Diagnosis and initial treatment of ischemic stroke. (National Guideline Clearinghouse)
BIBLIOGRAPHIC SOURCE: Institute for Clinical Systems Improvement (ICSI). Diagnosis and initial treatment of ischemic stroke. Bloomington (MN): Institute for Clinical Systems Improvement (ICSI); 2006 Feb. 66 p. [119 references]
SUMMARY CONTENTClinical Highlights and Recommendations
Screening (Ambulatory) Algorithm Annotations
This contact may occur with one of several medical system personnel, including primary care physicians, other medical specialty physicians, emergency medical personnel, nursing staff in a clinic or urgent care setting or even non-medical triage personnel. This does not refer to the ED evaluation. This contact may be by phone or in person. Potential staff contacts should be educated in the importance of stroke symptom recognition and the appropriate triage measures that should be taken.
This should include detail as to the location, severity, duration of symptoms, and any aggravating or relieving factors. Symptoms that are commonly associated with ischemic stroke or transient ischemic attack (TIA) diagnoses include:
Less common symptoms that may represent ischemic stroke or TIA include sudden onset vertigo, double vision, nausea or vomiting, stupor or coma, difficulty deglución, voz ronca, y/o sacudida de una extremidad.
This discussion is not meant to represent a detailed guide to discerning between ischemic stroke and other diagnoses. If there is any uncertainty as to symptom causation, the evaluation should proceed as though ischemic stroke or TIA is confirmed so as not to delay appropriate emergency treatment if needed.
Some of the diagnoses outlined in Annotation #2, "Immediate Screening for Ischemic Stroke" may warrant ED evaluation because of the urgency of the problem itself or the inability of the contact person to distinguish the other condition from ischemic stroke. In these uncertain cases, the contact person should continue on to box #5 in the Screening (Ambulatory) Algorithm.
Refers to ongoing symptoms suggestive of cerebral ischemia. If symptoms have resolved and were present for less than 24 hours, this is clinically defined as a TIA.
Key Point:
Si los síntomas se resuelven completamente y luego recurren, para los propósitos de determinar si thrombolysis esta indicada, el tiempo de comienzo sería el último momento en que el paciente se encontraba normal (simplemente antes del principio del segundo conjunto de síntomas). Los pacientes pueden ser incapaces de dar esta información si tienen una afasia o obnubilación. Los familiares u otros testigos pueden ser necesarios para dar esta información. Si el paciente estar durmiendo y despierta con el problema, el tiempo de principio será el momento que el paciente fue visto normal poco antes de quedarse dormido.
Patients with stable mild deficits present longer than 24 hours may be transported to the ED for evaluation and treatment by means other than 911. As a rule, they should be admitted to the hospital to assure thorough and expeditious evaluation and treatment. Outpatient evaluation and treatment is an acceptable alternative if it can be done as quickly as it could be done inpatient and if all goals of inpatient assessment (diagnosis of mechanism, initiation of appropriate secondary prevention, prevention of complications, early assessment for and deployment of rehabilitative services) can be successfully addressed.
Patients presenting with history suggestive of TIAs may have neurological deficits they are unaware of. To avoid missing the thrombolytic treatment window, patients with possible TIAs presenting within 2 hours of symptom onset should be triaged like patients with stroke.
This work group recommends that the physician strongly consider hospitalization for TIA patients who appear in the ED within 48 hours of the event to expedite work-up and possibly administer tPA if the deficit recurs.
Patients should be taken to the ED urgently.
Patients with a single episode of transient ischemic symptoms greater than 48 hours from presentation but within the last two weeks should be considered for an expedited outpatient evaluation within 72 hours. Those with several TIAs (greater than 4) in that time frame require immediate evaluation and hospitalization.
Risk of recurrence in this group may be lower than those with early presentation. Prompt outpatient evaluation by a physician within one week is appropriate.
Refer to Annotation #14, "High Risk for Immediate Future Events?"
Also, refer to the Support for Implementation section, "Other Resources Available" in the original guideline document.
