The point of this case study is to research and explore ischemic cerebral vascular accidents and their treatment in the pre-hospital environment. It will include the epidemiology and incidence of strokes, the clinical presentation as well as the aetiology and pathophysiology. This case study will then determine how to appropriately manage these patients in the pre-hospital setting. Stroke is a medical emergency and some of the main signs and symptoms include headache, weakness or paralysis, and slurred speech1,2 Cerebral vascular accident is a main cause of death in Australia and the paramedic needs to act fast in order to preserve life1,3 This case study uses peer-reviewed journal articles, medical practice websites and clinical textbooks.
Epidemiology/Incidence of the Patient’s Clinical Presentation and Relevance to Paramedic Practice
Cerebral vascular accidents (CVA) are the second largest killer within Australia and the leading cause of disability for Australian adults1,4 They are a global epidemic and are not restricted to certain groups of individuals.3 In 2012, roughly 50,000 Australians had either a recurrent or new stroke and in 2009 approximately one-third of Australians became disabled after experiencing a stroke.1,3,5 In 2016 stroke was responsible for nearly 6 million deaths worldwide.6 The cost of cerebral vascular accidents within Australia is estimated to be around $5 billion yearly.1,4 In Australia the burden of CVA patients on the ambulance service has increased by 10% in areas where there have been stroke campaigns initiated such as FAST.7 80% of these patients are now entering the emergency department through ambulances and therefore paramedics play a major role in rapidly transporting these patients to the correct facility.8
Patients Clinical Presentation
A cerebral vascular accident is an interruption or blockage of blood flow to an area of the brain1,9 This can lead to the sudden onset of neurological deficits which vary depending on the part of the brain affected.1,10 This injured area of the brain, if left untreated leads to disability and death.10 Common CVA signs this patient is presenting with are the sudden onset of headache, slurred speech, confusion and hemiplegia.2,3,10 Other typical neurological symptoms include visual disturbances, altered level of consciousness, hemiparesis and dysphasia.2,3,9,10
Vital sign survey shows this patient is hypertensive (210/110), this is a common sign of a CVA and occurs in 80% of patients.11,12 The main belief is that it is a compensatory response by the brain to increase perfusion to the penumbra.11,12 This patient’s Sp02 is within normal limits at 99% room air however, their pulse rate is tachycardic at a rate of 120 which can indicate a large infarct.1,13
Many factors increase a person's risk of CVA, the patient is 70 years old, age is a risk factor because with age changes occur in the nervous system which leads to a decrease in blood flow.1,14,15 Atherosclerosis is also a risk factor and is responsible for the narrowing of blood vessels increasing the risk of thrombotic CVA and is caused by problems such as high cholesterol.14-16 Others include atrial fibrillation, AMI, valve disease, recent surgery and other events that have the potential to create a clot, increasing the risk of embolic CVA.1,10 A transient ischemic attack occurs when the clot resolves without intervention and is another risk factor for CVA.1 Other risk factors include smoking, insufficient exercise, alcohol abuse and family history.1,15
Aetiology and Pathophysiology of Case presentation
An ischemic cerebral vascular accident is caused by a blockage in an artery that leads to the brain. The brain needs a constant supply of oxygen and nutrients such as glucose and without which the brain tissue will begin to die within a matter of minutes.9,14
This blockage is caused by a variety of illnesses, but the main cause is from a thrombus.1,10 This occurs when a clot forms in a blood vessel leading to occlusion of the vessel, preventing blood flow to part of the brain, which is primarily caused by atherosclerosis.1,14,16 Embolic CVA is the blockage of a blood vessel due to a clot that has broken off and travelled through the bloodstream becoming lodged in a blood vessel that supplies the brain.1,10 Cerebral vascular accident can also occur from a range of other issues that cause hypoperfusion of the brain tissue causing poor perfusion.1,10 Therefore, injury to the cerebral tissue in an ischemic CVA is directly due to the absence of blood supply.1 Haemorrhagic stroke occurs when a blood vessel within the brain ruptures.1
This lack of blood supply leads to the symptoms and signs of a CVA because the blood supply provides the tissue with the oxygen and nutrients that it needs to survive.14 Neurons are extremely reliant on the constant supply of blood and without it will die within a matter of minutes.1,10,14,17 This leads to the typical clinical presentation of a CVA as neurons are specific for communication between cells.14 However, due to the arrangement of vessels in the brain, the brain receives blood from multiple vessels to reduce the chance of injury.14
Pre-hospital management
A primary survey needs to be performed first to ensure the patient has an adequate airway, breathing, and circulation to sustain life.1-3,9,18 Secondary assessments should then begin with a full vital sign survey, a thorough history followed by a neurological assessment.1,9,18 The history needs to include risk factors of stroke.3 The vital sign survey should include a 12 lead ECG to determine if the stroke may have been caused by an embolus due to do to a cardiac-related issue such as atrial fibrillation.3 However, due to a lack of diagnostic equipment in the prehospital environment paramedics are unable to differentiate between ischemic and haemorrhagic CVA.1,2
