A Transfer Strategy Utilizing a Helicopter and a Ground Ambulance Together Does Not Prolong Door-In-Door-Out Times in Thrombectomy Patients: A Retrospective Analysis.

Background: An interfacility transfer should commence immediately to a hospital with endovascular capability to perform mechanical thrombectomy when a patient is diagnosed with a large vessel occlusion (LVO) stroke. The turnaround time in the primary stroke center (PSC) is called door-in-door-out time (DIDO). We investigated DIDOs from two PSCs and how the implementation of a helicopter emergency medical service (HEMS) unit for patient transportation together with a ground ambulance affected the DIDO.

Methods: We retrospectively identified thrombectomy candidates transferred to Tampere University Hospital from two PSCs, Seinäjoki and Kanta-Häme Central Hospitals, from February 2019 until October 2022. A HEMS unit was dispatched to transport the patients from Seinäjoki after June 2020. Patient medical records and DIDOs were also analyzed and compared with ground transport and air transport between the two PSCs. Factors for faster DIDOs were determined by linear regression analysis.

Results: The DIDOs of 129 patients were analyzed. The median (interquartile range) DIDO in the total population was 50 (35-71) minutes, and the PSCs achieved equal DIDOs. The strongest factors of the DIDO were the prehospital prenotification (B = -55.6, p < 0.001), the same ambulance continuing the interfacility transport (B = -33.8, p < 0.001), and the patient's age (B = 0.65, p = 0.039). HEMS dispatch or transport was not associated with any delays in DIDO.

Conclusion: The prehospital prenotification of a stroke patient to a PSC should include a discussion of whether the patient is a thrombectomy candidate. The same ambulance should be engaged for the mission and continue with the same patient to the thrombectomy facility.