Key Points:
Analysis of a population-based sample of TIA episodes (n=209) yielded the ABCD score identifying those at high risk of stroke. The elements of the scale from this derivation sample are:
A - for age. Over the age of 60 years old =1 point
B - for blood pressure. A systolic greater than 140 mm Hg or diastolic greater than 90 mm Hg = 1 point;
C - for clinical features. These include:
Unilateral weakness = 2 points
Speech disturbance without weakness = 1 point
Other = 0 points
D - for duration of symptoms:
Duración Symptoms greater than 60 minutes = 2 points
Duracion Symptoms 10-59 minutes = 1 point
Symptoms lasting less than 10 minutes = 0 points.
Not settled is whether the assessment of those at low risk can be safely pursued at a more leisurely pace or foregone altogether.
Recent reports highlight the frequent early recurrence of symptoms of stroke and other cardiovascular events as well as the value of early intervention. Whether hospitalization would help to mitigate further injury by ensuring appropriate surgical intervention when needed (carotid endarterectomy) or increasing the percentage of patients receiving appropriate prophylaxis early in their course is not clear. However, it would seem prudent to admit most patients to the hospital with transient ischemic attack that occurred within 48 hours of presentation in order to expedite their evaluation and address these issues promptly given the immediate risk of recurrence. Furthermore, hospitalization would enable timely administration of lytic therapy in the interval of greatest risk, the initial 24 to 48 hours. The factors which predict high risk of recurrence might influence decision making in this patient group. Although the data available cannot define an appropriate triage decision for all patients, this information should serve as a guide for appropriate and safe management of the patient with TIA. Certain diagnostic entities if suspected may require hospitalization for specific management even with presentation later than 24 hours from TIA occurrence (e.g., carotid or vertebral artery dissection, specific coagulopathy or arteriopathy, cerebral venous thrombosis.)
In summary, the Committee recommends consideration of hospitalization for patients with first TIA within the past 24 to 48 hours to facilitate early deployment of lytic therapy, if necessary, and to expedite institution of definitive secondary prevention. For others, multiple and increasingly frequent symptoms ("crescendo TIAs") and the clinical features described above might also justify hospitalization rather than expedited ambulatory management. Whatever the strategy, speed is key. Patients managed in the outpatient setting should be fully educated about the need to return immediately if symptoms recur to allow use of lytic therapy.
Refer to the original guideline document for additional information on risk assessment which can help identify patients at high risk of stroke.
Evidence supporting this recommendation is of classes: B, D, M, R
Patients with fewer than five TIAs within a two-week time frame may be evaluated by a physician within 72 hours. A more emergent evaluation with hospitalization is indicated if there are features suggestive of crescendo TIAs or factors predictive of a high risk of future events. (See Annotation #14, "High Risk for Immediate Future Events?")
Refer to the Support for Implementation section, "Knowledge Products and Resources" in the original guideline document.
Emergency Department Treatment Algorithm Annotations
Key Points:
Patients presenting to the ED soon after the onset of symptoms may be candidates for treatment with IV tissue plasminogen activator (tPA) and will therefore require a rapid evaluation and treatment initiation. Although the time window from onset of symptoms to treatment can be up to 180 minutes, the evaluation in the ED will require at least 30 minutes in most cases (CT scan of head, laboratory tests performed and results returned, IV access obtained, and neurological exam and history). The guideline committee has therefore chosen 150 minutes as a practical cutoff time for this triage decision. Those who are not candidates for thrombolytic therapy could be evaluated according to usual ED routine.
There are important exceptions to this time limitations guideline for triage of the patients into the "Stroke Code" process. In certain instances, the time for evaluation may be shorter and this time limit of 150 minutes for triage to "Stroke Code" evaluation may be too conservative, and could be 165 or 170 minutes. One example would be the patient who is already in the hospital and has received the appropriate laboratory evaluation, who already has an IV access, and for whom much of the history is already known. In that case, a brief neurologic exam and rapid evaluation with CT may be the only items required prior to treatment and could theoretically be performed in 10 to 15 minutes.
Refer to the original guideline document for information on tPA tested in large, randomized, placebo-controlled clinical trials.
Evidence supporting this recommendation is of classes: A, C, D, R
Key Points:
Intra-arterial thrombolytic therapy may be a treatment option for selected patients presenting in an early time frame but beyond the 3-hour time window for intravenous tPA. Please note that the management during and following intra-arterial treatment is outside the scope of this guideline.
