Merced County Yes Yes 75mg/dL No 25gm IV if BS<75mg/dL, glucagon 1 U IM if no IV; repeat dextrose in 3-5 min if no response and continued hypoglycemia. Oral glucose if known diabetic and intact gag.
Monterey County Yes Yes 70mg/dL No D50% 25gm IV if BS<70
Mountain Valley Yes Yes 60mg/dL No 25gms IV push; if BS<60mg/dL, repeat 1x; recheck BS in 5min after each dose; if no IV with BS<60, give glucagon 1U IM, may repeate 1x, recheck BG 5min after each dose
Napa County Yes Yes 60mg/dL Yes Glucose paste 15gm PO if pt able to hold head upright, has gag reflex and can self-administer med; or D10% IV 25g 250mL or if no IV, D10% IO; if symptoms reverse and BS >60, slow D10% to remainder of dose; if no improvement after 5 minutes after D10% and BS still <60, give another D10% in 5g increments at 5-10min intervals reassessing BS levels and mental status every 5min
Northern California Yes Yes 75mg/dL No Glucose paste po if suspected hypoglycemia, adequate gag reflex, hold head upright; check BS, then D50 up to 35 gm IV if BS<75; repeat 25 gm IV x1 in 5min if BS still <75; if altered LOC and BS<75 and no IV, 1mg glucagon IM; no glucose if suspected CVA unless BS<75; if BS>250 treat with 500cc NS
North Coast Yes No N/A No  
Orange County Yes Yes 80mg/dL No Oral glucose if airway reflexes intact, 50% dextrose 50mL IV, may repeat x1 if BS<80; glucagon 1mg IM if IV unable; IO ok for 50% dextrose if unable IV and no response to glucagon
Riverside County Yes No N/A No  
Sacramento County Yes No N/A No  
San Benito County Yes Yes 70mg/dL No Treat as needed
San Diego County Yes Yes 60mg/dL No If patient awake and gag, give 3 oral glucose tabs or paste (15g total); D50 25gm IV SO if BS<60; if pt remains symptomatic and BS remains <60 MR SO; if no IV, glucagon 1ml IM SO if BS<60
San Joaquin County Yes Yes 60mg/dL No Paste if known diabetic, can hold head upright, can self-administer medication and has intact gag; If BS<60, then D50% 25gm or D10 50cc IV/IO bolus repeated every min until GCS 15; max dose D10 is 10cc/kg
San Luis Obispo County Yes No N/A No  
San Mateo County Yes Yes 80mg/dL No Avoid hyperglycemia
Santa Barbara County Yes Yes 60mg/dL Yes If low BS suspected PO 15 g if BS<60, pt awake and able to swallow safely; if unable to swallow safely, glucagon IM 1 mg; if <60 and not able to swallow, D10W 25 mg IVP, glucagon if no IV; recheck BG 5 min after IV D bolus complete or 10 min after glucagon admin; if still <60, D10 IV 250 cc
Santa Clara County Yes Yes 80mg/dL No If suspected hypoglycemia, 1 tube oral glucose paste, repeat in 5-15 min if no improvement; if BS<80, no oral/can’t oral D50 25 gm IVP; if no improvement, repeat dextrose or glucagon 1 mg IM; if no IV, and BS<80 and no improvement, glucagon 1mg IM
Santa Cruz County Yes Yes 70mg/dL No Treat as needed
Sierra-Sacramento Yes No N/A No  
Solano County Yes Yes 60mg/dL No Treat as needed
Tuolumne County Yes Yes 75mg/dL No 25-50 gms IV push; 1 U IM glucagon if no IV access
Ventura County Yes Yes 60mg/dL Yes If low BS suspected, PO 15 gm; If <0, D10W 10gm (preferred), D5W 10gm, D50W 12.5gm; Glucagon 1mg IM if no IV access Recheck BS 5 min after Dex or 10 min after glucagon; if still <60 D10W preferred or D5 or D50
Yolo County Yes No N/A No  
  100% 73%   24%  
Table 2 | Blood glucose in patients with suspected stroke. Glucagon dose in various prehospital protocols is listed in units milliliters and milligrams according to local protocol. We have copied them verbatim to demonstrate variation in presentation and practice. | LEMSA, local EMS agencies; BS, blood sugar; EMS, emergency medical services; IM, intramuscular; CVA, cerbrovascular accident; IV, intravenous; BG, blood glucose; PO, per os (by mouth)
Supplemental O2

Clinical Question

Does the prehospital administration of oxygen to patients with normal oxygen saturations improve outcomes in cases of suspected acute ischemic stroke?

