Stroke (1) PDF

Prepared by Alaa Mostafa Mohamed Lecturer of critical care &emergency nursing  Introduction A stroke is now referred to as a “brain attack” to encourage health care professionals and the public to think about stroke with the same urgency as a “heart attack”. Ischemic brain injury o...

Prepared by Alaa Mostafa Mohamed Lecturer of critical care &emergency nursing  Introduction A stroke is now referred to as a “brain attack” to encourage health care professionals and the public to think about stroke with the same urgency as a “heart attack”. Ischemic brain injury occurs when arterial occlusion lasts longer than 2 to 3 hours.  Definition Stroke is a descriptive term for the sudden onset of acute neurologic deficit persisting for more than 24 hours and caused by the interruption of blood flow to the brain.  Epidemiology Each year, approximately 795,000 people have a stroke; 610,000 of these are first attacks, and 185,000 are recurrent attacks. The incidence of stroke in men is greater than in women.  Classification Early identification of the type of stroke is critical because appropriate treatment for one classification can be lethal for the other. Classification  Risk factors Age and sex Hypertension Hyperlipidemia Atrial fibrillation Prosthetic heart valves Diabetes mellitus Collagen disorders Smoking Oral contraceptive use Cardiac disease Recent neck trauma  Initial Assessment Tools Triage of the patient with a possible stroke must be immediate and accompanied by rapid assessment and intervention. Several prehospital stroke scales are available; the most widely used are the Cincinnati Prehospital Stroke Scale  Initial Assessment Tools Patients with suspected stroke who present to the emergency department (ED) should be assessed within 10 minutes of arrival. Further assessment should include immediate computed tomography (CT).  Ischemic Stroke Ischemic stroke results from interruption of blood flow to the brain. This interruption can be the result of a local thrombus or embolus occludes a cerebral artery. Emboli generally originate in the heart or large arteries following atrial fibrillation, acute myocardial infarction (MI), or surgery.  Ischemic Stroke Pathophysiology: Local thrombus or embolus Decrease blood flow to the brain Oxygen deprivation Microscopic necrosis of the neurons and infarction  Ischemic Stroke Pathophysiology:  The ischemic cascade begins within seconds to minutes after perfusion failure, creating a zone of irreversible infarction and surrounding area of potentially salvageable tissues which called “ischemic penumbra".  Ischemic Stroke Pathophysiology:  The goal of acute stroke management is to salvage the ischemic penumbra.  Ischemic Stroke Pathophysiology:  After a huge thrombotic stroke massive cerebral edema and an increase in ICP to the point of herniation and death can occur.  Clinical manifestations Sudden onset of facial weakness Sudden onset of unilateral weakness Sudden confusion or trouble speaking (expressive aphasia) or understanding what is being said (receptive aphasia) Sudden onset of headache, nausea, and vomiting (most typical of hemorrhagic stroke)  Clinical manifestations More subtle deficits may include: ❖ Dysphagia ❖ Sudden visual disturbance ❖ Sudden onset vertigo, ataxia ❖ Sudden numbness or tingling  Further Assessment and Diagnosis To facilitate assessment and diagnosis, five questions need to be explored. Question 1: Is This a Stroke?  Determine whether the following symptoms are the result of a stroke or a stroke mimic:  Seizures  Syncope  Hypoglycemia or hyperglycemia  central nervous system tumor or hematoma. Question 2: When Did the Symptoms Begin?  Creative interrogation of the patient, family, EMS personnel, or bystanders is necessary.  Further Assessment and Diagnosis Question 3: Are Airway, Breathing, and Circulation Adequate?  ABC should be rapidly assessed before transporting the patient for CT scan. Question 4: Are Focal Deficits Present?  The initial examination is a brief, not full, neurological examination; the Cincinnati Prehospital Stroke Scale is adequate for this brief assessment.  Further Assessment and Diagnosis Question 5: What Immediate Diagnostic Procedures Are Recommended? Based on the American Heart Association’s 2010 guidelines, the following diagnostic procedures should be done:  Immediate CT scan of the head  Blood glucose  Serum electrolytes and renal function tests  12-lead electrocardiogram  Cardiac biomarkers  Complete blood count, including platelet count ,PT, and INR  Activated partial thromboplastin time (aPTT)  Oxygen saturation  Lumbar puncture if SAH is suspected and CT is negative for blood  In-Depth Neurological Examination  The American Stroke Association guidelines recommend using a standardized tool for assessing stroke deficits. The most validated tool for determining stroke severity is the National Institutes of Health Stroke Scale (NIHSS).  