Abstract WP278: Air versus Ground Transportation During Inter-Hospital Transfer of Patients for Endovascular Thrombectomy Evaluation

Abstract

Introduction: Mode of transport utilized during inter-hospital transfers can influence delays in patients with suspected large vessel occlusion (LVO). We hypothesized that air transport is advantageous over ground in this patient population. Method: Suspected LVO patients transferred to our hub from 13 spoke hospitals within our tele-stroke network at UT-Houston, from September 2015 to April 2018 were retrospectively analyzed. Patients were dichotomized into air vs. ground transport. Travel time was calculated as time from transfer center activation to arrival at hub. For each spoke, average air miles/hour and ground miles/hour indices were calculated for comparison. Air transport was considered advantageous if the difference in indices was positive. Results were stratified by time of the day [diurnal (6a-6p) vs. nocturnal (6p-6a)]. Results: In a total of 339 patients, 290 (86%) used air transport, while 49 (14%) used ground. Baseline age, gender, race, use of IV-tPA, mRS in the 2 groups were similar, except air group had higher NIHSS [median 15 vs. 12, p = 0.048]. Overall, mean ground indices were smaller compared to air indices (21.35 ± 10.76 vs. 25.77 ± 14.33, p = 0.006). The advantage of air transport was maintained when stratified by time of the day but more notable during nocturnal hours [air 25.12 ± 14.93 vs. ground 19.85 ± 10.14, p = 0.021)] compared to diurnal hours [(air 28.82 ± 13.68 vs. ground 25.00 ± 10.80, p = 0.17)]. Difference between air and ground indices (y axis) was positively correlated with ground distance (x axis) (Pearson rho = 0.80, 95% CI 0.42 to 0.93, p<0.001) indicating efficiency of air transport becomes more profound as distance increases (Figure 1). Ground transport was faster for distances <20 miles. Conclusion: Irrespective of time of the day, air transport is faster mode of transporting patients during inter hospital transfers and should be utilized particularly for spokes situated farther away (over 20 miles) from hub and during nocturnal hours.