Current Prehospital Treatment Recommendation

Level A Recommendations

None given.

Level B Recommendations

Oxygen should be delivered to a titrated dose of 94%oxygen saturation

Level C Recommendations

None given.

No Recommendation

Summary of Current Evidence

Every stroke patient should be assessed initially for airway compromise and treated accordingly. Airway compromise occurs more frequently in older patients, those with a severe stroke, or those with symptoms of dysphagia. Approximately 63% of patients with a hemiparetic stroke develop hypoxia.51

The evidence for oxygen use is less clear for normoxic patients. One randomized study compared the effect of 3L/min oxygen treatment for 24 hours versus no supplemental oxygen treatment on acute stroke patients and demonstrated no difference in survival and disability scores in those receiving oxygen.52 One a priori subgroup analysis of those with a more severe stroke demonstrated a statistically significant worsening of survival with supplemental oxygen. Several factors limited the conclusions of that study: a portion of the treated patients did not receive oxygen, patients had late time to therapy, and the study included hemorrhagic stroke patients. A more recent randomized trial with relatively few patients demonstrated short-term improvements but no long-term clinical differences between those given supplemental oxygen and those given no treatment.53 The research on this subject is limited.

Current practice for acute stroke patients includes the use of supplementary oxygen to maintain oxygen saturation above 94%.32,,54 Beyond 94%, oxyhemoglobin is saturated and no further physiologic benefit is derived.


LEMSA Advise routine use regardless of SpO2% Advise titrated dose Titration dose Advise against with normal SpO2% Notes
Alameda County No Yes 94-99% No  
Central California Yes No N/A No Low flow for suspected stroke (6L/min NC)
City and County of San Francisco No No N/A No Oxygen as indicated
Coastal Valleys No Yes 94-98% No  
Contra Costa County No Yes 94% No Low flow for BLS
El Dorado County No No N/A No Appropriate rate
Imperial County No Yes 94% Yes  
Inland No No N/A No  
Kern County No Yes 94% No Monitor/pulse oximetry
Los Angeles County No No N/A No As needed
Marin County No No N/A No  
Merced County Yes No N/A No High flow, as tolerated
Monterey County No No No No Routine medical care
Mountain Valley No No N/A No As appropriate
Napa County No Yes 94-97% No  
Northern California Yes No N/A No  
North Coast Yes No N/A No Oxygen therapy
Orange County No Yes 95% No High flow mask if oxygen sat less than 95%
Riverside County No No N/A No  
Sacramento County No Yes 94% No Use lowest flow rate possible
San Benito County No Yes 95% No Treat life threats
San Diego County No Yes 94-98% Yes  
San Joaquin County No No N/A No  
San Luis Obispo County No No N/A No Evaluate for hypoxia
San Mateo County No No N/A No As indicated
Santa Barabara County Yes No N/A No High flow for spO2<95%, low flow for >95%
Santa Clara County No No N/A No  
Santa Cruz County No No N/A No Treat life threats
Sierra-Sacramento Yes Yes 94-100% No 2L NC
Solano County Yes No N/A No High flow as tolerated
Tuolumne County No No N/A No As appropriate
Ventura County No Yes 94% No  
Yolo County No Yes 94% No  
  21% 39%      
Table 3 | Oxygen administration in patients with suspected stroke. | LEMSA, local EMS angencies; MI, myocardial infarction, STEMI, ST segment elevation myocardial infarction; SL, sublingual
Patient Positioning

Clinical Question

In what position should patients with possible strokes be transported?

