Abstract TP268: Utilization and Appropriateness of Emergency Medical Services Air Transport in Acute Ischemic Stroke Care

Abstract

Introduction: Although air (helicopter) transfer is largely accepted as improving outcomes in time sensitive conditions including acute ischemic stroke (AIS), inappropriate triage of these patients when they are ineligible for acute stroke therapies places patients and providers at unnecessary risk and wastes limited healthcare resources. Extension of the endovascular therapy time window to twenty-four hours further increases the burden on stroke systems of care. As the tertiary flagship institution and only comprehensive stroke center (CSC) in a rural state, we sought to identify how accurate our triage system was at identifying ischemic stroke patients appropriate for air transfer. Hypothesis: A significant percent of AIS patients inappropriately utilize HelicopterEmergency Medical Services (HEMS). Based on information known prior to transfer, the majority are avoidable. Methods: We defined inappropriate utilization basedon time from last known normal (LKN), stroke severity and baseline functional status. A retrospective chart review was performed on all stroke alerts that arrived at our hospital by HEMS in 2017. Results: Of the 141 acute stroke patients transferred by HEMS, 23 (16%) were deemed inappropriate; 14 (61% ) were outside the acute treatment time windows for either IV tPA or Endovascular Therapy (EVT); 5(22%) were ineligible for EVT (NIHSS<6); 2 (9%) were ineligible for EVT (mRS≥3); and 2 (9%) were flown despite negative angiographic studies performed at transferring institution. At an average cost of $18,500/flight, $425,500 in total was attributed to inappropriate transport. Thirteen (57%) of the patients were interfacility transfers where the decision to arrange HEMS occurred after a physician’s evaluation. Conclusion: HEMS transport for AIS patients plays a crucial role in delivering the best care. However, a significant percent of patients do not meet criteria for its appropriate utilization, most commonly when pre-established LSN are outside of acute treatment windows. Furthermore, inappropriate transfers were initiated in spite of outside hospital physician evaluation over 50% of the time. These results represent a unique opportunity to coordinate education and buildeffective triage paradigmsacross a system of stroke care.