Written by Clay Smith
Spoon Feed
The prehospital screening tools for large vessel occlusion (LVO) with the best accuracy were: FAST-ED, RACE, and LAMS. Cincinnati Prehospital Stroke Scale (CPSS) was the worst.
More letters than a Scrabble game
LVO occurs in 30% of ischemic strokes and is best treated with endovascular thrombectomy (EVT). It would be ideal for EMS to direct patients with LVO to an EVT-capable stroke center. Several tools to detect LVO exist. ACEP recommends LAMS and RACE. What’s the best rapid screening tool for LVO?
This was a prospective single center study of 390 stroke alert patients (111 of which ultimately had true LVO on imaging) in which the data points from 9 LVO screening tools were prospectively gathered by emergency physicians prior to CT. The performance of RACE, LAMS, FAST-ED, VAN, LARIO, CG-FAST, FAST-PLUS, ACT-FAST, and CPSS were evaluated. None of them were stellar. The top 3 performers for overall accuracy were FAST-ED, RACE, and LAMS. The worst was CPSS. See the graphics for overall performance of all 8 and ROC curves.
How will this change my practice?
For those involved in prehospital care and EMS medical direction, this is important. For starters, if your EMS crew is using the Cincinnati Prehospital Stroke Scale, this suggests it’s time to change. None of these scores are great screening tools, but they could be of benefit in directing patients to EVT-capable facilities. It seems reasonable to go with the ACEP-recommended LAMS and RACE scores, but FAST-ED is definitely worth a look. Given its simplicity, my money is on LAMS, with just 3 things to know: facial droop, arm drift, and grip.
Editor’s note: The test characteristics of CPSS will be biased here because the EMS system would have brought these patients specifically to this centre because they screened positive by CPSS. Personally, I’d rather high sensitivity above overall accuracy to get me to an EVT capable centre if there is high concern for a stroke. ~Nick Zelt
Source
Accuracy of Published Screening Tools for Large Vessel Occlusion in Patients With Suspected Acute Ischemic Stroke: A Prospective Cohort Study. Ann Emerg Med. 2025 Sep 19:S0196-0644(25)01092-3. doi: 10.1016/j.annemergmed.2025.07.030. Epub ahead of print. PMID: 40974366.
