Effects of state-wide implementation of the Los Angeles Motor Scale for triage of stroke patients in clinical practice

Abstract

Background The prehospital identification of stroke patients with large-vessel occlusion (LVO), that should be immediately transported to a thrombectomy capable centre is an unsolved problem. Our aim was to determine whether implementation of a state-wide standard operating procedure (SOP) using the Los Angeles Motor Scale (LAMS) is feasible and enables correct triage of stroke patients to hospitals offering (comprehensive stroke centres, CSCs) or not offering (primary stroke centres, PSCs) thrombectomy. Methods Prospective study involving all patients with suspected acute stroke treated in a 4-month period in a state-wide network of all stroke-treating hospitals (eight PSCs and two CSCs). Primary endpoint was accuracy of the triage SOP in correctly transferring patients to CSCs or PSCs. Additional endpoints included the number of secondary transfers, the accuracy of the LAMS for detection of LVO, apart from stroke management metrics. Results In 1123 patients, use of a triage SOP based on the LAMS allowed triage decisions according to LVO status with a sensitivity of 69.2% (95% confidence interval (95%-CI): 59.0–79.5%) and a specificity of 84.9% (95%-CI: 82.6–87.3%). This was more favourable than the conventional approach of transferring every patient to the nearest stroke-treating hospital, as determined by geocoding for each patient (sensitivity, 17.9% (95%-CI: 9.4–26.5%); specificity, 100% (95%-CI: 100–100%)). Secondary transfers were required for 14 of the 78 (17.9%) LVO patients. Regarding the score itself, LAMS detected LVO with a sensitivity of 67.5% (95%-CI: 57.1–78.0%) and a specificity of 83.5% (95%-CI: 81.0–86.0%). Conclusions State-wide implementation of a triage SOP requesting use of the LAMS tool is feasible and improves triage decision-making in acute stroke regarding the most appropriate target hospital.

European Stroke Organisation (ESO) guidelines on mobile stroke units for prehospital stroke management

“…Despite many efforts to speed up and optimise acute stroke patient management, still only 0.8-1.3% of acute ischaemic stroke (AIS) patients receive their intravenous thrombolysis (IVT) within the so-called golden hourthe first 60 min after symptom onset, when chances of full recovery are highest. 1,2 Many reports on stroke scales, [3][4][5][6][7] emergency medical service (EMS) training and educational programmes, [8][9][10][11][12] structured EMS pre-notification to hospital stroke teams, [13][14][15] emergency department streamlining [16][17][18][19][20] and different triage pathways (mothership vs drive the doctor vs drip and ship) [21][22][23][24][25][26][27][28][29][30][31] have all demonstrated an improvement of treatment numbers and times, but timely delivery of the available and highly beneficial reperfusion therapies [IVT and mechanical thrombectomy (MT)] to AIS patients is still underachieved. Furthermore, delays in onset to treatment times correlate to longer bolus to reperfusion times in AIS patients with proximal intracranial occlusions treated with IVT.…”

National implementation of reperfusion for acute ischaemic stroke in England: How should services be configured? A modelling study

“…From among many such tests, we have used the RACE 21 to exemplify pre-hospital selection because there is a good level of published detail available and it has also recently been shown to be the best performing among a range of 8 similar pre-hospital clinical scales, 44 but other triage scales have been implemented, such as LAMS. 45 Though RACE improves selection of LAO patients, we found applying RACE still has the potential to destabilise the current organisation of care through its low specificity; furthermore the latest trial data suggest that the widespread use of such pre-hospital selection does not confer the anticipated benefits in terms of improved outcomes from bypass and earlier treatment with MT. 40 More sophisticated pre-hospital pathways, such as supporting paramedics with centralised triage 33 or advances in technology, such as use of biomarkers 46 or ultrasound devices 47 for detecting LAO, may be necessary to achieve the requisite balance of sensitivity and specificity.…”

Modeling the Impact of Prehospital Triage on a True-Life Drip and Ship Mechanical Thrombectomy Urban Patient Cohort

“…The Cincinnati Prehospital Stroke Severity Scale did not differ statistically significantly from other currently used triaging systems in ELVO predictive performance [ 25 ]. In a prospective study, the use of LAMS proved superior compared to the conventional protocol of transferring patients to the nearest stroke hospital using geocoding [ 26 ]. Ultimately, this could lead in a substantially decreased number of secondary transfers [ 26 ].…”

“…In a prospective study, the use of LAMS proved superior compared to the conventional protocol of transferring patients to the nearest stroke hospital using geocoding [ 26 ]. Ultimately, this could lead in a substantially decreased number of secondary transfers [ 26 ]. False-negative results might include cases with good collateral circulation, in whom delays can be tolerated with less resultant morbidity [ 19 ].…”