This is not a routine treatment. The availability of this option will be institution dependent, and patients must be highly selected. If considering this treatment option for a patient, a physician must explain to patients and family that this is an experimental treatment with substantial risk. Despite the limitations of available study data, in cases of more severe presentation with basilar artery or middle cerebral artery (MCA) occlusion, intra-arterial thrombolytic treatment may be appropriate since the prognosis without treatment is poor.
If the patient is an appropriate candidate for this treatment, consideration should be given to immediate transfer to an institution offering this intervention. If an endovascular interventionist skilled in this technique is available to the hospital, this person should be mobilized quickly.
See the original guideline document for criteria for consideration of angiographic evaluation for intra-arterial treatment.
Evidence supporting this recommendation is of classes: A, C, D
The goal of the stroke code is to rapidly administer tPA in appropriately screened candidates. The onset of symptoms to treatment can be up to 180 minutes, but the National Institutes of Health (NIH) recommendation of "door to drug" is within 60 minutes.
Stroke Code Algorithm Annotations
The guideline committee uses the term "stroke code" to refer to a process in the ED for the rapid evaluation and treatment of patients who have presented in a time frame qualifying them for thrombolytic therapy. This process may take many forms. It might include a formal "stroke team" that is called whenever a possible candidate for tPA has presented or it may include the ED staff who have been trained in the rapid evaluation and treatment of stroke victims. The general concept is one which includes:
Key Points:
Review History and tPA Treatment Indications and Contraindications and Baseline NIHSS
Take a complete patient history including a review of indications and contraindications for treatment with tPA. The contraindications for treatment should be considered relative contraindications.
The recommendations for treatment indications and contraindications were modified from the Institute for Clinical Systems Improvement (ICSI) Technology Assessment Work Group for tPA for Acute Ischemic Stroke. They are based upon the National Institute of Neurologic Disorders and Stroke (NINDS) study recommendations with amendments to include recommendations from clinical practice at Mayo Clinic and treatment guidelines from the Stroke Treatment in the Community study.
See ICSI technology assessment Tissue-type Plasminogen Activator for Acute Ischemic Stroke TA # 28, 2005.
Evidence supporting this recommendation is of class: D
Clinical Contraindications
Patients with this blood pressure (BP) excluded only if it remains elevated on consecutive measurements. Also exclude if aggressive treatment is required to lower BP into appropriate range.
History Contraindications
Laboratory Contraindications
Glucose should always be measured prior to giving tPA; other parameters should be checked before treatment if there is reason to believe they may be abnormal (e.g., INR and aPTT should be checked if patient has been exposed recently to warfarin or heparin or if there is history of liver disease).
Radiology Contraindications
Once indications and contraindications have been reviewed, documentation of why patient was included or excluded must occur.
Perform Vital Signs Every 15 Minutes with Neuro Checks
A history and neurological examination must be performed to assess whether the presentation is consistent with a stroke diagnosis and to estimate the severity of the deficit. Use of the NIHSS by physicians and nursing staff is encouraged as this would provide a uniform method of evaluation for comparison between examiners during the early hours of the stroke evaluation. The guideline committee encourages use of the NIHSS as an initial evaluation tool and after resuscitation or treatment to assess for change.
The NIHSS is a quantitative measure of neurologic deficit in stroke patients that covers the key aspects of the neurological exam including level of consciousness and orientation, eye movements, visual fields, facial weakness, motor strength in limbs, coordination, sensation, language and comprehension of language, articulation, and neglect. It can be performed in rapid fashion (5-8 minutes) which is an important feature in this clinical setting.
Evidence supporting this recommendation is of classes: B, C, D, R
Refer to the original guideline document for additional details.
Record Weight (Estimate If Needed)
Necessary/critical laboratory tests are:
Recommended laboratory tests include:
Others to consider:
These tests are used to evaluate for dehydration, metabolic disorders which might influence neurologic status (especially hypoglycemia and hyperglycemia), hematologic disorders such as polycythemia which may affect cerebral perfusion, or coagulopathies which could affect the treatment decision. Prior to administration of tPA, the platelet count and glucose level should be reviewed. If the patient is known to be on warfarin or has received heparin within the last 24 hours, the prothrombin time and partial thromboplastin time should be reviewed prior to treatment. A urine or serum pregnancy test should be obtained in women of child bearing potential if there is substantial reason to believe the patient may be pregnant.