Current Prehospital Treatment Recommendation

Level A Recommendations

None given.

Level B Recommendations

None given.

Level C Recommendations

Patients should be laid flat as tolerated, unless precluded by clinical issues such as compromised respiratory status, secretions, or aspiration risk.

No Recommendation

Although it is reasonable to consider the early administration of opiates in selected patients without contraindications, insufficient evidence exists to support or refute its routine administration in the ED or prehospital setting in patients with chest pain of suspected ACS. There is only one poor quality study that demonstrated harm.

Summary of Current Evidence

No clinical outcome studies exist to define the optimal position for transporting a patient with an acute stroke. A small number of studies evaluate blood flow and other secondary measures that might be useful in answering that question.

For patients with head injuries, setting the head of bed at 30 degrees alleviates elevated intracranial pressure.55, 56 However, patients with strokes typically do not have elevated intracranial pressure. Cerebral blood flow and cerebral perfusion pressure both improved when the patient was put into the supine position.57, 58 Mean flow velocity increased in patients with persistent occlusions when they were laid flat.59, 60 The sitting position in patients who had suffered strokes caused reduced blood flow distal to the occlusion.61 When measured with tissue oxygenation index, cerebral oxygenation dropped in the upright patient and rose in the supine patient.62 Factors such as secretions, congestive heart failure, or respiratory distress frequently confound the acute stroke patient and preclude laying the patient flat because of effects on oxygen saturation and secretions. Oxygen saturation improved in stroke patients sitting upright, but that improvement was minimal.63, 64 Positioning patients on their sides minimally affected oxygen saturation.63, 65 Additionally, stroke patients frequently have sensory deficits in the laryngopharynx that can lead to aspiration.66 The evidence supports laying the head of the bed flat as tolerated in patients with suspected stroke.


LEMSA Recommend elevating head of bed Lateral decubitus Head of bed flat as tolerated Notes
Alameda County No No Yes Transport patient in supine position unless evidence of increasing ICP/intracranial hemorrhage, transport in semi fowlers with no more than 30 degrees head of bed elevation
Central California No No No  
San Francisco No No No Position of comfort
Coastal Valleys No No No  
Contra Costa County No No No  
El Dorado County No No No  
Imperial County Yes Yes No  
Inland Counties No No No  
Kern County No No No  
Los Angeles County No No No  
Marin County No No No  
Merced County No Yes No If not contraindicated by injuries, place patient in left lateral decubitus position
Monterey County No No No  
Mountain Valley No No No  
Napa County No No No  
Northern California Yes No No 30 degrees
North Coast Yes Yes No Upright if gag reflex intact, left lateral with head elevated if gag reflex absent
Orange County No No No  
Riverside County No No No Position patient as clinically indicated to meet physiologic requirements
Sacramento County No No No  
San Benito County No Yes No Patients with depressed mentation or decreased gag reflex should be placed in a left lateral position
San Diego County No Yes No If secretion problems place on affected side
San Joaquin County No No No  
San Luis Obispo County No No No  
San Mateo County Yes (unless spinal immobilization indicated) No No  
Santa Barbara County No No No  
Santa Clara County Yes No No  
Santa Cruz County No Yes No If depressed mentation or decreased gag reflex
Sierra-Sacramento No No No  
Solano County No Yes No Position of comfort, left lateral decubitus if vomiting
Tuolumne County No No No  
Ventura County No No No  
Yolo County No No No  
  15% 21% 3%  
Table 4 | Patient positioning. | LEMSA, local EMS angencies; IV, intravenous; IM, intramuscular; IO, intraosseous; IN, intranasal
12-LEAD EKG

Clinical Question

Should a 12-lead ECG or cardiac monitoring routinely be performed in the prehospital setting for patients with suspected stroke?

Current Prehospital Treatment Recommendation

Level A Recommendations

None given.

Level B Recommendations

In patients with suspected stroke, a 12-lead ECG should be acquired and interpreted by prehospital or other emergency providers in a timely manner as long as it does not delay transport to a facility with tPA capabilities.

