Miller & Elmore explain the following guidelines for responding to a stroke;
Within 10 minute of arrival:
-Asses patient’s ABCs and vital signs
-Provide oxygen by nasal cannula
-Establish IV access
-Collect blood sample
-Perform a 12-lead electrocardiogram and attach patient to a cardiac monitor -Perform general neurological screening, including motor function, strength and equality
Within 25 minutes of arrival:
-Review patient’s history
-Establish the time of stroke onset
-Perform physical examination
-Determine patient’s level of consciousness using the Glasgow coma scale, and stroke severity
Smith, Johnston and Easton further add that clinical examination should be focused on the peripheral and cervical vascular system (carotid auscultation for bruits, blood pressure and pressure comparison between arms), the heart (dysrhythmia, murmurs), extremities (peripheral emboli), and retina. A neurological examination is performed to localise the site of the stroke, imaging study of the brain is nearly always performed and is requirement for patients being considered for thrombolysis.
Discuss your rationales for these orders.
MRI is currently preferred over CT for the diagnosis and localisation of ischemic stroke. Smith, Johnston, and Easton explain MRI has the potential for identifying a cerebral abnormality earlier and more clearly than other diagnostic tests. MRI uses a powerful magnetic field to obtain images of different areas of the body. Protons within the body align like small magnets in a magnetic field. In combination with radiofrequency pulses, the protons emit signals, which are converted to images. Wisselink & Panetta explain that with CT scanning, small hematomas, hemorrhagic infarcts, subarachnoid blood, clots surrounding aneurysms and arteriovenous malformations, shifts of the midline and deformities of the ventricles can be diagnosed. Acute ischemic stroke is usually not visualised with until frank infarct necrosis occurs, usually 15 to 30 hours after the initial insult. MRI demonstrates all of the above lesions, with the additional ability to image areas of hypoperfusion (eg, fresh ischemic infarctions).
Karch 2000 describes the therapeutic actions of mannitol. Elevates the osmolarity of the glomerular filtrate, thereby hindering the reabsorption of water leading to a loss of water, sodium, chloride; creates an osmotic gradient in the eye between plasma and ocular fluids, thereby reducing IOP; creates an osmotic effect, leading to decreased swelling in post-transurethral resection.
How would you explain the current understandings around this issue? Smith and Johnston et al explain a cautious approach to the management of elevated blood pressure is recommended in acute ischemic stroke. In general, frequent monitoring of blood pressure in hypertensive stroke is indicated and a persistent, severe hypertension (greater than 220 mm Hg systolic or more than 130 mm Hg mean arterial pressure) should be considered...