Perform Electrocardiogram (EKG)
An EKG should be performed for the purpose of screening for concomitant cardiac disease, either acute or chronic which may impact on immediate treatment decisions.
Perform CT Head Without Contrast
A CT scan without contrast must be performed prior to treatment with tPA, primarily for the purpose of excluding hemorrhage. Early signs of infarct should also be sought, as this finding confers greater risk of symptomatic intracerebral hemorrhage with tPA treatment. It is suggested that the greatest level of radiologic expertise possible be obtained for this reading with the caveat that this CT reading should not create excessive delays in the evaluation and treatment process. A process for rapid teleradiography CT readings should be organized and in place if needed.
Other Cardiac Assessment as Appropriate (Telemetry)
Key Points:
Educate Patient and Family
A process should be in place for the patient and family that will rapidly orient them to the suspected diagnosis, ED process, tests to be performed, tPA treatment and its risks, and other treatment measures to be considered. This could include both caregiver face-to-face interaction with the patient and family as well as teaching tools in written form. Education should be documented in the medical record.
Treat Hypertension if greater than 185 systolic and 110 diastolic
Patients with this BP excluded only if it remains elevated on consecutive measurements. Also exclude if aggressive treatment is required to lower BP into appropriate range (e.g., if more than a few doses of any medication is required or if nitroprusside drip is required.)
Recommendations for Management of BP in the setting of acute ischemic stroke, tPA candidate:
Refer to the original guideline document for discussion of supporting evidence and the American Heart Association (AHA) recommendations for the management of patients with acute ischemic stroke.
In general, discontinuation of a patient's usual daily antihypertensive regimen is not advised as this may result in unwanted rebound hypertensive effects. Exceptions to this practice might include holding these medications if the BP is low and holding diuretic therapy regardless of the BP, to avoid any problems with volume depletion that might contribute to hemoconcentration that could limit blood flow.
Evidence supporting this recommendation is of classes: A, D, R
Two intravenous (IV) lines should be started so that tPA may have a dedicated line.
Start IV Fluids
Treatment with a 0.9% normal saline at a rate of 75 to 125 cc/hr or 2-3 L/day should be administered for the avoidance of dehydration. The rate may be adjusted for febrile patients.
Evidence supporting this recommendation is of classes: A, C, D, R
Interventions for patients with temperatures of greater than 37.5 degrees C (99.5 degrees F) include appropriate dosing of acetaminophen (1 gram orally or 650 mg rectally every 4-6 hours, not to exceed 4-6 grams in 24 hours) and regular monitoring of temperature status (every 4 hours). For those patients with extreme hyperthermia greater than 39.4 degrees C (103 degrees F), aggressive interventions including cooling blankets and ice packs are encouraged. Secondary causes for temperature elevation should be sought.
In human studies, early hyperthermia in acute stroke is associated with increased risk of poor outcome, higher mortality, and increased infarct volume. The causality and the relationship of temperature elevation to these poor outcomes are not fully understood. Whether intervention with cooling methods will result in improved outcomes is unknown. [Conclusion Grade III: See Conclusion Grading Worksheet A -- Annotation #27 (Hyperthermia) in the original guideline document]
Evidence supporting this recommendation is of classes: B, D, M, R
Treat Hyperglycemia
Hyperglycemia may adversely influence clinical outcome.
It is unclear whether early hyperglycemia in the setting of acute stroke may be a marker of physiologic stress or an independent predictor of poor outcome. Usual management of hyperglycemia with gentle dosing of subcutaneous insulin in a timely manner during acute ischemia would seem prudent until ongoing clinical trials address the appropriateness of more aggressive treatment measures. [Conclusion Grade III: See Conclusion Grading Worksheet B - Annotation #27(Hyperglycemia) in the original guideline document]
Evidence supporting this recommendation is of classes: A, B
Refer to Algorithm Annotation #26, "Evaluation (Should Occur Concurrently With Intervention)," for criteria.