Level C Recommendations

In a patient presenting with signs or symptoms of stroke and ST segment elevation myocardial infarction (STEMI), EMS should consider bypassing the nearest tPA capable facility for a facility with a catheterization lab.

No Recommendation

N/A

Summary of Current Evidence

Cardiac monitoring detects significant cardiac pathology that can cause stroke or occur concurrent with stroke. Monitoring leads to earlier intervention. It is recommended in the prehospital setting and throughout the first 24 hours of care.32

Stroke patients frequently have cardiac arrhythmias or ECG abnormalities including ST segment depression, prolonged QTc interval, atrial fibrillation, T-wave inversion, conduction defects, premature ventricular beats, and left ventricular hypertrophy.67, 73 One study showed ECG abnormalities in 60% of patients with cerebral infarction and 44% of patients with transient ischemic attack (TIA).67 In some of those events, such as atrial fibrillation, the cardiac event may have led to the stroke. In others, such as ST segment depressions, it is poorly understood why stroke patients develop ST segment depressions after their cerebral event. Atrial fibrillation, atrio-ventricular block, ST elevation, ST depression, and inverted T waves predicted mortality in patients with ischemic stroke.67, 72 Care in units with cardiac monitoring led to improved outcomes at discharge, likely because of earlier intervention.69 The non-specific ECG changes do not change management in the prehospital setting, but significant arrhythmias may change management.


LEMSA Consider 12 Lead ECG Advised cardiac monitoring Notes
Alameda County Yes No Obtain 12-Lead ECG when a dysrhythmia or ACS symptoms are present (specifically watch for STEMI and/or A fib)
Central California No Yes Treat any arrhythmia
San Francisco No No  
Coastal Valleys Yes (if possible) No  
Contra Costa County No Yes  
El Dorado County No No  
Imperial County Yes (consider) Yes (consider)  
Inland Counties Yes (consider) No  
Kern County Yes Yes  
Los Angeles County Yes (only if arrhythmia on monitor) Yes (only if arrhythmia on monitor)  
Marin County No No  
Merced County No Yes Treat rhythm as appropriate
Monterey County No No Routine medical care
Mountain Valley No Yes  
Napa County Yes No Treat rhythm as appropriate
Northern California Yes (do not delay rapid transport) Yes  
North Coast No Yes  
Orange County No Yes  
Riverside County No No  
Sacramento County No Yes  
San Benito County No No  
San Diego County No Yes Monitor ECG
San Joaquin County No Yes ECG monitoring, Treat rhythm disturbances as appropriate
San Luis Obispo County Yes (Consider) No  
San Mateo County No Yes  
Santa Barbara County No Yes  
Santa Clara County No No Cardiac monitoring and ECG when medic suspects patient may have cardiac ischemia or any dysrhythmias
Santa Cruz County No No  
Sierra-Sacramento Yes (if no delay in transport or patient care) Yes No
Solano County No Yes  
Tuolumne County No Yes ECG monitoring
Ventura County No Yes  
Yolo County Yes No  
  33% 58%  
Table 5 | 12 Lead ECG and cardiac monitoring in patients with suspected stoke. | LEMSA, local EMS agencies; ECG, echocardiogram; EMS, emergency medical services
Background photo courtesy of CodeSTEMI.tv
STROKE REGIONALIZATION

Clinical Question

What parameters should be outlined in the stroke protocol to direct expeditious and appropriate transport? Should there be dispatch at high priority, documentation of time patient was “last seen normal,” limiting time on scene, hospital notification, transport to primary or comprehensive stroke center (CSC), and retriage from primary to CSCs?

Current Prehospital Treatment Recommendation

Level A Recommendations

Time “last seen normal” should be documented.

Suspected stroke patients should have a high-priority dispatch.

Hospitals should be notified of a suspected stroke patient prior to arrival.

Level B Recommendations

Scene times should be minimized and be 15 minutes or less if practical.

