Zhao Henry, Coote Skye, Pesavento Lauren, Churilov Leonid, Dewey Helen M, Davis Stephen M, Campbell Bruce C V
From the Department of Medicine and Neurology, Royal Melbourne Hospital (H.Z., L.P., S.M.D., B.C.V.C.), and The Florey Institute of Neuroscience and Mental Health (L.C.), University of Melbourne, Parkville, Australia; and Eastern Health Clinical School, Eastern Health, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia (S.C., H.M.D.).
Stroke. 2017 Mar;48(3):568-573. doi: 10.1161/STROKEAHA.116.016056.
Clinical large vessel occlusion (LVO) triage scales were developed to identify and bypass LVO to endovascular centers. However, there are concerns that scale misclassification of patients may cause excessive harm. We studied the settings where misclassifications were likely to occur and the consequences of these misclassifications in a representative stroke population.
Prospective data were collected from consecutive ambulance-initiated stroke alerts at 2 stroke centers, with patients stratified into typical (LVO with predefined severe syndrome and non-LVO without) or atypical presentations (opposite situations). Five scales (Rapid Arterial Occlusion Evaluation [RACE], Los Angeles Motor Scale [LAMS], Field Assessment Stroke Triage for Emergency Destination [FAST-ED], Prehospital Acute Stroke Severity scale [PASS], and Cincinnati Prehospital Stroke Severity Scale [CPSSS]) were derived from the baseline National Institutes of Health Stroke Scale scored by doctors and analyzed for diagnostic performance compared with imaging.
Of a total of 565 patients, atypical presentations occurred in 31 LVO (38% of LVO) and 50 non-LVO cases (10%). Most scales correctly identified >95% of typical presentations but <20% of atypical presentations. Misclassification attributable to atypical presentations would have resulted in 4 M1/internal carotid artery occlusions, with National Institutes of Health Stroke Scale score ≥6 (5% of LVO) being missed and 9 non-LVO infarcts (5%) bypassing the nearest thrombolysis center.
Atypical presentations accounted for the bulk of scale misclassifications, but the majority of these misclassifications were not detrimental, and use of LVO scales would significantly increase timely delivery to endovascular centers, with only a small proportion of non-LVO infarcts bypassing the nearest thrombolysis center. Our findings, however, would require paramedics to score as accurately as doctors, and this translation is made difficult by weaknesses in current scales that need to be addressed before widespread adoption.
临床大血管闭塞（LVO）分诊量表旨在识别LVO患者并将其转送至血管内治疗中心而绕过非LVO患者。然而，人们担心对患者的量表误分类可能会造成过度伤害。我们研究了可能发生误分类的情况以及这些误分类在具有代表性的卒中人群中的后果。
从2个卒中中心连续的救护车启动的卒中警报中收集前瞻性数据，将患者分为典型（具有预定义严重综合征的LVO和无该综合征的非LVO）或非典型表现（相反情况）。五个量表（快速动脉闭塞评估量表[RACE]、洛杉矶运动量表[LAMS]、急诊目的地现场评估卒中分诊量表[FAST-ED]、院前急性卒中严重程度量表[PASS]和辛辛那提院前卒中严重程度量表[CPSSS]）源自医生记录的基线美国国立卫生研究院卒中量表得分，并与影像学结果进行比较分析其诊断性能。
在总共565例患者中，31例LVO（占LVO的38%）和50例非LVO患者（占10%）出现非典型表现。大多数量表能正确识别>95%的典型表现，但<20%的非典型表现。非典型表现导致的误分类会造成4例M1段/颈内动脉闭塞漏诊，这些患者美国国立卫生研究院卒中量表得分≥6分（占LVO的5%），以及9例非LVO梗死患者（占5%）绕过最近的溶栓中心。
非典型表现占量表误分类的大部分，但这些误分类大多无害，使用LVO量表将显著增加及时转送至血管内治疗中心的比例，只有一小部分非LVO梗死患者会绕过最近的溶栓中心。然而，我们的研究结果要求护理人员的评分要与医生一样准确，而目前量表的缺陷使得这一要求难以实现，在广泛应用之前需要加以解决。
