Prehospital Triage Strategies for the Transportation of Suspected Stroke Patients in the United States

Abstract

Background and Purpose: Ischemic stroke patients with large vessel occlusion (LVO) could benefit from direct transportation to an intervention center for endovascular treatment, but non-LVO patients need rapid IV thrombolysis in the nearest center. Our aim was to evaluate prehospital triage strategies for suspected stroke patients in the United States. Methods: We used a decision tree model and geographic information system to estimate outcome of suspected stroke patients transported by ambulance within 4.5 hours after symptom onset. We compared the following strategies: (1) Always to nearest center, (2) American Heart Association algorithm (ie, directly to intervention center if a prehospital stroke scale suggests LVO and total driving time from scene to intervention center is <30 minutes, provided that the delay would not exclude from thrombolysis), (3) modified algorithms with a maximum additional driving time to the intervention center of <30 minutes, <60 minutes, or without time limit, and (4) always to intervention center. Primary outcome was the annual number of good outcomes, defined as modified Rankin Scale score of 0–2. The preferred strategy was the one that resulted in the best outcomes with an incremental number needed to transport to intervention center (NNTI) <100 to prevent one death or severe disability (modified Ranking Scale score of >2). Results: Nationwide implementation of the American Heart Association algorithm increased the number of good outcomes by 594 (+1.0%) compared with transportation to the nearest center. The associated number of non-LVO patients transported to the intervention center was 16 714 (NNTI 28). The modified algorithms yielded an increase of 1013 (+1.8%) to 1369 (+2.4%) good outcomes, with a NNTI varying between 28 and 32. The algorithm without time limit was preferred in the majority of states (n=32 [65%]), followed by the algorithm with <60 minutes delay (n=10 [20%]). Tailoring policies at county-level slightly reduced the total number of transportations to the intervention center (NNTI 31). Conclusions: Prehospital triage strategies can greatly improve outcomes of the ischemic stroke population in the United States, but increase the number of non-LVO stroke patients transported to an intervention center. The current American Heart Association algorithm is suboptimal as a nationwide policy and should be modified to allow more delay when directly transporting LVO-suspected patients to an intervention center.

Decrease in intravenous thrombolysis and poor short-term functional prognosis for acute ischemic stroke during the COVID-19 pandemic

“…The restrictions on traffic might be an important factor that patients who lived in villages and towns around Wenzhou could arrive at the hospital formerly [ 13 ]. The restrictions increased the time for patients to arrive at a district medical center so that patients and their relatives were more likely to go to their local hospital [ 14 ]. Another reason was that more patients exceeding the treatment time window which decreased the number of patients who received treatment successfully.…”

Large Vessel Occlusion Stroke Detection in the Prehospital Environment

“…This is not as daunting as it may seem. Multiple modeling studies have found that LVO triage may not result in overwhelmed stroke centers or missed thrombolysis opportunities [13,30,36,41]. If sensitivity is prioritized, CPSS ≥ 2 would be a strong and easy stroke severity tool choice because it performs just as well as other tools at their sensitive score cutpoints (86% sensitivity and 61% specificity) and would require little to no additional EMS training [25].…”

Appropriate Air Medical Services Utilization and Recommendations for Integration of Air Medical Services Resources into the EMS System of Care: A Joint Position Statement and Resource Document of NAEMSP, ACEP, and AMPA

“…(82)(83)(84) Similar to the evolution of STEMI care over time, the care of LVO stroke is transitioning from the current "drip and ship" strategy to an approach in which the ground EMS team providing 9-1-1 response considers bypass of local hospitals that lack interventional therapies in favor of direct transport to primary and comprehensive stroke centers capable of performing endovascular therapies, even if transport time is extended 60 minutes or more. (85,86) A recent evaluation of seven different LVO prediction algorithms in use in the EMS setting showed wide variability in sensitivity (38-62%) and specificity (80-93%), high negative predictive values (95-96%), but poor positive predictive values (21-32%), with no specific algorithm outperforming the others across all of the measures of predictive value that the study evaluated. (87) Further, the best performing algorithm (RACE, PPV 32%) unfortunately also had the lowest prehospital feasibility score (78%).…”