Patients with a possible stroke should be transported to the nearest facility with tPA capabilities, preferably a PSC or CSC.

Level C Recommendations

The integration of CSCs into EMS systems is rapidly evolving. Stroke systems should include formalized, rapid processes for higher level of care transports of patients with persistent LVOs to CSCs.

No Recommendation

N/A

Summary of Current Evidence

Early use of IV tPA is more effective at one hour than at three hours.85 It should not be used outside of the four and a half hour window. Recent AHA recommendations endorse the use of endovascular therapy after tPA for persistent LVOs.86 The efficacy of that therapy is also time sensitive. Thus, EMS protocols must guide timely evaluation and transport to appropriate facilities for those definitive interventions.

EMS should dispatch responders to suspected stroke patients with a high priority and attempt to shorten the time between the receipt of the call and the delivery of the patient to the emergency department. On initial history, responders must document “last seen normal time.”32 Use of specific language, rather than using the standard EMS run times, facilitates clear communication. Furthermore, paramedics can facilitate tPA delivery and definitive care by obtaining a medication list and pre-thrombolysis check list as well as the physician orders for life sustaining treatment (POLST). AHA recommends call to dispatch time of less than 90 seconds, EMS response time less than eight minutes, and an on-scene time less than 15 minutes.32 Higher priority of dispatch and hospital notification of a stroke both led to shorter times from ambulance call to arrival,87 assessment by a doctor,4 door to needle time,57, ,87-91 and door to imaging time.22, 88, 92-95 Patients received tPA more frequently at hospitals notified prior to patient arrival.10, 90, 94-96 Another study showed that one way to decrease on scene time was to explicitly direct an on-scene time of 15 minutes or less. That led to reductions in on-scene time over those with no instructions and those with general instructions to limit on scene time.97

A study published in 2010 concluded that 22% of people living in the continental U.S. have access to a primary stroke center (PSC) within 30 minutes, 43% have access within 45 minutes, and 55% have access within 60 minutes.98 Fewer patients have timely access to a CSC. Patients admitted to designated stroke centers versus community hospitals had increased tPA delivery rates.99 Additionally, admitting patients to designated stroke centers versus community hospitals was associated with increased tPA rates and decreased 30-day mortality.100 In a centralized model, where patients were transported to a stroke center preferentially over a community hospital, EMS transports occurred more frequently, they were given higher priority, more false positives were identified, more patients received tPA, and door-to-needle times were shorter.101, 102

Throughout the U.S., more communities are shifting to a two-tiered system that includes PSCs and CSCs. Both assess for strokes and deliver tPA, but the CSCs also offer endovascular recanalization to patients with persistent LVOs. In light of the new AHA recommendations, that intervention is an evolving standard of care. The existence of both presents a transport dilemma to EMS. Should a patient with a suspected stroke be sent immediately to a CSC or initially to a PSC? If transport time to the CSC is longer, would it benefit the patient to go initially to the PSC to get tPA? As discussed above, some stroke scales can help to identify severity of stroke. In the future, these may direct transport decisions. The limited sensitivity and specificity of existing stroke scales may cause increased transport time in patients with a false positive on the stroke scale and delay in tPA administration for acute stroke patients with a false negative.

In California, hospitals sought PSC certification more frequently after counties developed protocols directing transport of patients with strokes to PSCs.103 EMS protocols indicating patients should go to PSCs may be beneficial for the patients and may also drive changes in hospital certification. A number of novel interventions such as Stroke Emergency Mobile Units or the incorporation of telemedicine may influence organization of stroke systems in the future.104-128