The most valuable part of pre-hospital management is the ability of the paramedic to quickly identify the CVA.3,19 The paramedic should perform a Melbourne Ambulance Stroke Screen (MASS) assessment to identify eligibility for acute stroke referral.19,20 The hemiplegia and slurred speech qualify this patient, however, further investigations to determine a specific onset within 24 hours and location within 60 minutes of stroke centre are also requirements.19 Early notification of the intended hospital means staff can clear resources to cut delays between arrival and patient treatment.8
Early identification needs to be rapid because the longer the brain is without blood supply the risk of disability and death increases.10.19 The paramedic has a role in the reversal of this injury because transportation to a stroke centre means interventions can be performed which break down the clot and restore blood flow to the ischemic brain tissue, possibly reversing injury.9,10,19 Gaining IV access is also a priority for the paramedic because it means the patient can be taken straight to scans and the contrast injected earlier.2,3,21
This patient is presenting with hypertension with a blood pressure (BP) of 210/110. The drastic lowering of this patient’s BP should be avoided as hypertension is thought to be a physiological response to increase perfusion.1,17 Lowering blood pressure has the potential to increase tissue damage.1,22 The body has natural vasodilators which cause vasodilation to increase blood flow to the affected area, by reducing the blood pressure there is less opportunity for adequate perfusion.1,14,22 The patients’ blood pressure needs to be monitored and the paramedic should lower cautiously if it rises above 220 systolic therefore avoiding adverse systemic issues arising whilst maintaining adequate tissue perfusion.1,22,23 The level to which we would lower this blood pressure to is 185/110.22,23 The paramedic should investigate other causes of high blood pressure which for this patient may be the pain caused by the headache and should be treated with appropriate analgesia.1
This patient’s headache should be relieved by the analgesia, the paramedic should utilize the appropriate pain scale and use the score to determine analgesia choice.1,2,24 If the patient’s pain was mild to moderate the best pain relief option would be paracetamol, however, due to the suspicion of stroke, the patient may have dysphagia and nothing should be given orally until the paramedic can eliminate dysphagia.1,24 For a more severe headache Morphine, Fentanyl, Methoxyflurane can be used as appropriate.24 Other non-pharmaceutical approaches can also be considered.24
This patient should be positioned supine with the head elevated 45 degrees.2,17 This allows for optimal cerebral perfusion whilst simultaneously avoiding increased intracranial pressure (ICP) due to oedema.1,17 Increased intracranial pressure is a potential problem for CVA patients because the injury to the brain tissue can lead to oedema.1
Conclusion
Cerebral vascular accidents are one of Australia’s biggest killers with a wide range of neurological signs and symptoms. These signs include sudden onset headache, slurred speech, weakness or paralysis and confusion. CVA is due to interruption of blood flow to an area of the brain and can lead to disability and death. Therefore, quick assessment by the paramedic and early transport to hospital are crucial for good patient outcome. There are many risk factors which indicate possible CVA and the paramedic should ask about these in a thorough history. Pre-hospital management includes a primary survey followed by an in-depth history, neurological assessment and vital sign survey. IV access needs to be gained, treatment of hypertension is not always necessary however if there is a possibility of adverse effects, blood pressure should be lowered cautiously, the patient should be positioned with the head elevated 45 degrees, and analgesia should be considered.
Reference
Curtis K, Ramsden C. Emergency and trauma care for nurses and paramedics. 2nd ed. Chatswood (NSW): Elsevier; 2016.
Queensland Ambulance Service. Stroke/Transient ischaemic attack [Internet]. 2019 [cited 2019 Sep 12]. Available from: https://www.ambulance.qld.gov.au/docs/clinical/cpg/CPG_Stroke%20Transient%20Ischaemic%20Attack.pdf
Journal of emergency medical services. ‘Time is brain’ in Prehospital Stroke Treatment. [Internet]. 2012 [cited 2019 Sep 12]. Available from: https://www.jems.com/articles/print/volume-37/issue-6/patient-care/time-brain-prehospital-stroke-treatment.html
Anderlini D, Wallis G, Marinovic W. Stroke hospital admission rates in Brisbane and Queensland in 2015: Data from 11,072 cases. Int J Stroke. [Internet]. 2019 [cited 2019 Sep 16];14(4):417-421. doi:10.1177/1747493018801221
Australian Institute of Health and Welfare. Stroke and its management in Australia: an update [Internet]. 2013 [cited 2019 Sep 14]. Available from: https://www.aihw.gov.au/getmedia/3d56c949-68a4-46f3-bc7c-c40c89904d38/13994.pdf.aspx?inline=true
World Health Organization. The top 10 causes of death [Internet]. 2018 [cited 2019 Sep 14]. Available from: https://www.who.int/news-room/fact-sheets/detail/the-top-10-causes-of-death
Bray JE, Mosley IE, Bailey ME, Barger BE, Bladin CE. Stroke Public Awareness Campaigns Have Increased Ambulance Dispatches for Stroke in Melbourne, Australia. Stroke. [Internet]. 2011 [cited 2019 Sep 14];42(8):2154-2157. doi:10.1161/STROKEAHA.110.612036
Bray JE, Coughlan K, Mosley I, Barger B, Bladin C. Are suspected stroke patients identified by paramedics transported to appropriate stroke centres in Victoria, Australia? Internal Medicine Journal. [Internet]. 2014 [cited 2019 Sep 14];44(5):515-518. doi:10.1111/imj.12382
Australian Resuscitation Council. The ARC guidelines [Internet]. c2017 [cited 2019 Sep 14]. Available from: https://resus.org.au/guidelines/
Merck Manual. Ischemic Stroke [Internet]. 2017 [cited 2019 Sep 14]. Available from: https://www.merckmanuals.com/professional/neurologic-disorders/stroke/ischemic-stroke