Prehospital Stroke Triage

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Over the past 5 years, there has been a dramatic expansion of the treatment strategies used to treat patients with acute ischemic stoke. As some of these treatments involve specific resources only available at certain institutions, appropriate triage of patients in the prehospital environment is becoming ever important. On one hand a patient who would best benefit from endovascular treatment triaged to a center without that capability will undoubtedly suffer a delay in care. On the other hand, over-triaging stroke patients to a comprehensive stroke center could overwhelm the resources of that center, potentially impacting the care of patients at that center. In the podcast below, we talk with Dr. Jason McMullan of the UC EM Division of EMS and Dr. James Li, PGY-3 who both have recent publications focusing on this phase of patient care.

McMullan J, Khatri P. Getting the Right Patient to the Right Place in the Right Amount of Time—A Role for Both Mobile Stroke Units and Prehospital Clinical Scales. JAMA Neurol. Published online September 03, 2019. doi:10.1001/jamaneurol.2019.2839

In this commentary, Drs McMullan and Khatri discuss an article by Helwig et al which looked at a modified Los Angeles Motor Scale vs a Mobile Stroke Unit for secondary triage of stroke patients in the prehospital environment. In the podcast, Dr. McMullan summarizes his take on the approach to prehospital stroke triage.

James L. Li, Jason T. McMullan, Heidi Sucharew, Joseph P. Broderick, Brian Katz, Pamela Schmit & Opeolu Adeoye (2019) Potential Impact of C-STAT for Prehospital Stroke Triage up to 24 Hours on a Regional Stroke System, Prehospital Emergency Care, DOI: 10.1080/10903127.2019.1676343

Background and Purpose: Thrombectomy for large vessel occlusion acute ischemic stroke (AIS-LVO) may benefit patients up to 24 hour since last known normal (LKN). Prehospital tools, like the Cincinnati Stroke Triage Assessment Tool (C-STAT), are used to select hospital destination for suspected AIS-LVO patients. The objective of this study was to estimate the potential impact of the expanded thrombectomy time window on suspected AIS-LVO cases transported to the regional comprehensive stroke center (CSC).

Methods:From June to November 2015, C-STAT was performed by prehospital providers following a positive prehospital Cincinnati Prehospital Stroke Scale (CPSS) stroke screen in suspected stroke/TIA patients. There was no preferential triage based on C-STAT results. Final diagnoses, including the presence of AIS-LVO was ascertained via medical record review. Impact of positive C-STAT cases on CSC volumes was estimated for up to 24 hours since LKN.

Results: Of 158 patients with prehospital suspicion for stroke/TIA, 105 were CPSS positive within 24 hours of onset and had complete C-STAT and clinical data available for analysis. Forty-six percent (17/37) of C-STAT + were non-strokes. C-STAT sensitivity and specificity for LVO were 71% (95% CI 36-92) and 67% (95% CI 58-80), respectively. C-STAT triage would increase transport of prehospital suspected stroke cases to the CSC by 11% (12/105) within six hours and 21% (22/105) within 24 hours. Of 37 C-STAT + patients, only 5 (13.5%) had LVO as final diagnosis.

Conclusions: Preferential triage of prehospital suspected stroke patients using C-STAT would increase the number of patients transported to the CSC by 11% within six hours and an additional 10% from six to 24 hours. For every patient with LVO as final diagnosis, approximately an additional 6 non-LVO patients would be triaged to a CSC.