LEMSA Advise documenting the duration of symptoms Limit time on the scene Transport to a stroke center Hospital prenotification Notes Designated primary stroke centers Comprehensive stroke centers ReTriage from primary to comprehensive
Alameda County Yes (“Last seen normal”) Yes Yes Yes   Yes No No
Central California Yes (“Last seen normal”) Yes No Yes   No No No
San Francisco No Yes Yes No If potential stroke is suspected with symptoms for 4.5 hours or less, immediately transport patient to a designated Stroke receiving hospital No No No
Coastal Valleys Yes (“Time of onset” or “last time patient known to be at baseline”) Yes No Yes   No No No
Contra Costa County Yes (“Last seen normal”) Yes Yes Yes   Yes No No
El Dorado County Yes (“Time of onset”) Yes (15 minutes) Yes Yes   No No No
Imperial County Yes (“Time of onset”) Yes No Yes Take patient to hospital with CT if suspected stroke and alert receiving hospital early. No No No
Inland Counties Yes (“Last seen normal”) Yes Yes (NSRC) Yes Transport Immediately No No No
Kern County Yes (“Onset observed within 4 hours”) No Yes (appropriate facility) Yes Transport to appropriate facility in accordance with stroke policy Yes No No
Los Angeles County Yes (“Time of sypmtom onset” and “last known well time”) No Yes Yes   No No No
Marin County Yes (“Last known normal”) No Yes Yes Call stroke if last seen normal <4 hours, rapid transport to patient’s preferred Primary Stroke Center, PSC as long as the estimated transport time is not more than 15 minutes longer than the nearest PSC; Preferred PSC: patient’s preference or PSC with patient’s medical records; No preferred PSC: transport to the closest PSC; Early Stroke Notification No No No
Merced County No Yes No No   No No No
Monterey County Yes (“Last known well”) Yes (15 minutes) Yes Yes   No No No
Mountain Valley Yes (“Time of onset”) No No No   No No No
Napa County Yes (“Time of onset”) Yes Yes (CVA receiving center) Yes   No No No
Northern California Yes (“Last seen normal”) Yes No Yes   No No No
North Coast No Yes No Yes Transport code 3 if unconscious or conscious with progressive symptoms. Code 2, for others No No No
Orange County Yes (“Time of onset”) No Yes Yes   No No No
Riverside County Yes (“last known well”) Yes (limit scene time to 10 mins. or less) Yes Yes   No No No
Sacramento County Yes (“Last observed to be normal”) No Yes (If CPSS >0 and onset 4 hours or less) Yes   No No No
San Benito County Yes (“Time since symptoms onset/last time seen in premorbid state”) No No Yes   No No No
San Diego County Yes (“Last time known normal”) Yes Yes Yes For suspected stroke with major deficit with onset of symptoms <4 hrs, expedite transport Yes No No
San Joaquin County No Yes No Yes   No No No
San Luis Obispo County Yes (“Last seen normal”) No No Yes   No No No
San Mateo County Yes (“Time seen at Baseline”) Yes (if symptoms present for <7 hrs) No Yes   No No No
Santa Barbara County Yes (“Last time seen normal”) Yes No Yes Consult with ED physician for further treatment measures No No No
Santa Clara County Yes (“Last seen normal”) No Yes (if last seen normal <6 hours) Yes   No No No
Santa Cruz County Yes (“Time since symptoms onset/last time seen in premorbid state”) No No Yes   No No No
Sierra-Sacramento Yes (“Time of onset of symptoms or when patient last seen normal”) No Yes (If symptoms <4 hours and within 30 min of stroke receiving center) Yes   No No No
Solano County Yes (“Time of symptom onset”) Yes No Yes   No No No
Tuolumne County No No No No   No No No
Ventura County Yes (“Time last known well”) Yes Yes Yes   No No No
Yolo County No No Yes (stroke symptoms less than or equal to 4.5 hours and within 45 min of stroke receiving center) Yes   No No No
  82% 61% 52% 88%        
Table 7 | Stroke regionalization. | LEMSA, local EMS agencies; EMS, emergency medical services; CT, computed tomography; NSRC, neurovascular stroke receiving center
FLUIDS & VASCULAR ACCESS

Clinical Question

Should normal saline be routinely given to patients with suspected stroke, and what type of vascular access should be attempted?