It is designed to be conducted quickly over 7 minutes. Patients with no deficits and normal mental status will have a score of 0, while scores of 15 to 20 reflect a severe stroke. In-Depth Neurological Examination  Therapeutic Interventions The Brain Attack Coalition has established time goals for delivering stroke care for all patients arriving within 6 hours of symptom onset or “last seen normal.” Therapeutic Interventions The goals of treating the stroke patient are:  To restore blood flow (arterial recanalization)  To optimize hemodynamics and maintain cerebral perfusion,  To minimize the damage and salvage the penumbra  Therapeutic Interventions All these goals can be achieved by establishing adequacy of ABCs:  Administer supplemental oxygen if oxygen saturation via pulse oximetry is less than 92%.  Consider advanced airway as needed.  Obtain second IV line with normal saline solution.  Therapeutic Interventions Intravenous Thrombolytic Therapy  Recombinant tissue-type plasminogen activator (rt-PA) is the only treatment approved by the U.S.  The goal is to begin fibrinolytic reperfusion therapy within 3 hours of onset of symptoms.  The dose of rt-PA is 0.9 mg/kg.  10% of the total dose is given as an IV bolus over 1 minute.  The remaining 90% is given as a continuous infusion over 1 hour.  Therapeutic Interventions  Once cerebral hemorrhage has been ruled out by CT scan, specific inclusion and exclusion criteria are used to identify the patient as a candidate for thrombolytic therapy. INCLUSION CRITERIA EXCLUSION CRITERIA RELATIVE EXCLUSION CRITERIA - Stroke resulting from ischemia - Head trauma or previous stroke - Minor or rapidly improving - within previous 3 months stroke symptoms - Age ≥18 years - Arterial puncture at noncompressible - Major surgery or serious trauma - site in previous 7 days within previous 14 days - Onset of symptoms 15 seconds - Serum glucose 185 mm Hg Diastolic >110 mm Hg  Nursing intervention for patients receiving rt-PA Before administration of rt-PA 1. Obtain an accurate patient weight to guide medication dosing. 2. Explain the risks and benefits of thrombolytic therapy to the patient and family. 3. Maintain a SBP less than 185 mm Hg and a DBP less than 110 mm Hg.  Nursing intervention for patients receiving rt-PA During and after administration of rt-PA 1. Assess for complications of thrombolytic therapy:  Bleeding  Angioedema  Anaphylactic reaction  Further deterioration in neurologic status 2. Perform neurologic assessment and obtain vital signs every 15 minutes for the first 2 hours, then every 30 minutes for 4 to 6 hours  Nursing intervention for patients receiving rt-PA During and after administration of rt-PA 3. Choose the optimal position for the head of the bed:  Elevate the head of the bed to 30 degrees for patients with increased intracranial pressure (ICP) or chronic respiratory problems  Maintain the head of bed flat to maximize cerebral blood flow for all other ischemic stroke patients.  Nursing intervention for patients receiving rt-PA During and after administration of rt-PA 4. Record an accurate intake and output. 5. For the first 24 hours, do not administer antithrombotics such as aspirin, heparin, clopidogrel, warfarin, or nonsteroidal anti-inflammatory drugs. 6. Transfer the patient to the intensive care unit where adequate monitoring can occur. The goal should be to transfer the patient out of the ED within 3 hours of arrival. 7. Maintain a systolic blood pressure of 180 mm Hg or less and a diastolic blood pressure of 105 mm Hg or less.  Nursing intervention for patients receiving rt-PA During and after administration of rt-PA 4. Document the following information:  Time of onset of stroke symptom or time “last seen normal”  NIHSS on admission to the ED  Patient’s weight  Weight-based calculated dose of rt-PA  Time rt-PA bolus was started  Results of swallow screen if performed in ED  Management of Blood If treatment for hypertension is indicated, it should be done cautiously, lowering the BP by only 15% to 25% in the first 24 hours.  Labetalol (Trandate) is a first-line agent of choice in stroke because it works quickly, is not too aggressive, and is short acting.  Administer labetolol, 10 mg intravenously, over 1 to 2 minutes and observe for change in BP.  Dose may be repeated or increased to 20 mg.  Transient Ischemic Attack Definition  Transient ischemic attack (TIA) is a brief episodes of neurologic dysfunction resulting from focal cerebral ischemia not associated with permanent cerebral infarction.  Transient Ischemic Attack  10% to 15% of patients experiencing a TIA have a stroke within 3 months, with half of these occurring within 48 hours.  The ABCD assessment tool has been recognized as a means of predicting the patient’s risk of having a stroke after a TIA. RISK FACTOR POINTS Points Age ≥60 years 1 ABCD 2-DAY COMMENT Blood pressure SCORE STROKE SBP ≥140 mm Hg or DBP ≥90 mm Hg 1 RISK 0–3 1% Hospital observation Clinical features of TIA (choose one) may be unnecessary Unilateral weakness with or without 2 without another speech impairment or 1 indication (e.g., new Speech impairment without unilateral atrial fibrillation) weakness 4–5 4.1% Hospital observation Duration of symptoms justified in most 2 TIA duration ≥60 minutes 2 situations 1 TIA duration 10–59 minutes 6–7 8.1% Hospital observation Diabetes history 1 worthwhile Total ABCD2 score 0–7  Hemorrhagic Stroke  Stroke symptoms can be the result of intracranial hemorrhage rather than ischemia. The differentiation is important because anticoagulants and fibrinolytic therapy are contraindicated in patients with hemorrhagic stroke.  