Treatment should consist of tPA 0.9 mg/kg intravenously to a maximum dose of 90 mg. Ten percent of this dose should be given as a bolus over 1 to 2 minutes and the remainder infused over one hour. This dosing may be based upon actual or estimated weight.
Key Points:
Aspirin (ASA)
Patients who are not candidates for tPA should be promptly given ASA in a dose of 160 to 325 mg orally, rectally, or by nasogastric tube and should be continued on a similar daily dose. Exceptions to this approach would include avoiding treatment in those with contraindications to ASA therapy (e.g., ASA allergy, gastrointestinal hemorrhage).
Evidence supporting this recommendation is of classes: A, M
Considerations with Heparin Use
Results from the International Stroke Trial provide powerful evidence against the routine use in patients with acute ischemic stroke, of any heparin regimen as intensive as the moderate dose subcutaneous regimen utilized in this very large clinical trial (unfractionated heparin - 12,500 units subcutaneous twice daily).
This would include the adjusted dose continuous infusion of unfractionated heparin that is commonly employed for the treatment of stroke in the United States. The commonly cited indication of vertebrobasilar distribution ischemia or ischemic stroke in the setting of atrial fibrillation was analyzed separately and there was no measurable benefit in these specific subgroups. Similarly, the weight of available data regarding use of full dose low-molecular-weight heparin for the acute treatment of stroke do not support their routine use for limiting disability or decreasing mortality in this setting.
The routine use of acute anticoagulation treatment with unfractionated heparin, low-molecular-weight heparin, or heparinoid in acute ischemic stroke is not supported by the available evidence. This treatment does not appear to improve clinical outcome from the index stroke. There may be subgroups who benefit, but further studies of this problem are required for confirmation. [Conclusion Grade I: See Conclusion Grading Worksheet C- - Annotation #31 (Heparin) in the original guideline document]
Despite these discouraging results, the use of continuous heparin infusion in acute stroke has continued to be common in clinical practice. Given these data, if the decision is made to use full dose continuous heparin infusion for a specific indication (e.g., large vessel atherothrombosis or dissection), physicians are strongly recommended to discuss with their patients the lack of proof for this therapy and to detail the potential hazards of therapy.
Heparin Use for VTE Prophylaxis
Lower doses of these agents, (e.g., enoxaparin 40 mg subcutaneously daily or unfractionated heparin 5,000 IU subcutaneously twice daily), are beneficial for the prevention of deep vein thrombosis or pulmonary embolus in those stroke victims with limited mobility and can be advocated for that purpose. Pharmacologic prophylaxis should be considered for patients at high risk for VTE including an estimated length of stay of 4 days or more.
For patients of high risk for VTE where pharmacologic prophylaxis is contraindicated, elastic stockings are recommended and consider intermittent pneumatic compression (IPC) if confined to bed.
Evidence supporting this recommendation is of classes: A, R
Treat BP if greater than 220/120 or MAP greater than 130
Recommendations - Ischemic stroke, not a tPA candidate:
Note: Dosing examples are included in the original guideline document.
It is important to recognize that these recommendations must be tailored to the individual, dependent on the patient's acute presentation and whether or not there is a previous history of hypertension. Young patients without a previous history of hypertension may be less tolerant of the higher extremes of BP in this setting. Specific comorbidities which may require a more aggressive use of antihypertensive therapy in this setting include:
In general, discontinuation of a patient's usual daily antihypertensive regimen is not advised as this may result in unwanted rebound hypertensive effects. Exceptions to this practice might include holding these medications if the BP is low and holding diuretic therapy regardless of the BP, to avoid any problems with volume depletion that might contribute to hemoconcentration that could limit blood flow.
Continue to treat hyperthermia, hyperglycemia, or hypoglycemia
Refer to Annotation #27, "Intervention (Should Occur Concurrently with Evaluation"), above.
Initiate deep vein thrombosis (DVT) prophylaxis
Consider DVT prophylaxis in any patient admitted to the hospital with weakness related to an ischemic stroke. The risk of DVT is high (25% to 50%), and prophylaxis with subcutaneous heparin decreases the incidence (10% to 20%). The risk of pulmonary embolism appears to be decreased as well, although numbers have been small and statistical significance not achieved.