Summary of Current Evidence

No strong evidence supports or refutes routinely giving fluid boluses to stroke patients. Patients who have suffered a stroke are typically either euvolemic or hypovolemic.32 Hypotension occurs infrequently after stroke but leads to poor outcomes.74 A variety of hydration regimens on normotensive stroke patients resulted in no conclusive standard fluid regimen.75-82 A bolus of intravenous (IV) fluid acutely improved cerebral perfusion in focal ischemia from subarachnoid hemorrhage-induced vasospasm, a clinical scenario similar to ischemic stroke.83, 84

It is useful to start a large bore IV access in any patient with a suspected stroke who may be receiving tPA and who could have subsequent hemorrhage. However, transport should not be delayed for this. Because of bleeding risk, multiple attempts at starting IV access should be limited. No studies negate or support the use of intraosseous access in stroke patients, but it is more invasive and carries theoretical greater risk of bleeding.

Current Prehospital Treatment Recommendation

Level A Recommendations

None given.

Level B Recommendations

None given.

Level C Recommendations

Patients with low systolic blood pressure and no contraindications should be given a bolus of IV fluids.

An IV should be placed as long as it does not delay transport and more than two attempts are not required.

An IV should not be placed in the external jugular vein.

No Recommendation

N/A


LEMSA Advise NS bolus Advise defined bolus quantity Advised TKO Location Notes
Alameda County No No Yes Yes No more than 1 AC attempt and no more than 2 IV attempts total, 18 GA, no smaller than 20 GA proximal to wrist, AC preferred
Central California No No Yes No  
San Francisco No No Yes No NS TKO, If SBP<90 or poor perfusion, NS bolus
Coastal Valleys No No Yes No  
Contra Costa County Yes (If hypotensive or poorly perfused) Yes (consider 250-500 cc if hypotensive) Yes No  
El Dorado County No No Yes No Twin cath or a second line is preferred for thrombolytic candidates. Limit IV attempts to two.
Imperial County No No No No IV prn
Inland Counties No No No No Vascular Access
Kern County No No No No IV Line/Saline Lock
Los Angeles County No No No No Venous access prn
Marin County No No No No  
Merced County Yes Yes (If SBP less than 90, then 500cc fluid boluses as indicated) Yes No  
Monterey County Yes (if appropriate) No No No  
Mountain Valley No No Yes No  
Napa County No No Yes No  
Northern California Yes No Yes No Don’t delay rapid transport to establish IV, SBP at a minimum of 120mmHg, do not exceed 1.5L NS
North Coast No No Yes No  
Orange County No No No Avoid IO and EJ  
Riverside County No No No No  
Sacramento County No No No No  
San Benito County No No No No  
San Diego County Yes Yes No IV/IO adjust prn 250cc IV/IO with clear lungs to maintain BP>120
San Joaquin County No No No No 10cc/kg bolus if signs of shock present, max of 2L
San Luis Obispo County No No No No Establish vascular access
San Mateo County No No No No Consider IV/IO
Santa Barbara County Yes (500cc to keep SBP >100, Max 1L) No Yes No  
Santa Clara County No No No   18G catheter minimum for CT scan, AC placement if possible. No more than 2 IV attempts
Santa Cruz County No No No No IVF if suspected shock
Sierra-Sacramento No (May bolus up to 1L) No Yes No  
Solano County No No Yes No  
Tuolumne County No No Yes No IV if HTN, in unstable IO OK if unable to gain IV access
Ventura County No No No No IV/IO access
Yolo County No No Yes No  
  18% 9% 48% 12%  
Table 6 | Normal saline administration. | LEMSA, local EMS agencies; NS, normal saline; TKO, to keep open; EMS, emergency medical services; SBP, systolic blood pressure; IO, intraosseous infusion; EJ, external jugular; IV, intravenous; prn, pro re nata (when necessary); BP, blood pressure; CT, computed tomography; AC, antecubital; IVF, intravenous fluids; HTN, hypertension
Interfacility tPA

Clinical Question

Should tPA be delivered to patients by paramedics with confirmed strokes being transferred to CSCs for a higher level of care?

Current Prehospital Treatment Recommendation

Level A Recommendations

None given.

Level B Recommendations

None given.