Intracerebral Hemorrhagic Stroke Intracerebral hemorrhage (ICH) is bleeding directly into cerebral tissue. ICH destroys cerebral tissue, causes cerebral edema, and increases ICP. Causes of ICH:  Hypertension  Coagulopathy  Anticoagulation  Arteriovenous malformation (AVM)  Aneurysm  Illicit drug use  Signs and Symptoms Signs and Symptoms Patients with ICH can deteriorate quickly; rapid recognition and treatment is essential.  These patients typically present with sudden onset of focal neurological deficit that progressively worsens.  Sudden and severe headache.  Vomiting.  High blood pressure (often systolic BP >220 mm Hg).  Decreased level of consciousness, may rapidly progress to coma.  Intracerebral Hemorrhagic Stroke Diagnostic Procedures As with ischemic stroke, after ABCs are assessed and managed, imaging with CT and MRI should be the first priority for a patient with sudden neurological deficits.  Therapeutic Interventions Goals for blood pressure management should be to perfuse the brain adequately without increasing the risk for expansion of the hemorrhage. 1. If SBP is >200 mm Hg or MAP is >150 mm Hg, consider aggressive reduction of blood pressure with continuous intravenous infusion, with frequent blood pressure monitoring every 5 minutes. 2. If SBP is >180 mm Hg or MAP is >130 mm Hg and there is evidence or suspicion of elevated ICP, consider reducing blood pressure using intermittent or continuous intravenous medications to keep cerebral perfusion pressure >60 to 80 mm Hg. 3. If SBP is >180 mm Hg or MAP is >130 mm Hg and there is no evidence or suspicion of elevated ICP, consider a modest reduction of blood pressure (e.g., target B.P of 160/90 mm Hg) using intermittent or continuous intravenous medications to control blood pressure and clinically reexamine the patient every 15 minutes.  Subarachnoid Hemorrhage About 3% of all strokes are spontaneous subarachnoid hemorrhage (SAH) and these account for 5% of stroke deaths. SAH carries a high rate of disability and mortality, with approximately 50% of these patients not surviving the initial injury.  Subarachnoid Hemorrhage Causes and risk factors Cerebral aneurysms are the leading cause of nontraumatic SAH. Risk factors for aneurysmal SAH include:  Family history of SAH  Hypertension  Cigarette smoking  Female gender  Increasing age  Alcohol abuse  Use of stimulants such as cocaine.  Subarachnoid Hemorrhage  Signs and Symptoms Sudden intense, unrelenting headache. Often described as the “worst headache of my life.” Altered level of consciousness Vomiting or nausea Photophobia (intolerance to light) Nuchal rigidity  Focal deficits, possibly including hemiparesis  Subarachnoid Hemorrhage Diagnostic Procedures CT without contrast is the first line of imaging Lumbar puncture if the CT is negative but SAH is suspected  Subarachnoid Hemorrhage Initial treatment is focused on preventing rebleeding of the aneurysm.  Maintain systolic BP of 90 to 140 mm Hg.  Administer analgesics as needed for pain.  Short-acting sedatives may be required for agitated patients.  Subarachnoid Hemorrhage Perform frequent complete neurologic assessments to detect deterioration. Maintain body temperature at less than 37.5° C Initiate VTE prophylaxis with elastic stockings or pneumatic compression devices; do not give anticoagulants. Admit patient to intensive care unit. The patient may be a candidate for surgical clipping or endovascular coiling of the aneurysm; anticipate transfer to a tertiary care center.  General nursing intervention for patients with different stroke types 1. Establishing adequacy of ABCs by:  Administer supplemental oxygen if oxygen saturation via pulse oximetry is less than 92%.  Consider advanced airway as needed.  Obtain second IV line with normal saline solution.  General nursing intervention for patients with different stroke types 2. Performing frequent complete neurologic assessments to detect deterioration. 3. Keep patient NPO until he or she has passed a bedside swallow test.  General nursing intervention for patients with different stroke types 4. Managing increased ICP by:  Raising the head of the bed to 30 degrees  Keeping the patient's head in neutral position  Avoiding excessive hip flexion  Avoiding clustering nursing intervention  Administering analgesia and sedation.  Considering more aggressive ICP treatment that may include administering osmotic diuretics (Mannitol), hypertonic saline, and neuromuscular blockade and draining of cerebrospinal fluid.  General nursing intervention for patients with different stroke types 5. Administering antipyretics to maintain normothermia. 6. Keeping serum glucose below 140 mm Hg; avoiding hypoglycemia. 7. Maintain patient’s attention when talking with the patient, speak slowly, and give one instruction at a time; allow the patient time to process. 8. Provide support to the family and give them information about the expected outcome of the stroke.