All patients should receive patient education that includes signs and symptoms of VTE and therapy options and encouraged to ambulate early and perform flexion/extension exercises. Elastic stockings should be used for patients at high risk for VTE. IPC should be considered for patients at high risk for VTE who have contraindications to pharmacologic prophylaxis.
Unfractionated heparin at 5,000 units every 12 hours is the standard dose; 5,000 Units every 8 hours has been used in larger individuals. Low- molecular-weight heparin and heparinoids may be slightly more effective for DVT prophylaxis (decreased incidence from 22% with heparin to 13% with enoxaparin or danaparoid), and theoretically potentially safer (less risk of bleeding), but it has not been conclusively demonstrated in studies.
Low-molecular-weight heparin is renally cleared. For patients with a creatinine clearance (CrCl) less than 30 mL/min, use unfractionated heparin. The patient should be monitored for the possible development of heparin-induced thrombocytopenia (HIT) and bleeding. Obtain a platelet count and hemoglobin every other day beginning on the second day of heparin therapy.
Evidence supporting this recommendation is of class: M
Perform swallow evaluation
Early evaluation of swallow should be performed in patients at risk of aspiration so that an appropriate diet adjustment may be instituted. Patients at risk include those with facial weakness, significant dysarthria, excessive drooling, sputtering, choking, gurgling, wet voice, or pocketing food in mouth. Clear liquids by mouth and in some cases any food or fluid should be avoided in this setting until a swallow evaluation has established the patient's level of risk for aspiration with the various consistencies.
Swallow evaluation and dietary adjustments based on this information and early mobilization as effective treatments for prevention of medical complications have not been adequately evaluated in randomized clinical trials. However, in the absence of this level of proof, since these interventions are safe and have a reasonable probability of improving care by decreasing complications, it is reasonable to advocate their use in this setting. Several previously published guidelines advocate these practices.
Initiate rehabilitation early
Early mobilization within 48 hours of admission is advocated by means of early initiation of appropriate rehabilitation swivels or other nursing intervention for the purpose of preventing complications related to immobility including deep vein thrombosis, contractures, joint disorders, and pressure sores/decubitus ulcers.
Perform Nutritional Status Assessment
Assessment of the patient's baseline nutritional status and the implementation of treatments to correct any major nutritional problems are recommended. Poor nutritional status in patients admitted for stroke is associated with increased morbidity and mortality. Trials are currently underway to assess whether more intensive nutritional interventions improve outcomes for patients after stroke.
Evidence supporting this recommendation is of class: R
Ischemic Stroke Emergency Department Management (not a thrombolysis candidate) Algorithm Annotations
Refer to Annotation #26, "Review History and tPA Treatment Indications and Contraindications and Baseline NIHSS."
Refer to Annotation #26, "Perform Exam with Neuro Checks and Vital Signs Every 15 Minutes."
Refer to Annotation #26, "Draw Blood for Lab Tests."
Refer to Annotation #26, "Perform EKG."
Refer to Annotation #26, "Perform CT Head Without Contrast."
Refer to Annotation #27, "Educate Patient and Family."
Refer to Annotation #33, "Treat BP if Greater Than 220/120 or MAP Greater Than 130."
Refer to Annotation #27, "Treat Hyperthermia, Treat Hypo- or Hyperglycemia, and Treat Hypertension."
Refer to Annotation #31, "Initiate Aspirin Unless Contraindicated (see Annotation Discussion)."
Key Points:
Patients with acute ischemic stroke or TIA (occurring less than 24 to 48 hours before presentation) should generally be admitted to the hospital unless it is clearly based on expert opinion that outpatient evaluation and treatment is appropriate. The purpose would be to determine whether thrombolysis should be considered. This also allows for a thorough and rapid evaluation and treatment, especially to evaluate whether the patient is at high-risk for immediate future events.
Please refer to Annotation #14, "High Risk for Immediate Future Events?"
In patients with ischemic stroke occurring days to weeks prior to initial clinical evaluation with stable neurologic deficits, admission to the hospital is not always required. However, the following comorbidities or complications should be considered as possible reasons for admission to the hospital.