Level C Recommendations

tPA should be initiated promptly on patients with confirmed strokes and no contraindications and, for persistent LVO, they should be transported as quickly as possible to a CSC for possible endovascular therapy.

It is the responsibility of the sending physician to select appropriate means of transport and the appropriate level of the transporting staff.

No Recommendation

N/A

Summary of Current Evidence

The majority of acute stroke patients will be assessed and imaged at a PSC or community hospital. A subset of those patients will not respond to tPA and will require timely endovascular therapy at a CSC. The tPA infusion will need to be continued during transport. Recent studies indicate that this combination of tPA followed by endovascular intervention for persistent LVOs is rapidly becoming the standard of care.86

The use of prehospital tPA presents several logistical challenges. One study showed poor compliance with monitoring of blood pressure, delivery of antihypertensives and discontinuation of tPA with worsening neurological status. Despite these differences, there were similar neurological outcomes and intracranial hemorrhage rates between patients in whom guidelines were followed rigorously and those in whom they were not.129 Their mean transport time from PSC to CSC was 38 minutes +/- 20 minutes.129 There are also logistical issues such as the implementation of infusion pumps in the field and the fact that tPA is not in the current scope of practice of paramedics in California.

Some areas are successfully sending nurses from the initial hospital with the patient and the tPA running in a hospital pump. That model avoids the complications of training paramedics in delivery of tPA and the use of new pumps. The practice is still evolving and requires further study.

Results

We reviewed protocols from all 33 LEMSAs within the state of California. Some LEMSAs had individualized stroke protocols, while others had stroke protocols embedded within those for altered mental status.

Use of a Stroke Scale

Most (85%) LEMSAs directed the use of a stroke scale (See Table 1). The majority used CPSS. Of the 15% that did not specifically use a stroke scale, 9% recommended specific neurological exams that encompassed major key components of a stroke scale.

Blood Glucose Evaluation

All LEMSAs recommended evaluation of blood glucose as part of their protocols for patients with suspected strokes (See Table 2). Seventy-three percent recommended a titrated dose of dextrose to correct low blood glucose. The titrated dose ranged from 60 to 80mg/dL.

Supplemental Oxygen

Twenty-one percent of the LEMSAs advised routine use of oxygen regardless of oxygen saturation (See Table 3). Thirty-nine percent of LEMSAs advised a titrated dose of oxygen. The oxygenation goal of titration ranged from 94 to 100%.

Patient Positioning

Three percent of LEMSAs recommend laying the head of bed flat as tolerated. Some (15%) recommend elevating the head of bed, and 21% recommend the lateral decubitus position (See Table 4).

12-lead ECG and Cardiac Monitoring

Fifty-eight percent of LEMSAs recommended cardiac monitoring, and 33% recommended a 12-lead ECG in patients with suspected strokes (See Table 5). Of those, some recommended both and some recommended one or the other.

Normal Saline Administration or Fluid Assessment

Eighteen percent of LEMSAs recommended a normal saline bolus (See Table 6). Almost half (48%) recommended an IV line with minimal fluid. Twelve percent of LEMSAs gave direction about IV line location, gauge, or number of attempts.

Stroke Regionalization

More than half (52%) of LEMSAs directed transport of patient to a stroke center. Eighty-eight percent recommended hospital notification from the field (See Table 7). Eighty-two percent of LEMSAs recommended documentation of duration of symptoms. Of those, most recommended documentation of “last seen normal.” Sixty-one percent of LEMSAs gave explicit directive to limit time on the scene, but only nine percent gave a specific time limit.

Interfacility tPA

No LEMSAs commented on tPA during interfacility transport.

CONCLUSION

Stroke is a complicated disease process. The science guiding optimal identification and treatment of stroke patients is evolving. Because of the difficulty in identifying stroke patients and the importance of their rapid transport to stroke centers, stroke presents a complex challenge for prehospital providers. The evidence-based recommendations presented in this paper will inform EMS medical directors and guide creation of protocols for identifying and treating stroke patients.

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