Today we're going to be talking to you about the FAST-VAN Stroke Screening Assessment Tool. It's an assessment tool looking specifically at large vessel occlusion strokes. I am Ruth Whalen, I'm clinical nurse specialist for stroke services in Saskatoon Health Region and with me is Sanchea Wazalu, senior neurology resident. What's the big deal about stroke?
Stroke is a third leading cause of death in Canada. 20 to 30 percent of patients who have a stroke will die within the first 30 days. of the onset of symptoms and about 40% will die within the first year.
It's a leading cause of disability in Canada, affects a huge population of people, occurs every nine minutes and costs both in medical bills, lost wages and decreased productivity of the patient suffering the stroke. There are two main types of stroke. The first is an ischemic stroke and this is the one that we're really looking at when we use the FASTFAN tool. It's a large vessel occlusion and this occlusion is caused by thrombus forming within the vessel or traveling up from another area of the body and occluding that artery. The other type of stroke is a hemorrhagic stroke and this can either be intercerebral hemorrhage where small perforating arteries rupture within the brain or aneurysmal subarachnoid hemorrhage when a larger aneurysm ruptures within the brain.
We can also talk about TIA. which is a transient ischemic attack where the patient has stroke symptoms that fluctuate or are transient, and they last for minutes to kind of a maximum an hour. When a stroke occurs, there's a core area of infarct that dies immediately because of the lack of blood flow, and then there's an area around that core called the penumbra, which, if the patient receives timely treatment, can be saved from the stroke evolving into that area. The first investigations that are done are a CT of...
the head and a CT angiogram. The CT of the head looks for acute changes with an ischemic stroke that shows up dark on the CT. Initially there can be no signs of an acute stroke going on, but later on can develop this dark area.
A CT angiogram looks at the blood vessels specifically to see if there is a large clot hanging out. And this plain head CT really shows the effect of a hemorrhagic stroke and how it transforms over time. Important to remember with stroke treatment that time is brain. The faster we treat, the more brain that we can save. For the last 20 years, the standard of care in treating ischemic stroke has been TPA.
TPA is a clot-busting drug that can be given to certain patients who present within four and a half hours of the onset of their stroke symptoms. The problem with TPA, it's very strict criteria and it limits who is a candidate for the treatment. The fact that TPA has been the only option for stroke treatment for the past 20 years is a big problem.
But now there's a new therapy that can be used in addition to TPA. In February 2015, five randomized controlled trials were published demonstrating the success of endovascular therapy in the treatment of ischemic stroke caused by large vessel occlusions. Endovascular therapy is a minimally invasive procedure that is done within the conventional angio suite by a trained neurosurgeon. interventional neuroradiologist.
In the procedure the physician gains access to the blood vessels through the femoral artery. They proceed up into the brain locating the area of occlusion and then remove the clot causing the obstruction either with suction or with a mechanical device. Endovascular therapy can be done with or without tpa here's an example of some clot that came out of a patient who had a large vessel occlusion patients that have a confirmed large vessel occlusion with a small area of infarct and a lasting normal under 12 hours are generally good candidates for endovascular therapy there are eight primary stroke centers in the province of saskatchewan A primary stroke centre has a CT scanner which allows for advanced neurovascular imaging.
Once this imaging is completed, the radiologist, ED physician, along with the neurologist can make decisions around treatment of stroke. A tertiary stroke centre provides all the same care as a primary stroke centre. However, it also offers the patient endovascular therapy.
The only site in Saskatchewan that is a tertiary stroke centre is at Royal University Hospital in Saskatoon Health Region. Because there's only one tertiary stroke center in our province, we want to get patients having a large vessel occlusion to Saskatoon as fast as possible. That's why we want to implement the FAST-VAN stroke screening tool. This is our FAST-VAN assessment for identifying large facial occlusions with stroke. It starts off with the FAST assessment that we know from the Heart and Stroke Foundation that goes with facial drooping, arm weakness unilaterally, or speech being slurred speech or jumbled speech.
And if you have one of these positive, you're identified as having a potential stroke. We have some video with EMS to show the different signs with FAST. Okay, John, I'm just going to do a stroke assessment on you here, okay?
Can you give me a big smile? Good. Your right side's a little bit droopy there.
I want you to squeeze my hands as hard as you can. Try and hurt me. Good. Now I'm going to get you to hold your arms up, and I'm going to let go, and you keep your arms up.
Okay. Okay. Good.
Based on that video, we could see there was a simulated right facial droop. His right arm was weak and he was nonverbal in his speech. So even though it was hard to differentiate if he had slurred speech, we wouldn't really count that.
So he was FAST positive. So we'd then go on to the second part of our assessment with Van. And Van is looking at large vessel occlusion, so a clot.
being stuck in one of the major arteries and we look for the different signs of vision, aphasia, or neglect and we'll go through each one of these steps and we'll see that if you screen positive for one of these three or more you're considered to have a large clot and you should be evaluated for endovascular therapy. So starting off with V for vision we're looking for a gaze deviation so the eyes going over to one side and when instructed they're unable to bring it across the midline and all the way to the other side. I see you're looking at me over here.
Can you look at my hand over here where I'm making noise? Not really wanting to move those eyes too much, eh? A for aphasia, this is looking at fluency or comprehension, and this is the aloss ability to either express speech and or understand speech. So simply just ask the patient to name a pen and see if they can verbalize that.
This is different than slurred speech which would be included in your FAST assessment. Can you tell me what this is? Lastly we have N for neglect which is ignoring one side of the body and this is typically going to be the left side of the body. This is tested by having the patient close their eyes and then telling them to move the arm that you're touching.
Start by touching just the left arm, then just touch the right arm. Then touch them both, the right and the left, at the same time. Neglect will be positive if they're unable to identify that both arms are being touched at the same time.
If the patient is having difficulty with understanding or feeling that each hand is touched individually, This would not count as being positive for neglect. Now I'm going to touch one arm or the other and I want you to wiggle your hands to tell me which arms I'm touching okay? Good, good. How about now?
Good. With our example patient we saw that he was positive for V because his eyes are deviated to the left and could not cross over to the right. He was aphasic because he was non-verbal in all regards and not able to name the pen, but he didn't show any neglect and so this would be a positive VAN screen. Once again, this is our FAST VAN screen looking for large vessel occlusions and ischemic stroke to better triage patients to endovascular therapy. FAST identifying a potential stroke and then VAN standing for vision aphasia or neglect.
If one of these three is positive, the patient may have a potential clot and may be amendable to endovascular intervention. This is our screening form that will be sent out. It includes the different steps in the FASFAN screen and also room to document patient information.
Thank you very much for your time. Our contact information is provided if there's further questions. FASFAN!